Microbiota-Gut-Brain Axis: Modulator of Host Metabolism and Appetite.

The gut harbors an enormous diversity of microbes that are essential for the maintenance of homeostasis in health and disease. A growing body of evidence supports the role of this microbiota in influencing host appetite and food intake. Individual species within the gut microbiota are under selective pressure arising from nutrients available and other bacterial species present. Each bacterial species within the gut aims to increase its own fitness, habitat, and survival via specific fermentation of dietary nutrients and secretion of metabolites, many of which can influence host appetite and eating behavior by directly affecting nutrient sensing and appetite and satiety-regulating systems. These include microbiota-produced neuroactives and short-chain fatty acids. In addition, the gut microbiota is able to manipulate intestinal barrier function, interact with bile acid metabolism, modulate the immune system, and influence host antigen production, thus indirectly affecting eating behavior. A growing body of evidence indicates that there is a crucial role for the microbiota in regulating different aspects of eating-related behavior, as well as behavioral comorbidities of eating and metabolic disorders. The importance of intestinal microbiota composition has now been shown in obesity, anorexia nervosa, and forms of severe acute malnutrition. Understanding the mechanisms in which the gut microbiota can influence host appetite and metabolism will provide a better understanding of conditions wherein appetite is dysregulated, such as obesity and other metabolic or eating disorders, leading to novel biotherapeutic strategies.

van de Wouw M ，Schellekens H ，Dinan TG ，Cryan JF ... -  《-》

The Microbiota and the Gut-Brain Axis in Controlling Food Intake and Energy Homeostasis.

Romaní-Pérez M ，Bullich-Vilarrubias C ，López-Almela I ，Liébana-García R ，Olivares M ，Sanz Y ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

[Advances in host-microbe metabolic axis].

Pi Y ，Gao K ，Zhu W 《-》

The microbiota-gut-brain axis in obesity.

Changes in microbial diversity and composition are increasingly associated with several disease states including obesity and behavioural disorders. Obesity-associated microbiota alter host energy harvesting, insulin resistance, inflammation, and fat deposition. Additionally, intestinal microbiota can regulate metabolism, adiposity, homoeostasis, and energy balance as well as central appetite and food reward signalling, which together have crucial roles in obesity. Moreover, some strains of bacteria and their metabolites might target the brain directly via vagal stimulation or indirectly through immune-neuroendocrine mechanisms. Therefore, the gut microbiota is becoming a target for new anti-obesity therapies. Further investigations are needed to elucidate the intricate gut-microbiota-host relationship and the potential of gut-microbiota-targeted strategies, such as dietary interventions and faecal microbiota transplantation, as promising metabolic therapies that help patients to maintain a healthy weight throughout life.

Torres-Fuentes C ，Schellekens H ，Dinan TG ，Cryan JF ... -  《The Lancet Gastroenterology & Hepatology》

Gut microbiota, nutrient sensing and energy balance.

The gastrointestinal (GI) tract is a highly specialized sensory organ that provides crucial negative feedback during a meal, partly via a gut-brain axis. More specifically, enteroendocrine cells located throughout the GI tract are able to sense and respond to specific nutrients, releasing gut peptides that act in a paracrine, autocrine or endocrine fashion to regulate energy balance, thus controlling both food intake and possibly energy expenditure. Furthermore, the gut microbiota has been shown to provide a substantial metabolic and physiological contribution to the host, and metabolic disease such as obesity has been associated with aberrant gut microbiota and microbiome. Interestingly, recent evidence suggests that the gut microbiota can impact the gut-brain axis controlling energy balance, at both the level of intestinal nutrient-sensing mechanisms, as well as potentially at the sites of integration in the central nervous system. A better understanding of the intricate relationship between the gut microbiota and host energy-regulating pathways is crucial for uncovering the mechanisms responsible for the development of metabolic diseases and for possible therapeutic strategies.

Duca FA ，Lam TK 《-》