Metabolic & Cardiometabolic
gut microbiome causes insulin resistance
📅 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: Animal studies (Animal)
How the studies fall
What the evidence shows
A gut microbiota → bile-acid → intestinal-IL-22 axis (B. vulgatus) drives insulin resistance + ovarian dysfunction in PCOS.
The evidence (7)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Vrieze A, Van Nood E, Holleman F, Salojärvi J, Kootte RS, Bartelsman JF, Dallinga-Thie GM, Ackermans MT, Serlie MJ, Oozeer R, Derrien M, Druesne A, Van Hylckama Vlieg JE, Bloks VW, Groen AK, Heilig HG, Zoetendal EG, Stroes ES, de Vos WM, Hoekstra JB, Nieuwdorp M 2012 · Gastroenterology | RCT | mixed | moderate | Vrieze 2012 lean-donor FMT raised insulin sensitivity in MetSyn men; human gut->IR but not PCOS/BA-specific ⚠️ correction-on-file (Crossref) - kept, corrigendum not retraction |
| Patel E 2026 · Frontiers in endocrinology | observational | supports | low | Narrative review of PCOS: gut dysbiosis contributes to intestinal permeability/endotoxemia worsening insulin resistance and hormonal dysfunction; reviews dietary interventions (Mediterranean, low-GI, probiotics) that improve insulin sensiti |
| Mustika A, Gorica E, Harbuwono DS, Kurniawati EM, Hadinata E, Hidayat AA, Siahaan SCPT, Hendarto H, Santini A, Nurkolis F 2026 · Marine drugs | mechanism | mixed | low | Hypothesis-driven review proposing a gut-SIRT1-kisspeptin axis in PCOS, in which gut dysbiosis alters bile-acid signaling and microbial metabolites, contributing to metabolic (insulin resistance) and neuroendocrine dysfunction; authors expl |
| pcos-fmt-2024 2024 · BMC microbiology | animal | supports | moderate | FMT from PCOS patients to germ-free mice induces IR+ovarian dysfunction; replicates causal gut->PCOS-IR |
| 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 (human data emphasis) on PCOS pathogenesis, describing gut dysbiosis/intestinal barrier dysfunction and altered bile-acid + SCFA + tryptophan metabolite signaling as contributors to PCOS hyperandrogenism, ovulatory dysfunct |
| qi-2019 2019 · Nature medicine | animal | supports | high | Flagship B.vulgatus up GDCA/TUDCA down in PCOS women; FMT to mice causes IR+ovarian dysfunction via IL-22 ⚠️ correction-on-file (Crossref) - kept, corrigendum not retraction |
| Ridaura VK, Faith JJ, Rey FE, Cheng J, Duncan AE, Kau AL, Griffin NW, Lombard V, Henrissat B, Bain JR, Muehlbauer MJ, Ilkayeva O, Semenkovich CF, Funai K, Hayashi DK, Lyle BJ, Martini MC, Ursell LK, Clemente JC, Van Treuren W, Walters WA, Knight R, Newgard CB, Heath AC, Gordon JI 2013 · Science | animal | mixed | high | Ridaura 2013 obese-twin microbiota FMT transmits metabolic phenotype to germ-free mice; general not PCOS/BA. ANIMAL |
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