Impact of colonic urea secretion on the human gut microbiota.

Microbes are everywhere and reach the highest densities on earth in the gastrointestinal tracts of animals, including humans. In ruminants, they play a very important role in the salvage of nitrogen and enable these animals to extract high levels of nutrients from low-protein feed. A mechanism involving urea secretion into the rumen is responsible for this mutually beneficial host-microbiome interaction. There are several indications that a similar mechanism is at play in humans. Although in our gut this process will by no means match the nutritional importance it has in ruminants, I think the substantial amount of urea secreted in our colon greatly affects the composition and abundance of our microbial companions. Several diseases are associated with specific differences in gut microbial composition.  Gathering knowledge about factors that drive such differences is a first step towards curing these diseases. In this project, I will characterize the effect of colonic urea secretion on the gut microbiome. Next, I will try to change the microbiota composition by manipulating the colonic urea excretion. Such modulation strategies could lead to the treatment of microbiome-related diseases.