Schistosoma mansoni infection causes consistent changes to the fecal bacterial microbiota of mice across and within sites

Schistosomiasis is a neglected tropical disease caused by several blood fluke species in the genus Schistosoma. Schistosoma mansoni enters the mammalian host via skin penetration and sexually reproduces in mesenteric vasculature. Schistosoma mansoni eggs penetrate both serosal and epithelial intestinal barriers, and are excreted with feces. Consequent physical damage or immune responses may disrupt normal gut microbiota. Reported microbiome composition may vary considerably with both biotic and abiotic factors, including differences between study sites (e.g. microbial milieu of animal facilities and technicians), and study organisms (e.g. dietary background of experimental mice). In this study, we evaluate the fecal bacterial microbiome of mice in three experiments at two locations in order to assess Schistosoma-associated microbiome composition changes, as well as potential effects of study location on microbiome composition. When analyzing overall composition and diversity, the largest visible differences were between institutions. However, there were clear and specific changes due to schistosome infection and these specific changes were reproducible, regardless of the institution at which the experiment was performed.