Table 2.

Summary of risk ratios with probiotics versus placebo in IBS

Treatment, # of trials (n)	RR (95% CI); p-value
Probiotics overall, 35 trials (n=4306)	0.81 (0.74–0.89); P<0.00001
Combination probiotics, 20 trials (n=1878)	0.79 (0.69–0.92); P=0.002
Lactobacillus, 8 trials (n=893)	0.82 (0.63–1.06); P=0.13
Saccharomyces boulardii, 2 trials (n=579)	0.92 (0.82–1.03); P=0.14
Bifidobacterium, 2 trials (n=484)	0.71 (0.44–1.16); P=0.18
Escherichia, 2 trials (n=418)	0.86 (0.79–0.93); P=0.0003
Streptococcus, 1 trial (n=54)	0.72 (0.53–0.99); P=0.04