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 gastrointestinal complaint associated with infrequent, difficult defecation adversely affecting quality of life. Standard therapies do not always bring about satisfactory relief. Thus, there is a need to explore other approaches to manage this disorder that are safe and deliver long-term efficacy.
Probiotics are viable microorganisms that when administered in sufficient quantity deliver beneficial affects to the host 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. There is a need to accumulate further evidence with well-designed trials. 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. 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. Rome II criteria and not Rome III have been validated in Asian populations.
J Gastroenterol Hepatol. 2013;28(7):1141-1147. © 2013 Blackwell Publishing