Antibiotics disrupt gut bacteria in infants

Wed, Jan 2, 2013, 00:00

New research from scientists in Cork and Canada shows that broad-spectrum antibiotics disrupt the gut bacterial flora in infants which could negatively influence their long-term health.

The authors of the study say the merits of administering broad spectrum antibiotics – those that kill many bacterial species – in infants should be reassessed and the potential to use more targeted, narrow-spectrum antibiotics for the shortest period possible should be examined.

In the study, nine infants were treated with intravenous ampicillin/gentamicin within 48 hours of birth, and over the two-month study period, their gastrointestinal flora were compared with that in nine infants who received no antibiotics.

At four weeks, beneficial bacteria, including Bifidobacteria and Lactobacilli, were significantly reduced in the treated group, and although the numbers bounced back by the study’s end, the species diversity did not. The researchers used advanced DNA sequencing to identify the species of gut flora, and to quantify their numbers.

The study was published recently by the journal Antimicrobial Agents and Chemotherapy and was carried out by researchers in the Alimentary Pharmabiotic Centre based in Teagasc, University College Cork, and in Cork University Maternity Hospital, with colleagues in The Hospital for Sick Children, Toronto, Ontario, Canada.

“This is the first sequencing-based study to demonstrate the negative effects of short-term antibiotic treatment on the beneficial gut bacteria populations in infants,” said senior author Catherine Stanton of the Alimentary Pharmabiotic Centre based at Teagasc Food Research Centre, Fermoy, Cork, Ireland.

By altering the gut microbiota, and thus the immune system very early in life, Ms Stanton said the antibiotics could negatively influence long-term health, by increasing the risk of developing asthma, allergy and obesity.