Probiotics offer benefits that go beyond digestion. But the main reason people take probiotics to aid with digestion, and there is a lot of research showing that this is a good idea. Research appearing in the Korean Journal of Gastroenterology (2006; 47(6): 413-9) looked at 40 subjects with irritable bowel syndrome (IBS) and the effect treatment with probiotics had on the condition. The subjects were randomly divided into two groups. One group was given a probiotic supplement and the second group was given a placebo.  Subjects were evaluated at two weeks and at four weeks. The group receiving the probiotis (which consisted of Streptococcus faecium and Bacillus subtilis) had fewer episodes of abdominal pain and a reduction in the severity of the pain. The amount of intestinal gas produced remained the same in both groups. There are other studies that support the use of probiotics for IBS. Research appearing in the Journal of Pediatric Gastroenterology and Nutrition (2010 July; 51(1): 24-30) looked at the effect probiotic supplementation had on children with irritable bowel syndrome (IBS). The subjects of the double-blind, placebo-controlled study were 59 children and adolescents between the ages of four and 18, who were suffering from IBS. The subjects were randomly assigned to receive either a placebo or a high dose probiotic supplement for six weeks. The subjects who received the probiotics experienced less pain, bloating, and other symptoms when compared to the placebo group.

Research appearing in the World Journal of Gastroenterology (2010 Sept 7; 16(33): 4145-51) looked at the effect supplementation with probiotics had on patients with mild to moderate ulcerative colitis. The 30 subjects were being treated with sulfasalazine. It was found that giving a probiotic  supplement (containing Lactobacillus delbruekii and Lactobacillus fermentum) was more effective than treating the patients with the drug alone. Addition of the probiotic reduced inflammation, as evidenced by lower levels of certain chemicals in the blood (IL-6, TNF-alpha, NF-kappaB p65). The authors concluded that, “Oral supplementation with probiotics could be helpful in maintaining remission and preventing relapse of UC (ulcerative colitis).”