Abstract C078: The association between the oral microbiome and body mass index among Black women

Abstract Background. The prevalence of obesity (defined as ≥30 kg/m2) has increased by 40% over the past two decades. Black women have the highest prevalence of obesity of any US population group, with 57% of Black women classified as obese. The adverse health consequences of obesity include increased risk for type 2 diabetes, cardiovascular disease, cancer, and premature mortality. Evidence has mounted from animal and human studies that the gut microbiota, in particular bacteria, is associated with obesity. Few studies have examined the association between the oral microbiota and obesity. Methods. In the current study, we included Black Women’s Health Study participants who donated a saliva sample using an oral wash kit and whose oral microbiome was sequenced in prior nested case-control studies of pancreatic and lung cancer. Participants were cancer-free at the time of oral wash collection. A total of 624 participants with whole metagenome shotgun sequencing data were available for this research. Body mass index (BMI, kg/m2) was calculated and classified according to the World Health Organization: normal weight (18.5–24.9 kg/m2, n=132), overweight (25.0–29.9 kg/m2, n=228), and obesity (≥30.0 kg/m2, n=264). Raw sequencing reads were processed using PathoScope (v 2.0). Data were filtered based on total read counts for individual operational taxonomic units (OTUs) and average relative genus abundance. Thus, 3,629 OTUs representing 103 genera were retained. We corrected for batch effects using ComBat-Seq. We conducted differential abundance analyses, adjusting for age, smoking, alcohol, diabetes, and tooth loss. For detecting differentially abundant microbes, we used DESeq2, Limma, and ANCOM-BC, both separately and in combination, at the genus and species levels. Results. Fifty-two genera were differentially abundant by BMI category in at least one of our analyses. Of these, three genera—Corynebacterium, Haemophilus, and Solobacterium—were commonly differentially abundant across all analyses. Notably, Solobacterium was more abundant in individuals with obesity, compared to individuals with normal or overweight, whereas Corynebacterium and Haemophilus were less abundant in individuals with overweight but not normal weight or obesity. On the species level, 98 species were differentially abundant by BMI category in at least one of our analyses. Three species were differentially abundant across all analyses: Cardiobacterium valvarum, Neisseria bacilliformis, and S. moorei (the only known species of Solobacterium). Conclusions. Our findings demonstrate that multiple oral microbial taxa are significantly differentially abundant by BMI category in Black women, who have a higher prevalence of obesity than any other race-gender group and suffer greatly from the adverse health effects of obesity. In particular, women with obesity had a higher abundance of S. moorei. This bacterium was also recently identified as more abundant in the gut microbiome of Chinese men and women with obesity and the abundance decreased with a weight loss intervention. Citation Format: Jessica L. Petrick, Howard J. Fan, Lynn Rosenberg, Julie R. Palmer, W. Evan Johnson. The association between the oral microbiome and body mass index among Black women [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C078.