the controls of intestinal bacteria could lead to personalized diets

Rates of obesity are increasing worldwide; one-third of the world's population is currently overweight and nearly a fifth is obese. Public health policy has focused primarily on nutrition to reverse this increase, but the impact of these policies has been limited. The latest scientific data suggest why this strategy fails: a diet is not suitable for everyone. Dietary advice must be personalized.

The reason that a diet is not suitable for everyone can be found in our guts. Our previous research had shown that microbes in the digestive tract, called intestinal microbiota, were linked to the accumulation of abdominal fat. Our gut microbiota is primarily determined by our diet, lifestyle and health. It is therefore difficult to know exactly how food and intestinal microbes influence fat accumulation and ultimately the risk of disease. Our latest study provides new information on these interactions.

Animal studies have been helpful in showing that intestinal microbes alone can reduce fat accumulation and thus improve health. However, it is difficult to translate these results into humans, especially since we can eat very different foods.

Intestinal microbes do not lie

In our study, we sought to unravel the effect of intestinal microbes and diet on abdominal fat accumulation in 1,700 twins in the UK. We found that intestinal microbiota composition predicts belly fat more accurately than diet alone.

We identified some specific nutrients and microbes that were bad for us and related to an increase in belly fat, as well as some nutrients and many microbes that were good for us and related to a reduction in belly fat. The observed link between belly fat and bad nutrients, such as cholesterol, was not affected by the gut microbiota.

In contrast, we found that the gut microbiota plays an important role in the beneficial effect of good nutrients, such as fiber or vitamin E. We show that some intestinal bacteria play an important role in linking some beneficial nutrients to a fat. reduced stomach. In other words, changes in a person's diet are less likely to lead to weight loss if the bacteria involved are not in their gut.

The diet alone did not have a significant impact on the observed links between intestinal microbes and belly fat, as some intestinal bacteria were linked to fat accumulation in the belly, regardless of the diet. This confirms what we have already observed in mice, namely that the gut microbiota alone could affect fat accumulation. Our results also provide further evidence that the human gut microbiota plays an important role in the individualized response to food.

Personalized dietary advice

One of the limitations of our study is that we have analyzed the measures taken at a given moment. This means that we can not establish a causal link. We also looked at dietary intakes reported in the study diets, but did not assess the effect of total food consumption. Another disadvantage is that most people report wrong what they eat. Researchers are working to improve the way in which diet reports are reported, which should lead to more specific work in the future.

Our results mean that in the future you may need to have your gut microbiota checked so that your doctor or dietitian can give you personalized dietary advice. Although bacteria may be partly responsible for increasing the rate of obesity, it is better to stick to a healthy, varied diet rich in fiber, fruits and vegetables, which turn, could help improve the gut microbiota.