Researchers have uncovered links between microbes in the mouth and metabolic conditions like obesity, pre-diabetes, and fatty liver disease. The study analyzed oral swabs from over 9,000 participants using advanced sequencing techniques. Experts suggest these findings could lead to simple swab-based screenings.
A large-scale study by Imran Razzak at Mohamed bin Zayed University of Artificial Intelligence in Abu Dhabi examined oral swabs from 9,431 participants in the Human Phenotype Project. The team used whole metagenomic sequencing to map microbial DNA and linked specific bacteria and their pathways to 44 metabolic traits, including liver fat, blood sugar levels, and visceral fat. These traits relate to high blood pressure, pre-diabetes, obesity, and fatty liver disease, according to the findings published on bioRxiv with DOI: 10.1101/2025.10.28.685004. The preprint appeared before today's date of 2026-05-01, presenting the research as current discoveries. Lindsey Edwards at King’s College London, who was not involved, described it as “one of the most ambitious attempts yet to map how the oral microbiome reflects metabolic health across multiple organ systems.” Bacteria such as Streptococcus parasanguinis and Oribacterium sinus showed higher abundance in people with elevated body mass index and body fat, echoing prior work by Aashish Jha at New York University Abu Dhabi. Microbial functions like polyamine biosynthesis correlated with poorer liver measures and glucose control, while ceramide breakdown pathways tied to worsening blood sugar. Razzak noted, “they are credible leads for future mechanistic work,” hypothesizing that the oral microbiome may actively contribute to metabolic disease rather than just indicating it. Jha proposed mechanisms including bacterial products entering the bloodstream via inflamed gums, seeding the gut, or influencing blood sugar and vascular health. Associations held after adjusting for factors like gum disease, age, sex, smoking, and diet. Edwards called the potential for buccal swabs to detect risks “compelling,” amid rising metabolic disorders, though Razzak and others stressed the need for further validation in diverse populations and clinical settings.
