Calorie restriction disrupts microflora and colony-forming resistance

von Schwartzenberg, RJ, Bisanz, JE, Lyalina, S. et al. Calorie restriction disrupts microflora and colony-forming resistance. Nature (2021). https://doi.org/10.1038/s41586-021-03663-4

Commentary

This study investigated the effects of extreme dietary restriction.

Diet is a factor in shaping the gut microbiota, and although it is known that the host's dietary environment can alter the microbiota, the actual results are not well understood.

A randomized human intervention study was conducted using a very low calorie diet. The results showed improved metabolism, but severe caloric restriction led to a decrease in bacterial abundance and a restructuring of the gut microbiota. When the post-diet microbiota was transplanted into the mice, weight and obesity were reduced compared to mice that received the pre-diet microbiota.

And this weight loss was associated with impaired nutrient absorption and enrichment of Clostridium difficile. This situation coincided with a decrease in bile acids, which was sufficient to replicate the metabolic phenotype of the mice in a toxin-dependent manner.

The findings underscored the importance of diet-microbiota interactions in regulating host energy balance and the need to understand the role of diet in interactions between pathogenic and beneficial symbionts.