Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China.
Centre for Gut Microbiota Research, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China.
Microbiol Spectr. 2023 Feb 14;11(1):e0281422. doi: 10.1128/spectrum.02814-22. Epub 2023 Jan 10.
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. 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.
最近的研究为胃肠道疾病中存在口腔-肠道微生物轴提供了证据；然而，在健康个体中是否存在类似的轴仍存在争议。在这里，我们通过分别对 470 名健康中国成年人的口腔冲洗液和粪便样本进行 16S rRNA V3-V4 和 ITS1 区域的测序，描述了细菌和真菌微生物组。我们假设，在健康的中国成年人中，细菌和真菌微生物组的口腔-肠道传播是有限的。我们的研究结果表明，健康个体的口腔和肠道微生物组在分类组成、α 和β多样性、代谢潜力和网络特性上存在差异。贝叶斯分析表明，绝大多数个体的细菌和真菌口腔-粪便贡献可以忽略不计或很低。对常见扩增子序列变异体（ASV）的详细检查还表明，除了少数细菌和真菌 ASV 外，同一个体的口腔和粪便样本之间的共享情况有限。关联分析表明，具有潜在传播能力的真菌 ASV 的共享与宿主因素有关，包括年龄较大和体重指数较高。我们的研究结果表明，健康成年人的细菌和真菌微生物组的口腔-肠道传播是有限的。个体口腔和肠道微生物组之间大量共享的细菌或真菌成员的检测可能表明存在需要详细检查的医疗条件。健康的口腔-肠道微生物轴是一个具有重要意义和临床相关性的话题；然而，我们目前对它的理解仍然存在偏见和不完整。通过对来自大量健康中国成年人的配对口腔冲洗液和粪便样本中的细菌和真菌微生物组进行特征描述，我们提供了新的证据，表明非西方人群和跨生物领域的口腔-肠道微生物组传输是有限的。我们的研究建立了健康的口腔-肠道微生物轴的重要基线，可将其与其他疾病状况进行比较。此外，我们的研究结果具有实际意义，即个体口腔和肠道内大量共享的细菌或真菌成员的检测可以作为潜在医疗条件的指标。
