Cesarean section-induced gut dysbiosis increases risk of obesity and insulin resistance in high-fat diet mouse model (microbiomejournal.biomedcentral.com)

• CS-induced gut dysbiosis causally linked to increased obesity and insulin resistance in HFD-fed mice
• Human CS infant microbiota transplant led to metabolic disturbances in germ-free mice
• HMO supplementation and Bacteroides fragilis partially reversed metabolic effects via FGF-21 reduction

"A study in Microbiome demonstrates that cesarean section (CS)-induced gut dysbiosis causally increases obesity and insulin resistance risk in mice fed a high-fat diet. In two experiments, CS delivery alone did not alter metabolic outcomes when gut microbiota remained similar to vaginal delivery. However, germ-free mice colonized with human infant CS microbiota developed significantly more weight gain and insulin resistance, accompanied by altered serum cytokines and metabolic gene expression. These effects were partially reversed by human milk oligosaccharide supplementation or administration of Bacteroides fragilis, which reduced circulating FGF-21 levels. The findings suggest microbiota-targeted therapies may mitigate metabolic disease risk after CS birth."