To obtain the subject promoter capable of being not assimilated by enteric deleterious bacteria and opportunistic bacteria but assimilated by only Bacillus bifidus of most effective bacteria in high selectivity, and promoting the growth of the enteric Bacillus bifidus by using ghatti gum as an active ingredient.

This promoter contains ghatti gum as an active ingredient. The ghatti gum is branched polysaccharides composed of L-arabinose, D- galactose, D-mannose, D-xylose and D-glucuronic acid, and the content thereof is 0.1-20 wt.%. Vitamins such as pantothenic acid and riboflavin can be used in combination with the ghatti gum, and other vegetable fibers, oligosaccharides, minerals and the like can be formulated therewith. The daily dose is about 0.1-10 g, and the dose is preferably administered by dividing the dose into one to several times.