To provide a high-safety composition having an excellent cytoprotection effect on gastric epithelial cell.

The agent for gastric epithelial cell cytoprotection includes an acidic xylooligosaccharide containing a glucuronic acid group as an active ingredient. The protecting agent has an excellent protection action on gastric mucosa (inhibitory action on cell vacuolation by Helicobacter pylori, inhibitory action on urease and inhibitory action on adhesion of Helicobacter pylori on gastric epithelial cell). The cytoprotection agent is useful as a food additive.