Whipworm infection in mice increases co-infection of enteric pathogens, but promotes clearance of Ascaris larvae from the lungs.

Infection with intestinal whipworms (Trichuris spp.) causes widespread morbidity and may alter responses to enteric and extraintestinal co-infections. Here, we show that Trichuris muris infection in mice increases co-infection with two evolutionary divergent enteric pathogens, the bacterium Citrobacter rodentium and the helminth Heligmosomoides polygyrus. Co-infection caused reduced weight gain and promoted type-1-biased inflammation. In contrast, T. muris-infected mice were more resistant to migrating Ascaris suum larvae in the lungs. Our results highlight the divergent nature of pathogen interactions, and suggest that whipworm infection is a risk-factor for co-infections with other pathogens within the gastrointestinal tract.