Effects of Probiotic Supplementation on Mental Health and the Risk of Depression in Women with Polycystic Ovary Syndrome: A Systematic Review of Randomized Controlled Trials

Background: Polycystic ovary syndrome (PCOS) is commonly associated with psychological disorders, including depression and anxiety. Women with PCOS also tend to experience poorer sleep quality and greater daytime sleepiness than healthy individuals. To the best of our knowledge, no systematic reviews have investigated the impact of probiotic supplementation on mental health and sleep patterns in women with PCOS. Emerging evidence indicates that probiotic therapy may be a promising adjunct for enhancing mental well-being and sleep quality within this population. Objectives: This systematic review aimed to evaluate the effects of probiotic supplementation on depression, anxiety, and sleep quality in adult women with PCOS. Methods: PubMed, Cochrane, and Scopus were searched for randomized controlled trials (RCTs) involving women aged 18–45 years old, with diagnosed PCOS, who received probiotic/synbiotic supplements and enriched foods compared with placebo. Studies had to assess mental health, depressive symptoms, or sleep disorders using validated questionnaires. Five publications met the Population, Intervention, Comparison, and Outcome inclusion criteria (PICO) and were included in the final analysis. Results: Probiotic supplementation was associated with significant improvements in sleep quality (assessed by Pittsburgh Sleep Quality Index, PSQI), depressive symptoms (assessed by Depression, Anxiety and Stress Scale, DASS 21) and some domains of quality of life (measured by Polycystic Ovary Syndrome Health Related Quality of Life Questionnaire, PCOSQ-26). Conclusions: Although probiotic supplementation may benefit mental health and sleep parameters in women with PCOS, this evidence is limited due to the small number of studies, modest sample sizes, and methodological variability. Further research with larger, more rigorous studies is needed to confirm these findings.