Citrus aurantium L. 'Daidai' alleviates HFD-induced obesity by regulating gut microbiota

The gut is the main location for bacterial colonization in the body. The human gut harbors approximately 10^14 microorganisms, with over 1000 different species, totaling 2 kg of microbial biomass. The number of genes carried by these gut microbiota is 100-150 times the number of genes in the human genome, which has earned them the title of the second brain of the body.Bacteria residing in the human digestive tract can be mainly classified into four groups: Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, which collectively make up over 99% of all gut microbiota. In healthy adults, Firmicutes and Bacteroidetes predominate. The abundance of gut microbiota varies significantly in different populations due to various factors such as age, dietary structure, and geographic location.Gut microbiota not only regulates intestinal development, modulates human nutrition and metabolism, bile acid metabolism, and prevents pathogen colonization, but also maintains gut barrier and immune function. It is closely related to obesity, cardiovascular disease, diabetes, metabolic syndrome, non-alcoholic fatty liver disease, inflammatory bowel disease, and so on.