Abstract

Segmented filamentous bacteria (SFB) are unique immune modulatory bacteria colonizing the small intestine of a variety of animals in a host-specific manner. SFB exhibit filamentous growth and attach to the host's intestinal epithelium, offering a physical route of interaction. SFB affect functions of the host immune system, among them IgA production and T-cell maturation. Until now, no human-specific SFB genome has been reported. Here, we report the metagenomic reconstruction of an SFB genome from a human ileostomy sample. Phylogenomic analysis clusters the genome with SFB genomes from mouse, rat and turkey, but the genome is genetically distinct, displaying 65-71% average amino acid identity to the others. By screening human faecal metagenomic datasets, we identified individuals carrying sequences identical to the new SFB genome. We thus conclude that a unique SFB variant exists in humans and foresee a renewed interest in the elucidation of SFB functionality in this environment. Hans Jonsson et al. report the metagenomic reconstruction of the genome of a potentially immune modulatory segmented filamentous bacteria (SFB) from a human ileostomy sample. They demonstrate that the genome clusters closely with SFB genomes from other species. They also detect the unique SFB variant in human faecal metagenomics datasets.

Published in

Communications biology
2020, volume: 3, number: 1, article number: 485
Publisher: NATURE PUBLISHING GROUP

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