Giving children with acute gastroenteritis probiotics will not help them recover more quickly, according to two large randomised controlled trials. At least if the probiotic includes Lactobacillus rhamnosus.

The research, published in the New England Journal of Medicine, provides solid evidence against the adjunctive treatment, which, as the study authors point out, has been recommended by many health professionals and authoritative bodies.

“Many experts consider acute infectious diarrhoea to be the main indication for probiotic use,” they said.

However, the two studies, both conducted on children aged three months to four years with a less than 72-hour history of acute vomiting and diarrhoea, failed to show any benefit of taking a five-day course of the probiotics.

One of the studies conducted across six tertiary paediatric centres in Canada, involved almost 900 children with acute gastroenteritis randomly assigned to receive either a combination probiotic (L. rhamnosus and L. helveticus) or placebo.

The other very similar study, this one involving US centres, included 970 children with gastroenteritis and tested the effectiveness of giving the single probiotic Lactobacillus rhamnosus against placebo.

The results of the two trials, using almost identical outcome measures were the same – the probiotics did not make a difference.