Both subcutaneous semaglutide and calorie restriction improves pancreatic cell hyperplasia and gut microbiota in high-fat diet-induced obese mice.

BACKGROUND: Obesity has emerged as a global health crisis, with its prevalence having increased alarmingly over recent decades. There is significant damage to pancreatic islets due to obesity, as well as metabolic syndrome. Improving the function of β-cells in obese patients is meaningful for treatment. Thus, GLP-1 receptor agonists like semaglutide may be beneficial for islet structural remodeling and their endocrine function in diet-induced obese mice and associated with food intake. However, whether the specific impact of semaglutide on obesity is the same as calorie restriction(CR) has not been investigated. METHODS: In this study, Five-week-old male C57BL/6 mice were divided into two dietary groups and fed for 12 weeks a control diet or a high-fat diet (HFD). Then, for an additional four weeks, the main groups were resampled to include treatment (Semaglutide, SME, 40 µg/kg), or CR, totaling four groups: Control, Model, Model + SME, Model + CR. Immunofluorescence, Western blot, and RT-qPCR were used in the study. RESULTS: Semaglutide or CR was capable of ameliorating hyperglycemia and insulin sensitivity, and reduces the lesion on the islet, increases islet cell proliferation, and recovers islet size and alpha- and beta-cell masses. Moreover, the changes include improvement of METTL3/14, pancreatic duodenal homeobox 1 (PDX-1), and insulin signaling. Meanwhile, Semaglutide or CR significantly decreases the abundance of Firmicutes, Proteobacteria, and Verrucomicrobia, but increases the Bacteroides content. CONCLUSIONS: Semaglutide plays a positive role in alleviating β-cell dysfunction by regulating gut microbiota, and METTL3/14, PDX-1, insulin signal pathway-related genes may be associated with CR.