Abstract
Given the advent of massively parallel DNA sequencing, human microbiome is analyzed comprehensively by metagenomic approaches. However, the inter- and intra-individual variability and stability of the human microbiome remain poorly characterized, particularly at the intra-day level. This issue is of crucial importance for studies examining the effects of microbiome on human health. Here, we focused on bacteriome of oral plaques, for which repeated, time-controlled sampling is feasible. Eighty-one supragingival plaque subjects were collected from healthy individuals, examining multiple sites within the mouth at three time points (forenoon, evening, and night) over the course of 3 days. Bacterial composition was estimated by 16S rRNA sequencing and species-level profiling, resulting in identification of a total of 162 known bacterial species. We found that species compositions and their relative abundances were similar within individuals, and not between sampling time or tooth type. This suggests that species-level oral bacterial composition differs significantly between individuals, although the number of subjects is limited and the intra-individual variation also occurs. The majority of detected bacterial species (98.2%; 159/162), however, did not fluctuate over the course of the day, implying a largely stable oral microbiome on an intra-day time scale. In fact, the stability of this data set enabled us to estimate potential interactions between rare bacteria, with 40 co-occurrences supported by the existing literature. In summary, the present study provides a valuable basis for studies of the human microbiome, with significant implications in terms of biological and clinical outcomes.
Highlights
The microbiome is one of the important factors in human health, playing a role in numerous diseases including cardiovascular disease, inflammatory rheumatism, type II diabetes, colorectal carcinoma, psoriasis, colitis, and inflammatory bowel disease [1,2,3,4,5]
Using the Illumina MiSeq platform, we obtained a total of 3,886,475 paired-end sequences of partial 16S rRNA V4 region from 81 oral plaque samples
Samples were comprised of supragingival plaques from three types of lower teeth of three individuals collected at three consecutive time points on three non-consecutive days
Summary
The microbiome is one of the important factors in human health, playing a role in numerous diseases including cardiovascular disease, inflammatory rheumatism, type II diabetes, colorectal carcinoma, psoriasis, colitis, and inflammatory bowel disease [1,2,3,4,5]. PCR amplification and the sequencing of 16S rRNA fragments present in human samples (e.g., oral plaque, saliva, and feces) enable comparative analyses of bacterial compositions between patients and controls. Such a situation allows for a comprehensive assessment of microbial species associated with various human diseases, including rare and unculturable species. It is important to determine whether the human microbiome exhibits such periodic fluctuations over the course of a day, to other omics dynamics, as recently reported for the gut microbiome [17]–[18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
