GCG and diabetes mellitus: The underlying mechanism may be involved in the anti-inflammatory effect of liraglutide on the intestinal immune system, such as TReg cells and Th1 lymphocytes (Charpentier et al., 2021).Additionally, there was an increased fasting serum glucagon in prediabetic mice, which glucagon played a pathophysiologic role in metabolic disease such as diabetes and obesity (Knop et al., 2012; Morita et al., 2021).