Metabolic & Cardiometabolic
PCOS decreases gut microbiome diversity
Part of: • PCOS
📅 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: All trials, pooled (Meta-analysis)
How the studies fall
What the evidence shows
PCOS reduces gut-microbiome alpha-diversity.
The evidence (7)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Kaliappa GD et al 2026 · study_type: observational | observational | mixed | moderate | Case-control metagenomics: PCOS showed 'marked gut microbial dysbiosis' by alpha/beta diversity yet 'comparable species richness' to controls vs healthy age-matched women. |
| Chen 2024 · Microbiol Spectr | observational | supports | low | PCOS women had reduced gut microbiota diversity and richness vs healthy controls |
| zou-2023 2023 | meta-analysis | contradicts | moderate | Pooled PCOS effect on microbiota minimal/inconsistent. |
| Chen 2025 · Sci Rep | animal | contradicts | low | DHEA-induced PCOS rats showed INCREASED alpha/beta diversity, conflicting with reduced-diversity claim |
| Yang 2024 · BMC Microbiol | observational | contradicts | low | PCOS showed altered gut community structure and lower diversity vs healthy women |
| solaleyva-2023 2023 | meta-analysis | supports | moderate | Alpha-diversity SMD -0.20 (small; high RoB). |
| Li YM et al 2026 · study_type: observational | observational | contradicts | moderate | 16S reanalysis (PCOS n=24 vs HC n=12) + public data (PCOS n=98 vs HC n=71), all normal-weight: 'no significant differences in beta and alpha diversity between PCOS and normal controls.' |
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