Fat matters: Fermented whole milk potentiates the anti-colitis effect of Propionibacterium freudenreichii

Inflammatory bowel diseases (IBD) constitute a growing concern in western countries. They coincide with gut microbiota dysbiosis, including a loss of immunomodulatory bacteria. Accordingly, probiotic products containing selected immunomodulatory bacterial strains mitigate IBD. Selected strains of Propionibacterium freudenreichii display promising modulatory properties and prevent colitis in animal models. Dairy matrices protect propionibacteria immunomodulatory surface antigens during digestive transit. However, the functional role of the dairy matrix components in such fermented dairy products remains unknown. In the present workthis study, P. freudenreichii CIRM-BIA129, a probiotic strain known for its anti-inflammatory properties, was used to ferment whole milk, skim milk or skim milk ultrafiltrate. The preventive potential of fermented products was tested in DSS-induced mice colitis, in comparison with their unfermented counterparts. P. freudenreichii-fermented milk prevented colitis. Dairy fat in the fermented product potentiated the anti-colitis effects of the probiotic. This work opens new perspectives for developing immunomodulatory functional fermented foods.