FROM THE JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM

The diversity of gut microbiota in women with polycystic ovary syndrome (PCOS) is much less diverse, a problem which may be caused by androgen levels, according to a study from the Journal of Clinical Endocrinology and Metabolism.

“This study demonstrated that Caucasian women diagnosed with PCOS using the Rotterdam criteria had a reduction in overall species richness [alpha diversity] of the gut microbiome, compared to healthy women, and changes in the composition of the microbial community [beta diversity]” wrote Pedro J. Torres and his associates. “Interestingly, our study found that the biodiversity of the microbiome strongly correlated with hyperandrogenism.”

Dr. Torres of the University of California, San Diego, and his colleagues recruited 163 women at the University of Poznan (Poland) and conducted analysis on fecal samples to determine the effects of PCOS on the gut microbiome. Each woman underwent a battery of tests to determine whether she had PCOS or polycystic ovarian morphology (PCOM). Ovarian morphology was determined from a transvaginal ultrasound evaluation. The women were assessed for body mass index and hirsutism. Blood samples were taken to test for hormonal abnormalities common with PCOS and metabolic issues, like type 2 diabetes mellitus and glucose tolerance. Fecal samples were taken to analyze the gut microbiota of each study participant; analysis of the fecal samples generated gut microbial diversity profiles for each of the 163 women. Analysis of the samples was conducted at the University of California, San Diego.

Of the subjects, 48 were healthy, 42 had PCOM, and 73 were diagnosed with PCOS. The researches noted that, compared with healthy women and those with PCOM, women with PCOS had higher levels of serum total and free testosterone, as well as higher rates of hirsutism and fewer menses per year. These women also had higher levels of serum luteinizing hormone and increased ratios of luteinizing hormone to follicle stimulating hormone.

The DNA analysis of fecal samples yielded 481 sequence variants from the fecal swabs. Women with PCOS were found to have lower alpha diversity in their gut microbiome, as evidenced by abundance (P = .04) and Faith’s phylogenetic diveristy (P = .02). The luteinizing hormone to follicle stimulating hormone ratio also appeared to affect the alpha diversity of women with PCOS, as seen in observed sequence variants and Faith’s phylogenetic diversity (P = .08).

Beta diversity analysis, or the biodiversity between samples, revealed that hyperandrogenism could be a primary driver of changes in the gut microbiome. Using permutational multivariate analysis of variance, researchers determined that hyperandrogenism significantly affected beta diversity (P = .0009).

Androgens may help affect the gut microbiome in important ways, and changes in the gut microbiome may influence how the pathology of PCOS develops, according to Mr. Torres and his colleagues; however, more studies should be conducted to determine the effects of androgens on the gut microbiome.

“If hyperandrogenism drives the microbial composition of the gut, it would be interesting to determine if treatment of PCOS with androgen antagonists or oral contraceptives results in recovery of the gut microbiome and improvement of the PCOS metabolic phenotype” wrote Mr. Torres and his colleagues. “Moreover, it would be informative to determine whether the gut microbiome of women diagnosed with PCOS using the criteria of oligomenorrhea and polycystic ovaries is distinct from that of women diagnosed with the other subtypes of PCOS that include hyperandrogenism.”

The authors had no relevant financial disclosures to report.

ilacy@frontlinemedcom.com

SOURCE: Torres PJ et al. J Clin Endocrinol Metab. 2018 Jan 23. doi: 10.1210/jc.2017-02153 .

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