Short-term changes in the oral microbiota of dogs after chewing different types of autoclaved bones

The presence of dental calculus is one of the main issues associated with periodontitis in dogs. Mechanical removal of plaque and dental calculus can be performed through periodic oral prophylaxis conducted by veterinary dentists, and by continuous chewing of various items. Recent studies have demonstrated the effectiveness of bones as dental calculus agent removal in adult dogs. However, their effect regarding removal of oral microbiota remains unknown. The aim of the present study was to evaluate the effect of autoclaved spongy bone (SB) or compact bone (CB) supplementation on the oral microbiota of adult dogs with pre-existing dental calculus. The V4 region of the 16S rDNA gene was used for Illumina MiSeq next-generation sequencing. Transition was observed on the phyla proportion of the SB group, where the saliva sample initially presented a predominance of Bacteroidetes (51.3%) and Proteobacteria (33.0%), and changed to Proteobacteria (52.4%) and Bacteroidetes (33.9%). The gingival sulcus changed from Bacteroidetes (66.7%) and Proteobacteria (17.5%) prior to SB supplementation to Proteobacteria (76.3%) and Bacteroidetes (18.5%). No changes were observed in the proportion of saliva and gingival sulcus phyla in group CB. Moraxella sp. and Bergeyella zoohelcum increased in both saliva and gingival sulcus after SB supplementation. Saliva and gingival sulcus in the CB group showed increases in Porphyromonas species after 13 days’ supplementation. This study showed that chewing SB had a profound impact on both saliva and gingival sulcus microbiota, while CB did not cause substantial changes in the microbiota in either environment.