Abstract
Recent studies have provided evidence on the presence of an oral–gut microbiota axis in gastrointestinal diseases; however, whether a similar axis exists in healthy individuals is still in debate. Here, we characterized the bacterial and fungal microbiomes in paired oral rinse and stool samples collected from 470 healthy Chinese adults by sequencing the 16S rRNA V3–V4 and ITS1 regions, respectively. We hypothesized that there is limited oral–gut transmission of both the bacterial and fungal microbiota in healthy Chinese adults. Our results showed that the oral and gut microbiota in healthy individuals differed in taxonomic composition, alpha and beta diversity, metabolic potential, and network properties. Bayesian analysis showed that the vast majority of subjects had negligible or low bacterial and fungal oral-to-stool contribution. Detailed examination of the prevalent amplicon sequence variants (ASVs) also revealed limited cases of sharing between the oral and stool samples within the same individuals, except a few bacterial and fungal ASVs. Association analysis showed that sharing of the potentially transmissible fungal ASVs was associated with host factors, including an older age and a higher body mass index. Our findings indicate that oral–gut transmission of both bacterial and fungal microbiota in healthy adults is limited. Detection of a large amount of shared bacterial or fungal members between the oral and gut microbiome of an individual may indicate medical conditions that warrant detailed checkup.
IMPORTANCE The oral–gut microbiota axis in health is a fundamentally important and clinically relevant topic; however, our current understanding of it remains biased and incomplete. By characterizing the bacterial and fungal microbiomes in paired oral rinse and stool samples from a large cohort of healthy Chinese adults, here we provided new evidence that oral–gut microbiota transmission is limited in non-Western population and across biological domains. Our study has established an important baseline of a healthy oral–gut microbiota axis, with which other disease conditions can be compared. Besides, our findings have practical implications that detection of a large amount of shared bacterial or fungal members between the oral cavity and gut within the same individual as an indicator of potential medical conditions.
IMPORTANCE The oral–gut microbiota axis in health is a fundamentally important and clinically relevant topic; however, our current understanding of it remains biased and incomplete. By characterizing the bacterial and fungal microbiomes in paired oral rinse and stool samples from a large cohort of healthy Chinese adults, here we provided new evidence that oral–gut microbiota transmission is limited in non-Western population and across biological domains. Our study has established an important baseline of a healthy oral–gut microbiota axis, with which other disease conditions can be compared. Besides, our findings have practical implications that detection of a large amount of shared bacterial or fungal members between the oral cavity and gut within the same individual as an indicator of potential medical conditions.
| Original language | English |
|---|---|
| Article number | e0281422 |
| Pages (from-to) | 1-11 |
| Number of pages | 11 |
| Journal | Microbiology Spectrum |
| Volume | 11 |
| Issue number | 1 |
| Early online date | 10 Jan 2023 |
| DOIs | |
| Publication status | Published - 14 Feb 2023 |
Bibliographical note
Funding Information:This work was partially supported by the Research Grants Council of Hong Kong SAR, China (project number CUHK 14161017 to Z.C.), a seed fund for gut microbiota research from the Faculty of Medicine, The Chinese University of Hong Kong (to P.K.S.C.), a Research Matching Grant from University Grants Committee, Hong Kong SAR (project number 8601687 to P.K.S.C.), and a direct grant from The Chinese University of Hong Kong (grant number 2019.046 to C.K.C.L.).
Publisher Copyright:
Copyright © 2023 Cheung et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.