Mapping the microbiota of young French people to better understand the links with health and certain diseases: a vast project of collecting and analyzing stool, "Le French Gut", is expanding to children and adolescents aged 3 to 17.
The microbiota, a complex ecosystem of billions of microorganisms populating our intestines, is already recognized as a key player in good health: digestion, immunity, protection of the intestinal lining… But its potential help in better preventing and treating chronic diseases (diabetes, obesity, cancer, Parkinson's, neurodevelopmental disorders…) remains to be clarified.
For the past three years in France, an ambitious project has aimed to collect 100,000 samples in several phases by 2029 to better understand the role of the gut microbiota and the potential links between its imbalances and various diseases. This includes identifying microbiota profiles in healthy individuals and using them as a kind of barometer.
This participatory research - led by the National Research Institute for Agriculture, Food and the Environment (Inrae) and the Assistance Publique-Hôpitaux de Paris (AP-HP), with other public and private partners - was until now only open to adults.
But while there are studies concerning the microbiota in the first years of life, "it's a black hole" for 3-18 year olds, yet a "critical period" of transitions (physiology, hormones, diet, lifestyle), according to Alexis Mosca, a specialist in digestive diseases at Robert Debré AP-HP hospital.
The "French Gut Kids" project aims to collect stool samples from 10,000 children aged 3 to 17, both healthy and ill, from all regions of France. In practice, the children must register with a parent on a website, answer questions about their diet and health, and send the sample by mail.
Objectives: to characterize the diversity of the intestinal microbiota, to study the impact of diet, lifestyle and family environment, to understand the transmission of bacteria from parent to child, to explore the links with common childhood pathologies (asthma, intestinal diseases…).
– “Not science fiction” –
To also raise awareness among 6-13 year olds, an educational kit – podcast about Cocco and Lacto bacteria, video and interactive digital device – will circulate in places where they are received, starting with the AP-HP, and on social networks.
With French Gut, for young people as well as adults, the challenge is to answer "a burning question: is (the microbiota) a central factor in many pathologies, or not?", summarized Professor Robert Benamouzig, head of the gastroenterology department at Avicenne AP-HP hospital and coordinator of the project, to the press.
He recalled that the context is one of "an explosion, on an epidemiological level, of chronic diseases" and of questions about the influence of factors related to the environment and lifestyle, such as for "colon cancer in people under 50".
At this stage, the target of 30,000 adult volunteers, mostly women aged 30-70, has been reached. Nearly a third of the participants report having one or more chronic illnesses (high blood pressure, digestive disorders, respiratory diseases, depression, endometriosis, etc.).
"Already 5,000 microbiota samples have been sequenced, 10,000 will be by the end of this year and 30,000 by the end of 2026," said Dr. Patrick Veiga (Inrae), scientific director.
Initial findings included: "a depletion of the intestinal microbiota as a function of the accumulation of diseases," and "what struck us was the drop in microbiota diversity for 18-29 year olds," a source of questions, he said.
The hope, in the long term, is to use the microbiota to provide information on the presence of a pathology, its rate of progression, but also to predict the response to a treatment, such as immunotherapy in cancers.
“We can imagine a fecal test, at a reasonable cost, microbiota doctors who know how to read these results (...), preventive actions, correction of treatments. This does not seem like science fiction to me,” said Professor Benamouzig.
On the other hand, caution is advised regarding current "microbiota tests," which are increasingly used in some countries: as "there are still no reference thresholds," these tests "are recreational" but "not useful," summarized Dr. Veiga.
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