Final Report Summary - COHABIT (Consequences of helminth-bacterial interactions)
Intestinal worms (helminthes) infect over 2 billion people across the world. Although these can cause serious health problems such as malnutrition their long co-evolution with mammals has resulted in a close relationship with our immune system, to the point that they are thought to regulate immunity in beneficial ways and to prevent diseases such as allergic asthma. However, very little is known about how this occurs. In addition to helminths, our intestine also harbors millions of bacteria, collectively known as the microbiota. These bacteria have dominated the news in recent years with growing evidence supporting an important role for our microbiota in influencing metabolism, immunity and overall health. As part of our project we uncovered a role for ‘cross-talk’ between intestinal helminths and the microbiota. Helminth infection increased production of specific metabolites - called “short-chain fatty acids” - by the microbiota, and these metabolites modulated the immune system of mice such that allergic asthma was reduced. In a related project we uncovered a role for the microbiota in providing protection against helminth infection. This was due to an ability of the microbiome to increase intestinal contractions which helped to prevent the helminth parasites from infecting the tissue following their ingestion. This work highlights the importance and complexity of tripartite interactions between our microbiome, the intestine and parasitic pathogens with implications for pathogen burdens and immune disease such as allergy. Our group is now exploring how helminth-bacterial cross talk impacts on our other immune and physiological parameters including obesity.