Oral microbiota signatures in obesity with or without acanthosis nigricans in a Chinese cohort.

The oral microbiota is the second most complex microbial community in the human body. It has been suggested that poor oral health may be associated with an increased risk of obesity. However, both previous observational and mechanistic studies on oral microbiota do not take into account the obesity-related acanthosis nigricans (AN), which is the most common dermatological manifestation in individuals with obesity. This study aimed to investigate the altered composition, function and diagnostic value of the oral microbiota in obesity with or without acanthosis nigricans (AN). We characterized the oral bacteria signature in a Chinese cohort (ChiCTR2300073353) of 99 patients with obesity and obesity-related AN (Ob_AN) and 50 healthy controls using 16S rRNA gene V3-V4 region sequencing. The microbial richness (abundance-based coverage estimators and observed species indices) was significantly greater in the Ob_AN and obesity groups than in the control group; however, microbial diversity (Shannon index) did not differ significantly. Distinct separation in the microbial community amongst the three groups was observed. species, including , and , were associated with composition alterations and predicted functions (significant downregulation of ATP-binding cassette transporters) associated with microbial dysbiosis in the obesity and Ob_AN groups. Moreover, and genera assessments could indicate obesity and obesity-related AN risk. The notable reduction of plenty of oral microbiota and high levels of spp. may play a critical role in obesity with AN. Oral microbiota may serve as biomarkers for diagnosing, preventing and even treating obesity-related AN.