To test the efficacy of Lactobacillus reuteri on infantile colic and to evaluate its relationship to the gut microbiota.
Fifty exclusively breastfed colicky infants, diagnosed according to modified Wessel's criteria, were randomly assigned to receive either L reuteri DSM 17 938 (108 colony-forming units) or placebo daily for 21 days. Parental questionnaires monitored daily crying time and adverse effects. Stool samples were collected for microbiologic analysis.
Forty-six infants (L reuteri group: 25; placebo group: 21) completed the trial. Daily crying times in minutes/day (median [interquartile range]) were 370 (120) vs 300 (150) (P = .127) on day 0 and 35.0 (85) vs 90.0 (148) (P = .022) on day 21, in the L reuteri and placebo groups, respectively. Responders (50% reduction in crying time from baseline) were significantly higher in the L reuteri group versus placebo group on days 7 (20 vs 8; P = .006), 14 (24 vs 13; P = .007), and 21 (24 vs 15; P = .036). During the study, there was a significant increase in fecal lactobacilli (P = .002) and a reduction in fecal Escherichia coli and ammonia in the L reuteri group only (P = .001). There were no differences in weight gain, stooling frequency, or incidence of constipation or regurgitation between groups, and no adverse events related to the supplementation were observed.
L. reuteri DSM 17 938 at a dose of 108 colony-forming units per day in early breastfed infants improved symptoms of infantile colic and was well tolerated and safe. Gut microbiota changes induced by the probiotic could be involved in the observed clinical improvement.