A recent study published in Annals of Gastroenterology evaluated the impact of probiotic containing products on stool frequency and intestinal transit time ITT in constipated adults. The study also aimed to assess the factors that influence the efficacy of these products. A systematic review of randomized controlled trials was conducted to measure weekly stool frequency or ITT in constipated adults who were given probiotic containing supplements. Overall 21 studies 23 comparisons involving 2656 subjects were included. Probiotics containing Lactobacillus or Bifidobacterium species were used in all the studies. A mean increase in weekly stool frequency of 0.83 was noted with probiotic containing products. Following adjustment for publication bias the mean difference in weekly stool frequency came out to be 0.30. The effects on stool frequency were noted to be greater in studies where functional constipation was diagnosed using Rome III or Rome II or III criteria compared to non Rome diagnosis techniques. Products containing probiotics effectively reduced ITT. High heterogeneity was noted among studies but no evidence of publication bias. Therefore supplementation with products containing Lactobacillus or Bifidobacterium species seem to enhance stool frequency and diminish ITT in constipated adults. However considering the heterogeneity in outcomes caution must be exercised in interpreting the results.3 References 3. Miller LE Ouwehand AC Ibarra A. Effects of probiotic containing products on stool frequency and intestinal transit in constipated adults systematic review and meta analysis of randomized controlled trials. Ann Gastroenterol. 2017 30 6 629 639. doi 10.20524 aog.2017.0192.