Grant: Team Grant: Health Effects of Ultra-Processed Foods-Mechanisms of Health Eff-LOI

Ultraprocessed foods cause overeating, which is a key driver of the obesity epidemic. The colour, texture and flavour of ultraprocessed foods are designed to make food consumption more enjoyable by making the food hyperpalatable. However, we hypothesise that a major mechanism whereby ultraprocessed foods cause overeating is by their ability to inhibit a nerve circuit that normally serves to limit food intake by inducing the feeling of fullness, also known as satiety. Further, we hypothesize that the inhibition of this nerve circuit is due to the microbiota metabolising ultraprocessed food ingredients, leading to the generation of chemicals that impair the function of the cells that make up this satiety circuit. To explore this, we will grow bacterial communities from young adults in the absence and presence of key ingredients of ultraprocessed food, and analyse the secretory products of these bacterial communities. Using mouse bioassays, we will characterise the effects of these secretory products on the cells that convey satiety signals to the brain in order to limit food intake. We predict that bacteria exposed to ultraprocessed foods will impair the function of these cells and we will explore how this happens. We will also use chemical assays to identify the chemicals produced by gut bacteria in response to ultraprocessed foods. Lastly, we will determine whether the gut bacterial community composition is changed following exposure to ultraprocessed foods. Together, these studies will explore a novel way in which ultraprocessed foods contribute to the obesity epidemic by promoting overeating.