The incidence of non-communicable diseases, such as autoimmune, allergic and metabolic diseases have been on the rise over the last decades, particularly in Western countries, for poorly understood reasons. Such a rapid increase suggests the involvement of environmental factors in these now called “western lifestyle diseases”.

Among the most dramatic changes in Western lifestyle is the shift from a traditional diet towards the highly processed western diet, enriched in fat and carbohydrates while deprived in dietary fibre. Dietary fibre, defined as complex carbohydrates indigestible by the host, represents the major source of energy for the gut microbiome.

The gut microbiome is constituted of trillions of bacteria that inhabit the gut and profoundly impact on immune cell development and function. Dietary fibre is fermented by the gut bacteria with the short chain fatty acids (SCFAs), acetate, butyrate and propionate, released as end products. SCFAs affect host cell function through their binding on the G-protein receptors GPR43, GPR109a and GPR41 with different affinities.

We hypothesize that insufficient consumption of dietary fibre will disrupt the communication gut bacteria-host cells that will contribute to disease development.

This presentation will focus on our results showing that in mice, low dietary fibre consumption detrimentally affects gut bacterial composition, gut epithelial cell function as well as immune cell activity contributing to colitis and food allergy development. These effects involved the receptors GPR109a and GPR43.

These results suggest that safe and cost-effective strategies around dietary fibre supplementation or dietary advices could prevent the development of common western lifestyle diseases.