© Le French Gut
Among all the things we owe our mums is a lifelong gift of health: the foundation of our gut microbiome. This vast community of billions of microorganisms—mostly bacteria—plays a central role in digestion, immunity, and metabolism throughout life. During the first two years, this microbial core develops and stabilizes depending on factors such as breastfeeding, family environment, and exposure to pets or antibiotics.
Scientists have a good understanding of how the microbiome evolves in early life and again in adulthood. Thousands of studies have described how these microbial communities change over time and how such shifts are linked to disease risk or even longevity. But a black box remains: what happens to the gut microbiome between the ages of 3 and 18?
This is precisely the question a new project called Le French Gut Kids wants to answer. A large team of scientists plans to recruit 10.000 children and teenagers from all over France. Until 2029 they will closely examine their lifestyles and ‘bellies’ to understand how gut microbiota evolves between infancy and adulthood, and to identify markers that could help predict health trajectories and disease risk later in life.
“We are witnessing more disease and mental health problems in childhood and adolescence. At the same time we are also seeing disorders in adults and the roots of those may lie in the very first years of life”, says Hervé Blottière, scientific leader of the project.
“Childhood is a very critical window for building the microbiome you will carry for the rest of your life. We want to capture the beginning of the story and answer questions such as the role of food, lifestyle and environment in gut diversity; how the microbiome is built from birth; how microbes are transferred from parents to children; and how all this relates to several common diseases”, adds Blottière.
Launched in November, the project builds on the 2022 initiative Le French Gut. Both initiatives are coordinated by the INRAE -the National Research Institute for Agriculture, Food and Environment in France- in collaboration with AP-HP (Assistance Publique- Hôpitaux de Paris) and supported by a 15-member consortium.
“We want to capture the beginning of the story and answer questions such as the role of food, lifestyle and environment in gut diversity; how the microbiome is built from birth; how microbes are transferred from parents to children; and how all this relates to several common diseases”
Another goal of the study is to raise awareness among children and teens about the importance of the gut microbiome for health, and how to take care of it, particularly through diet. In this sense, educational materials have been developed for use in primary and secondary schools. There is also a podcast about bacteria, as well as videos, exhibitions, and interactive digital content.
To dig into children and teens gut health, participants are asked to complete questionnaires and send stool samples to a central laboratory. Recruitment relies partly on parents already involved in Le French Gut, which has enrolled 30.000 volunteers -mostly women aged between 30 and 70. Social media and influencers are also being used, “a really powerful tool”, describe the researchers. Anyone interested can register at: https://lefrenchgut.fr/
One of the main challenges of the project will be ensuring a sample that truly represents French society, not just people from higher educational backgrounds. Another challenge is managing and analyzing the vast amount of data generated. “A huge amount of information will come from parents, children, metagenomics, health registers. We will need computational resources to work with it and ‘brain power, from clinicians to bioinformaticians, microbiologists or ecologists”, explains Patrick Veiga, scientific director of Le French Gut Kids and Research Director of the MetaGenoPolis unit at INRAE.
“At the end of the project, we’d like to provide guidance for society and policy makers that can have a real impact on public health”, says Veiga. These recommendations could include changes such as enriching school canteen menus with fiber-rich foods, polyphenols and yoghurt, replacing less healthy options. The project also aims at developing tailored recommendations for specific subgroups of children.
“At the end of the project, we’d like to provide guidance for society and policy makers that can have a real impact on public health”
Researchers working on healthy ageing often stress that it begins early in life—not at 60. The ambition of Le French Gut Kids is to identify health trajectories from a young age and, ideally, to intervene when those trajectories point towards poorer outcomes. Being able to detect and correct them early on, Veiga says, “would be a dream”.
