In the animal kingdom, juvenile growth takes place during the post-natal stages preceding sexual maturation and ushers in the most profound physiological changes in an organism’s lifetime. These changes are governed by the complex interplay between the animal’s genotype and its nutritional environment. In humans, 155 million kids today are plagued by childhood malnutrition worldwide and chronic undernutrition at the juvenile stage, a condition defined as a prolonged reduced intake of key nutrient (such as proteins), leads to severe stunting (i.e. flattened linear growth) and long-term negative neurological, immunological, metabolic and reproductive consequences.
Recent studies, including our own, establish that the microbial communities colonizing the body surfaces (i.e microbiota), especially the activities and constituents of the gut microbiota, can alter animal growth trajectory. In fact, children suffering malnutrition carry an “immature” gut microbiota that fails to be remedied by classical re-nutrition strategies. In addition, in various animal models, we and others, have shown that selected strains of microbiota members can buffer the deleterious impact of undernutrition on juvenile growth dynamics.
Despite our recent progress, the molecular mechanisms behind such microbiota mediated host benefit remain poorly understood. This is partly due to the fact that the gut microbiota is a complex ecosystem comprising up to hundreds microbial species in mammals, mostly bacteria. They construct multiplex, high-order nutritional, metabolic and signalling networks among themselves and with the host such that these interactions directly influence host physiology.
In this context, we aim at deciphering how commensal bacteria shape the juvenile animals’ response to their nutritional environment and how juveniles in such nutritional environment influence the ecology and physiology of their bacterial partners. Hence, we study microbial ecology and physiology as well as animal development and physiology.
To probe the mechanisms at play in an unbiased way we use gnotobiology (animal breeding under strictly controlled microbial environments) coupled to genetics, functional genomics, imaging and biochemical approaches in bacteria (mostly using the model commensal bacteria, Lactobacillus plantarum and Acetobacter spp.) and in drosophila (Drosophila melanogaster).
We also use microbial interventions (using Lactobacillus plantarum) on conventional mice (Mus musculus) to contemplate the influence of such microbial environment on stunting in mammals. In addition, we capitalize on a novel gnotobiotic mice model harbouring a minimal microbiota composed of 15 bacterial strains representing the most dominant bacterial families found in conventional laboratory mice to investigate how such controlled microbiota influences host developmental and physiological features upon stunting and to study how such nutritional condition influences the ecological dynamics of the members of this microbiota.
Finally, we develop collaboration with R&D companies to translate our basic research outputs into products designed to improved animal or human health and well-being.