For this study, published in the Journal of Experimental Biology, Garland and his team divided a group of mice into four groups. Half were fed the standard, “healthy’ diet, and half received the less healthy “Western” diet. Half had access to an exercise wheel.
After three weeks, all the mice were returned to how they normally would be kept in a lab — a standard diet and no exercise. They stayed this way for 14 weeks when the scientists checked the diversity and abundance of bacteria in them.
They found that Muribaculum bacteria increased in mice fed a standard diet who had access to a running wheel and decreased in mice on a high-fat diet, whether they had exercise or not.
Researchers wrote this species of bacteria, and the family of bacteria it belongs to, might influence the amount of energy available to its host.
Garland and his team found that, for children, eating a Western diet high is fat and sugar had a longer-lasting effect on the microbiome than exercise did.
The takeaway, Garland said, is essentially, “You are not only what you eat, but what you ate as a child!”