Welcome to the Chassaing lab website
Located in Paris, INSERM U1016, CNRS UMR8104, Université Paris Cité


Research interest: Role of the microbiota in health and disease, with a focus on chronic inflammatory diseases

Environmental factors-mediated modulation

of the intestinal microbiota

We are highly interested in studying some environmental factors that can alter the intestinal microbiota. We have previously reported that emulsifiers, highly used by the food industry, are able to detrimentally alter the intestinal microbiota, characterized by an increased ability to penetrate the normally protective mucus layer and an increase pro-inflammatory potential. We reported that the consumption of emulsifying agent is sufficient to induce intestinal inflammation that will manifest as chronic colitis in genetically susceptible host. Moreover, in unimpaired host, such food additives are inducing the development of metabolic syndrome characterized by diabetes and an increase in body weight, as well as by an increased susceptibility to colonic carcinogenesis.

Our ongoing research on this area is focusing on the mechanisms beyond such observations:

- how dietary emulsifiers are able to directly impact the intestinal microbiota?

- how the altered microbiota will subsequently drive deleterious phenotypes?

Innate immunity / microbiota relationship

in health and disease

We have studied for many years how the host is controlling the intestinal microbiota in order to keep it under control and at a proper/safe distance from the intestinal mucosa. We have for example demonstrated that the flagellin receptor TLR5 is playing a central role in keeping the intestinal microbiota under control. Animals lacking the TLR5 receptor develop intestinal inflammation that can manifest with the development of chronic colitis or metabolic syndrome. In the liver, we have recently demonstrated that TLR5 is playing an important protective role during western-style diet consumption.

Our current research is focusing on:

- characterizing the microbiota members driving intestinal inflammation

- identifying some therapeutic approaches to beneficially alter the intestinal microbiota

The gut brain axis: a dietary point of view

We are developing our research toward the gut and brain axis in order to understand how alterations of the intestinal microbiota by dietary components can be detrimental for the brain and behavior. Our preliminary data support a central role played by the microbiota on anxiety-related behavior.


We are now trying to:

- better characterize the consequences of an altered microbiota on behavior

- how diet-induced alterations of the intestinal microbiota can lead to neuro-inflammation

- what are the molecular mechanisms connecting the altered microbial community and the associated altered behaviors ?

Modulation of the intestinal microbiota using pre- and pro-biotics approaches

While our research is mainly focusing on detrimental impacts of the microbiota, our expertise in this field of research, our data-set of identified detrimental bacteria and metabolites, as well as the numerous animal models available in the laboratory lead us to work on the development of tools aiming to beneficially alter the intestinal microbiota.

Among other approaches, we are:

- using dietary factor to modulate the microbiota and prevent its deleterious effects

- using probiotics to beneficially modulates the host/microbiota relationship

- using approaches to in vivo modulate bacterial gene expression in order protect against intestinal inflammation and neuro-inflammation.