Probiotics improve stool consistency in chronic constipation
Probiotic supplementation improves stool consistency in adults with chronic constipation, a randomized study shows.
“In addition, the beneficial effect of Lactobacillus plantarum (L. plantarum) on stool consistency remained after the probiotic supplementation was discontinued,” added the researchers.
At week 4, the primary endpoint of stool consistency was significantly better in patients taking probiotics than placebo, as measured on the Bristol Stool Form Scale (p=0.029). The improvement in stool consistency remained even 4 weeks after discontinuation of probiotics at week 8 (mean score, 3.7 vs 3.1; p=0.002). [Dig Dis Sci 2018 63:2754–2764]
Faecal microbiomes sampled from the probiotic group showed significantly more abundant L. plantarum than those from the placebo group at 4 weeks (p=0.029), which according to the researchers, was sustained until 8 weeks although the difference between groups was no longer significant.
“We found that probiotic treatment altered the composition of the faecal microbiota, especially L. plantarum … The improved stool consistency might have been induced by this increased proportion of L. plantarum,” said the researchers. They also believed that the mucosal colonization by probiotics might have helped sustain the improvement in stool consistency after probiotic discontinuation.
Faecal Streptococcus thermophilus (S. thermophilus), the other probiotic strain studied, did not increase in abundance after probiotic intake.
Levels of serum cytokines such as TNF-α and the ratio of interleukin (IL)-10/IL-12 were also not significantly different between the two groups.
“Our findings support the notion that the beneficial effects of probiotics in patients with constipation are modulated by the gut microbiota, rather than by intestinal inflammation,” said the researchers.
Although there was improvement in stool consistency, bowel movement frequency did not change significantly with probiotic supplementation. Nonetheless, participants taking probiotics experienced better quality of life compared with those in the placebo group throughout the study (p=0.044 at 4 weeks and p=0.049 at 8 weeks).
The double-blind trial involved 171 adults (mean age 39 years, 86 percent female) with chronic constipation in Korea, who have been diagnosed with IBS-C* or functional constipation based on the Rome IV criteria. They were randomized 1:1 to receive probiotics (1.0×108 CFU/g L. plantarum LRCC5193 and 3.0×108 CFU**/g S. thermophilus MG510) or a placebo daily for 4 weeks. After the end of the intervention, the participants were followed up for another 4 weeks during the wash-up period.
As the study was single-centre from a university hospital, the researchers cautioned that this may limit the generalizability of the findings. Also, the relatively short duration of the probiotic treatment could explain why there was no significant change in the frequency of complete spontaneous bowel movement.
“The mechanism whereby probiotics benefit patients with chronic constipation should be clarified in further studies,” suggested the researchers.