Exploration of Human Salivary Microbiomes—Insights into the Novel Characteristics of Microbial Community Structure in Caries and Caries-Free Subjects

Abstract

Recently, high-throughput sequencing has improved the understanding of the microbiological etiology of caries, but the characteristics of the microbial community structure in the human oral cavity with and without caries are not completely clear. To better understand these characteristics, Illumina MiSeq high-throughput sequencing was utilized to analyze 20 salivary samples (10 caries-free and 10 caries) from subjects from the same town in Dongxiang, Gansu, China. A total of 5,113 OTUs (Operational Taxonomic Units, 97% cutoff) were characterized in all of the salivary samples obtained from the 20 subjects. A comparison of the two groups revealed that (i) the predominant phyla were constant between the two groups; (ii) the relative abundance of the genera Veillonella, Bifidobacterium, Selenomonas, Olsenella, Parascardovia, Scardovia, Chryseobacterium, Terrimonas, Burkholderia and Sporobacter was significantly higher in the group with caries (P < 0.05); and (iii) four genera with low relative abundance (< 0.01% on average), including two characteristic genera in caries (Chryseobacterium and Scardovia), significantly influenced the microbial community structure at the genus and OTU levels. Moreover, via co-occurrence and principal component analyses, the co-prevalence of the pathogenic genera was detected in the caries samples, but in the caries-free samples, the function of clustered genera was more random. This result suggests that a synergistic effect may be influencing the assembly of the caries microbial community, whereas competition may play a more dominant role in governing the microbial community in the caries-free group. Our findings regarding the characteristics of the microbial communities of the groups with and without caries might improve the understanding of the microbiological etiology of caries and might improve the prevention and cure of caries in the future.

Salivary Microbiome Diversity in Caries-Free and Caries-Affected Children

“…Furthermore, we found that the genus Scardovia , which was newly recognized as cariogenic bacteria involved in the later stage of severe early childhood caries [29], was significantly more frequently detected in the caries-affected group than in the caries-free group, with a low relative abundance in the total sequences. This finding is consistent with that of a previous study [30]. …”

The dynamics of the oral microbiome and oral health among patients receiving clear aligner orthodontic treatment

“…In comparison with caries‐active individuals, caries‐free and/or periodontally healthy individuals exhibit a greater diversity of bacterial populations (Li, Ku, Xu, Saxena, & Caufield, ). In this study, the average number of detected OTUs per patient was 8,885, which is in agreement with previous reports about adult saliva microbiotas (Zhou et al, ). As shown in Figures , the alpha diversity, which reflects internal biodiversity, and the beta diversity, which represents the variation in microbial community structure, all showed no significant difference between Group B and Group P. Hence, the general biodiversity and microbial community structure did not change significantly six months after the Invisalign procedure.…”

“…High‐throughput technologies based on 16S rRNA gene sequencing have been widely used in bacterial phylogeny and taxonomy studies due to the highly conserved, omnipresent, and large‐volume (1,500 bp) characteristics of the 16 rRNA gene (Janda & Abbott ). Illumina MiSeq high‐throughput sequencing is one of the cutting‐the‐edge techniques for microbial community analysis, considering its advantages in accuracy, coverage, sequencing depth, and low cost, and it has been increasingly used in the investigation of the oral microbiome in different diseases (Wang et al, ; Zhou et al, ).…”

Altered gut microbiota and microbial biomarkers associated with chronic kidney disease

“…Dielma fastidiosa was reported in the human gut (Ramasamy, Lagier, Nguyen, Raoult, & Fournier, ). The relative abundance of Scardovia was significantly higher in the salivary samples in the group with caries (Zhou et al., ). Scardovia wiggsiae was associated with the elevated sugar intake (Keller, Kressirer, Belstrøm, Twetman, & Tanner, ).…”