Supplements · Metabolic & Cardiometabolic · Gut & Microbiome
inulin decreases insulin resistance
Part of: 🧪 inulin-type fructans
📅 Last reviewed: 2026-07-15 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
Inulin (prebiotic fiber) improves insulin resistance / glucolipid metabolism in PCOS, mediated by gut microbiota and SCFA production.
The evidence (6)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Yin T, Lai L, Lin X, Zhang L, Huang J, Huang K, Wong M, Ming K 2026 · Journal of ovarian research | meta-analysis | mixed | low | 26 RCTs, PCOS, prebiotics/probiotics/synbiotics pooled: HOMA-IR SMD -0.79 (95%CI -1.48,-0.11), insulin SMD -0.60; biotics classes pooled, not inulin-isolable |
| Samimi M, Dadkhah A, Haddad Kashani H, Tajabadi-Ebrahimi M, Seyed Hosseini E, Asemi Z 2019 · Probiotics Antimicrob Proteins | RCT | mixed | moderate | Synbiotic 12wk in PCOS improved insulin metabolism markers vs placebo [SCOPE/CO-INT temper 2026-07-15: SYNBIOTIC (probiotic+prebiotic) trial — cannot isolate inulin's contribution] ⚠️ correction-on-file (Crossref) - kept, corrigendum not retraction |
| Rao M, Gao C, Xu L, Jiang L, Zhu J, Chen G, Law BYK, Xu Y 2019 · J Diabetes Res | meta-analysis | mixed | moderate | Inulin-type carbs MA: improved some glycemic indices but insulin-resistance effect modest/controversial |
| Geng L, Yang X, Sun J, Ran X, Zhou D, Ye M, Wen L, Wang R, Chen M 2025 · Advanced Science | observational | supports | moderate | Inulin improved hyperandrogenism + glucolipid metabolism in PCOS cohort and mice; FMT from inulin-treated patients transferred insulin-sensitivity benefit to mice (causal chain: fiber→microbiota→SCFA→metabolism). |
| Ziaei R, Shahshahan Z, Ghasemi-Tehrani H, Heidari Z, Nehls MS, Ghiasvand R 2024 · Food Sci Nutr | RCT | supports | moderate | inulin-type fructans lowered fasting insulin/HOMA-IR in overweight PCOS (12wk) |
| Du X, Su H, Huang Y, Liu J, Li Q, Yang X, Tao X, Li R 2026 · Frontiers in endocrinology | observational | supports | low | Narrative review of PCOS gut microbiome pathogenesis; summarizes prior prebiotic/probiotic trial evidence, no new primary inulin data or effect size |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.