The intestinal microbiota – formerly called the intestinal flora – occupies an important place in the health of individuals. Doctor, holder of a doctorate, professor of nutrition at the University Hospital of Rouen in France, the Dr Pierre Déchelotte devotes his research here and oversees the INSERM laboratory “Nutrition, Inflammation and dysfunction of the intestinal-brain axis”. We spoke to this internationally renowned researcher.
Dr Déchelotte, why is the intestine called the second brain?
If the intestine is the second brain, the microbiota is the third brain. This third brain is located inside the second brain, and both speak to the first, above!
For about thirty years, we have shown that in our digestive tract, there are many neurons, which explains why we spoke 20 to 25 years ago about the second brain. But it’s more complicated than that.
We are familiar with food-absorbing cells, but there are also many immune cells that play a role in regulating the intestinal barrier. There are endocrine cells that produce many hormones that play an important role in regulating hunger and satiety, but also in regulating motricity and digestive sensitivity. All these cell types communicate with each other.
Therefore, this intestinal brain should be understood as something more universal.
You studied eating disorders, in particular anorexia nervosa, related to the microbiota. Can the development of an eating disorder start from the microbiota?
We have compiled over 15 years a whole series of publications to suggest that part of the maintenance mechanism, or even the trigger of anorexia, or perhaps other eating disorders such as binge eating or bulimia, may attributed to an imbalance of the microbiota.
There is actually dysbiosis, a significant imbalance of the microbiota, in anorexia nervosa. With bulimia, data is still very limited, but we will publish new results soon. With binge eating, which leads to obesity, we are at the beginning of the story: our Belgian colleagues reported recently that the microbiota of compulsive patients is not the same as that of non-compulsive patients.
We’ve also done a lot with some bacterial protein that can regulate food.
Your research has shown that a strain of probiotics, now sold in France, has a good effect on satiety and weight loss. Can you tell me more about it?
For several years, we have shown, effectively, first in animal models, then through a clinical study in humans, that the Hafnia alvei HA 4597 strain has a satiating effect and promotes the reduction of weight in overweight people.
However, it is not a treatment for obesity, but a dietary supplement that strengthens the natural mechanisms of satiety. We are constantly looking for other microbiota modulators that may be beneficial in nutrition. Hafnia alvei HA4597 and Lactobacillus plantarum WJL strains (interesting for growth and renutrition) are already being sold in France and some specific European countries by our start-up TargEDys and the Biocodex laboratory. For others, you have to wait a little longer.
Can improving the microbiota contribute to the recovery of people suffering from binge eating?
What we are currently saying to a hyperphagia patient is that one must first try to understand the mechanisms that lead to hyperphagia. Often there is major stress, anxiety-depressive disorder or other compulsive disorder. We will first discuss the eating habits of cognitive behavioral therapies, with re-examination of food and possibly medications, in particular serotoninergics, such as fluoxetine and sertraline, that work well in compulsive disorders.
But not all patients respond to these relatively common treatments. Therefore, it is also necessary to re -educate the microbiota, and the best re -education starts with food. If we manage to calm the constraints, which are usually in fatty and sweet foods, we will reduce dietary imbalance and gradually correct dysbiosis. For example, by reducing sugars and fats, and increasing fiber, we will favor certain species, such as butyrate makers, and we will reduce certain specific numbers of other species that rely on massive fat intake, and therefore, ultimately. , we are again teaching the microbiota through food. But this is not always enough, hence the interest of a more direct intervention in certain probiotics with evaluated efficacy.
You just arrived from an international congress on prebiotics. What is new in this matter?
In fact, the PROBIOTA 2022 congress, recently held in Copenhagen, brought together 400 researchers and industrialists from around the world to review recent developments. This is a field in strong expansion. Weight control remains an important issue, and our work has been the subject of a plenary conference, in addition to the amazing developments of Patrice Cani’s (Belgium) team on Akkermansia Muciniphila, another strain that seems very useful in reducing the risk of diabetes.
There has also been a lot of communication on the modulation of stress, anxiety, the microbiota and some probiotics. In other words, the microbiota that surprises us is not over yet!
What do you think of microbiota analysis kits?
Currently, it is not as satisfactory as prevalent as a commercial microbiota analysis. […] But this is a field that is changing very rapidly, and a new generation of more advanced tests and above all better combined at the medical level should soon see the light of day. We do this too.
♦ To learn all about the microbiota, you can take a collaborative activity where Dr.r Déchelotte participated in addition to other European experts.
♦ Intestinal microbiota and human health Jean-Michel Lecerf, Nathalie DELZENNE Elsevier Editions