The composition of the gut microbiome may reveal distinct signatures associated with race, ethnicity, and age of onset in patients with colorectal cancer, according to a recent study published by Hein et al in the Journal of Immunotherapy and Precision Oncology. The findings provide insights into potential new preventive treatments involving the manipulation of the gut microbiome.
Background
In recent decades, early-onset colorectal cancer diagnoses have increased among patients younger than 50 years, raising concern in the cancer community. According to the American Cancer Society, patients younger than 55 years now comprise about 20% of all colorectal cancer cases. Hispanic populations have been found to have a higher risk of receiving a diagnosis of early-onset colorectal cancer; however, the genetic characteristics of their tumors may not differ from those developed at an older age, prompting researchers to explore other factors that may be contributing to this disparity.
Study Methods and Results
In the recent study, researchers examined the composition and abundance of the gut microbiome in 64 patients with colorectal cancer treated between October 2020 and August 2022—with the goal of understanding the potential links between microbiome signatures and diseases and treatment outcomes. The patients were categorized into groups based on race, ethnicity, and age of colorectal cancer onset. The researchers noted that about 50% of the participants were younger than 51 years, and 47% of them identified as Hispanic.
They then collected and sequenced stool samples from the patients to identify microorganisms and used multiple statistical methods to compare the microbiomes across demographics such as age and race. The researchers discovered that White Hispanic patients had a significant enrichment of bacteria in the family Prevotellaceae—which are known for both improved glucose metabolism and higher rates of inflammatory disease– and chemotherapy-induced toxicity. In Hispanic patients, Prevotellaceae bacteria may also be linked to obesity.
When comparing ages, the researchers found no common microorganisms among younger or older patients. Nonetheless, younger patients had less diverse gut microbiome compositions, which was generally associated with poorer health outcomes.
Conclusions
“Our study used serial statistical methods to look at the makeup of the gut microbiome in diverse groups of patients undergoing treatment for [colorectal] cancer, and the result suggests that the particular microbial taxa Prevotellaceae may be involved in the pathogenesis of the disease,” explained co–senior study author Nina Sanford, MD, Assistant Professor of Radiation Oncology, Chief of the Gastrointestinal Radiation Oncology Service, and a member of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern. The researchers hope to assess the effect of Prevotellaceae bacteria on cancer progression in further studies.
“If we identify a distinctive signature in human populations, it would be useful to investigate whether this specific microorganism directly causes the disease or changes the response to treatment,” indicated co–senior study author Andrew Koh, MD, Associate Professor of Pediatrics in the Division of Pediatric Hematology and Oncology and of Microbiology as well as a member of the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern.
The research highlighted that potential therapeutic strategies for preventing or treating early-onset colorectal cancer in the future could include microbiome manipulation such as dietary modifications, selective antibiotics, precision probiotics, and fecal microbiota transplant.
“Our study will spark the conversation about urging further exploration into the microbiome’s role in [colorectal] cancer and its broader implications for colorectal health,” concluded Dr. Sanford.
Disclosure: The research in this study was supported by grants from the National Institutes of Health, the UT Southwestern and Children’s Health Pediatric Cellular and ImmunoTherapeutics Program, the Harold C. Simmons Comprehensive Cancer Center Early Onset Colorectal Cancer Pilot Funding Program, and the National Cancer Institute Cancer Center Support Grant. For full disclosures of the study authors, visit meridian.allenpress.com.
