Dysbiotic alteration in the fecal microbiota of patients with polycystic ovary syndrome Original paper

What was studied?

This study investigated dysbiotic alteration in the fecal microbiota of patients with polycystic ovary syndrome (PCOS). The focus keyphrase dysbiotic alteration in the fecal microbiota of patients with PCOS appears throughout because it defines the core scientific aim: characterizing how gut microbial structure, taxonomic composition, and predicted functional pathways differ between PCOS patients and healthy controls in Northeast China. Using 16S rRNA sequencing, the researchers examined alpha diversity, beta diversity, taxonomic abundance shifts across phylum-to-genus levels, and microbial functional predictions generated by PICRUSt2. They also analyzed microbial signatures via linear discriminant analysis effect size (LEfSe). Overall, the work sought to identify microbial taxa and metabolic capacities most strongly associated with PCOS pathology, with particular importance placed on short-chain fatty-acid (SCFA)–producing bacteria and bile-acid–related taxa.

Who was studied?

Thirty-four women were recruited from the China-Japan Union Hospital: 17 individuals diagnosed with PCOS using the 2003 Rotterdam criteria and 17 age-matched, healthy women with regular menstrual cycles and normal hormone levels. Participants averaged 25.53 years (PCOS) and 23.87 years (controls), with no significant differences in age or height. PCOS participants had higher weight and BMI. All underwent fasting blood sampling and provided fresh fecal samples for microbial sequencing, ensuring consistent biospecimen handling.

Most important findings

PCOS participants demonstrated markedly reduced alpha diversity across observed OTUs, Chao1 richness, Shannon and Simpson indices, and Pielou evenness. Beta diversity plots showed clear community separation between groups, indicating distinct microbial ecosystems. At the phylum level, PCOS samples showed reduced Firmicutes and Bacteroidota, with increased Actinobacteriota and Proteobacteria. At the genus level, the most defining enrichment was Bifidobacterium, while 11 key genera were consistently depleted: Bacteroides, UCG-002, Eubacterium coprostanoligenes group, Dialister, Firmicutes_unclassified, Ruminococcus, Alistipes, Christensenellaceae R-7 group, Clostridia UCG-014 unclassified, Roseburia, and Lachnospiraceae. These depleted genera included major SCFA-producers (Roseburia, Ruminococcus, Alistipes), organisms with known metabolic benefits involving acetate, propionate, and butyrate. PICRUSt2 functional predictions showed PCOS-associated shifts toward stress-response pathways and reductions in pathways related to core metabolic and DNA-repair functions.

Key implications

The study reveals a clear dysbiotic alteration in the fecal microbiota of patients with PCOS, supporting the view that PCOS is partly a gut-microbiota–mediated metabolic disorder. Depletion of SCFA-producing taxa suggests potential disruption in anti-inflammatory and insulin-sensitizing metabolites central to PCOS pathophysiology. Enrichment of Bifidobacterium—usually interpreted as beneficial—may play a different role here, given its bile-salt hydrolase (bsh) genes, which may influence bile-acid metabolism implicated in PCOS progression. These microbial signatures provide candidate biomarkers for microbiome-based diagnostics and potential therapeutic targets involving diet, probiotics, prebiotics, or fecal microbiota transplantation.

Citation

Chen K, Geng H, Ye C, Liu J. Dysbiotic alteration in the fecal microbiota of patients with polycystic ovary syndrome.Microbiol Spectr. 2024;12(8):e04291-23. doi:10.1128/spectrum.04291-23