The effect of probiotics, prebiotics, and synbiotics on hormonal and inflammatory indices in women with polycystic ovary syndrome: a systematic review and meta-analysis

Polycystic ovary syndrome (PCOS) is among the most prevalent endocrine disorders in women and can lead to many other disorders and chronic diseases. Thus, early diagnosis and treatment of this syndrome is important. Using probiotics, prebiotics, and synbiotics supplementations to treat PCOS seems appropriate because of their useful effects and low complications. To assess the effects of probiotics, prebiotics, and synbiotics on hormonal indices such as testosterone, dehydroepiandrosterone sulfate (DHEA-S), sex hormone binding globulin, Free Androgen Index (FAI), and inflammatory indices, such as high sensitive C reactive protein (hsCRP), malondialdehyde (MDA), total glutathione (GSH), nitric oxide (NO), and total antioxidant capacity (TAC) as the primary outcomes and the hirsutism score as the secondary outcome. All published articles from the beginning until 10 November 2018 in English (Cochrane Library, Web of Sciences, Google Scholar, PubMed, Scopus, and ProQuest) and Persian (SID and Magiran) databases were searched. The effect of interventions on the outcomes was reported with a standard mean difference (SMD) and confidence interval of 95%. In case of high heterogeneity, the random effect model was used instead of the fixed effect model. The statistical heterogeneity of the included clinical trials was tested using the Chi square test and I2. Thirteen studies with 855 participants with PCOS(438 women in the intervention group and 417 women in the control group) were included in the meta-analysis. Results of the meta-analysis showed that the SHBG (SMD: 0.56; 95% CI 0.26–0.86; P = 0.0002) and NO (SMD: 0.38; 95% CI 0.09–0.68; P = 0.01) concentration increased significantly in the probiotics and synbiotics groups compared to the placebo group. FAI (SMD: − 0.58; 95% CI − 0.95 to − 0.21; P = 0.002) and MDA (SMD: − 0.76; 95% CI − 1.46 to − 0.05; P = 0.03) concentration in the probiotics and synbiotics groups reduced significantly compared to the placebo group. The results of meta-analyses on other hormonal and inflammatory indices such as testosterone, DHEAS, GSH, hsCRP, TAC, and hirsutism score showed that there were no significant differences between the intervention and control groups. Using synbiotics and probiotics in women with polycystic ovary syndrome improve hormonal (FAI, SHBG) and inflammatory (NO, MDA) indices in these patients.