Probiotics (‘friendly’ bacteria) appear to reduce the severity and length of bouts of gastroenteritis, according to a recent Cochrane study (an analysis of all the available evidence) especially in children.
Use of probiotics was found to be safe and can be combined with rehydration fluids and other treatment if required.
http://onlinelibrary.wiley.com/o/cochrane/clsysrev/articles/CD003048/frame.html
