Prolonged use of antibiotics could lead to bowel cancer, study finds

Long-term use of antibiotics has been associated with an increased risk of bowel polyps.

Bowel polyps are small growths on the inner lining of the large bowel or rectum. They are not usually cancerous but some may turn into cancer unless they are removed.

The research, led by a team from Harvard medical school, found that those who had taken antibiotics for two months or more were 36% more likely to be diagnosed with bowel polyps than those who had not taken them for any extended period when they were in their 20s and 30s.

The researchers said the findings are preliminary and should not be interpreted as a reason to avoid taking antibiotics.

Nevertheless, an association between antibiotics and bowel polyps is “biologically plausible”.

Sheena Cruickshank, a senior lecturer in immunology at the University of Manchester, said that anything that disturbs our gut bacteria, such as changes in diet, inflammation or antibiotic use, may have an impact on our health.

“This study’s findings imply that any risk is very slight and also quite variable. Whilst the data adds to our growing knowledge of the importance of the gut bacteria to our health, I would be concerned about advising people to avoid using antibiotics,” Cruickshank said in a statement.

She, however, noted that antibiotics can be life-saving and are crucial medicines for treating bacterial infections if prescribed and used appropriately.

Lisa Wilde, director of research and external affairs at Bowel Cancer UK, on her part, said the results of the study add to a growing body of knowledge on how the bacteria that live in our bodies affects our health.

“We know that 41,200 people are diagnosed with bowel cancer every year, it’s the 4th most common cancer in the UK. There are several known factors that increase your risk of getting the disease,” Wilde said.

“Some of these are things you can’t do anything about, for example, age and genetics. But you can make changes to your lifestyle to help stack the odds against bowel cancer, such as being of a healthy weight, taking more exercise, cutting down on alcohol and stopping smoking.

“It’s vital that people continue to take any antibiotics they have currently been prescribed, and speak to your GP for any concerns about your bowel health.”