Gut microbiome signatures may help unravel disparities in early-onset colorectal cancer

May 2024 

A recent study published in the Journal of Immunotherapy and Precision Oncology suggests that the makeup of the gut microbiome may reveal distinct characteristics or signatures associated with race, ethnicity, and age of onset in patients diagnosed with colorectal cancer (CRC).  

The gut microbiome refers to the trillions of microorganisms, including bacteria, fungi, parasites, and protozoa, that colonize our gastrointestinal system. The gut microbiome influences our health in many ways, playing a key role in our immune health and protecting us against pathogens (microorganisms that can cause disease). The microbiome, however, can become imbalanced for a variety of reasons such as diet and lifestyle factors, resulting in increased chances of developing certain illnesses.  

In the last few decades, the incidence of early-onset CRC diagnoses (those that occur in people below the age of 50), has increased. The gut microbiome has been an important topic of research to understand what factors may be contributing to the rising rates of CRC in younger people. 

The study 

In the study, the gut microbiomes of 64 patients with CRC were analyzed. The patients were categorized based on their race, ethnicity, and age of diagnosis. About half of the patients were below the age of 51, and 47% were Hispanic. Stool samples were collected from the patients to identify which microorganisms were present in their microbiome, and statistical methods were used to compare data between the patients and compare based on age and race.  

The researchers did not identify microbiota signatures that were common to younger CRC patients compared to older CRC patients. They did find, however, that younger patients had less diversity of microorganisms in their gut microbiomes, which was generally linked to poorer health outcomes.  

White Hispanic patients were found to have significantly higher concentrations of bacteria in the family Prevotellaceae. This family of bacteria is associated with increased rates of glucose metabolism (the process of breaking down carbohydrates into glucose, the energy molecule used to fuel our cells), higher rates of inflammatory disease, and chemotherapy-induced toxicity. Furthermore, bacteria in the Prevotellaceae family may also be connected to obesity.  

Conclusions 

By examining and comparing the composition of the gut microbiome in different groups of patients receiving treatment for CRC, findings suggest that bacteria in the Prevotellaceae family may be involved in the development of the disease. The researchers aim to continue investigating the effects of Prevotellaceae bacteria on early age onset cancer progression and understand whether this family of microorganisms has any direct impact on the disease or its response to treatment. A better understanding of the impact of the microbiome on early age onset CRC could translate to potential therapeutic strategies such as modifying the microbiome through dietary changes, selective antibiotics, precision probiotics, and fecal microbiota transplant (a procedure that transplants healthy gut microorganisms through donor stool to a patient).