Interview – Prof. Alexandre Persat

The gastrointestinal tract of many insects and animals is colonized by an abundant microbial community known as the gut microbiota. In humans, this population is so dense that it contains at least as many cells as our own body does, and at least hundred times more genes than the number of human genes. We know that this population plays a crucial role in human health and disease. For example, some of the gut-residing bacterial species help us transform foods for better absorption, reinforce our immune system and protect us from infections. Conversely, an imbalance in the gut microbiota (or dysbiosis) is associated with metabolic and neurodegenerative diseases, and even affects our behavior. 

Most knowledge of the composition and function of microbiota has been generated from sequencing of fecal content or intestinal tissue of animals. While these help us correlate the microbial signature present in the digestive tract of an animal with phenotypes such as disease or metabolism, little is known about the mechanisms by which microbes modulate such as variety of host behaviors. This makes forward engineering of the microbiota complex, decreasing our ability to manipulate this community to improve health and fight diseases.

My lab is particularly interested in understanding how physical environment of the intestine affect microbiota composition. We are using engineering technologies to reproduce intestinal microenvironments in the lab and study their impact in a mechanistic manner. We grow model microbiota in microfluidic device that replicate the flow of nutrients microbes experience in the gut. This allows us to carefully study the impact of flow, but also of fluctuating food consumption or even antibiotic treatments. We also use novel organoid technologies that allow us to bring these investigations is a more physiological context without animal experiments. This in turn leads us to connect the physiology of the microbiota with human metabolism and health.

To know a bit more about you…

  • What is your best culinary memory?

Armenian dishes from my grandmother such as borek and dolma are my “madeleine de Proust”.

On a serious note, we all know that food systems are under pressure…

  • What would you like to see tomorrow in your supermarket?

I don’t think there is any aspect more important than sustainability, at all levels. As a result, I don’t want to see more in supermarkets, rather less! I think we are on the right track, with an increasing demand of simpler, elemental food. We may be on the right track, with trends of simpler, healthier foods arising everywhere. Unfortunately, this is not the norm as it is increasingly expensive and remains time consuming. It is important that healthy nutrition becomes more affordable.

Sustainability is also critical on the production side: the environmental cost of the food market is not acceptable. We ought to consume less meat products and more local seasonal foods. These aspects have an impact on intestinal microbiota: our gut flora is composed of bacterial species that feed on the nutrients we eat. We are in better health when our microbiota is diverse, which is maintained under a diet rich in fibers and limited in fat.