HDR defense :

Towards new probiotic approaches targeting Clostridioides difficile: the potential of bifidobacteria

The gut microbiota plays a central role in maintaining human health, performing essential functions such as protection against pathogens, immune regulation and metabolism. Its disruption, or dysbiosis, is now recognised as a key factor in the development of numerous diseases. Clostridioides difficile (C. difficile) infections are a particularly striking example of this: this major nosocomial pathogen specifically exploits the dysbiosis induced by antibiotic treatments to establish itself and cause recurrent infections. The therapeutic challenge is all the more complex given that antibiotics, whilst constituting the standard of care, paradoxically perpetuate the dysbiosis that promotes these relapses.

It is against this backdrop that I initiated a research programme within the MICALIS unit focusing on the use of bifidobacteria as a probiotic alternative targeting this pathogen. The projects carried out within this framework have enabled the establishment of an integrated pipeline, ranging from the selection and in-depth characterisation of strains to their evaluation in preclinical models, and have provided robust proof of concept for their anti-C. difficile activity. My future projects aim to broaden this approach by increasing the diversity of the strains studied, incorporating an immunological component using cellular models, and validating the most promising candidates in murine models of relapse.

Jury members:

• Olga SOUTOURINA, Professeure des Universités, Université Paris-Saclay, I2BC UMR9118
• Anne-Judith WALIGORA-DUPRIET, Professeure des Universités, Université Paris Cité, Faculté de pharmacie
• Marianne CHEMALY, Directrice Scientifique Sécurité Sanitaire des Aliments, Anses, Unité HQPAP, Laboratoire de Ploufragan-Plouzané-Niort
• Vincent THOMAS, PharmD PhD HDR, Senior Team Leader Gut Microbiology and OneBiome, Medical and Nutritional Science, Danone Global Research & Innovation Centre
• Muriel THOMAS, Directrice de recherche INRAE, Institut MICALIS UMR1319