iXOS® (Xylooligosaccharides Prebiotic)

Evidence Level
Moderate
1 Clinical Trial
3 Documented Benefits
3/5 Evidence Score

iXOS® (Compound Solutions) is a patented xylooligosaccharide (XOS) prebiotic fiber derived from non-GMO corn cobs — providing one of the most selective and effective prebiotic fibers for feeding Bifidobacterium and Lactobacillus species in the gut microbiome. XOS requires remarkably low doses (1–2g/day) to achieve significant bifidogenic effects — 2–5x lower than FOS, GOS, or inulin — making it ideal for inclusion in capsule-format supplements, functional foods, and protein powders without bulking the serving size.

Studied Dose 1–2g/day iXOS® for prebiotic bifidogenic effects (much lower than other prebiotics at 5–15g/day); effective at just 1g/day in clinical studies
Active Compound Xylooligosaccharides (XOS, degree of polymerization 2–10) — iXOS® by Compound Solutions; non-GMO corn cob derived; standardized for xylobiose and xylotriose content

Highly selective bifidogenic prebiotic at low dose

iXOS® (XOS) preferentially feeds Bifidobacterium species — beneficial bacteria associated with immune function, metabolic health, and reduced gut inflammation — at doses as low as 1g/day. This selectivity for beneficial bacteria over pathogenic species, at a dose 5–10x lower than inulin or FOS, makes iXOS® the most formulator-friendly prebiotic for inclusion in capsules and functional foods.

Gut microbiome diversity and health

Multiple clinical studies confirm XOS supplementation significantly increases Bifidobacterium counts, improves microbiome diversity, reduces pathogenic bacteria ratios, and improves gut transit time. These microbiome improvements translate to better immune function, reduced systemic inflammation, improved metabolic markers, and enhanced short-chain fatty acid (SCFA) production.

Metabolic and immune health benefits

XOS fermentation by gut bacteria produces butyrate, propionate, and acetate — short-chain fatty acids (SCFAs) that feed colonocytes, regulate immune T-cell differentiation, and improve insulin sensitivity. Clinical studies link XOS supplementation to improved blood glucose, reduced LDL cholesterol, and enhanced mucosal immune defense.

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Selective Bifidobacterium fermentation and SCFA production

XOS passes undigested to the colon where Bifidobacterium species — possessing specific beta-xylosidase enzymes — selectively ferment it as a preferred substrate. This selective fermentation increases Bifidobacterium abundance and produces butyrate (colonocyte fuel, anti-inflammatory, histone deacetylase inhibitor), propionate (hepatic gluconeogenesis inhibitor, satiety signal), and acetate — SCFAs with systemic metabolic and immune benefits.

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XOS Prebiotic and Bifidobacterium Growth — RCT
PubMed

Randomized, double-blind, placebo-controlled trial of XOS (1–2.8g/day) effects on gut microbiome composition, Bifidobacterium counts, and metabolic markers.

Healthy adults and metabolic syndrome subjects. Multiple RCTs across dose ranges.

XOS at 1g/day significantly increased Bifidobacterium counts, improved microbiome diversity, reduced fasting blood glucose, and improved lipid profiles vs. placebo. Effects achieved at doses 5–10x lower than inulin or FOS. No significant GI side effects at therapeutic doses.

Common Potential side effects

Excellent GI tolerance at 1–2g/day — significantly better than FOS or inulin
Mild bloating at higher doses (>5g/day)
Corn-derived — relevant for corn allergy (rare); non-GMO

Important Drug interactions

No established drug interactions at prebiotic doses
Immunosuppressants — microbiome changes could theoretically affect drug metabolism; no clinical concern established