Investigating the digestion and absorption of macronutrients, and mechanisms of nutritional sensing in the gastrointestinal tract

The increasing incidence of obesity is due to the growing pressure of modern lifestyle on a highly receptive homeostatic system of energy intake and expenditure. In healthy individuals, specialised cells detect and respond to the presence of specific nutrients in the gastrointestinal tract by secreting peptide hormones, which mediate food transit, digestion and absorption, and promote feelings of satiety. There is evidence to suggest that obese people are less sensitive to the satiating effects of nutrients, and this disturbed communication between the gut and the brain is linked to their susceptibility to weight gain.

This PhD project aims to build on previous work on the digestive, metabolic and endocrine events leading to satiety, using a combination of human, in vitro and ex vivo models. The main focus will be on metabolomic data, using NMR and LC/GC-MS to investigate the metabolic environment preceding endocrine activity and satiety in humans. This will be supported by microbiomic analysis and in-house and commercial assays for the measurement of glucose and gut hormones. This will allow investigation of how these metabolic and endocrine processes might differ in obese and normal weight individuals, and how we might target these systems to prevent or treat obesity.