XOS (Xylooligosaccharides)
Commonly used for
NutritionConstipation
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What is it? / Overview
XOS is a highly fermentable prebiotic fiber that selectively stimulates beneficial bacteria, particularly Bifidobacterium species. Human studies suggest improvements in gut microbiota composition and bowel health at relatively low doses.
How is it used? / Administration
Form: Xylooligosaccharides
Typical dose studied: 1–4 g/day (benefits seen with doses as low as 1.4 g/day)
Timing: With meals
Lower doses often effective compared with many other prebiotic fibers. Introduce gradually to reduce bloating.
How well does it work? / Evidence
~ Moderate evidence
Who should avoid it?
Avoid with: IBS / Irritable bowel syndrome
Interacts with: Separate from oral medications by ~2 hours if significant GI symptoms occur
Already taking it? Increase gradually to improve tolerance.
Research & references
Finegold SM et al. (2014). XOS increases bifidobacteria in human gut microbiota. Food & Function. An R et al. (2022). Oligosaccharides and glycemic control meta-analysis. Food & Function. Aachary AA, Prapulla SG. (2011). XOS as emerging prebiotic review. Comprehensive Reviews in Food Science and Food Safety.
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