I'm in the process of trying probiotics with my son, but Dr. Fasano's remarks in the article below about developing resistance gave me pause.
Dr. Fasano is the Chief, Division of Gastroenterology & Nutrition at Mass General, and he is conducting research on GI issues funded by Autism Speaks.
Below is an excerpt of the guidance he offers on giving probiotics to children:
While I’m extremely sympathetic to parents who want to help relieve their children’s distress, I think we have yet to reach the point where we can say, “Yes, let’s give probiotics a try in children.” Currently, there are only two scenarios where science provides solid support for using probiotics. They include helping relieve food allergies and treating inflammatory bowel disease.
I have a great concern about widespread use of probiotics. We don’t want to make the mistakes we did in the past with penicillin, for example. We overused this antibiotic and others to the point that many types of bacteria became resistant to them. If we use probiotics the same way as we used penicillin, we may weaken their usefulness as a treatment tool.
I have other concerns with the probiotics sold today. The Food and Drug Administration (FDA) does not regulate them as medications because they are considered supplements. As a result, there’s little to no quality control. The product you buy may contain ridiculously low levels of probiotics or no “live” probiotics at all. Worse, the probiotics may be mixed with potentially harmful bacteria.
http://www.autismspeaks.org/blog/2013/01/11/guidance-probiotics