2024, Vol. 28 ›› Issue (2): 308-314

Role and mechanism of intestinal flora metabolites in obesity regulation

Yang Qihang1, Pu Rui1, 2, Chen Ziyang1, 2, Leng Siyi1, Song Yongjing1, Liu Hui3, Du Guangyou1   

Abstract: BACKGROUND: Gut microbiota is closely related to host energy balance and metabolism. The metabolites of intestinal flora can regulate the occurrence and development of obesity and can be a new target for the prevention and treatment of obesity.
OBJECTIVE: To summarize the interaction between the intestinal flora and obesity, as well as the specific mechanism underlying regulation of obesity by metabolites of intestinal flora, thereby providing a new reference and basis for the prevention and treatment of obesity.
METHODS: “Intestinal microbiota, intestinal bacteria, intestinal microbiota metabolites, short-chain fatty acids, bile acids, ipopolysaccharide, trimethylamine N-oxide, medium-chain fatty acids, tryptophan derivatives, obesity” were used as search terms in Chinese and English. Literature related to obesity from 1990 to 2022 was retrieved in PubMed and CNKI databases. According to inclusion and exclusion criteria, 88 articles were finally selected.
RESULTS AND CONCLUSION: Intestinal flora is closely related to the occurrence and development of obesity. For example, changes in the   Firmicutes to Bacteroidetes ratio can be used as a biomarker for the diagnosis of obesity, and the occurrence of obesity can be delayed by the colonization of probiotics such as Bifidobacterium breve, Lactobacillus and Akkermansia. Intestinal flora is mainly mediated by the metabolites of intestinal flora to participate in the regulation of obesity. For example, short-chain fatty acid can regulate adipogenesis by regulating signaling pathways such as G protein-coupled receptors 41, 43 and peroxisome proliferator-activated receptor γ, thus delaying the occurrence and development of obesity. Bile acids can increase insulin sensitivity and body energy expenditure by promoting the activation of G protein-coupled receptor 5 and farnesol X receptor. In addition, lipopolysaccharide, trimethylamine oxide, medium-chain fatty acids and tryptophan derivatives are also widely involved in the occurrence and development of obesity through various signaling pathways. Further studies have found that metabolites of the same bacterial community exert heterogeneous effects in the specific process of regulating obesity via different signaling pathways. For example, under the influence of high-fat diet, acetic acids can activate the parasympathetic nervous system, leading to hyperphagia and liver insulin resistance and thus accelerating the physiological course of obesity.

Key words: intestinal flora, obesity, intestinal flora metabolite, short-chain fatty acid, bile acid, lipopolysaccharide, trimethylamine N-oxide