Gut health plays an important role in both the development and progression of colon cancer. Diet and a balanced microbiome are important factors in reducing the risk of colon cancer.

The health of the gut and the balance of the microbiome inside the gut play an important role in colon cancer.

Changes in the gut microbiome can contribute to both the development and progression of colorectal cancer. In fact, there is a link between certain strains of bacteria and colon cancer.

Read on to learn about the link between gut health and colon cancer, the effects of diet and alcohol, the gut’s microbiome, and how the microbiome may help as a screening tool for colorectal cancer.

The gut is one of the most complex networks in the human body, and a growing amount of research suggests a link between gut health and colon cancer.

Experts believe changes to the gut microbiome contribute to both the development and progression of colorectal cancer. If the gut microbiome is out of balance — known as dysbiosis — there is a greater risk of developing colorectal cancer.

The gut is host to a large number of microorganisms, including bacteria. Studies have found that certain kinds of bacteria are more prevalent in people with colorectal cancer. Bacteroides fragilis, Enterococcus faecalis, and Escherichia coli (E. coli) are examples of bacteria linked to colorectal cancer.

Researchers believe a change in colonic flora may create an environment in which tumors can develop.

Recent researchTrusted Source has also found that colibactin, a type of toxin made by certain strains of E. coli, has a strong link to colon cancer among people between the ages of 40 and 70.

Researchers believe that diet has a substantial effect on the risk of colon cancer. Roughly 60% of colorectal cancer cases in developed countries are due to diet and lifestyle.

A number of studiesTrusted Source have linked diets high in processed and red meats with colon cancer.

Researchers observe that a diet high in fiber can reduce the risk of colon cancer. They believe this is because a high fiber diet contains short-chain fatty acids, which have antitumor properties.

The Centers for Disease Control and Prevention (CDC) advisesTrusted Source that a diet low in animal fats but high in whole grains, fruits, and vegetables can reduce the risk of developing colorectal cancer.

The American Cancer Society (ACS)Trusted Source guidelines for diet and exercise recommend a healthy eating pattern that prioritizes:

  • foods high in nutrients
  • fruits in a variety of colors, especially whole fruits
  • whole grains
  • a variety of vegetables, including red and orange vegetables, dark green vegetables, and legumes that are rich in fiber, like peas and beans

The same guidelines recommend limiting or excluding:

  • highly processed foods
  • refined grains
  • sugar-sweetened beverages
  • red and processed meats

Since 1987, the International Agency for Research on Cancer has classedTrusted Source alcohol as a group 1 carcinogen (a substance that causes cancer). There is a strong body of evidence that suggests alcohol can cause many types of cancer, including colorectal cancer.

Among moderate to heavy drinkers, the risk of colorectal cancer is 1.2 to 1.5 timesTrusted Source higher than for those who don’t drink.

All types of alcohol increase the risk of cancer. According to the ACS, alcohol is one of the most importantTrusted Source modifiable risk factors for cancer, together with body weight and tobacco use.

The ACS guidelinesTrusted Source for diet and physical activity suggest it’s best not to drink any alcohol. However, it advises that women who choose to drink alcohol should have no more than one drink of alcohol a day, and men who choose to drink alcohol should have no more than two drinks a day.

Given the role of the gut microbiome in the development and progression of colorectal cancer, the use of targeted therapies that may change the gut microbiome is an exciting area of research.

Studies suggestTrusted Source that targeting and altering the composition of the gut microbiome could inhibit the development of colorectal cancer. Ways to do this include:

  • antibiotics
  • fecal microbiota transplant
  • probiotics
  • prebiotics
  • dietary modifications

In addition, targeted therapies could also assist in boosting the efficacy of cancer treatments like chemotherapy and immunotherapy.

Preclinical studiesTrusted Source have shown that oral administration of certain forms of bacteria like Bacteroidales can increase the efficacy of first-line chemotherapy treatments as well as certain immunotherapies used in the treatment of colorectal cancer. Probiotics and prebiotics were also found to inhibit the development of intestinal tumors.

Research has found that fecal microbiota transplants may reverse the imbalance of the microbiome and reduce inflammation in the intestine. They assist the immune response to cancer as well as boost the efficacy of anticancer treatments.

The relationship between microbiota and colorectal cancer is complex. Research has demonstrated that the gut microbiota of people with colorectal cancer is less rich and diverse than that of people without colorectal cancer.

Researchers are exploring the possibility of using fecal microbiota to screen for an early diagnosis of colorectal cancer. However, research to date has shown inconsistent results in the efficacy of these kinds of biomarkers for colorectal cancer.

As the microbiome is a complex system, further research is needed before scientists can harness it as a screening tool for colorectal cancer in a clinical setting.

Gut health plays an important role in colon cancer risk.

Scientists believe that changes to the gut microbiome can contribute to the development and progression of colorectal cancer.

Diet plays a significant role in colon cancer risk. Red and processed meats as well as alcohol consumption are associated with an increased risk of colorectal cancer.

Targeted therapies that seek to alter the gut microbiome may help stop the development of colorectal cancer and increase the efficacy of cancer treatment. But further research is needed before healthcare professionals can use the gut microbiome to screen for early colorectal cancer in a clinical setting.