Effects of a Probiotic Fermented Milk on Functional Constipation

A Randomized, Double-blind, Placebo-Controlled Study

Mena Mustapha Mazlyn; Lee Hun-Leong Nagarajahl Arshad Fatimah; A Karim Norimah; Khean-Lee Goh


J Gastroenterol Hepatol. 2013;28(7):1141-1147. 

In This Article

Abstract and Introduction


Background and Aim Evidence suggests that probiotics reduce certain constipation-related symptoms. Lactobacillus casei strain Shirota has never been tested as treatment for functional constipation in otherwise-healthy subjects. To evaluate the efficacy of this probiotic among adults with functional constipation was aimed.

Methods Subjects with functional constipation (Rome II-defined) were randomized to intake L. casei strain Shirota fermented milk or placebo once daily for 4 weeks under double-blind condition. Primary outcomes were constipation severity and stool frequency; secondary outcomes were stool consistency and quantity.

Results In intent-to-treat population, compared with baseline, constipation severity and stool frequency improved in both probiotic (n = 47) and control groups (n = 43), but improvements were comparable in both groups at week 4 (α = 5% level). In probiotic group, stool consistency and quantity at week 4 improved significantly versus baseline but not versus control. Considering that the study agent is non-pharmaceutical and the purpose of supplementation is for long-term effect, re-evaluation at α = 10% was conducted, which showed significant improvement in constipation severity at week 4 (P = 0.058). Magnitude of the probiotic effect on stool consistency was small but grew over time, d = 0.19, 95% confidence interval 0.00–0.35 (Week 4), d = 0.29, 95% confidence interval 0.11–0.52 (postintervention). Post-hoc exploratory analysis suggests incomplete evacuation may decrease with probiotic intake.

Conclusions Four-week administration of L. casei strain Shirota did not alleviate constipation severity or stool frequency, consistency, and quantity when compared with control. With re-evaluation at α = 10% level, improvement in constipation severity was significant at week 4. To obtain conclusive results, further studies with longer intervention are warranted.


Chronic constipation is a common[1] gastrointestinal complaint associated with infrequent, difficult defecation[2] adversely affecting quality of life.[3] Standard therapies do not always bring about satisfactory relief.[4] Thus, there is a need to explore other approaches to manage this disorder that are safe and deliver long-term efficacy.[4]

Probiotics are viable microorganisms that when administered in sufficient quantity deliver beneficial affects to the host[5] and are generally considered safe.[6,7] Studies have found probiotics useful in alleviating certain symptoms of constipation among adults,[8–10] although clinical application is still considered investigational.[11] There is a need to accumulate further evidence with well-designed trials.[12] Lactobacillus casei strain Shirota (LcS) has shown some beneficial effects in constipation-related conditions.[13–15] Yet, its efficacy has never been tested in Rome-defined functional constipation, a standard definition used in constipation research in recent years.[16] In our placebo-controlled trial, we aimed to determine the effectiveness of 4-week intervention of LcS among otherwise-healthy adults with Rome II-defined functional constipation.[2] Rome II criteria[2] and not Rome III[17] have been validated in Asian populations.[18]