The ketogenic diet has gained popularity as a tool for weight loss, but the mechanisms behind its metabolic changes are still unknown. Recent research in mice and humans suggests that the ketogenic diet may protect against obesity by increasing specific bile acids and decreasing calorie absorption in the intestines. However, the long-term health effects of this diet are not clear, and experts recommend plant-based diets like the Mediterranean diet for more favorable gut microbiome diversity.
The ketogenic diet is a low-carbohydrate eating pattern that has been widely studied for weight loss. While its effectiveness is acknowledged, the exact ways in which it leads to weight loss remain unclear. Some researchers believe that gut bacteria and their byproducts play a role in the diet’s metabolic benefits, but the specific bacteria and byproducts involved are not well understood.
A study published in Nature Metabolism found that following a ketogenic diet resulted in changes to the gut microbiome in mice, increasing blood levels of specific bile acids. These bile acids, taurodeoxycholic acid and tauroursodeoxycholic acid, were associated with decreased calorie absorption in the intestines, potentially leading to weight loss and improved blood sugar levels.
In mice, a ketogenic diet altered blood levels of bioactive metabolites and decreased body weight and fasting blood sugar levels. Further experiments showed that supplementation with an amino acid reversed these effects and reduced specific bile acids linked to weight and glucose changes. Two of these bile acids were found to significantly lower body weight and blood sugar levels in mice.
The researchers also conducted an observational study in humans, finding similar associations between specific bile acids and metabolic traits. These findings suggest that the ketogenic diet may reduce body weight and fasting blood sugar levels through changes in bile acids, which interfere with calorie absorption in the intestines.
Registered dietitians who were not involved in the study cautioned against the long-term use of the ketogenic diet, citing concerns about its impact on gut microbiome diversity. They recommended plant-based diets such as the Mediterranean or DASH diets, which have been associated with improved long-term health outcomes and better overall well-being. Further research is needed to fully understand the mechanisms and long-term effects of the ketogenic diet on weight loss and metabolic health.
