Gut microbiota and physical exercise in obesity and diabetes- A systematic review

Background and aim: The gut microbiota (GM) plays an essential role in maintaining health, and imbalance in its composition is associated with the physiopathogenesis of metabolic diseases, such as obesity and type 2 diabetes mellitus (T2DM). Diet and antibiotics are known modulators of GM, but the influence of physical exercise in modulating the diversity and abun-dance of hindgut bacteria is still poorly understood. The aim of this systematic review was to investigate the scientific evidence about the effect of physical exercise on GM modulation in sub-jects with obesity and T2DM. Methods and results: A search in PubMed, Web of Science, Scopus, Cochrane and Embase data-bases using keywords related to gut microbiota, physical exercise and metabolic diseases was performed. Eight clinical studies met the inclusion criteria, six in subjects with obesity and two in individuals with T2DM. In three studies carried out in individuals with obesity, exercise was able to positively modulate the diversity of GM and the abundance of some species of bac-teria, mostly by increasing the Bifidobacteriaceae family, and the Bacteroides and Akkermansia genera, and by decreasing the Proteobacteria phylum. The studies in subjects with T2DM found that physical exercise may reduce metabolic endotoxemia markers. Conclusions: Physical exercise may be a beneficial modulation strategy of GM composition in metabolic diseases, specifically aerobic exercises carried out for at least 6 weeks with moderate or high intensity. Nevertheless, well-designed clinical trials are needed to clarify the role of phys-ical exercise on GM in subjects with obesity and T2DM. (c) 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Ital-ian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.