Julian Walters

Professor Walters's principal interests are the Molecular and cellular function of the small intestine -- in particular how the development and differentiation of the mucosal epithelial cells affects nutrient transport. This include the effects of inflammatory diseases of the intestine causing malabsorption, such as coeliac disease and Crohn's disease, and the changes in gene expression during active disease and the repair process. Recent research has resulted in a paradigm shift in the understanding of chronic Bile Acid Diarrhoea (also known as Bile Salt Malabsorption or Bile Acid Malabsorption). Rather than malabsorption, underproduction of the ileal hormone FGF19 results in excessive hepatic bile acid synthesis, exceeding the normal capacity for absorption. A review showed that about one-third of patients with IBS-D have BAD and this represents around 1% of the adult population. FGF19 production in the ileum is stimulated by bile acids and this is deficient in patients with BAD. Blood levels of this hormone are low. Drugs known as FXR agonists (obeticholic acid is the first in class) are able to stimulate production of FGF19 and give symptomatic improvement. Prof. Walters aims to increase the awareness of BAD and to develop new treatments that are well tolerated.

• Faculty of Medicine