Therapy with probiotics and synbiotics for polycystic ovarian syndrome: a systematic review and meta-analysis

Several randomized controlled trials (RCTs) have investigated the use of probiotic/synbiotic in PCOS patients, without clarifying the real use in clinical practice. The aim of this meta-analysis was to evaluate the effectiveness of probiotics and synbiotics on metabolic, hormonal and inflammatory parameters of PCOS.

Electronic databases (MEDLINE, Scopus, EMBASE, ScienceDirect, The Cochrane Database of Systematic Reviews and ClinicalTrials.gov) were searched from their inception until May 2019. The study protocol was registered in PROSPERO with number CRD42018111534. Randomized controlled trials (RCTs) of PCOS's women undergoing therapy at least 8 weeks with probiotics or synbiotics or without therapy were included. The primary outcomes were changes in anthropometric parameters, glucose/insulin metabolism, lipid profile, sex hormones profile, inflammation markers.

587 patients were included in nine RCT. The administration of probiotic/synbiotic were associated with a significant improvement in FPG, FBI, HOMA I-R, BMI. It also modified Ferriman-Gallway, serum triglycerides, serum testosterone, hs-CRP, NO, TAC, GSH, and MDA. Subgroup analysis of the type of intervention showed that probiotics were associated with greater testosterone and FPG reduction; synbiotics administration resulted in a more pronounced decrease of the FBI. Subgroup analyses on the duration of therapy showed that, probiotic/synbiotic administration had a significantly greater effect on QUICK-I in the case of women with 12-weeks of therapy than in the 8-weeks therapy group. Nevertheless, we did not observe any significant difference was observed in terms of FBI, HOMA-IR, and FPG.

Probiotics and synbiotics seem to either an effect on/influence metabolic, hormonal and inflammatory parameters, or can influence them. Consequently, it could lead to an improvement of fertility in PCOS.