Two Key Actinomycetota Taxa in the Human Gut Microbiota are Associated with Schistosoma mansoni Infection Burden

In this study, we sought to identify key microbial taxa associated with human gut dysbiosis during S. mansoni infection and whether the changes are linked to the intensity of helminth infection. Stool samples were obtained from 20 persons infected with schistosomiasis and an equal number of uninfected persons from an endemic rural community in Ghana. Infection intensity was scored as egg count per gram (EPG) using the Kato-Katz method. Positive stool samples were further stratified as low-moderate (<400 EPG, n=15) and high (>400 EPG, n=5) infection burden. The composition and diversity of the gut microbiota and potential microbial markers associated with S. mansoni infection intensity were determined from 16S rRNA amplicon sequence analyses. No difference in {beta}-diversity was observed between positives and negatives (PERMANOVA: R2= 0.012, p= 0.723), although there was an increased abundance of Bifidobacterium (p= 0.008) in infected stool samples compared to the negatives. Further analyses showed that Bifidobacterium (p= 0.003) and Collinsella (p= 0.029) were elevated considerably among the low-moderate infected samples, while the pathobiont Escherichia-Shigella was reduced (p= 0.0078). Our findings show that intestinal schistosomiasis results in human gut microbiota dysbiosis, which is only distinguished when the intensity of infection is considered, with two key Actinomycetota species assuming importance depending on the infection burden. Author SummaryThis study investigates the relationship between Schistosoma mansoni infections, a major cause of intestinal schistosomiasis, and the human gut microbiome. Using samples from an endemic region in Ghana, the research examines how infection intensity impacts gut bacteria. The findings reveal that certain beneficial bacteria, such as Bifidobacterium and Collinsella, become more abundant in cases of low to moderate infection, potentially maintaining immune regulation and gut health. However, these effects are not seen in high-infection instances, possibly due to the aggressive hallmarks of high-intensity helminth infections. Understanding these dynamics could be pivotal for developing microbiome-based interventions to improve treatment outcomes for schistosomiasis and similar parasitic infections. This study sheds light on the complex interplay between infectious parasites and gut microbes, emphasising the promise of microbiome research in enhancing public health efforts in areas where parasitic diseases persist.