Compositions For Preventing and/or Treating Demyelination

Field of the Invention

[0001] The present application relates to compositions comprising sialic acid and/or fucose to enhance cognitive function. More specifically, the present application is directed to compositions for use in enhancing cognitive function by preventing and/or treating diseases or conditions associated with demyelination.

Background

[0002] Neurons are responsible for generating electrical impulses and chemical signals to transit information around the brain and rest of the body. Each neuron includes a cell body from which extends an axon and dendrites. An axon is a long, slender projection that conducts electrical impulses known as action potentials, away from the cell body.

[0003] A neuron does not act alone, it requires a support network of glial cells called astrocytes and oligodendrocytes. Glial cells provide a supporting function to neurons and the nervous system overall.

[0004] Oligodendrocytes are responsible for forming a myelin sheath around the axon. The myelin sheath wraps around the axon where it functions as an electrical insulator. This serves to ensure rapid and efficient conduction of the action potential via saltatory conduction. Myelin is composed of about 70% lipids, including cholesterol, galactosylceramide/sulphide, ganglioside (including sialic acid) and inositol phosphate.

[0005] Myelination begins in the brain stem and cerebellum before birth but is not completed in the frontal cortex until late in adolescence. Breast feeding has been shown to contribute to more rapid myelination in the brain.

[0006] Demyelination, the phenomenon of the loss of myelin, causes neurological deficits such as vision changes, and behavioural and cognitive impairment. Demyelinating diseases are a group of heterogenous neurological diseases in which selective destruction to myelin primarily occurs. Inflammatory demyelinating disease may be caused by the autoimmune system. Multiple sclerosis is the most prevalent and representative disease of demyelination. In diseases characterised by primary demyelination, the myelin sheaths and oligodendrocyte cells are damaged, whilst other components of the central nervous system (CNS) remain relatively intact.

[0007] Demyelination is not limited to demyelinating diseases. Neurodegenerative diseases such as Alzheimer’s disease also involve a demyelination component. Common brain injuries such as ischemic stroke are also accompanied by the destruction of the myelin sheath and apoptosis of oligodendrocyte cells.

[0008] Remyelination of demyelinated lesions occurs spontaneously and is the natural repair mechanism. Remyelination is mediated by a pool of oligodendrocyte precursor cells (OPC) distributed throughout the CNS that are activated and subsequently migrate to the lesion where they differentiate into oligodendrocytes.

[0009] Remyelination can prevent axonal degeneration and can restore function. However, the lack of remyelination in some patients has been attributed to a failure of OPC differentiation.

[0010] OPCs and oligodendrocytes and are vulnerable to inflammation, DNA damage and amyloid-beta accumulation, with the latter being associated with the onset of Alzheimer’s Disease. Degeneration of OPCs and oligodendrocyte cells results in an age-dependent decrease in the brain’s remyelination capability leading to significant structural changes in myelin as an adult brain undergoes aging.

[0011] The impacts on the myelination process by nutrients within the brain are integrated by three fundamental aspects: (a) the survival and proliferation of OPCs; (b) the differentiation of the OPCs into oligodendrocytes, and (c) myelin deposition.

[0012] The identification of nutrients that promote survival and proliferation of OPCs and oligodendrocytes represents a major unmet need, not only for the prevention of demyelination in an aging-brain but also for the treatment of diseases or conditions having a demyelination component. Summary of Invention

[0013] The inventors have found that a composition comprising a source of sialic acid and/or a source of fucose can advantageously be used to prevent and/or treat a disease or condition associated with demyelination.

[0014] According to a first aspect of the invention there is provided a composition comprising a source of sialic acid and/or a source of fucose for use in the prevention and/or treatment of a disease or condition associated with demyelination.

[0015] The source of sialic acid may be exogenous sialic acid or endogenous sialic acid, or a combination thereof.

[0016] Preferably, the exogenous sialic acid is selected from the group consisting of N- glycolylneuraminic acid (NGNA), N-acetylneuraminic acid (NANA), N-Acetyl-D- mannosamine, neuraminic acid, 5-N-Acetyl-4-0-acetyl-neuraminic acid, 5-N-Acetyl-7-0- acetyl-neuraminic acid, 5-N-Acetyl-8-0-acetyl-neuraminic acid, 5-N-Acetyl-9-0-acetyl- neuraminic acid, 5-N-Acetyl-4,9-di-0-acetyl-neuraminic acid, 5-N-Acetyl-7,9-di-0-acetyl- neuraminic acid, 5-N-Acetyl-8,9-di-0-acetyl-neuraminic acid, 5-N-Acetyl-7,8,9-tri-0-acetyl- neuraminic acid, 5-N-Acetyl-9-0-L-lactyl-acetyl-neuraminic acid, 5-N-Acetyl-4-0-acetyl-9- O-lactyl-acetyl-neuraminic acid, 5-N-Acetyl-8-0-methyl-neuraminic acid, 5-N-Acetyl-9-0- acetyl-8-O-methyl-neuraminic acid, 5-N-Acetyl-8-0-sulpho-neuraminic acid, 5-N-Acetyl-9- O-phosphoro-neuraminic acid, 5-N-Acetyl-2-deoxy-2,3-didehydro-neuraminic acid, 5-N- Acetyl- 9-0-acetyl-2-deoxy-2,3-didehydro-neuraminic acid, 5-N-Acetyl-2-deoxy-2,3- didehydro-9-O-lactyl-neuraminic acid, 5-N-Acetyl-2,7-anhydro-neuraminic acid, 4-0- Acetyl-5-N-glycolyl-neuraminic acid, 7-0-Acetyl-5-N-glycolyl-neuraminic acid, 8-0-Acetyl- 5-N-glycolyl-neuraminic acid, 9-0-Acetyl-5-N-glycolyl-neuraminic acid, 7,9-Di-0-acetyl-5- N-glycolyl-neuraminic acid, 8,9-Di-0-acetyl-5-N-glycolyl-neuraminic acid, 7,8,9-Tri-O- acetyl-5-N-glycolyl-neuraminic acid, 5-N-glycolyl-9-0-lactyl-neuraminic acid, 5-N-glycolyl- 8-0-methyl-neuraminic acid, 9-0-Acetyl-5-N-glycolyl-8-0-methyl-neuraminic acid, 7,9-di- 0- Acetyl-5-N-glycolyl-8-0-methyl-neuraminic acid, 5-N-glycolyl-8-0-sulpho-neuraminic acid, N-(0-acetyl)glycolylneuraminic acid, N-(0-Methyl)glycolylneuraminic acid, 2-Deoxy- 2,3- didehydro-5-N-glycolyl-neuraminic acid, 9-0-Acetyl-2-deoxy-2,3-didehydo-5-N- glycolyl- neuraminic acid, 2-Deoxy-2,3-didehydro-5-N-glycolyl-9-0-lactyl-neuraminic acid, 2-Deoxy- 2,3-didehydro-5-N-glycolyl-8-0-methyl-neuraminic acid, 2,7-Anhydro-5-N- glycolyl- neuraminic acid, 2,7-Anhydro-5-N-glycolyl-8-0-methyl-neuraminic acid, 2-Keto-3- deoxynononic acid, 9-0-Acetyl-2-keto-3-deoxynononic acid, and combinations thereof.

[0017] Preferably, the endogenous sialic acid is provided a sialylated human milk oligosaccharide (HMO), preferably the sialylated oligosaccharide is a sialyllactose. Preferably, the sialyllactose is 3'-sialyllactose (3’-SL) and/or 6'-sialyllactose (6’-SL).

[0018] The source of fucose may L-fucose and/or D-fucose. Preferably, the fucose is L- fucose.

[0019] The fucose may be provided as exogenous fucose, an endogenous fucose, or a combination thereof.

[0020] Preferably, the endogenous fucose is provided by a fucosylated HMO selected from the group consisting of 2'-fucosyllactose (2’-FL), 3’-fucosyllactose (3’-FL), difucosyllactose, lacto-N- fucopentaose I, lacto-N-fucopentaose II, lacto-N-fucopentaose III, lacto-N- fucopentaose V, lacto-N-fucohexaose, lacto-N-difucohexaose I, fucosyllacto- N- hexaose, fucosyllacto-N-neohexaose (such as fucosyllacto-N-neohexaose I, fucosyllacto-N-neohexaose II), difucosyllacto-N-hexaose I, difuco-lacto-N-neohexaose, difucosyllacto-N-neohexaose I, difucosyllacto-N-neohexaose II, fucosyl-para-Lacto-N- hexaose, tri-fuco-para-Lacto-N-hexaose I and any combination thereof.

[0021] Preferably, the fucosylated human milk oligosaccharide is a fucosyllactose. More preferably, the fucosyllactose is 2’-FLand/or 3’-FL.

[0022] The composition may comprise a blend of: a. a source of sialic acid, and b. a source of fucose.

[0023] Preferably, the composition comprises a blend of exogenous sialic acid, endogenous sialic acid provided by 3’-SL and/or 6’-SL, and endogenous fucose provided by 2’-FL and/or 3’-FL.

[0024] In an embodiment, the blend provides:

(a) a total daily dosage of exogenous sialic acid in the range of about 0.05g to about 2g, more preferably between about 0.75g and 1.5g; (b) a total daily dosage of 3’-SL and/or 6’-SL in the range of about 0.5g to about 6g, more preferably between about 3g and 5g; and

(c) a total daily dosage of 2’-FL and/or 3’-FL in the range of about 0.5g to about 6g, more preferably between about 3g and 5g.

[0025] In a particular embodiment, the total daily dosage of exogenous sialic acid is about 1g, the total daily dosage of 3’-SL and/or 6’-SL is about 4g and the total daily dosage of 2’-FL and/or 3’-FL is about 4g.

[0026] The composition may further comprise a probiotic. Preferably, the probiotic exhibits sialidase and/or fucosidase activity. An example of a suitable probiotic is Bifidobacterium bifidum.

[0027] In some embodiments, the composition is a dietary supplement. In some other embodiments, the composition is a pharmaceutical composition. In some other embodiments, the composition is a nutritional composition.

[0028] In embodiments in which the composition is a dietary supplement, the composition supports and maintains a normal state of myelination expected in a healthy subject by preventing demyelination and/or enhancing remyelination.

[0029] In some embodiments, the disease or condition associated with demyelination may be selected from the group consisting of multiple sclerosis, amyotropic lateral sclerosis, acute disseminated encephalomyelitis, diffuse cerebral sclerosis, necrotizing haemorrhagic encephalitis, stroke, spinal cord injury, schizophrenia, bipolar disorder, acute brain injury, Parkinson’s disease, dementia, optic neuritis, neuromyelitis optica, transverse myelitis, acute disseminated encephalomyelitis (ADEM), Leber hereditary optic neuropathy, adrenoleukodystrophy, adrenomyeloneuropathy, metachromatic leukodystrophy, Krabbe’s disease, transverse myelitis, Pelizaeous-Merzbacher disease, Guillain-Barre syndrome (GBS), Balo’s disease, Schilder’s disease, and chronic inflammatory demyelinating polyneuropathy (CIDP).

[0030] In some embodiments, the condition associated with demyelination is ageing.

[0031] In addition to preventing demyelination and promoting remyelination in neurological tissues, a composition according to the invention which includes a sialylated HMO and/or fucosylated HMO as an endogenous source of sialic acid and fucose, respectively, advantageously also provides an additional benefit of correcting gut microbiome dysbiosis.

[0032] According to a second aspect of the invention, there is provided a method for preventing or treating a disease or condition associated with demyelination in a subject, the method comprising administering a composition comprising an effective amount of sialic acid and/or fucose.

[0033] According to a third aspect of the invention, there is provided a method of enhancing the formation of oligodendrocytes in a subject, the method comprising administering a composition comprising an effective amount of sialic acid and/or fucose.

[0034] According to a fourth aspect of the invention, there is provided the use of a composition comprising sialic acid and/or fucose in the manufacture of a medicament for the treatment of a disease or condition associated with demyelination.

Definitions

[0035] “Adult’ means a human subject over 13 years of age.

[0036] "Child' means a human subject ranging in age from 12 months to 13 years. In some embodiments, a child is a subject between the ages of 1 and 12 years old. In other embodiments, the terms "children" or "child" refer to subjects that are between one and about six years old, or between about seven and about 12 years old. In other embodiments, the terms "children" or "child" refer to any range of ages between 12 months and about 13 years.

[0037] “Executive function" means the ability to recognise, evaluate, and make a choice among a variety of alternative options and strategies. The term encompasses goal- directed behaviour, planning and/or cognitive flexibility.

[0038] “Fucose" means a hexose deoxy sugar found in a wide variety of natural products both in D- and L-form. L-fucose (6-deoxy-L-galactose) is a monosaccharide that is a common component of many N- and O-linked glycans and glycolipids produced by mammalian cells. L-fucose is, for instance, a moiety in several human milk oligosaccharides. [0039] “Exogenous fucose" means fucose which is intentionally included in the composition rather than as an element of another component. This may also be referred to as “bound” fucose acid. Contrariwise, “Endogenous fucose” or “Inherent fucose” or “Fucose from endogenous sources" each refer to fucose present in the composition that is not added as such but is naturally present in other components or ingredients of the composition.

[0040] " Fucosylated oligosaccharide" means an oligosaccharide having a fucose residue. It has a neutral nature. Some examples are 2’-FL (2'-fucosy I lactose), 3’-FL (3- fucosyllactose), difucosyllactose, lacto-N-fucopentaose I, lacto- N-fucopentaose II, lacto- N-fucopentaose III, lacto-N-fucopentaose V, lacto-N-difucohexaose I, fucosyllacto-N- hexaose, Difucosyllacto-N-hexaose I, Difucosyllacto-N-neohexaose II.

[0041] The “gut’ of a subject may also be referred to as the gastrointestinal system, the gastrointestinal tract, the digestive system, and/or the digestive tract, of a subject

[0042] "Infant' means a human subject ranging in age from birth to not more than one year and includes infants from 0 to 12 months corrected age. The phrase "corrected age" means an infant's chronological age minus the amount of time that the infant was born premature. Therefore, the corrected age is the age of the infant if it had been carried to full term. The term infant includes low birth weight infants, very low birth weight infants, extremely low birth weight infants and preterm infants. "Preterm" means an infant born before the end of the 37 ^th week of gestation. "Late preterm" means an infant from between the 34 ^th week and the 36 ^th week of gestation. "Full term" means an infant born after the end of the 37 ^th week of gestation. "Low birth weight infant" means an infant born weighing less than 2500 grams (approximately 5 lbs, 8 ounces). "Very low birth weight infant" means an infant born weighing less than 1500 grams (approximately 3 lbs, 4 ounces). "Extremely low birth weight infant" means an infant born weighing less than 1000 grams (approximately 2 lbs, 3 ounces).

[0043] "N-acetylated oligosaccharide(s)" means both "N-acetyl-lactosamine" and "oligosaccharide(s) containing N-acetyl-lactosamine". They are neutral oligosaccharides having an N-acetyl-lactosamine residue. Suitable examples are LNT (lacto- N-tetraose) and LNnT (lacto-N-neotetraose). [0044] “Nutritional composition" means a substance or composition that satisfies at least a portion of a subject’s nutrient requirements. “Nutritional composition(s)" may refer to liquids, powders, solutions, gels, pastes, solids, concentrates, suspensions, ready-to-use forms of enteral formulas, oral formulas, formulas for infants, follow-up formulas, formulas for paediatric subjects, formulas for children, and/or young child milks

[0045] “Paediatric subject’ means a human no greater than 13 years of age. In some embodiments, “paediatric subject’ refers to a human subject that is between birth and 8 years old. In some embodiments, “paediatric subject’ refers to a human subject that is between 1 and 6 years of age. In some other embodiments, “paediatric subject’ refers to a human subject that is between 6 and 12 years of age. The term “paediatric subject’ may refer to infants (preterm or full term) and/or children, as described below.

[0046] “Prebiotic" means a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the digestive tract, which can improve the health of the host. Prebiotics exert health benefits, which may include, but are not limited to: selective stimulation of the growth and/or activity of one or a limited number of beneficial gut bacteria; stimulation of the growth and/or activity of ingested probiotic microorganisms; selective reduction in gut pathogens; and, favourable influence on gut short chain fatty acid profile. The prebiotic of the composition may be naturally-occurring, synthetic, or developed through the genetic manipulation of organisms and/or plants, whether such new source is now known or developed later.

[0047] “Probiotic” means microorganisms, such as bacteria or yeast, which have been shown to exert a beneficial effect on the health of a host subject. Probiotics can usually be classified as ‘viable’ or ‘non-viable’. The term ‘viable probiotics’ refers to living microorganisms, with the amount of a viable probiotic being detailed in colony-forming units (CFU). Probiotics that have been heat-killed, or otherwise inactivated, are termed ‘non-viable probiotics’ i.e. non-living microorganisms. Non-viable probiotics may still retain the ability to favourably influence the health of the host even though they may have been heat-killed or otherwise inactivated.

[0048] “Sialic acid’ is a generic term for the N- or O- substituted derivatives of neuraminic acid, a monosaccharide with a nine-carbon backbone. It is also the name given to the most common member of this group, N-acetylneuraminic acid (Neu5Ac or NANA). Sialic acids are found widely distributed in animal tissues and to a lesser extent in other species ranging from plants and fungi to yeasts and bacteria, mostly in glycoproteins and gangliosides. The amino group generally bears either an acetyl or glycolyl group but other modifications have been described. The hydroxyl substituents may vary considerably: acetyl, lactyl, methyl, sulphate, and phosphate groups have been found.

[0049] “Exogenous sialic acid’ means sialic acid which is intentionally included in the composition rather than as an element of another component. This may also be referred to as “free” sialic acid. Contrariwise, “Endogenous sialic acid’ or “Inherent sialic acid’ or “Sialic acid from endogenous sources" each refer to sialic acid present in the composition that is not added as such but is naturally present in other components or ingredients of the composition. The terms “endogenous” and “exogenous” are not being used herein to distinguish between sialic acid produced by the body (i.e. , “endogenous”, and sialic acid provided in the diet (i.e., “exogenous”).

[0050] "Sialylated oligosaccharide" means a charged sialic acid containing oligosaccharide, i.e. an oligosaccharide having a sialic acid residue. It has an acidic nature. Non-limiting examples include 3' sialyllactose (3’-SL) and 6' sialyllactose (6’-SL).

[0051] "Treating" or "Treatment' refers to any indication of success in amelioration of an injury, pathology, or condition, including any objective or subjective parameter such as abatement; remission; diminishing of symptoms or making the injury, pathology, or condition more tolerable to the patient; slowing the rate of degeneration or decline; making the final point of degeneration less debilitating; or improving a subject’s physical or mental well-being. The treatment or amelioration of symptoms can be based on objective or subjective parameters; including the results of a physical examination, neurological examination, and/or psychiatric evaluation.

[0052] The treatment may be prophylactic (to prevent or delay the onset or worsening of the disease, condition or disorder, or to prevent the manifestation of clinical or subclinical symptoms thereof) or therapeutic, i.e., the suppression or alleviation of symptoms after the manifestation of the disease, condition or disorder.

[0053] All percentages, parts, and ratios as used herein are detailed by weight of the total composition, unless otherwise specified. All amounts specified as administered “per day” may be delivered in a single unit dose, in a single serving, or in two or more doses or servings administered over the course of a 24 hour period.

[0054] All references to singular characteristics or limitations in the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary, by the context in which the reference is made.

[0055] All combinations of method or process steps disclosed herein can be performed in any order, unless otherwise specified or clearly implied to the contrary, by the context in which the referenced combination is made.

[0056] The compositions of the present disclosure can comprise, consist of, or consist essentially of any of the components described herein, as well as including any additional useful component.

[0057] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0058] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Brief description of the drawings

[0059] Figure 1 illustrates the dose dependent effect of L-Fucose on OPC and oligodendrocyte density;

[0060] Figure 2 illustrates the dose dependent effect of NANA on OPC and oligodendrocyte density; [0061] Figure 3 shows the relative distribution of (a) pre-myelinating oligodendrocytes and (b) mature, myelinating oligodendrocytes using immunostaining of myelin basic protein (MBP);

[0062] Figure 4 illustrates the effect of 100nM L-Fucose on the density of mature, myelinating, oligodendrocytes; and

[0063] Figure 5 illustrates the effect of 1 pM NANA on the density of mature, myelinating, oligodendrocytes.

Detailed Description

[0064] To the best of the inventors’ knowledge, compositions to prevent and/or treat conditions associated with demyelination have not previously been supplemented with sialic acid and/or fucose.

[0065] It is hypothesised that the provision of the compositions of the present application can positively affect the neurological health of a subject by promoting myelin recovery and remyelination. Remyelination would not only restore conduction and subsequent neurologic function but also protect axons from degeneration.

[0066] It is also hypothesised that the compositions of the present application promote remyelination by stimulating the differentiation of OPCs into oligodendrocytes, which in turn can be recruited to a site of demyelination.

[0067] The present disclosure is directed to compositions comprising sialic acid and/or fucose, to uses thereof, and to methods comprising administration of those compositions to a paediatric or adult subject. The compositions of the present disclosure support and improve neurological health and development.

[0068] Sialic acid and fucose are transported across the blood-brain barrier by simple diffusion and a stereospecific saturation transport system. Moreover, the brain can take up sialic acid and fucose after exogenous administration. It has thus been found that oral administration of sialic acid and/or fucose can enhance neurological conditions for brain benefits. [0069] A composition comprising sialic acid and/or fucose represents a feasible and effective approach to promote oligodendrocyte survival and proliferation in a dose dependent manner, resulting in a consistent increase in the number of oligodendrocyte precursor cells. Supplementation with sialic acid and/or fucose provides benefits for enhanced developmental myelination by which it translates into a fundamental benefit for brain development and normal brain function. Given the importance of functional myelination, supplementation of sialic acid and/or fucose is beneficial to paediatric and adult subjects by enhancing brain development and health. Because the nature and characteristics of sialic acid and/or fucose allow these nutrients to cross the blood brain barrier, they synergize with other nutrients to provide comprehensive brain development benefits. Moreover, the positive effects on enhanced developmental myelination from sialic acid and/or fucose can be beneficial for preterm infants as well as those diagnosed with white matter diseases (such as cerebral palsy and periventricular leukomalacia). Sialic acid and/or fucose can also be beneficial in other situations where myelination can be an issue, such as with patients having multiple sclerosis and in post radiation supplementation for promotion of recovery of OPCs.

[0070] The present invention therefore provides a composition comprising sialic acid and/or fucose for use in preventing and/or treating disorders associated with demyelination. The composition may be intended for a neurologically healthy paediatric subject or an adult subject. The composition may be intended for a paediatric subject or an adult subject with a compromised neurological health.

[0071] Preferably, the administration of a composition according to the invention enhances OPC survival and proliferation.

[0072] Preferably, the administration of a composition according to the invention to an in vitro oligodendroglial cell culture model exhibits a significant enhancement in the number of viable OPC cells as compared to the number of viable OPCs cultured in the absence of the composition.

[0073] Preferably, the administration of a composition according to the invention enhances OPC differentiation.

[0074] OPCs are platelet-derived growth factor receptor alpha (PDGFRA) positive cells.

Differentiated oligodendrocytes are CC1 antibody positive cells. Preferably, the administration of a composition according to the invention to an in vitro oligodendroglial cell culture model exhibits an enhancement in the number of CC1 antibody positive cells and a decrease in the number of platelet-derived growth factor receptor alpha (PDGFRA) positive cells as compared to in the absence of the administration of the composition.

[0075] Myelinating oligodendrocytes wrap around the axon, leaving the axolemma relatively uncovered at the regularly spaced nodes of Ranvier. The segment formed by oligodendrocytes between nodes of Ranvier is termed the “internode”, “internodal segment” or “myelin internodes”.

[0076] Preferably, the administration of a composition according to the invention to an in vitro oligodendroglial cell culture model enhances the formation of myelin within the myelin internodes as compared to in the absence of administration of the composition. The formation of myelin may be demonstrated by immunostaining for myelin-specific proteins, such as myelin basic protein (MBP).

[0077] Preferably, the administration of a composition according to the invention to an in vitro oligodendroglial cell culture model enhances the formation of myelin on demyelinated axons, thus demonstrating remyelination.

[0078] Sialic acids are a family of naturally occurring nine-carbon monosaccharides sugars found in milk. There are more than 50 types of known sialic acids. They differ from each other due to the difference in modifications, such as hydroxylation or acetylation at one of the 9-carbon positions. The most common types of sialic acids are Neu5Ac, neuraminic acid (Neu) or 2-keto-3-deoxynononic acid (KdN).

[0079] Sialic acid is present in human milk as sialic acid (Neu5Ac) or as part of oligosaccharides (i.e., sialogylcans); proteins (kappa casein), or lipids (gangliosides). Sialic acid is widely distributed throughout human tissues, the abundant source being found in the central nervous system. Sialic acid plays an important role in maintaining and improving brain health. Neural cell membranes contain around 20-fold higher levels of sialic acid than other cellular membranes, suggesting sialic acid plays a unique structural and functional role in neural tissue (Wang 2009).

[0080] Sialic acid is capable of crossing the blood-brain barrier and being incorporated into sialylglycoconjugates (sugar linked to sialic acid) in the brain. Oral administration of [ ¹⁴ C, ³ H]-labelled SL to 20-day-old mice showed that the bound form of sialic acid could be absorbed and incorporated into neural tissues (Nohle and Schauer 1984). In 3-day-old rats, oral administration of [ ¹⁴ C]-SL showed that 3% to 4% of the dose appeared in the brain after 6 hours (Witt, von Nicolai et al. 1979)

[0081] Sialic acid is a key component of lipids (e.g., gangliosides) and neural cell adhesion molecules (NCAMs). Gangliosides are glycosphingolipids that are high abundant in the nervous system and carry most of the sialic acid residues within the brain. Myelin is rich in glycosphingolipids NCAM and its polysialylated form (PSA-NCAM). Sialic acid is therefore believed to play an important role in neural development and function, learning, cognition, and memory.

[0082] The composition may comprise one or more sources of sialic acid.

[0083] The one or more sources of sialic acid may comprise exogenous sialic acid or endogenous sialic acid, or a combination thereof.

[0084] In some embodiments, the sialic acid may be provided within the composition as an exogenous sialic acid selected from the group consisting of N-glycolylneuraminic acid (NGNA), n-acetylneuraminic acid (NANA), N-Acetyl-D- mannosamine, neuraminic acid, 5- N-Acetyl-4-0-acetyl-neuraminic acid, 5-N-Acetyl-7-0- acetyl-neuraminic acid, 5-N-Acetyl- 8-0-acetyl-neuraminic acid, 5-N-Acetyl-9-0-acetyl- neuraminic acid, 5-N-Acetyl-4,9-di-0- acetyl-neuraminic acid, 5-N-Acetyl-7,9-di-0-acetyl- neuraminic acid, 5-N-Acetyl-8,9-di-0- acetyl-neuraminic acid, 5-N-Acetyl-7,8,9-tri-0-acetyl- neuraminic acid, 5-N-Acetyl-9-0-L- lactyl-acetyl-neuraminic acid, 5-N-Acetyl-4-0-acetyl-9- O-lactyl-acetyl-neuraminic acid, 5- N-Acetyl-8-0-methyl-neuraminic acid, 5-N-Acetyl-9-0- acetyl-8-O-methyl-neuraminic acid, 5-N-Acetyl-8-0-sulpho-neuraminic acid, 5-N-Acetyl-9- O-phosphoro-neuraminic acid, 5-N- Acetyl-2-deoxy-2,3-didehydro-neuraminic acid, 5-N- Acetyl- 9-0-acetyl-2-deoxy-2,3- didehydro-neuraminic acid, 5-N-Acetyl-2-deoxy-2,3- didehydro-9-O-lactyl-neuraminic acid, 5-N-Acetyl-2,7-anhydro-neuraminic acid, 4-0- Acetyl-5-N-glycolyl-neuraminic acid, 7- O-Acetyl-5-N-glycolyl-neuraminic acid, 8-0-Acetyl- 5-N-glycolyl-neuraminic acid, 9-0- Acetyl-5-N-glycolyl-neuraminic acid, 7,9-Di-0-acetyl-5- N-glycolyl-neuraminic acid, 8,9-Di- O-acetyl-5-N-glycolyl-neuraminic acid, 7,8,9-Tri-O- acetyl-5-N-glycolyl-neuraminic acid, 5- N-glycolyl-9-0-lactyl-neuraminic acid, 5-N-glycolyl- 8-0-methyl-neuraminic acid, 9-0- Acetyl-5-N-glycolyl-8-0-methyl-neuraminic acid, 7,9-di- 0-Acetyl-5-N-glycolyl-8-0-methyl- neuraminic acid, 5-N-glycolyl-8-0-sulpho-neuraminic acid, N-(0-acetyl)glycolylneuraminic acid, N-(0-Methyl)glycolylneuraminic acid, 2-Deoxy- 2,3-didehydro-5-N-glycolyl- neuraminic acid, 9-0-Acetyl-2-deoxy-2,3-didehydo-5-N- glycolyl-neuraminic acid, 2- Deoxy-2,3-didehydro-5-N-glycolyl-9-0-lactyl-neuraminic acid, 2-Deoxy-2,3-didehydro-5- N-glycolyl-8-0-methyl-neuraminic acid, 2,7-Anhydro-5-N- glycolyl-neuraminic acid, 2,7- Anhydro-5-N-glycolyl-8-0-methyl-neuraminic acid, 2-Keto-3- deoxynononic acid, 9-0- Acetyl-2-keto-3-deoxynononic acid, and combinations thereof.

[0085] The composition may be administered daily.

[0086] The total daily dosage of exogenous sialic acid may be varied depending on the requirement of the subject and/or the particular physical form of the exogenous sialic acid.

[0087] In some embodiments, the total daily dosage of exogenous sialic acid is at least 0.05g/day, at least 0.10g/day, at least 0.20g/day; at least 0.30g/day, at least 0.40g/day, at least 0.50g/day at least 0.60g/day, at least 0.70g/day, at least 0.80g/day, at least 0.90g/day, at least 1.00g/day, at least 1.10g/day, at least 1.20g/day, at least 1.30g/day, at least 1.40g/day, at least 1.50g/day, at least 1.60g/day, at least 1.70g/day, at least 1.80g/day, at least 1.90g/day or at least 2.0g/day.

[0088] In some embodiments, the total daily dosage of exogenous sialic acid is no less than about 0.05g/day.

[0089] In some embodiments, the total daily dosage of exogenous sialic acid is no more than about 2.0g/day.

[0090] In some embodiments, the total daily dosage of exogenous sialic acid provided is in the range of about 0.05g/day to about 2g/day, preferably between about 0.75g/day and 1.5g/day.

[0091] In some embodiments, the total daily dosage of exogenous sialic acid is about 1.0g/day.

[0092] The total daily dosage of exogenous sialic acid may be in the form of a single daily dosage. Alternatively, the total daily dosage may be administered in portions throughout the day e.g., two portions, three portions, etc. [0093] In other embodiments, an endogenous source of sialic acid is provided as an alternative or an additional source of sialic acid. For example, other components or ingredients are provided within the composition that include a bound sialic acid residue.

[0094] Human milk is a rich source of sialylated milk oligosaccharides (SMOs). More than 55 structurally distinct SMOs have been characterised.

[0095] In some embodiments, the endogenous source of sialic acid is a sialylated oligosaccharide.

[0096] The simplest and most predominant SMOs in human milk are 3’sialyllactose (3’- SL) and 6’sialyllactose (6’-SL), which are formed by the binding of the sialic acid by a-2,3 glycosidic linkages or a-2,6 glycosidic linkages to the terminal galactose unit of lactose in the 3 and 6 position, respectively.

[0097] In some embodiments, the sialylated oligosaccharide is a sialyllactose. Preferably, the sialyllactose is 3’-SL and/or 6’-SL.

[0098] In some other embodiments, the sialylated oligosaccharide is selected from the group consisting of sialyllacto-N-tetraoses (LST) such as LSTa, LSTb and LSTc and disiallylacto- N-tretaose.

[0099] The sialylated oligosaccharide may be obtained from a dairy source, via bacterial or yeast fermentation or chemically synthesised.

[0100] The composition may be administered daily.

[0101] The daily dosage of endogenous sialic acid may be varied depending on the requirement of the subject and/or the particular physical form of the endogenous sialic acid.

[0102] In some embodiments, the total daily dosage of a sialylated oligosaccharide is at least 0.5g/day, at least 1.0g/day, at least 1.5g/day; at least 2.0g/day, at least 2.5g/day, at least 3.0g/day at least 3.5g/day, at least 4.0g/day, at least 4.5g/day, at least 5.0g/day, at least 5.5g/day or at least 6.0g/day. [0103] In some embodiments, the total daily dosage of a sialylated oligosaccharide is no less than about 0.5g/day.

[0104] In some embodiments, the total daily dosage of a sialylated oligosaccharide is no more than about 6.0g/day.

[0105] In some embodiments, the total daily dosage of 3’-SL, 6’-SL or a combination thereof is at least 0.5g/day, at least 1.0g/day, at least 1.5g/day; at least 2.0g/day, at least 2.5g/day, at least 3.0g/day at least 3.5g/day, at least 4.0g/day, at least 4.5g/day, at least 5.0g/day, at least 5.5g/day or at least 6.0g/day.

[0106] In some embodiments, the total daily dosage of 3’-SL, 6’-SL or a combination thereof is no less than about 0.5g/day.

[0107] In some embodiments, the total daily dosage of 3’-SL, 6’-SL or a combination thereof is no more than about 6.0g/day.

[0108] In some embodiments, the total daily dosage of 3’-SL, 6’-SL or a combination thereof is in the range of about 0.6g/day to about 6g/day, preferably between about 3g/day and 5g/day.

[0109] In some embodiments, the total daily dosage of 3’-SL, 6’-SL or a combination thereof is about 4g/day.

[0110] In some embodiments, in which a single endogenous sialic acid is the only source of sialic acid (i.e., no exogenous sialic acid present within the composition), the amount of endogenous sialic acid will likely need to be increased to ensure sufficient free sialic acid will be liberated. For example, as it is hypothesised that 3’-SL contains about 1% sialic acid, a daily dose of 0.05g sialic acid, 5g of 3’-SL is expected to be required.

[0111] The daily dosage of endogenous sialic acid, provided for example by 3’-SL or 6’- SL or a combination thereof may be in the form of a single daily dosage. Alternatively, the total daily dosage may be administered in portions throughout the day e.g., two portions, three portions, etc. [0112] It is hypothesised that the provision of dietary sialylated oligosaccharide, such as 3’-SL and 6’-SL as a source of endogenous sialic acid not only stimulates OPC proliferation and hence promotes remyelination but will also lead to the enrichment of the ganglioside- bound sialic tissue throughout the brain (e.g., cerebellum, corpus callosum and cortical grey and white matter tissue) resulting in an improvement in cognitive function. Furthermore, it is hypothesized that the provision of dietary sialylated oligosaccharide will have a positive impact on the gut microbiome, as HMOs such as 3’-SL and 6’-SL are known to influence the composition of the microbiome by selecting for some commensal bacterial species, such as Bifidobacterium and Bacteroides, which indirectly prevents the colonization of pathogenic bacterial strains.

[0113] In order for any bound sialic acid provided as endogenous sialic acid within the composition to be made available as free sialic acid, it must be released by hydrolysis. Sialidases, also referred to as neuraminidases, the majority of which are exo- a -sialidases (EC 3.2.1.18), catalyze the hydrolysis of terminal sialic acids from complex carbohydrates on glycoproteins or glycolipids. Hydrolytic-sialidases, cleave the glycosidic bond of terminal sialic acids and release free sialic acid. Hydrolytic-sialidases usually have wide substate specificity and cleave a 2,3-, a 2,6-, or a2,8-linked terminal sialic acids. Hydrolytic-sialidases will therefore cleave the terminal sialic acid from 3’-SL and 6’-SL.

[0114] Commensal bacteria in the gut, such as Bifidobacteria spp., exhibit exo-a-sialidase activity to breakdown sialyloligosaccharides, such as 3’-SL and 6’-SL to liberate and/or consume the sialic acid.

[0115] Individuals with a dysbiosis of the gut microbiome may have a reduced population of commensal bacteria with sialidase activity. As a result, the ability to liberate the sialic acid from a sialylglycoconjugate may be compromised. Advantageously therefore, the composition further comprises a sialidase, preferably an exo- a-sialidase.

[0116] Accordingly, the composition may comprise a viable probiotic with a genome including gene(s) for a sialidase, preferably exo-a-sialidase. A number of gut bacteria employ sialidases in the release of host sialic acids, including multiple species of Clostridia, Bacteroides, certain subspecies/serovars/strains of Bifidobacterium longum, Vibrio cholerae, Ruminococcus gnavus and Akkermansia muciniphila. [0117] In some embodiments the probiotic may be Bifidobacterium bifidum (NCIMB 41171), Bifidobacterium breve (DSM20213), Bifidobacterium longum subsp infantis (ATCC15697) or a combination thereof.

[0118] The composition may comprise a probiotic in the range of about 1 x 10 ⁴ colony forming units per 100 kilocalories (CFU/100 kcal) to about 1.5 x 10 ¹² CFU/100 kcal. Preferably, the composition comprises a viable probiotic in the range of about 1 x 10 ⁶ CFU/100 kcal to about 1 x 10 ⁹ CFU/100 kcal. More preferably, the composition comprises a viable probiotic in the range of about 1 x 10 ⁷ CFU/100 kcal to about 1 x 10 ⁸ CFU/100 kcal.

[0119] The probiotic incorporated into the composition may be naturally-occurring, or developed through the genetic manipulation of organisms, whether such source is now known or later developed.

[0120] In addition to a probiotic metabolising the sialylglycoconjugate to liberate the sialic acid, advantageously the provision of a probiotic within the composition will also help to readdress the balance of commensal bacteria in the gut in individuals with a dysbiotic gut microbiota.

[0121] In some further embodiments, the composition may comprise a blend of exogenous and endogenous sialic acid.

[0122] In some embodiments, the composition may comprise a blend of exogenous sialic acid that comprises or consists of 3’-SL and/or 6’-SL.

[0123] In some embodiments, the daily dosage of exogenous sialic acid is in the range of about 0.05g/day to about 2g/day, preferably between about 0.75g/day and 1.5g/day; and the daily dosage of 3’-SL, 6’-SL or a combination thereof in the range of about 0.6g/day to about 6g/day, preferably between about 3g/day and 5g/day.

[0124] Fucose refers to a hexose deoxy sugar found in a wide variety of natural products both in D- and L-form. L-fucose (6-deoxy-L-galactose) is a monosaccharide that is a common component of many N- and O-linked glycans and glycolipids produced by mammalian cells. L-fucose is, for instance, a moiety in several human milk oligosaccharides. [0125] The composition may comprise fucose provided as exogenous fucose or endogenous fucose, or a combination thereof.

[0126] In some embodiments, the exogenous fucose may be provided as L-fucose and/or D-fucose.

[0127] In some other embodiments, the fucose within the composition is provided as endogenous fucose. Where the fucose is L-fucose this may be provided by a fucosylated oligosaccharide. The fucosylated oligosaccharide may be a fucosyllactose. Fucosy I lactoses are neutral trisaccharides composed of L-fucose, D-galactose, and D- glucose units.

[0128] In some embodiments the fucosylated oligosaccharide is selected from the group consisting of 2'-fucosyllactose (2’-FL), 3-fucosyl lactose (3’-FL), difucosy I lactose, lacto-N- fucopentaose I, lacto- N-fucopentaose II, lacto- N-fucopentaose III, lacto-N- fucopentaose V, lacto-N-fucohexaose, lacto-N-difucohexaose I, fucosyl lacto-N- hexaose, fucosyllacto- N-neohexaose (such as fucosyllacto-N-neohexaose I, fucosyllacto-N-neohexaose II), difucosyllacto-N-hexaose I, difuco-lacto-N-neohexaose, difucosyllacto-N-neohexaose I, difucosyllacto-N-neohexaose II, fucosyl-para-Lacto-N- hexaose, tri-fuco-para-Lacto-N- hexaose I and any combination thereof.

[0129] Preferably, the fucosylated oligosaccharide is a fucosyllactose. Preferably the fucosyllactose is 2 -FL and/or 3’-FL, which are highly abundant within human milk.

[0130] The fucosylated oligosaccharide may be obtained from a dairy source, via bacterial or yeast fermentation or chemically synthesised

[0131] In order for any bound fucose provided as endogenous fucose within the composition to be made available as free fucose, it must be released by hydrolysis. Gut bacteria encode a-L-fucosidases (E.C. 3.2.1.63) which catalyse the hydrolysis of terminal a-L-fucosidic linkages from fucosylated oligosaccharides.

[0132] Individuals with a dysbiosis of the gut microbiome may have a reduced population of commensal bacteria with a-L-fucosidase activity. As a result, the ability to liberate the L-fucose from a fucosylated oligosaccharide may be compromised. Advantageously therefore, the composition further comprises a a-L-fucosidase.

[0133] Accordingly, the composition may comprise a probiotic with a genome that includes gene(s) for a a-L-fucosidase.

[0134] It is hypothesised that the provision of dietary fucosylated oligosaccharide such as 2’-FL and 3’-FL as a source of endogenous fucose not only stimulate OPC proliferation and hence remyelination but will lead to the enrichment of ganglioside-bound sialic tissue throughout the brain (e.g., cerebellum, corpus callosum and cortical grey and white matter tissue) resulting in an improvement in cognitive function. Furthermore, it is hypothesized that provision of dietary fucosylated oligosaccharide will have a positive impact on the gut microbiome, as HMOs such as 2’-FL and 3’-FL are known to influence the composition of the microbiome by selecting for some commensal bacterial species, such as Bifidobacterium and Bacteroides, which indirectly prevents the colonization of pathogenic bacterial strains.

[0135] The daily dosage of endogenous fucose may be varied depending on the requirement of the subject and/or the particular physical form of the endogenous fucose. For example, in embodiments in which the endogenous fucose is provided by 2’-FL and/or 3’-FL the total daily dosage of 2’-FL and/or 3’-FL may be in the range of about 0.5g/day to about 6g/day, preferably between about 3g/day and 5g/day, and more preferably about 4g/day. The dose of endogenous fucose may be in the form of a single daily dosage. Alternatively, the total daily dosage may be administered in portions throughout the day e.g., two portions, three portions, etc.

[0136] In some embodiments, the composition comprises a blend of sialic acid in combination with fucose.

[0137] In some embodiments, the composition comprises a blend of exogenous sialic acid, exogenous sialic acid and endogenous fucose. For example, the blend comprises sialic acid, 3’-SL and/or 6’-SL, and 2’-FL and/or 3’-FL.

[0138] In an embodiment, a total daily dosage of sialic acid in the range of about 0.05g to about 2g, more preferably about 0.75g and 1 ,5g; a total daily dosage of 3’-SL and/or 6’-SL in the range of about 0.5g to about 6g , more preferably about 3g and 5g; and a total daily dosage of 2’-FL and/or 3’-FL in the range of about 0.5g to about 6g , more preferably about 3g and 5g.

[0139] The composition may also comprise non-viable or paraprobiotics. These may be naturally-occurring, synthetic, or developed through the genetic manipulation of organisms, whether such source is now known or later developed.

[0140] The composition may also comprise prebiotics. The prebiotic may comprise oligosaccharides (in embodiments in which sialyllactose and/or fucosy I lactose are present within the composition, additional oligosaccharides may be used), polysaccharides, or any other prebiotics that comprise fructose, xylose, soya, galactose, glucose, mannose, or any combination thereof. More specifically, the prebiotic may comprise polydextrose (PDX), polydextrose powder, lactulose, lactosucrose, raffinose, glucooligosaccharides, inulin, fructooligosaccharides, isomaltooligosaccharides, soybean oligosaccharides, lactosucrose, xylooligosaccharides, chitooligosaccharides, mannooligosaccharides, aribino-oligosaccharides, sialyloligosaccharides, fucooligosaccharides, galactooligosaccharides (GOS), and gentiooligosaccharides.

[0141] The composition may comprise a prebiotic in the range of about 1.0 g/L to about 10.0 g/L of the composition. Preferably, the composition comprises a prebiotic in the range of about 2.0 g/L and about 8.0 g/L of the composition. Alternatively, the composition may comprise a prebiotic in the range of about 0.01 g/100 kcal to about 1.5 g/100 kcal. Preferably, the composition comprises a prebiotic in the range of about 0.15 g/100 kcal to about 1.5 g/100 kcal.

[0142] The composition may comprise a prebiotic comprising PDX, GOS, or a combination thereof.

[0143] The composition may comprise PDX in the range of about 1.0 g/L and 10.0 g/L. Preferably, the composition comprises PDX in the range of about 2.0 g/L and 8.0 g/L. Alternatively, the composition comprises PDX in the range of about 0.015 g/100 kcal to about 1.5 g/100 kcal. Preferably, the composition comprises PDX in the range of about 0.05 g/100 kcal to about 1.5 g/100 kcal. More preferably, the composition comprises PDX in the range of about 0.2 g/100 kcal to about 0.6 g/100 kcal. [0144] The composition may comprise GOS in the range of about 0.015 g/100 kcal to about 1.0 g/100 kcal. Preferably, the composition comprises GOS in the range of about 0.2 g/100 kcal to about 0.5 g/100 kcal.

[0145] The composition may comprise PDX in combination with GOS. Advantageously, the combination of PDX and GOS may stimulate and/or enhance endogenous butyrate production. The composition may comprise dietary butyrate. Non-limiting examples of butyrate for use herein include butyric acid, butyrate salts, glycerol esters of butyric acid, and amide derivatives of amino acids. The composition may include a source of dietary butyrate that is present in an amount of from about 0.01 mg/100 Kcal to about 300 mg/100 Kcal. In some embodiments, the composition includes a source of dietary butyrate that is present in an amount of from about 0.1 mg/100 Kcal to about 300 mg/100 Kcal. In some embodiments, the composition includes a source of dietary butyrate that is present in an amount of from about 0.1 mg/100 Kcal to about 300 mg/100 Kcal. In some embodiments, the composition includes a source of dietary butyrate that is present in an amount of from about 1 mg/100 Kcal to about 275 mg/100 Kcal. In some embodiments, the composition includes a source of dietary butyrate that is present in an amount of from about 5 mg/100 Kcal to about 200 mg/100 Kcal. In some embodiments, the composition includes a source of dietary butyrate that is present in an amount of from about 10 mg/100 Kcal to about 150 mg/100 Kcal. In some embodiments, dietary butyrate is present in an amount of from about 0.6 mg/100 kcal to about 6.1 mg/100 kcal.

[0146] The composition may comprise lactoferrin. Lactoferrin may be present in the composition in an amount of at least about 15 mg/100 kcal. The composition may comprise lactoferrin in the range of about 15 mg/100 kcal to about 25 g/100 kcal. Preferably, the composition comprises lactoferrin in the range of about 5 g/100 kcal to about 20 g/100 kcal. More preferably, the composition comprises lactoferrin in the range of about 10 g/100 kcal to about 15 g/100 kcal. The composition may be specifically designed for a paediatric subject. When the composition is specifically intended for a paediatric subject, the composition may comprise lactoferrin in the range of about 15 mg/100 kcal to about 300 mg/100 kcal. Preferably, the composition comprises lactoferrin in the range of about 60 mg to about 150 mg/100 kcal. More preferably, the composition comprises lactoferrin in the range of about 60 mg/100 kcal to about 100 mg/100 kcal.

[0147] In embodiments in which the composition comprises only exogenous sialic acid, the composition may comprise one or more HMOs. The composition may include at least one fucosylated oligosaccharide, at least one N-acetylated oligosaccharide and/or at least one sialylated oligosaccharide.

[0148] The composition may comprise a HMO in the range of about 0.01 g/L to about 5.0 g/L. Preferably, the composition comprises an HMO in the range of about 0.05 g/L to about 4.0 g/L of the composition. More preferably, the composition comprises an HMO in the range of about 0.05 g/L to about 2.0 g/L of the composition. Alternatively, the composition may comprise an HMO in the range of about 0.01 g/100 kcal to about 2.0 g/100 kcal. Preferably, the composition comprises an HMO in the range of about 0.01 g/100 kcal to about 1.5 g/100 kcal.

[0149] The composition may comprise a source of long-chain polyunsaturated fatty acids (LCPUFAs). The source of LCPUFAs may comprise docosahexaenoic acid (DHA), a- linoleic acid, y-linoleic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), arachidonic acid (ARA), or any combination thereof. Preferably, the composition comprises a source of LCPUFAs comprising DHA, ARA, or a combination thereof.

[0150] The composition may comprise an LCPUFA in an amount of at least about 5 mg/100 kcal. The composition may comprise an LCPUFA in the range of about 5 mg/100 kcal to about 100 mg/100 kcal. Preferably, the composition comprises an LCPUFA in the range of about 10 mg/100 kcal to about 50 mg/100 kcal.

[0151] The composition may comprise DHA in the range of about 5 mg/100 kcal to about 80 mg/100 kcal. Preferably, the composition comprises DHA in the range of about 10 mg/100 kcal to about 20 mg/100 kcal. More preferably, the composition comprises DHA in the range of about 15 mg/100 kcal to about 20 mg/100 kcal.

[0152] The composition may comprise ARA in the range of about 10 mg/100 kcal to about 100 mg/100 kcal of ARA. Preferably, the composition comprises ARA in the range of about 15 mg/100 kcal to about 70 mg/100 kcal. More preferably, the composition comprises ARA in the range of about 20 mg/100 kcal to about 40 mg/100 kcal.

[0153] The composition may comprise both DHA and ARA. The weight ratio of ARA: DHA may be in the range of about 1 :3 to about 9:1. Preferably, the weight ratio of ARA: DHA is in the range of about 1 :2 to about 4: 1. The composition may comprise oils containing DHA and/or ARA. If utilised, the source of DHA and/or ARA may be any source known in the art such as marine oil, fish oil, single cell oil, egg yolk lipid, or brain lipid. The DHA and ARA may be sourced from single cell oils, DHASCO® and ARASCO® from DSM Nutritional Products, or variations thereof. The DHA and ARA may be in a natural form, provided that the remainder of the LCPLIFA source does not result in any substantial deleterious effect on the subject. Alternatively, the DHA and ARA may be used in refined form.

[0154] The composition may comprise p-glucan. Preferably, the p-glucan comprises p- 1 ,3-glucan. Preferably, the p-1 ,3-glucan comprises p-1 ,3;1 ,6-glucan. The composition may comprise p-glucan present in the range of about 0.010 grams to about 0.080 grams per 100g of composition. Alternatively, the composition may comprise p-glucan in the range of about 3 mg/100 kcal to about 17 mg/100 kcal. Preferably, the composition comprises p-glucan in the range of about 4 mg/100 kcal to about 17 mg/100 kcal.

[0155] The composition may comprise one or more suitable composition ingredient, wherein the suitable composition ingredient comprises choline, inositol, osteopontin (OPN) or a combination thereof.

[0156] The composition may comprise choline. Choline is a nutrient that is essential for normal function of cells. Choline is a precursor for membrane phospholipids and it accelerates the synthesis and release of acetylcholine, a neurotransmitter involved in memory storage. Without wishing to be bound by theory, it is believed that dietary choline and docosahexaenoic acid (DHA) act synergistically to promote the biosynthesis of phosphatidylcholine and thus, help promote synaptogenesis in human subjects. Additionally, choline and DHA act synergistically to promote dendritic spine formation, which is important in the maintenance of established synaptic connections. Furthermore, choline is associated with myelin repair.

[0157] The composition may comprise inositol. The inositol may be present as exogenous inositol, inherent inositol, or a combination thereof. The composition may comprise inositol in the range of about 10 mg/100 kcal to 40 mg/100 kcal. Preferably, the composition comprises inositol in the range of about 20 mg/100 kcal to 40 mg/100 kcal. Alternatively, the composition comprises inositol in the range of about 130 mg/L to about 300 mg/L.

[0158] The composition may comprise osteopontin (OPN). The thickness of the myelin sheath in spinal cords has been found to be decreased in the absence of milk OPN. [0159] The composition may comprise a compound that promotes oligodendroglial proliferation. The compound may be an antioxidant. The antioxidant may be epigallocatechin gallate (EGCG), a-lipoic acid, ferulic acid, allyl sufide, fisetin, kaempferol, ursolic acid or L-sulforaphane. The compound may be sodium cholesterol sulphur.

[0160] The composition may comprise vitamins. The composition may comprise vitamin A, vitamin B6, vitamin B7 (biotin), vitamin B12, vitamin C, vitamin D, vitamin E. The composition may comprise minerals. The composition may comprise selenium, calcium, iron, magnesium (e.g. magnesium threonate) or zinc.

[0161] The composition may comprise one or more emulsifier, as an emulsifier can increase the stability of the composition. The emulsifier may comprise, but is not limited to, egg lecithin, soy lecithin, alpha lactalbumin, monoglycerides, diglycerides, or any combination thereof.

[0162] The composition may comprise one or more preservative, as a preservative can extend the shelf-life of the composition. The preservative may comprise, but is not limited to, potassium sorbate, sodium sorbate, potassium benzoate, sodium benzoate, calcium disodium EDTA, or any combination thereof.

[0163] The composition may comprise one or more stabiliser, as a stabiliser can help preserve the structure of the composition. The stabiliser may comprise, but is not limited to, gum arabic, gum ghatti, gum karaya, gum tragacanth, agar, furcellaran, guar gum, gellan gum, locust bean gum, pectin, low methoxyl pectin, gelatine, microcrystalline cellulose, CMC (sodium carboxymethylcellulose), methylcellulose hydroxypropyl methyl cellulose, hydroxypropyl cellulose, DATEM (diacetyl tartaric acid esters of mono- and diglycerides), dextran, carrageenans, or any combination thereof.

[0164] The composition may be provided in an orally-ingestible form, a form to be expelled directly into a subject's intestinal tract, or both. The composition may be expelled directly into the gut.

[0165] The composition may be suitable for a number of dietary requirements. The composition may be kosher. The composition may be a non-genetically modified product. The composition may be sucrose-free. The composition may also be lactose-free. The composition may not contain any medium-chain triglyceride oil. No carrageenan may be present in the composition. The composition may be free of all gums.

[0166] When the composition is a dietary supplement, the dietary supplement may be provided in any form known in the art. The dietary supplement may be provided in a solid form preparation or a fluid preparation. When the dietary supplement is a solid form preparation, the dietary supplement may be provided as a tablet, a gummy, a capsule, a reconstitutable powder, or as dispersible granules. When the dietary supplement is a fluid preparation, the dietary supplement may be provided in the form of a gel, a suspension, a paste, or a reconstituted solution

[0167] The dietary supplement may be consumed daily. The dietary supplement may used as a prophylactic measure to minimise the risk of age-related demyelination leading to cognitive decline.

[0168] Alternatively, the composition is a pharmaceutical composition. The pharmaceutical composition may be provided in any form known in the art. The pharmaceutical composition may be provided in a solid form preparation or a fluid preparation. When the pharmaceutical composition is a solid form preparation, the pharmaceutical composition may be provided as a tablet, a gummy, a capsule, a reconstitutable powder, or as dispersible granules. When the pharmaceutical composition is a fluid preparation, the pharmaceutical composition may be provided in the form of a gel, a suspension, a paste, or a reconstituted solution. Preferably, the pharmaceutical composition is in the form of a tablet, a gummy, a capsule, a reconstitutable powder, or a reconstituted solution.

[0169] The pharmaceutical composition may be administered daily.

[0170] The duration of treatment can be determined based on several factors, including, for example, body weight and/or condition, the severity of symptoms, the incidence and/or severity of side effects. Preferably, the duration is at least 14 days, more preferably at least 3 weeks, even more preferably more than 4 weeks.

[0171] Alternatively, the composition is a nutritional composition. When the composition is a nutritional composition, it may be provided in any form known in the art. The nutritional composition may be provided in the form of a powder, a gel, a suspension, a paste, a solid, a liquid, a liquid concentrate, a reconstitutable powder, a reconstituted solution, or a ready- to-use product. Preferably, the nutritional composition is in the form of a reconstitutable powder, a reconstituted solution, or a ready-to-use product. Most preferably, the nutritional composition is provided in the form of a reconstitutable powder.

[0172] When the composition is a nutritional composition, the nutritional composition may be a nutritional supplement, an infant formula, a follow-up formula, a young child milk, a human milk fortifier, a children's nutritional product, or any other composition designed for a paediatric subject. Preferably, the nutritional composition is an infant formula, a follow-up formula, a young child milk, or a human milk fortifier.

[0173] The nutritional composition may be consumed daily.

[0174] The dietary supplement, pharmaceutical composition and/or nutritional composition may be used in a method of enhancing remyelination of demyelinated neurons in a subject having a disease or condition characterised by demyelination, the method comprising administering the supplement or composition according to the invention to the subject.

[0175] The disease associated with demyelination may be selected from the group consisting of multiple sclerosis, amyotropic lateral sclerosis, acute disseminated encephalomyelitis, diffuse cerebral sclerosis, necrotizing haemorrhagic encephalitis, stroke, spinal cord injury, schizophrenia, bipolar disorder, acute brain injury, Parkinson’s disease, dementia, optic neuritis, neuromyelitis optica, transverse myelitis, acute disseminated encephalomyelitis (ADEM), Leber hereditary optic neuropathy, adrenoleukodystrophy, adrenomyeloneuropathy, metachromatic leukodystrophy, Krabbe’s disease, transverse myelitis, Pelizaeous-Merzbacher disease, Guillain-Barre syndrome (GBS), Balo’s disease, Schilder’s disease, and chronic inflammatory demyelinating polyneuropathy (CIDP).

[0176] The condition may be ageing.

[0177] An enhancement of remyelination may be demonstrated by an improvement in a subject’s cognitive function. [0178] The improvement in cognitive function may be an improvement in executive function. Executive function is the ability to coordinate and integrate cognitive-perceptual processes in relation to time and space, determining how well a subject can recognise, evaluate and make a choice among a variety of alternative options and strategies. Skills that comprise executive function include attention, working memory, inhibitory control and cognitive flexibility.

[0179] The improvement in executive function may be an improvement reported by the subject following consumption of the composition according to the present invention.

[0180] The improvement in executive function may be an improvement measured by at least one standardised clinical neuropsychological test. Non-limiting examples of suitable neuropsychological tests are:

Winsconsin Card Sorting Test (WCST) - demonstrates mental flexibility

Stroop Task Test - demonstrates inhibitory control

Trail Making Test (TMT) - demonstrates mental flexibility

Clock Drawing Test (CDT) - demonstrates planning

Verbal Fluency Test (VFT) animals category - demonstrates verbal fluency

Verbal Fluency Test (VFT) F, A, S - demonstrates verbal fluency

Digits Forward and Backward subtests (WAIS-R or WAIS-III) - demonstrates working memory.

[0181] A subject having a disorder characterised by demyelination is likely to have test scores outside of the deemed “normal” ranges for one or more of these tests. Following administration of the composition according to the invention, improved executive function is demonstrated by an improvement in the subject’s score for one or more of these tests.

[0182] The enhancement of executive function may only be detectable after for example more than 30 days, more than 1 month, more than 6 months, more than 1 year, more than 5 years, more than 10 years, more than 20 years.

[0183] Common symptoms of demyelinating disorders include: vision loss, muscle weakness, muscle stiffness, muscle spasms, bladder and/or bowel control, and sensory changes. An enhancement of remyelination may be demonstrated by an improvement in at least one of these symptoms. The improvement may be an improvement reported by the subject. The improvement may be an improvement measured in a clinical setting. [0184] It is well within the purview of the skilled person to determine an effective dose based upon the information herein and the knowledge in the field. [0185] The scope of the present invention is defined in the appended claims. It is to be understood that the skilled person may make amendments to the scope of the claims without departing from the scope of the present disclosure.

EXAMPLES

[0186] Example 1 : Compositions

[0187] Table 1 illustrates example compositions within the scope of the present disclosure but is in no way intended to provide any limitation on the disclosure.

TABLE 1

[0188] EXAMPLE 2: The effect of L-fucose and NANA on the density of oligodendrocyte progenitor cells (OPCs) and survival, proliferation, and differentiation of oligodendroglial cells in vitro. 2.1 METHODOLOGY

[0189] OPCs were isolated from post-natal 7-9 days old rat or mouse brain cortices and processed according to the established protocols. Isolated OPCs were plated onto coverslips and then treated with varying concentrations of control or experimental compounds (L-Fucose or N-Acetylneuraminic acid (Neu5Ac/ NANA)) for 48 hours. 2.1.1 Control compounds

Triiodothyronine (T3) treatment of OPCs blocks proliferation and induces differentiation into oligodendrocytes. T3 was used at a concentration of 30ng/ml.

Platelet-derived growth factor (PDGF) is potent mitogen for the proliferation of OPCs and arrests differentiation into oligodendrocytes. PDGF was used at a concentration of 25ng/ml.

2.1.2 Experimental compounds

L-fucose was tested at various concentrations in the range of 10nM - 1 mM. Specifically, at 10nM, 100nM, 1 .M, 10 .M and 1 mM.

NANA was tested at various concentrations in the range of 100nM - 1 mM. Specifically, at 100nM, 1 jiM, 10 .M and 1mM.

2.1.3 Immunostaining

The number of OPCs and oligodendrocytes were quantified by immunostaining.

OPCs were quantified using Platelet Derived Growth Factor Receptor Alpha (PDGFRa) stain.

Mature oligodendrocytes were quantified using Myelin Basic Protein (MBP) stain.

Cell nuclei were quantified using DAPI stain.

All effects were quantified by dose-response analysis of OPC and oligodendrocytes.

3. RESULTS

3.1 L-Fucose

Figure 1 illustrates the effect of L-Fucose on OPC and oligodendrocyte density.

The panel of immunostaining images are representative images for the following treatment conditions:

(a) Vehicle (water);

(b) T3 at 30ng/ml; (c) PDGF at 25ng/ml;

(d) Vehicle (water);

(e) L-fucose at 10nM;

(f) L-fucose at 100nM

The dose dependent effect of L-fucose on OPC and oligodendrocyte density is shown in Figure 1 (g): OPC density per ,m ² and (h) oligodendrocyte density per ,m ² .

L-fucose at all concentrations tested (i.e., 10nM, 100nM, 1 .M, 10 ,M and 1 mM) resulted in the differentiation of OPCs into oligodendrocytes. This was similar to the effect observed with T3. The effect was significant at 100nM fucose and above.

As expected, the data for L-fucose contrasts with that found for PDGF, with the latter showing a proliferation of OPCs rather than their differentiation into oligodendrocytes.

3.2 NANA

Figure 2 illustrates the dose dependent effect of NANA on OPC and oligodendrocyte density.

The panel of immunostaining images are representative images for the following treatment conditions:

(a) Vehicle (water);

(b) T3 at 30ng/ml;

(c) PDGF at 25ng/ml;

(d) Vehicle (water);

(e) NANA at lOOnM;

(f) NANA at lOjiM

The dose dependent effect of NANA on OPC and oligodendrocyte density is shown in Figure 2 (g): OPC density per .m ² and (h) oligodendrocyte density per .m ² .

NANA at all concentrations tested (i.e., 100nM, 1 .M, 10 .M and 1 mM) resulted in the differentiation of OPCs into oligodendrocytes. This was similar to the effect observed with T3. The effect was significant at all concentrations of NANA tested. As expected, the data for NANA contrasts with that found for PDGF, with the latter showing a proliferation of OPCs rather than their differentiation into oligodendrocytes.

4. CONCLUSIONS

The in vitro study demonstrated that L-fucose and NANA promote OPC differentiation into oligodendrocytes.

[0190] EXAMPLE 3: The effect of L-fucose and NANA on the differentiation of OPCs into myelinating oligodendrocytes.

The formation of new myelin-forming oligodendrocytes is called oligodendrogenesis. This is a stepwise differentiation process consisting of three canonical stages: (1) the oligodendrocyte precursor cell (OPC), (2) the premyelinating oligodendrocyte (preOL), and (3) the mature, myelinating oligodendrocyte (OL).

Premyelinating oligodendrocytes constitute a population of terminally differentiated cells that are not OPCs but have not yet started to form myelin sheaths.

We investigated whether L-fucose and NANA cause the differentiation of OPCs into preOL or OL cells.

3.1 Methodology

3.1.1 OPC-DRGs co-cultures

Dorsal Root Ganglion (DRG) neurons obtained from E15 Sprague-Dawley rats were plated at a density of 150,000 cells per 25 mm cover glass on collagen-coated coverslips in the presence of 100 ng ml’ ¹ nerve growth factor (NGF). Neurons were maintained for three weeks and washed extensively with Dulbecco's Modified Eagle Medium (DM EM) to remove any residual NGF before seeding with OPCs.

OPC-DRG co-cultures were grown in chemically-defined medium composed of DMEM supplemented with B-27 supplement (Invitrogen), N-2 supplement (Invitrogen), penicillinstreptomycin, N-acetyl-cysteine, and forskolin. The OPC-DRG co-cultures were treated with varying concentrations of control or experimental compounds (L-Fucose or N-Acetylneuraminic acid (Neu5Ac/ NANA) for 9 days.

3.1.2 Control compounds

T3 was added to the co-cultures at the day of OPC seeding at a concentration of 30ng/ml.

3.1.2 Experimental compounds

L-fucose was tested at a concentration of 100nM.

NANA was tested at a concentration of 10 .M.

3.1.3 Immunostaining

Pre-myelinating and mature, myelinating oligodendrocytes were identified using immunostaining for MBP.

A myelin sheath insulates the axon over a single section and in general, each axon comprises multiple long myelinated sections separated from each other by short gaps called the nodes of Ranvier. Nodes of Ranvier are the short (-1 micron) unmyelinated regions of the axon between adjacent long (-0.2 mm - >1 mm) myelinated internodes.

Whilst preOL cells are positive for MBP, OL cells were visually distinguished from the preOL cells by MBP staining of the “tube-like structures” that are representative of myelinated internodes.

[0191] Results

As shown in Figures 4 and 5, the population of OLs in the OPC-DRG co-cultures treated with 100nM L-fucose and 10 .M NANA is similar to that of the co-cultures treated with T3.

[0192] Conclusion

L-fucose and NANA, at least at the concentrations tested in this in vitro model cause the differentiation of OPCs into OLs.