Background. Considering the observed role of probiotics in modulating gut microbiome, probiotics are discussed to be one potential complementary therapy for obesity management in recent years. The aim of the present study was to systematically review the meta-analyses of controlled trials and investigate the effects of probiotics on obesity. Methods. A comprehensive search was conducted on PubMed, Web of Science, and Cochrane Library web databases up to May 2020. Inclusion criteria were meta-analyses of controlled trials which evaluated the impact of probiotics on obesity in English language. Meta-analyses done on pregnant women, children, animal studies, or the effect of prebiotics on anthropometric indices were excluded. Results. Within 325 recorded studies, 20 studies met the inclusion criteria consisting of 16676 overweight/obese adults with different underlying disorders such as nonalcoholic fatty liver disease (NAFLD), or polycystic ovary syndrome (PCOS). The length of intervention varied from 2 to 26 weeks. Results of meta-analyses have shown a moderate effect of probiotics on body weight in overweight/obese adults: from 0.526kg/m² (95 CI: 0.810, 0.247) to 0.25kg/m² (95 CI: 0.33, 0.17). Body mass index (BMI) was changed from 1.46kg/m² (95 CI: 2.44, 0.48) to 1.08kg/m² (95 CI: 2.05, 0.11) in NAFLD. Probiotics could reduce BMI from 0.36kg/m² (95 CI: 0.74, 0.02) to 0.29kg/m² (95 CI: 0.54, 0.03) in patients with PCOS. Conclusion. It seems that the probiotic products could have beneficial effects as an adjunct therapy for care and management of obesity when used in high dose. However, due to heterogeneity of included studies, it is required to confirm our results by more meta-analyses of clinical trials.

Background: Ramadan Intermittent Fasting (RIF) has the potential to alter hormonal levels in the body. This study investigates the impact of RIF on hormonal levels among healthy individuals during Ramadan. Methods: A systematic review and meta-analysis of previously published studies were conducted, focusing on healthy non-athlete adults. The intervention examined was Ramadan Intermittent Fasting, and the primary outcomes assessed were changes in endocrine hormonal and biochemical parameters. The pooled effect measure was expressed as odds ratio (OR) and 95% confidence interval (CI) using the random-effects model. Results: A total of 35 original articles were retrieved, with a combined sample size of 1,107 participants eligible for the meta-analysis. No significant relationship was found between pre- and post-Ramadan hormonal levels of T3, T4, TSH, FT3, FT4, Testosterone, LH, FSH, Prolactin, PTH, Calcium, and Phosphorus (P-value<0.05). However, a substantial decrease in morning cortisol levels was observed across the studies (P-value: 0.08, Hedges’ g = -2.14, 95% CI: -4.54, 0.27). Conclusions: Ramadan Intermittent Fasting results in minimal hormonal changes and is a safe practice for healthy individuals. The fasting regimen appears to disrupt the circadian rhythm, leading to a decrease in morning cortisol levels.

International Journal of Endocrinology and Metabolism