Functional dysbiosis within dental plaque microbiota in cleft lip and palate patients

Kenta Funahashi,Keiko Muramoto,Yuichi Izumi,Ichiro Nakagawa,Yasuo Takeuchi,Takahiko Shiba,Takuya Ogawa,Takayasu Watanabe,Tsutomu Sekizaki,Keiji Moriyama

doi:10.1186/s40510-019-0265-1

Abstract

BackgroundDental caries is a polymicrobial disease and prevalent among cleft lip and palate (CLP) patients, although their oral hygiene is well maintained. Dysbiosis, the state of imbalance within the dental plaque microbiota, may cause caries prevalence among these patients. However, little is known about how dysbiosis occurs and affects cariogenicity. To find dysbiotic signs, here we conducted a metatranscriptomic analysis for the plaque microbiota in six CLP patients and four controls.MethodsTotal bacterial RNA was extracted from each sample and sequenced. Bacterial composition and functional profiles were estimated from 16S rRNA and mRNA reads, respectively. The mRNA reads were further used for estimating bacterial composition. Species listed in both rRNA-based and mRNA-based bacterial composition were identified as viable taxa with in situ function (VTiF), and the VTiF with a high mRNA-to-rRNA ratio were considered to be transcriptionally active. A network was constructed for each group by connecting two VTiF if their mRNA abundances were positively correlated.ResultsThe bacterial composition and functional profiles themselves did not provide remarkable signs of dysbiosis in the CLP group. However, the group-specific active taxa were identified, including streptococcal and Prevotella species in the CLP group. Moreover, the network structure was different between groups; Actinomyces johnsonii and several species in the CLP group were the active taxa, which were connected based on positive correlations with statistical significance.ConclusionsFunctional dysbiosis within the plaque microbiota was observed such as difference of the network structure between groups, and may be associated with cariogenicity. The observed functional dysbiosis was an invisible change within the microbiota in the oral cavity of CLP patients. This may emphasize the importance of maintaining good oral hygiene of the patients with cleft anomalies.

Highlights

Dental caries is a polymicrobial disease and prevalent among cleft lip and palate (CLP) patients, their oral hygiene is well maintained
We examined the presence of dysbiosis within dental plaque microbiota in the CLP group by profiling the bacterial composition, based on Reconstructed 16S rRNA (rc-rRNA)
Conclusions a variety of dietary, anatomical, and other non-bacterial factors among participants was not considered, we observed an aspect of functional dysbiosis within the plaque microbiota as the varied mRNA-torRNA ratio in CLP patients by conducting metatranscriptomic analysis

Summary

Introduction

Dental caries is a polymicrobial disease and prevalent among cleft lip and palate (CLP) patients, their oral hygiene is well maintained. In CLP patients, lack of separation between the oral and nasal cavities by the soft and hard palates is apparent at birth This anomaly causes esthetic problems and functional disorders such as difficulty in sucking, eating, breathing, and pronouncing words. Funahashi et al Progress in Orthodontics (2019) 20:11 cleaning, little is known why caries and gingivitis are prevalent among these patients Among several factors such as dietary habits, anatomical structure in the oral cavity, and material properties of tooth, bacteria have been studied as an important factor for caries etiology. Denaturing gradient gel electrophoresis, based on differences in fragment length, indicated that bacterial diversity was significantly lower in CLP patients than in controls [13] This method only showed differences in a fragment pattern, resulting in insufficient resolution for capturing whole bacterial species in the microbiota

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