The genetic and microbial influences in obesity

Abstract

Patients have been told for decades that weight gain and weight loss were the product of a simple energy balance equation. However, despite factoring in both body and organ size and composition, a 20% unexplained difference in resting energy expenditure exists between individuals. New understandings of the role of genetic variation between individuals are shedding light on this complex equation. In addition to host genetics, environmentally driven epigenetic factors appear to exert a powerful influence in the development of obesity. The intestinal microbiome may be a key environmental factor in the pathogenesis of this disease. However, both definitive demonstration of a causative role and what microbial shifts are implicated in both obesity and weight loss require further study. Attempts to modify the microbiota therapeutically are appealing, though results thus far have been clinically limited. The potential role of using diet, prebiotics, or probiotics to change the epigenetic and microbial environment to result in weight loss or weight loss maintenance, before or after surgically induced interventions, are intriguing applications for future obesity therapies.