A research is suggesting that people who take antibiotics for a long time – in their early to midlife – are more likely to develop growths on the bowel which can be a precursor to cancer (Bowel Cancer).
Researchers discovered that the pills are linked to a heightened risk of abnormal growths in the colon and rectum – known as polyps or colorectal tumours – adenomas – which precede the development of most cases of bowel cancer.
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.
More findings by these experts showed that the type and diversity of bacteria in the gut, referred to as the ‘microbiome,’ may have a key role in the development of cancer.
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 authors added that 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.
But the study does not look at how many polyps went on to become cancerous.
The authors say their research cannot prove that antibiotics lead to the development of cancer and acknowledge that the bacteria which the drugs are deployed to treat might also play an important role.
But they say there is a “plausible biological explanation” for the patterns seen.
Writing in the journal they said: “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.”
They added: “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.”
“There is increasing evidence that our microbiota are important in regulating our immune responses and many aspects of our normal functions, including digesting food and producing essential metabolites and vitamins,” said Dr Sheena Cruickshank, British Society for Immunology spokesperson, and Senior Lecturer in Immunology, University of Manchester.
“Thus, 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.
“Antibiotics are crucial medicines for treating bacterial infections and, if prescribed and used appropriately, can be life-saving.”
The research was published in the journal Gut.