Studies conducted in recent years have explored the relationship between the gut microbiota, consisting of around 800 different bacteria species, and metabolism. It has been suggested that specific intestinal microbial compositions can either protect from, or contribute to, obesity and other metabolic diseases.

First, I would like to discuss short-chain fatty acids (SCFA) and the vital role they play in influencing gut health. SCFA are produced by bacteria from fermentation of dietary products, mostly fibre, within the colon. Their primary role is to serve as a source of energy for cells within the colon and to stimulate repair and replacement. Of potential interest, butyrate may influence how energy (including glucose) is metabolised in the body and so hold a possible protective effect against metabolic disease and obesity.

The potential relationship between gut microbiota and obesity was analysed in this excellent 2017 study when faecal microbiota from both lean and obese subjects was transferred into mice, which then changed their feeding behaviour and subsequently their body mass to reflect the human source. The researchers suggested that butyrate positively influences energy balance and thus protects from diet-induced obesity.

Subsequent research has shown a broad variety of possible effects of butyrate on metabolism including an increase in mitochondrial activity, preventing metabolic endotoxemia, improving insulin sensitivity, increasing intestinal barrier function and protecting against diet-induced obesity.

These fascinating findings suggest a relationship between the gut microbiota and human metabolism. Further research is needed in humans to extend the experimental findings in mice and to establish if the gut microbiome may be changed (by prebiotics, probiotics, antibiotics or even faecal transplantation) to help reduce obesity and even, diabetes.

If you have any questions about gut microbiota and its relationship to obesity, please do not hesitate to contact Dr. Harris