Oral microbiome and obesity in a large study of low-income and African-American populations.

Few studies have evaluated the relationship of oral microbiome with obesity. We investigated the oral microbiome among 647 obese and 969 non-obese individuals from the Southern Community Cohort Study, through gene sequencing in mouth rinse samples. We first investigated 16 taxa in two probiotic genera, and . Among them, eight showed nominal associations with obesity ( < 0.05). Especially, (odds ratio [OR] = 0.67, 95% confidence interval [CI]:0.54, 0.83) and (OR = 0.57, 95% CI: 0.45, 0.73) were significantly associated with decreased obesity prevalence with false-discovery rate (FDR)-corrected of 0.01 and 5.41 × 10, respectively. Multiple other bacterial taxa were also significantly associated with obesity prevalence at FDR-corrected < 0.05. Among them, five in and two respectively in and were significantly associated with increased obesity prevalence. Significant associations with decreased obesity prevalence were observed for two taxa respectively in and . Most of these taxa were associated with body mass index at study enrollment and weight gain during adulthood. Also, most of these associations were observed in both European- and African-Americans. Our findings indicate that multiple oral bacterial taxa, including several probiotic taxa, were significantly associated with obesity.