Impact of real-world diet variations on the gut microbiota in humans and humanized mice. Humouse

The study aimed to clarify the impact of ‘real-world’ dietary variations on gut microbiota composition by asking healthy human volunteers to eat exclusively a vegetarian ready-made meal (‘healthy’) for three days followed by a meat-based ready-made meal and high-sugar drink (‘unhealthy’) for two days. We showed that the microbiota varied between individuals and within individuals regardless of diet. However, when we transferred microbiota from individuals on the healthy diet to germ-free mice fed the healthy human diet then swapped to the unhealthy human diet, we observed significant, often donor-specific, changes in the mouse microbiota following the mild dietary intervention. These results suggest that feeding humanized mice human diets may facilitate understanding of human microbiota responses to mild dietary changes.