At any age, taking antibiotics is known to disrupt naturally occurring gut flora by killing certain good bacteria.

Medical professionals sometimes recommend a course of probiotics alongside treatment to re-balance the body's microbal ecosystem.

A Greek study has now found that giving antibiotics to toddlers, which is sometimes unavoidable, could alter their metabolism and increase their risk of developing prediabetes.

"Increased consumption of antibiotics up to the age of 3 seems to decrease beneficial gut microbes and alter nutrient absorption and metabolism. This may lead to prediabetes, an early high-risk stage of Type 2 diabetes mellitus," explains Dr Charikleia Stefanaki, Research Associate in Pediatric Endocrinology at Athens University Medical School, Greece.

The link was established by team of scientists who analyzed stool samples from 10 prediabetic adolescents and 14 healthy control patients, aged between 12 and 17.

The prediabetic adolescents reported having taken antibiotics over three times a year by the time they were three years old. In fact, they were 8.5 times more likely to have taken antibiotics between birth and three years old than the healthy participants. Their stool samples were found to contain fewer species of Ruminococcus, a type of bacteria that forms colonies which nourish beneficial bacteria in the gut. The researchers suggest that this reduction could lead to unfavorable changes in gut flora, which may explain the onset of prediabetes.

To help reassure parents, the study's authors suggest that certain prebiotics (non-digestible fibers that nourish beneficial microbes) and probiotics could help reestablish a healthy balance of bacteria in the gut and reduce any risk of prediabetes that could be linked to increased antibiotic use in early childhood.

They also highlight the importance of using antibiotics correctly and only when really needed, especially in children. "Gut microbes are a delicate 'organ' frequently neglected by the medical community that produces vitamins, hormones and micronutrients, interacts with the gut's nervous system, and influences the gut's immune response," Charikleia Stefanaki points out.