Gut microbiome offers clues to disparities in rectal cancer

March 28, 2024
UT Southwestern study identifies clustering of specific gut bacteria associated with race, ethnicity in patients.

The composition of the gut microbiomes in a group of rectal cancer patients reveals distinct signatures by race, ethnicity, and age of onset, with white Hispanics showing significant presence of one specific type of bacteria, UT Southwestern Medical Center researchers report.

Published in the Journal of Immunotherapy and Precision Oncology, the study provides insights that could benefit future prevention efforts or therapies for rectal and colorectal cancer that involve manipulating the microbiome.

In this study, UTSW researchers examined the composition and abundance of the gut microbiome in groups categorized by race, ethnicity, and age of onset to understand the potential links between microbiome signatures and diseases and treatment outcomes.

Among 64 rectal cancer patients being treated at Parkland Health and UTSW between October 2020 and August 2022, half were younger than 51, and 30 patients were Hispanic. Stool samples collected from patients were sequenced to identify microorganisms. The researchers then compared the identified microbiome across demographics such as age and race. They used multiple statistical methods to improve comparison reliability rather than the widely used single statistical method.

UTSW researchers found that white Hispanic populations had a significant enrichment of Prevotellaceae, a bacterial family known for both improved glucose metabolism as well as higher rates of inflammatory disease and chemotherapy-induced toxicity. Among Hispanics, Prevotellaceae has also been linked with higher obesity, a potential risk factor for colorectal cancers.

When comparing ages, the researchers found no common microorganisms among younger or older patients. However, younger patients had less diversity in gut microbiome compositions, which was generally linked with poorer health outcomes, the study showed.

The next step may involve experiments to assess the effect of Prevotellaceae on cancer progression.

Potential therapeutic strategies for preventing or treating EOCRC in the future could include microbiome manipulation, such as dietary modifications, selective antibiotics, precision probiotics, and fecal microbiota transplant, according to the authors.

UTSW release on Newswise