Medeiros, Márcia MeloIngham, Anna CäciliaNanque, Line MøllerCorreia, ClaudinoStegger, MarcAndersen, Paal SkytFisker, Ane BaerentBenn, Christine StabellLanaspa, MiguelSilveira, HenriqueAbrantes, Patrícia2022-11-282022-11-2820221664-302XPURE: 47894535PURE UUID: d7f109dd-b5ff-4dc0-be6a-dc726265090ePubMed: 36386704PubMedCentral: PMC9649904Scopus: 85141831908ORCID: /0000-0002-7939-772X/work/123561867ORCID: /0000-0002-7484-2441/work/123561925ORCID: /0000-0002-5364-9087/work/177280816http://hdl.handle.net/10362/145858Copyright © 2022 Medeiros, Ingham, Nanque, Correia, Stegger, Andersen, Fisker, Benn, Lanaspa, Silveira and Abrantes.After the eradication of polio infection, the plan is to phase-out the live-attenuated oral polio vaccine (OPV). Considering the protective non-specific effects (NSE) of OPV on unrelated pathogens, the withdrawal may impact child health negatively. Within a cluster-randomized trial, we carried out 16S rRNA deep sequencing analysis of fecal and nasopharyngeal microbial content of Bissau-Guinean infants aged 4-8 months, before and after 2 months of OPV revaccination (revaccinated infants = 47) vs. no OPV revaccination (control infants = 47). The aim was to address changes in the gut and upper respiratory bacterial microbiotas due to revaccination. Alpha-diversity for both microbiotas increased similarly over time in OPV-revaccinated infants and controls, whereas greater changes over time in the bacterial composition of gut ( p adjusted < 0.001) and upper respiratory microbiotas ( p adjusted = 0.018) were observed in the former. Taxonomic analysis of gut bacterial microbiota revealed a decrease over time in the median proportion of Bifidobacterium longum for all infants (25-14.3%, p = 0.0006 in OPV-revaccinated infants and 25.3-11.6%, p = 0.01 in controls), compatible with the reported weaning. Also, it showed a restricted increase in the median proportion of Prevotella_9 genus in controls (1.4-7.1%, p = 0.02), whereas in OPV revaccinated infants an increase over time in Prevotellaceae family (7.2-17.4%, p = 0.005) together with a reduction in median proportion of potentially pathogenic/opportunistic genera such as Escherichia/ Shigella (5.8-3.4%, p = 0.01) were observed. Taxonomic analysis of upper respiratory bacterial microbiota revealed an increase over time in median proportions of potentially pathogenic/opportunistic genera in controls, such as Streptococcus (2.9-11.8%, p = 0.001 and Hemophilus (11.3-20.5%, p = 0.03), not observed in OPV revaccinated infants. In conclusion, OPV revaccination was associated with a healthier microbiome composition 2 months after revaccination, based on a more abundant and diversified bacterial community of Prevotellaceae and fewer pathogenic/opportunistic organisms. Further information on species-level differentiation and functional analysis of microbiome content are warranted to elucidate the impact of OPV-associated changes in bacterial microbiota on child health.3148813engMicrobiologyInfectious DiseasesSDG 3 - Good Health and Well-beingjournal article10.3389/fmicb.2022.1016220