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 2012 · Gastroenterology | RCT | mixed | moderate | [FT-verified] 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 · study_type: observational | 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 et al 2026 · study_type: mechanism | 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 | animal | supports | moderate | FMT from PCOS patients to germ-free mice induces IR+ovarian dysfunction; replicates causal gut->PCOS-IR |
| Du X et al 2026 · study_type: observational | 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 | 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 2013 · Science | animal | mixed | high | [FT-verified] Ridaura 2013 obese-twin microbiota FMT transmits metabolic phenotype to germ-free mice; general not PCOS/BA. ANIMAL |
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Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.