Continuous antibiotic use linked to colorectal cancer risk

A study conducted by the Nurses’ Health Study and published in the journal Gut has suggested that long-term use of antibiotics may increase the risk of bowel cancer.

The research involved examining data from 16,600 nurses who took antibiotics for varying lengths of time. It found that nurses who had taken antibiotics for two months or more, between the ages of 20 and 39, were more likely to be diagnosed with particular types of bowel polyps - known as adenomas - in later life, compared with people who had not taken long-term antibiotics in their 20s and 30s.

Meanwhile, women who had taken antibiotics for two months or more in their 40s and 50s were even more likely to be diagnosed with an adenoma decades later.

The authors of the research explained: "Antibiotics fundamentally alter the gut microbiome, by curbing the diversity and number of bacteria, and reducing the resistance to hostile bugs."

"This might all have a crucial role in the development of bowel cancer, added to which the bugs that require antibiotics may induce inflammation, which is a known risk for the development of bowel cancer."

"The findings if confirmed by other studies, suggest the potential need to limit the use of antibiotics and sources of inflammation that may drive tumour formation."

Responding to the findings, Dr Sheena Cruickshank, an immunology expert at the University of Manchester, maintained: "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.

"Antibiotics are crucial medicines for treating bacterial infections and, if prescribed and used appropriately, can be life-saving."