Whether alternative probiotics have the same effects as VSL 3 depends on the individual and the disease being treated. Results of over a dozen randomized clinical trials of a variety of probiotics on patients with Irritable Bowel Syndrome are summarized in an article by the Canadian Society of Intestinal Research.
A 2008 study of the safety and efficacy of high dose probiotic VSL 3 for ulcerative colitis in children, published in the American Journal of Gastroenterology, found that it aided in remission of symptoms and was well tolerated. In relation to Crohn's disease, also known as irritable bowel syndrome, beneficial effects on the immune system from VSL 3 were noted in a 2009 study on laboratory mice, reported by the Proceedings of the National Academy of Sciences in the United States.
There is much anecdotal evidence of the benefits of probiotics in foods, with yogurt as a popular example. Clinical trials of the efficacy of a variety of probiotics versus placebo have been conducted in the course of research on various gut problems, including antibiotic-associated diarrhoea, ulcerative colitis, pouchitis and lactose intolerance. Most of the studies were relatively small, and the results varied as to what symptoms were relieved and how much the quality of life of the subjects improved. The opinion that more studies are needed on the effects of probiotics has been expressed by many scientists and researchers and is supported by the U.K. National Health Service.