SCIENTISTS from Queen's University Belfast have found antibiotic use may increase the risk of developing colon cancer, potentially more so among younger people.
The link between antibiotics and colon cancer comes following a study of almost 40,000 people.
It compared antibiotic use and lifestyle factors of those who had colorectal cancer and those who did not. While no relationship was found with rectal cancer, antibiotic use was found to be associated with the development of colon cancer.
Researchers at QUB, University of Aberdeen and NHS Grampian found for the first time that, while the overall numbers remain relatively low, antibiotic use was linked with an estimated 50 per cent higher risk of colon cancer in people aged under 50 and an estimated nine per cent higher risk in those 50 and over.
The Cancer Research UK funded study analysed data from the Primary Care Clinical Informatics Unit Research national primary care database, identifying 7,903 people with colorectal cancer and compared them to 30,418 matched people without a cancer diagnosis.
The researchers controlled genetic and non-genetic factors, such as underlying health conditions, to determine whether antibiotic use is a risk factor for colon cancer.
They also adjusted for alcohol consumption, smoking and weight.
Early and later-onset colon cancer were investigated separately as evidence suggests risk factors may differ between early and later-onset disease.
Sarah Perrott from University of Aberdeen said: "We found antibiotic exposure was associated with colon cancer among all age groups.
"This, along with multiple other dietary and lifestyle factors, may be contributing to increased cases of colon cancer among young people."
Reasons behind this link are believed to be the impact of antibiotics on the natural diversity of bacteria within the gut microbiome, which can potentially lead to altered bacterial activity and interfere with normal immune function.
This can lead to chronic inflammation and theoretically increase the risk of cancer.
Researchers say prescribing antibiotics should be considered carefully and probiotic supplements could be useful to counteract negative effects of antibiotics.
Dr Ron McDowell from QUB added: "This study shows the value of using the high-quality data being routinely collected by our health service to inform clinical practice.
"Further studies are required to evaluate the long-term effects of antibiotics on gut health."
