Just for explanatory sake…Probiotics are friendly bacteria which may potential benefit health and prebiotics are foods which encourage friendly bacteria to grow in the gut.
Recent trials have failed to show a dramatic benefits of pro or prebiotics in Crohn’s Disease although there have been some trials showing a benefit with long term use in Ulcertative Colitis .
Many probiotic trials use bacteria at concentrations which are vastly greater than those found in probiotic yoghurts and often with different bacterial species. Therefore, even if there were positive trials, it would not necessarily be possible to infer that commercially available probiotic yoghurts were equally effective. “Guy’s and St Thomas’ Hospital London”.