Oral microbiota characteristics in Intra-oral halitosis patients and innovative therapeutic approaches

AbstractBackground: Intra-oral halitosis (IOH), defined as halitosis produced locally by the oral cavity except for systemic diseases, is one of the main causes of interpersonal interactions and psychological disorders in modern society. We compared the characteristics of different ecological sites of oral microbial in patients with IOH to propose a microbiota transplantation treatment based on the goal of restoring oral microecological balance.ObjectiveTo collect saliva, tongue, buccal mucosa, and jaw mucosa microbial samples from patients with IOH and healthy subjects to study the differences in microbial community composition in different ecological sites of their oral cavity, to explore the relationship between IOH and oral microbial, and to explore novel microbiological treatment approaches.MethodsThree healthy subjects (DZ group) and seven patients with IOH who visited the First Affiliated Hospital of Xinjiang Medical University with halitosis as their main complaint (KC group) were chosen at random among patients who visited the hospital between June 2017 and June 2022. Saliva, tongue, buccal mucosa, and jaw mucosa microbial samples were collected from both groups, and breath measurements and tongue scores were recorded independently in each. The microbiota in different ecological sites of the oral cavity was analyzed using the 16SrRNA method for taxonomic comparison, diversity analysis, and inter-group species difference analysis.ResultsThere were no statistically significant differences in the microbiota diversity of saliva (Z=-1.709, P=0.087), tongue (Z=-0.342, P=0.732), and buccal mucosa (Z=-1.481, P=0.138), or jaw mucosa (Z=-0.342, P=0.732). Adonis analysis showed statistically significant differences only between salivary microbiota groups (R2=0.175, P=0.011), but not between tongue (R2=0.125, P=0.25), and buccal mucosa (R2=0.144, P=0.128), or jaw mucosa (R2=0.132, P=0.178). The structure of salivary microbiota was altered in the 2 groups of study subjects, and among the top 10 species in terms of abundance, the differences were statistically significant at the phylum level for the Spirochaetes (Z=-2.165, P=0.03), at the family level for the Pasteurellaceae (Z=-2.393, P=0.017), and the genus level for the Haemophilus and Actinobacillus (Z= -2.393, P=0.017). LEfSe analysis showed that the saliva of the KC group showed a higher abundance of Microbacterium, Megasphaera, Proteobacteria, Campylobacter, and Spirochaetales.ConclusionsAlteration of oral microbiota structure is the root cause of Intra-oral halitosis, and salivary microbiota transplantation may be a new strategy to restore oral microbiota structure and treat Intra-oral halitosis.