[Frontier Leaders] Host-microbes symbiosis in health and disease.

Frontier Leaders Seminar

Title: Host-microbes symbiosis in health and disease

Speaker: Joel Doré

Affiliation: INRA, French National Institute for Agricultural Research, Paris, France

Abstract:

Aminals are holobionts ; they are microbial; their intestinal tract harbours a complex microbial ecosystem which plays a key role in nutrition and health. Interactions between food constituents, microbes and the host organism derive from a long co-evolution that resulted in a mutualistic association.

Investigations into the human intestinal metagenome, i.e. combined genomes of all dominant microbes, have paved the way, delivering an extensive gene repertoire representative of its functional potentials. The most redundant genomic traits of the intestinal microbiota are identified. These observations point towards the existence of enterotypes, i.e. ecological arrangements of microbiota sharing specific traits but yet independent of geographic origin, age, sex etc.. It also shows a unique segregation of the population into individuals with low versus high gene-counts. It not only gives an unprecedented view of the intestinal microbiota, but it also significantly expands our ability to look for specificities of the microbiota associated with diseases and to ultimately validate microbial signatures of prognostic and diagnostic value in immune-mediated diseases.

The current view is that of an intimate symbiosis linking the microbiota and the host with marked implications in terms of ecological dynamics but also monitoring and modulation.

On a metabolic standpoint, the intestinal ecosystem functions as an anaerobic digester in which dietary fibers and endogenous mucins are the key primary substrates and short chain fatty acids as well as fermentation gases, including methane, are the terminal products. Metagenomic data are expanding our understanding of key steps of the intestinal microbial food chain.

The newest view of durably altered symbiosis as a potential outcome of immune alterations stresses the importance of designing and implementing mitigation strategies. In this context, current developments of microbiotherapy approaches with Live Biotherapeutic Products and autologous fecal microbiota transfer will be illustrated as they provide new insights for the preservation of a healthy host-microbe symbiosis.

The intestinal microbiota should hence be regarded as a true organ, bearing ecological and functional characteristics with relevance for the rational design of innovative modulation strategies for health.

Short bio:

Research Director at INRA, Joël is Scientific Director of MetaGenoPolis, a Unit of the Micalis Institute “Food and Gut Microbiology for Human Health” and scientific board member of Microbiology Pole of the Doctoral School “Therapeutic Innovations” at Paris-XI University. Joël Doré also chairs the gut microbiota for health scientific web-platform. Joel joined INRA in 1983 and received his PhD from the University of Illinois at Urbana-Champaign, USA, in 1988. He aims to contribute to a better understanding of the intestinal ecosystem in order to support therapeutic choices in the medical area, as well as science-based recommendations in health nutrition