Analysis of Oral and Gut Microbiota Composition in Children with Dental Caries by NGS Approaches.

Microbiota composition differences between caries-active and caries-free children were evident at the family and species levels but not at the phylum level.

• Ten children with active caries and nine caries-free children were recruited.
• Four samples from different oral niches and stools were collected from each patient.
• NGS sequencing of 16S microbiota rDNA was performed using S5 Ion Torrent.
• No significant differences were found at the phylum composition level between the two groups.

Streptococcaceae were positively correlated with high degree of caries across all oral niches examined.

• Streptococcaceae correlation with caries was observed in teeth, saliva, and vestibular regions of the oral cavity.
• This finding was consistent across all sampled niches.
• The analysis was conducted using 16S rDNA NGS sequencing.

A total of 39 bacterial species were significantly modulated between caries-active and caries-free groups.

• Species-level analysis identified 39 bacterial species significantly different between the analyzed groups.
• Samples were taken from teeth, saliva, vestibular regions, and fecal material.
• Identification was achieved through NGS sequencing of 16S microbiota rDNA.

Administration of Streptococcus salivarius M18 DSM 14685 (Carioblis) exerted beneficial effects on oral microbiota dysbiosis but not on fecal microbiota dysbiosis.

• The probiotic used was Streptococcus salivarius M18 DSM 14685, commercially known as Carioblis.
• Probiotic administration determined a shift in oral microbiota composition towards a healthier state.
• No corresponding beneficial effect was observed in the faecal microbiota of treated children.
• The study evaluated the effect of probiotic administration on microbiota composition in caries-active children.

Dental caries were associated with increased abundance of Bifidobacterium adolescentis and Ruminococcus torques in the gut microbiota.

• This association between dental caries and these two gut bacterial species was reported as a first-time finding by the authors.
• Both Bifidobacterium adolescentis and Ruminococcus torques are described as related to other disorders.
• Fecal samples were collected alongside oral samples from each participant.
• The intestinal tract was confirmed to have a different microbiota composition compared to the oral cavity.

Modifications in microbiota composition associated with dental caries were observed in teeth, saliva, vestibular regions, and fecal samples.

• Samples were collected from four distinct niches: teeth, saliva, vestibular region of the oral cavity, and stools.
• Changes were identified in all sampled locations in the presence of dental caries.
• Dental caries were primarily associated with modifications in oral rather than gut microbiota composition.