The best evidence was observed for Bifidobacterium lactis, which increased stool frequency by 1.5 bowel movements per week and stool consistency, wrote researchers from King's College London, Queen Mary University of London, and University College London in the American Journal of Clinical Nutrition.
While the data appeared to support the potential benefits of B. lactis, they were less supportive for Lactobacillus casei Shirota, said the researchers, with no significant improvements observed for stool consistency and frequency.
“The results provide cautious optimism for the recommendation of specific probiotic species or strains in the management of functional constipation,” they wrote. “Further adequately powered RCTs with the use of standardized outcome measures are needed to determine which species/strains, doses, and duration of probiotics are efficacious in functional constipation.”
Costs
Functional constipation, also known as chronic idiopathic constipation (CIC), reportedly affects about 14% of the population. According to the London-based authors of the new paper, annual treatment costs in the US were estimated to be $1912–$7522 per patient in 2012.
“In addition to the economic costs, constipation greatly affects patients’ quality of life, with a significant impairment of both mental and physical components,” they added.
While a number of options are available to sufferers, including laxatives and stool softeners, many people are dissatisfied with these. This has led to the hypothesis that probiotics may offer benefits for people with constipation.
In order to assess the current state of the science, the London-based scientists analyzed data from 1,182 people in 14 randomized controlled trials.
The data showed that, overall, probiotics were associated with reductions in gut transit time, increased stool frequency. However, this was significant for B. lactis, but not L. casei Shirota. There were also benefits observed for bloating, but only for B. lactis.
Promise, but caution needed
“This meta-analysis provides clinically important information,” wrote the authors. “People with constipation have an impaired quality of life, and this is negatively correlated with symptom severity.
“Many people with constipation do not present to medical care centers and use self-management approaches. Almost half of patients taking over-the-counter or prescription laxatives are not satisfied with the relief they provide, suggesting a large unmet need for alternatives to drug treatment. Accessibility to widely available, nonprescription management approaches allows for greater self-management, which could reduce the financial burden of constipation to medical providers.
“Probiotics may improve whole gut transit time, stool frequency, and stool consistency, with subgroup analysis indicating beneficial effects of B. lactis in particular. However, caution is needed with the interpretation of these data due to their high heterogeneity and risk of bias.
“Adequately powered RCTs are required to better determine the species or strains, doses, and duration of use of probiotics that are most efficacious.”
Source: American Journal of Clinical Nutrition
2014, Volume 100, Pages 1075-1084, doi:10.3945/ajcn.114.089151
“The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials”
Authors: E. Dimidi, S. Christodoulides, K.C. Fragkos, S.M. Scott, K. Whelan