Obesity and gut–microbiota–brain axis: A narrative review

Abstract

Introduction Obesity is a major health problem that is associated with many physiological and mental disorders, such as diabetes, stroke, and depression. Gut microbiota has been affirmed to interact with various organs, including the brain. Intestinal microbiota and their metabolites might target the brain directly via vagal stimulation or indirectly through immune‐neuroendocrine mechanisms, and they can regulate metabolism, adiposity, homoeostasis and energy balance, and central appetite and food reward signaling, which together have crucial roles in obesity. Studies support the concept of bidirectional signaling within the gut–brain axis (GBA) in the pathophysiology of obesity, mediated by metabolic, endocrine, neural, and immune system mechanisms. Materials and methods Scopus, PubMed, Google Scholar, and Web of Science databases were searched to find relevant studies. Results The gut–brain axis (GBA), a bidirectional connection between the gut microbiota and brain, influences physiological function and behavior through three different pathways. Neural pathway mainly consists of the enteric nervous system (ENS) and vagus nerve. Endocrine pathway, however, affects the neuroendocrine system of the brain, particularly the hypothalamus–pituitary–adrenal (HPA) axis and immunological pathway. Several alterations in the gut microbiome can lead to obesity, by modulating metabolic pathways and eating behaviors of the host through GBA. Therefore, novel therapies targeting the gut microbiome, i.e., fecal microbiota transplantation and supplementation with probiotics and prebiotics, can be a potential treatment for obesity. Conclusion This study corroborates the effect of gut microbiome on physiological function and body weight. The results show that the gut microbiota is becoming a target for new antiobesity therapies.

Elucidation of Prebiotics, Probiotics, Postbiotics, and Target from Gut Microbiota to Alleviate Obesity via Network Pharmacology Study

“…Previous studies have demonstrated that the metabolites from the gut microbiota act as significant agents in a wide range of diseases, such as cancer, stroke, irritable bowel syndrome, and even mental disorders, including obesity [ 39 , 40 ]. In this study, we analyzed microbiota–substrate–metabolite–target (MSMT) networks and found that Lactobacillus paracasei JS1 , isoflavone, equol, and IL6 exhibited considerable connectivity in the networks, indicating significant antiobesity effects.…”

Gut dysregulation drives bone damage in tibial dyschondroplasia by disrupting glucose homeostasis

“…The dysfunction of the microbial community within the gut has been linked with several metabolic diseases such as obesity, non-alcoholic fatty liver, cardiovascular disease, diabetes, osteoporosis and many other diseases. [26][27][28][29] Although gut microbiota posseses an essential role in the regulation of blood GLU. 17 Little has been reported the mechanism of the gut microbiota composition and gut barrier on blood glucose homeostasis.…”

“…Thus, SCFAs are thought to play essential roles in maintaining host energy homeostasis and insulin sensitivity. 29,45 Both Blautia and Coprococcus are metabolically enriched butyrate-producing bacteria. Butyric acid is essential for maintaining gut health, and it provides energy to intestinal cells and sends signals to the host.…”

Beneficial Effects of Anti-Inflammatory Diet in Modulating Gut Microbiota and Controlling Obesity

“…These findings highlight a new line of communication between the gut microbiota and the brain. Mounting evidence indicates that the gut microbiota might target the brain via a direct pathway of electrical stimulation of the vagus nerve and an indirect means involving an immune–neuroendocrine mechanism [ 66 ]. Torres-Fuentes et al [ 67 ] reviewed and discussed the role of the gut–brain axis in obesity.…”