title: Active and secreted IgA-coated bacterial fractions from the human gut reveal an under-represented microbiota core.
abstract: Host-associated microbiota varies in distribution depending on the body area inhabited. Gut microbes are known to interact with the human immune system, maintaining gut homoeostasis. Thus, we studied whether secreted-IgA (S-IgA) coat specific microbial taxa without inducing strong immune responses. To do so, we fractionated gut microbiota by flow cytometry. We found that active and S-IgA-coated bacterial fractions were characterized by a higher diversity than those observed in raw faecal suspensions. A long-tail effect was observed in family distribution, revealing that rare bacteria represent up to 20% of total diversity. While Firmicutes was the most abundant phylum, the majority of its sequences were not assigned at the genus level. Finally, the single-cell-based approach enabled us to focus on active and S-IgA-coated bacteria. Thus, we revealed a microbiota core common to the healthy volunteers participating in the study. Interestingly, this core was composed mainly of low frequency taxa (e.g. Sphingomonadaceae).
authors.affiliation: 1] Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain [2] CIBER Epidemiología y Salud Pública (CIBERESP); Spain [3].
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Auria
authors.affiliation: 1] Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain [2] CIBER Epidemiología y Salud Pública (CIBERESP); Spain [3].
authors.forename: Francesc
authors.initials: F
authors.lastname: Peris-Bondia
authors.affiliation: 1] Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain [2] CIBER Epidemiología y Salud Pública (CIBERESP); Spain.
authors.forename: Mária
authors.initials: M
authors.lastname: Džunková
authors.affiliation: Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain.
authors.forename: Alex
authors.initials: A
authors.lastname: Mira
authors.affiliation: The Institute of Agrochemistry and Food Technology, Spanish National Research Council (IATA-CSIC), Valencia, 46100; Spain.
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Collado
authors.affiliation: 1] Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain [2] CIBER Epidemiología y Salud Pública (CIBERESP); Spain.
authors.forename: Amparo
authors.initials: A
authors.lastname: Latorre
authors.affiliation: 1] Joint Unit of Research in Genomics and Health, Centre for Public Health Research (CSISP) - Cavanilles Institute for Biodiversity and Evolutionary Biology (University of Valencia), Valencia, 46020; Spain [2] CIBER Epidemiología y Salud Pública (CIBERESP); Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Moya
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D044822:Biodiversity; D019295:Computational Biology; D058893:DNA Barcoding, Taxonomic; D005260:Female; D041981:Gastrointestinal Tract / Q000276:immunology* / Q000382:microbiology*; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D008297:Male; D054892:Metagenome; D064307:Microbiota; D017422:Sequence Analysis, DNA; D055815:Young Adult
chemical_list: D007070:Immunoglobulin A