How the gut parasitome affects human health

Abstract

The human gut microbiome (GM) is a complex ecosystem that includes numerous prokaryotic and eukaryotic inhabitants. The composition of GM can influence an array of host physiological functions including immune development. Accumulating evidence suggest that several members of non-bacterial microbiota, including protozoa and helminths, that were earlier considered as pathogens, could have a commensal or beneficial relationship with the host. Here we examine the most recent data from omics studies on prokaryota-meiofauna-host interaction as well as the impact of gut parasitome on gut bacterial ecology and its role as 'immunological driver' in health and disease to glimpse new therapeutic perspectives.

Keywords: big-data omics; human gut microbiome; meiofauna; prokaryota.

Figure 1.

Human gut biome characterized by bacteriome, virome and meiofauna.

Figure 2.

Immune response to gastrointestinal nematode infections. (a) Detection and transmission phase in the intestinal epithelial layer. Type 2 immunity against nematodes results from recognition of parasite-derived antigens that are continuously secreted during infection. Once a parasite has been detected by the epithelium and/or other nonhematopoietic cells, the signal is transmitted to cells of the innate immune system and an inflammatory cascade can be initiated. (b) Induction of immunity in the lymphoid tissue. Once the innate immune system has been alerted to the presence of nematodes, it propagates the signal to the mesenteric lymph nodes for an adaptive immune response. This role is mainly performed by the dendritic cells whose determine the T and B cell activation. (c) Expulsion of the parasites from the intestine and resolution of the response.