The Effect of Probiotic Yogurt on Constipation in Pregnant Women: A Randomized Controlled Clinical Trial

Background: Probiotics can alter the colonic microbiota and might improve bowel function. Objectives: The aim of this study was to evaluate the effect of the consumption of yogurt, enriched with Bifidobacterium and Lactobacillus 4.8 x 10(10) (CFU) on the symptoms of constipated pregnant women. Materials and Methods: This triple-blind randomized controlled trial was conducted on 60 constipated pregnant women who were diagnosed by the ROME III criteria in Tabriz, Iran from December 2014 to July 2015. Participants were randomly put into two groups including the treatment and the control group through block randomization. The treatment group received 300 g of yogurt enriched with Bifidobacterium and Lactobacillus 4.8 x 10(10) colony forming units (CFU) (n = 30) while the control group received conventional yogurt (n = 30) for 4 weeks. The defecation frequency, stool consistency, straining during defecation, sensation of anorectal obstruction, sensation of incomplete evacuation and manual manoeuvres to facilitate defecation were primary outcomes while the amount of defecation, stool colure, and quality of life were secondary outcomes. Results: The frequency of defecation was increased from 2.1 (0.8) at baseline to 8.3 (4.4) in the probiotic yogurt group vs. 2.3 (0.7) at baseline to 8.1 (4.3) in the conventional yogurt group at the end of 4th week. These results were based on the repeated measure ANOVA test and there was no statistically significant difference between the two groups (mean difference: 0.1; Confidence Interval 95%: -1.4 to 1.7; P = 0.872). Constipation symptoms including straining, anorectal obstruction, manipulation to facilitate defecation, consistency of stool and color of stool were improved significantly (P < 0.05) in both groups. In addition, the amount of defecation was significantly increased in both groups (P < 0.05), while incomplete evacuation was significantly reduced in the treatment group (P = 0.01). There was no statistically significant difference between the groups in the mean scores of physical (P = 0.726) and mental (P = 0.678) aspects of quality of life after the intervention with the adjusting of baseline scores. Conclusions: Consumption of 300 g/day probiotic and conventional yogurt can play a role in improving the symptoms of constipation during pregnancy.