DIVERSITY OF MUCOSAL ASSOCIATED GUT MICROBIOTA IN COLORECTAL AND NON-COLORECTAL CANCER TISSUES FROM PATIENTS IN NAIROBI, KENYA

Background: There is growing evidence that gut microbiota could significantly influence the development of colorectal cancer (CRC) a malignancy that currently ranks among the top causes of cancer-related illness and death globally. This study was purposed to examine the microbial diversity found in both malignant and non-malignant colon tissues. Objective: To determine the diversity of the colon bacterial flora in malignant and non-malignant tissues from the colon / rectum of patients attending the Aga Khan Cancer Clinic in Nairobi, Kenya. Design: A retrospective case-control study Setting: Aga Khan University Hospital and Jomo Kenyatta University of Agriculture & Technology Materials and methods: A total of sixty tissue blocks comprising those with cancer (thirty) and those without (thirty) were examined. The main outcome measures were; age, sex, colorectal malignancy, Colorectal non-malignancy, Cancer stage, Cancer grade, and subtype and type of microbiota. In addition history of changes in bowel habits, rectal bleeding, and abdominal pain were documented. Results: The males were 18 (60%), while the females were 12 (40%) of the total (30). Oscillospiraceae bacterium, Clostridales bacterium, Acetivibro sp, Eubacterium, Texcoconibacilllus texcoconensis and Staphylococcus sp were found in malignant (CRC) tissues. Invasive adenocarcinoma was the most dominant subtype, followed by mucinous adenocarcinoma. Distribution by stage; stage I had three, stage II sixteen and stage III were eleven tissues. Conclusion: This study shows that colorectal cancer patients have different patterns of mucosal-associated gut microbiota. These varied with sex and age. Further studies should be done to support the potential use of microbial markers for risk assessment and early CRC detection.