The Gut and Colorectal Cancer Awareness

With March being Colorectal Cancer Awareness month, discussions are increasing due to growing significance and the rising incidence of early-onset cases.

Maintaining a healthy gut microbiome through balanced nutrition and lifestyle choices may play a key role in prevention.

Personalized understanding and approaches are crucial for effective prevention, as colorectal cancer affects diverse populations across various ages and demographics.

Colorectal cancer (CRC) remains a major health concern in the U.S., with an estimated 154,270 new cases expected in 2025—107,320 cases of colon cancer and 46,950 cases of rectal cancer (American Cancer Society, 2025). Colorectal cancer (CRC) risk doesn’t affect everyone equally— rates depend on age, race, and where people live, showing that a complex mix of genetics, lifestyle and social factors is at play. 

CRC used to be an illness of old age, but that has changed. Early-onset CRC (EO-CRC), is now the most common cancer in people under age 50 and the most common cause of cancer death in males under 50 (Katella, 2024) and this death rate is increasing by 1% annually (American Cancer Society, 2025). Concurrently, incidence of CRC in older adults is declining due to increased screening.

CRC incidence and mortality rates vary significantly by race and ethnicity, with Black Americans experiencing the highest rates (41.9 cases and 16.8 deaths per 100,000), followed by Native Americans (39.3 cases and 14.0 deaths per 100,000) (Carethers, 2021). Jewish people of Eastern European descent (Ashkenazi Jews) have one of the highest colorectal cancer risks of any ethnic group in the world (American Cancer Society, 2025), while White Americans have lower rates at 37.0 cases and 12.9 deaths per 100,000 (Carethers, 2021). Biologically, males have higher CRC incidence and mortality than females across all groups. Ethnicity is found to explain gut microbiota differences better than factors like age, BMI, and sex, with 12 specific taxa varying across populations.

The gut microbiome is a known contributor in the pathogenesis of colorectal cancer (CRC). A recent study concluded it was possible to link an astounding 23-40% of gut bacteria to colorectal cancer and health, and even expand the scope of microbes that are linked to the cancer that were previously unknown. Some familiar bacterial names occur, as we see that CRC-associated gene-clusters are enriched in Bacteroidetes,Proteobacteria, and our key player Fusobacterium (Minot et al., 2024). Fusobacterium nucleatumis an established microbe in CRC (Kostic et al .,2013), and individuals positive for this microbe along with two other contributors – pks + Escherichia coli and ETBF – are of higher likelihood to have a worse prognosis than those who do not house these organisms (Miyasaka et al., 2024). Taxa such as Christensenellaceae, are heritable and linked to human genetics, influence metabolic processes such as butyrate production, which has protective effects against inflammatory bowel diseases and colorectal cancer (Brooks et al., 2018).

It's no secret that our diet affects our microbiome – and our microbiome affects nearly all of our body functions. This interaction between our diet and our microbiome has garnered great interest in disease reversal and prevention. Certain dietary patterns, such as those including high red meat (Bouvard V et al., 2015) or alcohol consumption (Gurjao et al., 2021), something we discussed in one of the previous blogs, are associated with an increased risk for cancer. Many providers emphasize a high-fiber diet due to its direct ability, along with complex carbohydrates, to feed the microbiome. A high-fiber diet has been reported in lowering the risk of developing colorectal cancers in individuals with F. nucleatum present (Mehta et al., 2017). A large emphasis in the research community is primarily how personalized nutrition strategies can improve health and furthermore, prevent cancer (Kolodziejczyk et al., 2019). 

A high-fiber diet can help regulate gut microbiota, potentially reducing colorectal cancer risk and improving treatment response when used alongside conventional therapy.

Not including skin cancers, colorectal cancer is the most common cancer diagnosed in both men and women in the U.S. Because many lifestyle-related risk factors have been associated with colorectal cancer, which means they can be altered to decrease risk. Risk factors include metabolic disorders such as Obesity and Type 2 Diabetes, and other habits such as smoking and excessive alcohol use (American Cancer Society, 2025).

A history of cholecystectomy (gallbladder removal), colon polyps, inflammatory bowel disease or abdominal radiation increase colorectal cancer risk. Family history, especially early-onset cases, also raises risk. Inherited syndromes like Lynch syndrome, familial adenomatous polyposis, and rarer genetic conditions further elevate the likelihood, often requiring earlier screening (American Cancer Society, 2025). Understanding colorectal cancer statistics is crucial for assessing personal risk and making conscious health decisions.

• Colorectal cancer is both common and develops without warning signs. It is preventable though making awareness and early detection crucial. Major health organizations, including the U.S. Preventive Services Task Force, have lowered the recommended screening age from 50 to 45 (U.S. Preventive Services Task Force, 2021). There are multiple ways to get screened, from stool tests like Cologuard to colonoscopy.
  
  
• Early screening improves outcomes, especially for those with risk factors. A diet rich in fiber as well as vitamins A, E, B6, and D3, along with omega-3s, may help regulate gut bacteria and lower cancer risk (Ajebli et al., 2024).
  
  
• Genetic testing may be necessary for those with inherited syndromes, and personalized nutrition (Kolodziejczyk et al., 2019) and lifestyle plans can support overall prevention and well-being.
  
  
• Advances in microbiome research may help predict colorectal cancer risk up to a decade in advance through understanding of microbiome signatures, allowing for earlier detection and prevention.