Abstract:
Previous studies show that L. casei Shirota (Lcs) ease certain constipation-related symptoms. Use of LcS as treatment in otherwise-healthy subjects with Rome II-defined functional constipation has not been investigated. The study was aimed to evaluate the effects of LcS in adults with functional constipation. After screening of potential subjects from a database, 100 adults living in the Klang Valley who were diagnosed with functional constipation and met all other eligibility criteria were recruited for the study. The subjects were randomised (stratified based on constipation severity score and age) to receive either fermented milk containing live LcS (3.0 x 1010 colony forming units) or placebo drink without LcS once daily for 4 weeks under single-blind condition after a run-in observation period of 2 weeks and followed by a 1-week post-intervention observation period. Primary outcomes were constipation severity score measured using the Chinese Constipation Questionnaire and stool frequency; secondary outcomes were stool consistency and stool quantity estimations. During the 7-week study period, subjects completed bowel movement diaries and constipation severity was assessed weekly via questionnaire. Subjects were required to maintain their usual diet and lifestyle, which was monitored weekly via questionnaire. Dietary intake, physical activity and stress levels were assessed twice using three-day 24-hour diet recalls, International Physical Activity Questionnaire and Depression, Anxiety and Stress Scale questionnaire respectively. Eighty two subjects completed the study. Intent-to-treat analysis showed trend of improvement in constipation severity and stool consistency with probiotic administration versus placebo; but the improvements were not significant with the 4-week intervention (n=90). With re-evaluation at α=10% level, improvement in constipation severity was significant at Week 4 (P=0.058). The magnitude of the probiotics effect on stool consistency grew over time and was small but statistically significant at Week 4 (d = 0.19, 95% CI [0.00, 0.35]) and at post-intervention (d = 0.29, 95% CI [0.11, 0.52]). This indicates the stool softening effect was significant in the study sample but cannot be generalized to the population. No trends of change were observed in stool frequency and quantity. Post-hoc analysis showed improvement in severity of incomplete evacuation. Diversity of diet may have influenced the results. Four-week administration of LcS did not alleviate constipation severity or stool frequency, consistency and quantity compared to placebo, thus, null hypothesis could not be rejected. To obtain conclusive results, further studies with longer intervention of 6 to 8 weeks are warranted as the intervention period may have been insufficient.
