Abstract A59: Racial comparisons of the gut microbiota of generally healthy black and white women for insights into colorectal cancer disparities

Abstract

Abstract Racial health disparities persist among black and white women for colorectal cancer (CRC). Since the gut microbiota has been linked to CRC, understanding racial differences in the gut microbiota may yield new insight into unexplained disparities in CRC incidence. Generally healthy non-Hispanic black or white females who were at least 19 years old provided survey data, anthropometrics, and stool samples. Fecal DNA was collected and isolated from a wipe. PCR was used to amplify the V4 region of the 16SrRNA gene and 250 bases were sequenced using the MiSeq platform. Microbiome data were analyzed using the QIIME package. OTU data were log transformed and normalized. Linear models in R Package “limma” were used to test statistical significance differences. Fecal samples were analyzed for 80 females (47 black, 33 white). Mean age and BMI were 39.9 years and 30.1 kg/m2, respectively. Blacks had a higher average BMI than whites (33.3 vs. 27.5 kg/m2; p<0.01) and larger waist circumference (98.3 vs. 86.6 cm; p<0.01). Unadjusted comparisons revealed no racial differences in alpha diversity. Racial differences were observed in beta diversity and abundance of top-10 OTUs. Blacks had higher abundances than whites of Faecalibacterium (p=0.03) and Bacteroides (p=0.04). The association between race and Bacteroides (logFC=1.72; 0=0.02) persisted in fully adjusted models. Black race was associated with a higher abundance of Bacteroides, which has been linked to CRC. Other racial differences in the gut microbiota were also observed. Efforts to cultivate an “ideal” gut microbiota may help reduce CRC risk and health disparities. Citation Format: Tiffany L. Carson, Fuchenchu Wang, Xiangqin Cui, Bradford E. Jackson, Liam Van Der Pol, Elliot J. Lefkowitz, Casey Morrow, Monica Baskin. Racial comparisons of the gut microbiota of generally healthy black and white women for insights into colorectal cancer disparities [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A59.