Caloric restriction promotes the growth of gut bacteria associated with an increased lifespan in mice, a paper published in Nature Communications reports. This finding suggests that caloric restriction might mediate its health-promoting effects on the host by inducing a healthy gut microbiota.
Caloric restriction through reduced food intake is known to increase lifespan in a range of model organisms. The gut microbiota is increasingly recognized for its role in host health and disease, and its composition is shaped mainly by the diet. Liping Zhao put mice on a life-long calorie-restricted diet and documented structural changes in their gut microbiota over time. The team reports that specific bacteria, such as the genus Lactobacillus, correlate positively with lifespan and are enriched by caloric restriction. Similarly, the calorie-restricted diet reduced the abundance of bacteria that correlate negatively with lifespan. These changes are associated with reduced serum levels of lipopolysaccharide-binding protein - a marker often associated with inflammation - which suggests that reduced inflammation caused by antigens from gut bacteria might be one of the health benefits transmitted by caloric restriction.
Further studies are needed to clarify how these structural changes in the gut microbiota may extend lifespan, and to validate whether they could serve as biomarkers for the development of dietary anti-ageing interventions.