Health is a gut issue

Obesity is a risk factor for cardiovascular disease, diabetes, osteoporosis and other conditions including some cancers. Other influences must be at work to determine which, if any, metabolic diseases obese individuals will suffer, and two papers in this issue of Nature look at the role one of these factors, the richness of the gut microbiome. Le Chatelier et al. analysed the gut microbial gene composition in non-obese and obese individuals and found marked differences in gene and species richness. Individuals with low richness exhibited increased adiposity, insulin resistance, dyslipidaemia and inflammation. Obese individuals with low microbial richness tended to gain more body weight than those with high microbial richness. The authors also demonstrate that analysis of just a few bacterial marker species was sufficient to distinguish between high and low bacterial richness. Cotillard et al. monitored gut microbe profiles during diet-induced weight loss and weight stabilization interventions in obese or overweight individuals. They report that increased consumption of high-fibre foods, such as fruit and vegetables, leads to an increase in bacterial richness and improves some clinical symptoms associated with obesity. This finding supports previous work linking diet to the composition of gut microbe populations, and suggests that a permanent change might be achieved by appropriate diet.