Research project led by Bailey Hanna, MS, RDN - no affiliate links, ads or sponsored products.
A single randomized, placebo-controlled trial evaluated the effects of a 4-strain probiotic on IBS symptoms. The study found no significant improvements in flatulence, global IBS symptoms, quality of life, or changes in bowel habits such as stool frequency or consistency. However, the probiotic demonstrated moderate beneficial effects in reducing pain, particularly in a subgroup of 58 participants with a Bristol stool form score of 3 or higher.
Key Takeaway
The evidence suggests that this 4-strain probiotic blend may be beneficial for reducing pain in IBS subtypes not primarily characterized by constipation.
Dosing Instructions:
Trial Duration
Reference:
Hong KS, Kang HW, Im JP, et al. Effect of probiotics on symptoms in Korean adults with irritable bowel syndrome. Gut Liver 2009; 3: 101–7.
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Effect of probiotics on symptoms in Korean adults with irritable bowel syndrome
Gut Liver 2009; 3: 101–7
ADULTS
No data
No subtype-specific analysis was performed, except for a post-hoc analysis on 58 individuals with a baseline Bristol stool form of 3 or higher. Additionally, a subgroup analysis of 10 patients with baseline Bristol stool form scales below 3 (indicative of constipation) showed no significant changes.
There were no statistically significant changes in bowel habits, including defecation frequency and stool consistency, in either the intent to treat group or the subgroup of 58 participants with a Bristol stool form score of 3 or higher.
By week 8, sum scores assessing pain, flatulence, and defecation for the entire intent to treat population were not statistically significant compared to placebo (p=0.064). However, in a subgroup analysis of individuals with a Bristol stool form score of 3 or higher at baseline, there was a significant improvement in global IBS symptoms.
In this subgroup, there was an absolute reduction of 90.6 points on the sum score, representing a 59% relative improvement from baseline by week 8. This amounted to a 28% therapeutic gain over placebo, and the difference was statistically significant (p=0.010).
After 8 weeks of treatment, significant reductions in pain scores were observed. The probiotic group experienced an absolute reduction of 31.9 points on the 100 mm VAS, representing a 63.4% mean relative symptom score reduction from baseline. The relative therapeutic gain over placebo was 25.7%, with the difference being statistically significant (p=0.045).
We calculated an effect size of 0.69 for this parameter, which falls within our moderate effect size range. Subgroup analyses of 58 patients with a baseline Bristol stool form score of 3 or higher showed more significant reductions in pain scores after 8 weeks of treatment (-33.9 points in the probiotic group vs. -13.3 points in the placebo group, p=0.006).
However, subgroup analyses of 10 patients with baseline Bristol stool form scores below 3 did not show any significant changes. The response rate for pain was 64% in the probiotic group compared to 44% in the placebo group (p=0.248). The response rate for defecation discomfort was 58% in the probiotic group versus 41% in the placebo group (p=0.317), and the response rate for the sum of scores was 56% versus 50% (p=0.750), respectively.
By week 8, there was a 54.1% relative improvement in symptom scores for flatulence in the treatment group. However, this improvement was not statistically significant compared to the placebo group, which experienced a 43.2% relative mean reduction from baseline (p=0.437).
There was no statistically significant change in quality of life (QOL) in either the intent-to-treat group or the subgroup of 58 participants with a Bristol stool form score of 3 or higher.
The study lacked variability data for the posttest. Effect sizes were calculated using variability data from the baseline instead.