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The gut plays a crucial role in determining our overall health and how we respond to medical treatments. It is home to a vast array of microorganisms, collectively known as the gut microbiota, which number in the trillions. Research has established the crucial role that these microorganisms play in maintaining gut health, and their impact on conditions, such as cancer, is now widely recognized. But how can we use the gut microbiota to predict and prevent colorectal cancer?

Dr. Doratha A. Byrd, an assistant member in Moffitt Cancer Center’s Cancer Epidemiology Program, focuses her research on the interrelationships among modifiable dietary and lifestyle exposures, the microbiome, and cancer risk and progression. She’s focused on using multilevel approaches to address cancer disparities within microbiome research.

In a presentation  at the American Association for Cancer Research Annual Meeting, Byrd shared a study aimed at creating a collection of fecal samples from diverse populations to better understand the link between the microbiome and cancer, particularly colorectal cancer.

We will investigate potentially unique associations of the gut microbiome with cancer among this diverse population.
Dr. Doratha A. Byrd, Cancer Epidemiology Program

Colorectal cancer is the second leading cause of cancer death in the United States. There are disparities in colorectal cancer rates among different groups, such as African Americans and those living in rural areas. Lifestyle, socioeconomic factors and environmental exposures likely play a role in these disparities as they can affect the composition of the gut microbiome and how it interacts with cancer.

“The trillions of microbes in the gut have consistently been associated with the development and progression of cancer,” Byrd said. “Few gut microbiome studies in the literature have been conducted among populations that are historically underrepresented in science and that are disproportionately impacted by cancer, such as African Americans and certain subgroups of Hispanic/Latino individuals.”

To improve knowledge in the field, microbiome studies should involve diverse populations and collect data on modifiable exposures that drive colorectal cancer disparities.

To better understand these disparities and the role of the microbiome in cancer, Byrd is collecting fecal samples from diverse patient populations using fecal immunochemical tests (FIT), including from those who may not have access to colonoscopy screenings.

“We will establish a prospective gut microbiome biobank cohort embedded within community clinics in the Tampa Bay area,” Byrd said. “We will investigate potentially unique associations of the gut microbiome with cancer among this diverse population.”

The goal is to collect fecal samples from a wide range of patients to create microbiome cohorts. These cohorts will be used to study different health conditions, including colorectal cancer, and understand how gut bacteria are involved. The findings suggest that FIT is a practical and cost-effective way to collect these samples and could be a valuable tool for research on cancer disparities.

To form these cohorts, Byrd collects and stores residual samples from FITs at community clinics conducting colorectal cancer screening in the Tampa Bay area. Participants complete a FIT, and the remaining sample is stored at Moffitt. Baseline data is collected and will be linked to medical records and cancer registry data for follow-up. The pilot study began in one Federally Qualified Health Center, and to date, 72 participants have been recruited.

Byrd’s study demonstrated the cost-effective and practical utility of using residual FIT samples to explore the relationship between gut bacteria and disease in diverse populations. The biobank will serve as a valuable resource for research on the microbiome’s impact on disease. Byrd intends to conduct additional pilot studies using FIT samples and to collaborate with other research institutions to gain further insights. Ultimately, her goal is to rigorously investigate whether potentially actionable gut microbiome exposures are associated with colorectal cancer disparities.