Congratulations to Ambre Riba, PhD, for her publication in Science Translational Medicine!

Ambre reports in her paper on a new infection model with the human enteropathogenic protozoon Giardia lamblia.

Giardia lamblia is an important causative agent of diarrhea in adult travelers. In contrast. Giardia lamblia infection in infants in endemic areas is not associated with diarrhea but reduced weight gain and growth. The underlying mechanism is unknown.

Using a new preclinical model, Ambre could show for the first time that Giardia lamblia induces bile secretion and consumes bile-derived lecithin. She also observed an altered bile acid metabolism and microbiota composition in infected individuals that led to enhanced expression of the metabolic regulator FGF15. Interestingly, Ambre also observed enhanced levels of the human homolog FGF19 in Giardia lamblia positive infants in an African study cohort. This identifies a potential mechanism for the reduced weight gain and growth caused by Giardia lamblia in children in endemic areas.