Colorectal cancer rates are rising significantly among younger adults in the U.S., and experts suggest that our gut health might be a factor.
Researchers in California have found a potential connection between a gut toxin called colibactin and the surge in cancer cases among individuals under 50.
Colibactin, produced by certain harmful gut bacteria, including the well-known foodborne pathogen E. coli, can damage colon cells. This damage is particularly alarming as colorectal cancer is now the second leading cause of cancer deaths in the U.S.
“Not every environmental factor or behavior we study leaves a mark on our genome,” said Ludmil Alexandrov, a professor at U.C. San Diego and part of the Moores Cancer Center. He emphasized that “colibactin is one of those that can. Its genetic imprint seems to be strongly associated with colorectal cancers in young adults.”
The American Cancer Society projects over 158,000 new cases of colorectal cancer and around 55,000 deaths this year. However, experts point out preventive measures against dangerous colibactin.
Understanding the impact of colibactin on gut health is crucial. Trillions of bacteria inhabit the human gut. At around six months of age, E. coli is notably prevalent, but this shifts as people grow older.
Currently, around 20-30 percent of adults harbor E. coli strains that can generate colibactin, according to microbiome researcher Christian Jobin from the University of Florida. Yet, having colibactin doesn’t guarantee colorectal cancer, which appears to be less common in regions like Africa and Asia compared to the U.S. and Western Europe.
The reasons for this discrepancy remain unclear. Jobin speculated that factors such as diet, inflammation, and medication might influence the E. coli strains that produce colibactin.
He theorized that a person’s birth circumstances, breastfeeding, antibiotic use, and exposure to ultraprocessed foods might contribute to these bacteria.
“All of these factors are known to significantly impact the microbiome, and there’s some evidence they may affect these [colibactin-producing] bacteria. But we really need to dig into each one,” Jobin noted.
Researchers from U.C. San Diego highlighted that many cancers might be linked to microbial or environmental exposures well before a diagnosis occurs.
“It might be more than just what occurs in adulthood—cancer could be influenced by experiences in early life, perhaps even during the initial years,” Alexandrov pointed out.
For infants, maintaining a healthy gut is vital for the well-being of their nervous, immune, and digestive systems. This early period is considered “critical,” according to Chicago’s Children’s Healthcare Associates.
Parents can foster this by breastfeeding, providing foods rich in beneficial bacteria, using formula supplemented with probiotics, and promoting skin-to-skin contact. Breast milk contains beneficial bacteria, and skin contact can help build a healthy gut.
It’s also advisable to avoid giving infants unnecessary antibiotics.
“While antibiotics can effectively treat ear infections or strep throat, they can also wipe out good gut bacteria. Use them judiciously, especially for non-bacterial infections like colds or flu,” cautioned Stanford Medicine.
For adults, similar guidance applies. Just one serving of probiotic-rich foods like yogurt, pickles, and sauerkraut can enhance levels of beneficial bacteria and combat harmful ones through acid production, according to the Children’s Hospital of Philadelphia. These foods also fight inflammation connected to chronic diseases like cancer.
Incorporating plenty of fiber into the diet is equally important. Foods rich in fiber, such as bell peppers and oats, act as prebiotics, nourishing good gut bacteria. Fiber can help shield against harmful bacteria, including E. coli, as found by researchers at the University of Cambridge.
Even a modest intake of three to five grams of prebiotics daily can positively affect gut health, according to Texas’s Lubbock Gastroenterology.
Staying hydrated and active can help prevent constipation and benefit the gut microbiome, as noted by Harvard Health.
Research indicates that sedentary individuals often have fewer health-boosting gut bacteria. Surprisingly, just 150 minutes of moderate exercise weekly can markedly improve gut health, as concluded in a recent study from Australia.
Additionally, adequate fluid intake supports mucous production that protects our digestive system, with recommendations suggesting women should drink about 11.5 cups daily and men around 15.5 cups, according to the Mayo Clinic.
Interestingly, research from the University of Toronto found that mice on low-carb diets exhibited less mucus, allowing more colibactin to affect their colon cells.
In contrast, a fiber-rich diet resulted in decreased levels of E. coli and reduced DNA damage. “Now we’re exploring which fiber sources offer the most benefit, and which might be less effective,” said postdoctoral fellow Bhupesh Thakur.
