The study, involving nearly 1,000 children aged 3 months to 4 years, provides evidence against the popular and costly use of probiotics -- live microorganisms believed to restore the balance of intestinal bacteria and boost the immune system.
"Probiotics had no effect on the children. Parents are better off saving their money and using it to buy more fresh fruits and vegetables for their children," said study co-author, Phillip Tarr, Professor at Washington University School of Medicine in St. Louis.
The findings, published in the New England Journal of Medicine, showed that a commonly used probiotic is not effective in improving symptoms in young patients with gastroenteritis, popularly known as "stomach flu".
The researchers evaluated a common probiotic known as Lactobacillus rhamnosus GG, or LGG, which is sold over the counter as Culturelle. Certain versions of the probiotic are intended for babies and children.
There are no treatments for pediatric acute gastroenteritis other than giving children fluids to prevent dehydration and, sometimes, medication to relieve nausea. The lack of options has prompted some physicians and parents to give ill children probiotics, the researchers said.