Themes and objectives

The symptoms of IBD are abdominal pain, prolonged diarrhea with possible bleeding, fatigue, fever and / or weight loss.

They are characterized by relapses with major syndromes followed by episodes of remission and are considered highly debilitating diseases. Multiple factors play a role in IBD: i) the genetic background; ii) immune status; iii) the microbiota, and iv) the environment. There is no cure for IBD and treatments are heavy and expensive. Research on alternative strategies with a more local and less destructive effect is therefore needed.

Mastitis is an inflammation of the mammary gland, most often due to a bacterial infection. This disease is a major problem in animal health.

It causes heavy economic losses in milk production and is the leading cause of antibiotic consumption for dairy cattle. In addition, milk producers have to face a strong societal demand for a more sustainable agriculture respectful of animal welfare. Agriculture has set itself the goal of using less input and in particular to reduce the use of antibiotics in veterinary medicine. The latter indeed raises a problem in terms of the environment (antibiotic residues) and public health (risk of emergence of antibiotic resistance).

In both contexts, beneficial lactic acid bacteria or commensal bacteria, as well as compounds thereof, could be an adjunct or an interesting alternative to current anti-IBD treatments or antibiotics.

They could be used to improve the prevention and treatment of IBD or mastitis that can cause significant side effects.

Within the LIA, we study our model bacteria Propionibacterium freudenreichii, Lactobacillus casei and Faecalibacterium prausnitzii.

We extend our research to other bacteria, lactic acid bacteria, propionic acid bacteria or commensal bacteria, isolated from the mammary microbiota, or the intestinal microbiota. Their immunomodulatory capacities are evaluated and characterized in vitro and in vivo on models of induced inflammation. We aim to identify the bacterial determinants involved in the observed probiotic effects (anti-inflammatory and tissue invasion inhibition) and to elucidate their mechanisms of actions on the host.