Experimental infection with the hookworm, Necator americanus, promotes gut microbial diversity in human volunteers with relapsing multiple sclerosis
Abstract Background Helminth-associated changes in gut microbiota composition have been hypothesised to contribute to the immune-suppressive properties of parasitic worms. Multiple sclerosis is an immune-mediated autoimmune disease of the central nervous system whose pathophysiology has been recently linked to alterations of gut microbial communities. Results In the present study we investigated, for the first time, qualitative and quantitative changes in gut microbial composition of human volunteers with remitting multiple sclerosis (RMS) prior to and following experimental infection with the human hookworm, Necator americanus ( N+ ), and following anthelmintic treatment, and compared the findings with data obtained from a cohort of RMS patients subjected to placebo treatment ( PBO ). Bacterial 16S rRNA high-throughput sequencing data revealed significantly decreased microbial alpha diversity in the gut microbiota of PBO compared to N+ subjects over the course of the trial; additionally, we observed significant differences in the abundances of several bacterial taxa with putative immune-modulatory functions between study cohorts. Parabacteroides were significantly expanded in the gut microbiota of N + individuals for which no relapses were recorded at the end of the trial. Conclusions Overall, these data lend support to the hypothesis of a contributory role of parasite-associated alterations in gut microbial composition to the immunomodulatory properties of hookworm parasites.