Prolonged Antibiotic Use Tied to Precancerous Colon Growths

Taking antibiotics for an extended period in early to middle adulthood might increase your risk for precancerous growths in your colon, a large study suggests.

Women who took antibiotics for two weeks or more in their 20s through their 50s were more likely to have colon lesions in their 60s than women who didn’t take the drugs for an extended period, researchers found. If not removed, these lesions, called polyps or adenomas, can lead to colon cancer.

“This suggests that alterations in the naturally occurring bacteria that live in one’s intestines caused by antibiotics might predispose individuals to colorectal cancer,” said lead researcher Dr. Andrew Chan.

Through the study was limited to women, the link likely also holds true for men, Chan said. “More research needs to be done to understand the interaction between alterations in one’s gut bacteria and future risk of colorectal cancer,” he said.

Antibiotics disrupt the diversity and number of bacteria in the gut, or “microbiome.” They also reduce resistance to toxic bacteria. All of this might play a role in the development of precancerous growths, Chan said.

For the report, Chan and his colleagues collected data on the more than 16,600 women 60 and older who took part in the Nurses Health Study.

The women provided a history of antibiotic use between ages 20 and 59. They also had had at least one colonoscopy between 2004 and 2010. Nearly 1,200 precancerous polyps in the colon were found during that time.



Use of antibiotics within the previous four years wasn’t associated with a heightened risk of polyps, but long-term use in the past was, Chan said.

The report was published online April 4 in the medical journal Gut.

My Take:
Please note that “long-term use” of antibiotics is as little as two weeks over the course of 35 years. I’m surprised that they found women that didn’t qualify to use as a control.

I have written several blogs about the potential negative impacts on taking probiotics long term. I believe a study on prolonged probiotic use would find a similar correlation with an increased risk of polyps.

However, short term use of probiotics after antibiotic therapy likely would reduce the risk of developing precancerous polyps.

The Bottom Line:
Avoid taking antibiotics if possible. When and if you must take an antibiotic limit the duration as much as possible without reducing the benefit. Finally, follow the antibiotic therapy with a short course (2-4 weeks) of probiotic therapy. Do not take probiotics long term.

Source: April 5, 2017 National Institutes of Health