Gut-brain axis as a bridge in obesity and depression: Mechanistic exploration and therapeutic prospects

Abstract

A recent study by Wang et al, published in the World Journal of Psychiatry, provided preventative and therapeutic strategies for the comorbidity of obesity and depression. The gut-brain axis, which acts as a two-way communication system between the gastrointestinal tract and the central nervous system, plays a pivotal role in the pathogenesis of these conditions. Evidence suggests that metabolic byproducts, such as short-chain fatty acids, lipopolysaccharide and bile acids, which are generated by the gut microbiota, along with neurotransmitters and inflammatory mediators within the gut-brain axis, modulate the host's metabolic processes, neuronal regulation, and immune responses through diverse mechanisms. The interaction between obesity and depression via the gut-brain axis involves disruptions in the gut microbiota balance, inflammatory immune responses, and alterations in the neuroendocrine system. Modulating the gut-brain axis, for example, through a ketogenic diet, the use of probiotics, and the supplementation of antioxidants, offers new remedial approaches for obesity and depression. Future research that explores the mechanisms of the gut-brain axis is needed to provide more evidence for clinical treatment.

Keywords: Gut-brain axis; Obesity; Depression; Gut microbiota; Mechanism

Core Tip: The gut-brain axis is a crucial pathway that links the intestines to the brain and influences host health through microbial metabolites, neural signals, immune responses, and endocrine pathways. Metabolic byproducts of microbes, such as short-chain fatty acids, lipopolysaccharide and bile acids, modulate appetite, emotional regulation, and immune-inflammatory responses via the gut-brain axis and are closely associated with the onset and progression of obesity and depression. Modulating the gut-brain axis, for example, through the use of prebiotics, specific ketogenic diet, and the supplementation of antioxidants, provides new therapeutic strategies for obesity and depression. Future research needs to delve deeper into the mechanisms of the gut-brain axis to develop more effective interventions.