Tooth loss may disrupt the oral-gut microbiota balance by shifting bacterial proportions, potentially impacting intestinal and overall health. This animal study was published earlier this month in BMC Oral Health.
Tooth loss led to reduced oral microbiota diversity, increasing Proteobacteria,a possible microbial signature of disease, and decreasing Muribacter. Meanwhile, there were more Firmicutes, which are referred to as bad gut microbes, and fewer of the good bacteria, Bacteroidota, the authors wrote.
"Tooth loss led to an increase in the proportion of certain bacterial phyla while decreasing others, potentially disrupting the balance of the gut microbiota," wrote the authors, led by Ling Dong of the Capital Medical University in Beijing.
For this study, mice were divided into a control group with intact teeth and an experimental group with extracted maxillary first molars. Researchers collected maxillary alveolar bone, intestinal tissues, and three salivary and fecal samples from each group, they wrote.
Oral microbiota in saliva was analyzed using 16S rRNA sequencing, while gut microbiota in feces was examined through metagenomic sequencing. Pearson correlation analysis was used to evaluate the relationship between changes in microbial communities.
In vivo experiments showed that tooth loss disrupted the balance of neighboring teeth, leading to an enlarged periodontal ligament and increased inflammatory factors in the periodontal microenvironment. Tooth loss significantly impacted intestinal health, causing mucosal structural changes, inflammatory cell infiltration in the lamina propria, and increased expression of inflammatory factors in intestinal tissue, they wrote.
Additionally, statistical analysis revealed a notable decrease in oral microbiota diversity after tooth loss, with increased Proteobacteria and reduced Muribacter. In the gut, there was an increase in Firmicutes and a decrease in Bacteroidota. Gut microbiota imbalance may significantly impact digestive health, potentially leading to gastrointestinal diseases and impairing nutrient absorption and metabolism.
Nevertheless, the study had limitations. The mouse model in this study may not fully reflect human health, as dietary patterns in mice can differ from those in humans, especially after tooth loss, the authors added.
"Although it does not fully replicate the complexity of human health and disease, it serves as a foundational step in exploring the relationship between tooth loss and microbiome alterations, paving the way for future studies in human populations," they concluded.
