Gut and obesity/metabolic disease: Focus on microbiota metabolites

Abstract

Obesity is often associated with the risk of chronic inflammation and other metabolic diseases, such as diabetes, cardiovascular disease, and cancer. The composition and activity of the gut microbiota play an important role in this process, affecting a range of physiological processes, such as nutrient absorption and energy metabolism. The active gut microbiota can produce a large number of physiologically active substances during the process of intestinal metabolism and reproduction, including short‐chain/long‐chain fatty acids, secondary bile acids, and tryptophan metabolites with beneficial effects on metabolism, as well as negative metabolites, including trimethylamine N‐oxide, delta‐valerobetaine, and imidazole propionate. How gut microbiota specifically affect and participate in metabolic and immune activities, especially the metabolites directly produced by gut microbiota, has attracted extensive attention. So far, some animal and human studies have shown that gut microbiota metabolites are correlated with host obesity, energy metabolism, and inflammation. Some pathways and mechanisms are slowly being discovered. Here, we will focus on the important metabolites of gut microbiota (beneficial and negative), and review their roles and mechanisms in obesity and related metabolic diseases, hoping to provide a new perspective for the treatment and remission of obesity and other metabolic diseases from the perspective of metabolites.

Potential effects of nutrition‐induced alteration of gut microbiota on inflammatory bowel disease: A review

“…95 For example, SCFAs not only enhance the release of GLP-1 and PYY of host L cells by activating GPR41 and GPR43 to suppress appetite and regulate food intake, 96 but promote lipolysis and protein synthesis by stimulating the secretion of growth hormone as well. 95 Furthermore, BAs can also promote the secretion of GLP-1 by activating Takeda GPR5 in intestinal L cells to delay gastric emptying and decrease intestinal absorption of glucose. 97 On the other hand, microbial metabolites affect the bioavailability of nutrients in intestinal lumen and intestinal absorptive capacity.…”

“…Gut microbial metabolites also play a crucial role in host nutrient digestion and absorption. On the one hand, microbial metabolites regulate the release of host hormones, such as glucagon‐like peptide‐1 (GLP‐1), polypeptide YY (PYY), and growth hormone, to further affect the intake and metabolism of nutrients 95 . For example, SCFAs not only enhance the release of GLP‐1 and PYY of host L cells by activating GPR41 and GPR43 to suppress appetite and regulate food intake, 96 but promote lipolysis and protein synthesis by stimulating the secretion of growth hormone as well 95 .…”

Microbiota in cancer: molecular mechanisms and therapeutic interventions

“…The gut microbiota has the ability to metabolize nutrients that contain methylamine, namely choline, lecithin, and l ‐carnitine. As a result of this process, trimethylamine (TMA) is produced, which then undergoes a further transformation into TMAO through the action of flavin monooxygenases (FMO) located in the liver 183 . Bile acids by gut microbiota activate FXR‐induced FMO3 expression and increase the development of hyperglycemia, hyperlipidemia, and atherosclerosis 184,185 .…”

Divergent selection for IMF in rabbits: A story told by plasma metabolites

“…Among those metabolites, the imidazole propionate was found, which is produced by gut-microbiota. The imidazole propionate can modulate host in ammation and metabolism, it has been positively related to obesity and diabetes 50,51 , and it has even been proposed as a predictor of α diversity 52 .…”