Research project led by Bailey Hanna, MS, RDN - no affiliate links, ads or sponsored products.
This 3-strain probiotic has been evaluated in two randomized, placebo-controlled trials in IBS populations. The first trial by Lorenzo-Zúñiga et al. explored different doses, comparing a high dose (10 to 30 Billion CFU/day) and a low dose (3-6 Billion CFU/day) over six weeks in individuals with IBS-D.1 Neither dose proved superior to placebo in terms of the number of treatment responders or overall symptom relief – effects we categorized beneath “global IBS symptoms.” However, both doses improved IBS quality of life scores and reduced gut-related anxiety, as measured via the IBS-QOL tool. Interestingly, the lower dose (3-6 Billion CFU/day) showed stronger effect size results in this study compared to the higher dose, suggesting a more robust clinical response at the lower dose.
The second trial by Barraza-Ortiz et al. assessed the probiotic blend either as a 3 Billion CFU dose taken alone in one group or taken along with 3x daily capsules containing 300 mg of simethicone and 60 mg of the antispasmodic alverine in another group.2 To isolate the effects of the probiotic intervention, we only assessed the group exclusively receiving the 3 billion CFU/day probiotic dose without the additional medications. Over six weeks, participants with IBS-D and IBS-M, recruited during a diarrheal phase of their illness, experienced significant improvements in stool consistency and reductions in Bristol stool scale scores, indicating improvements in diarrhea. Despite the small population size in the probiotic group, we calculated a very strong effect size for improvements in stool consistency, which were categorized as improvements in diarrhea. Additionally, this group reported significant reductions in abdominal pain and improvements in quality of life scores.
Key Takeaway:
Based on limited data from small-scale studies, this 3-strain probiotic blend, at a dose of 3-6 Billion CFU/day over six weeks, may help improve diarrhea, IBS quality of life, abdominal pain, and IBS-QOL mental health measures. These effects have been observed in individuals with IBS-D and/or IBS-M.
Dosing:
Trial Duration
References:
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I.31, a new combination of probiotics, improves irritable bowel syndrome-related quality of life
World J Gastroenterol 2014; 20(26): 8709–8716
ADULTS
Combination of a probiotic and an antispasmodic increases quality of life and reduces symptoms in patients with irritable bowel syndrome: a pilot study
Dig Dis. 2021;39(3):294-300
ADULTS 18-59 years
No data
When reviewing the data from the last four weeks of treatment, there was a slight increase in the number of responders in both treatment groups compared to the placebo group. Responders were defined as those who felt “considerably relieved” or “completely relieved” at least 50% of the time. In the high dose group, 42% of participants were responders, while in the low dose group, 32% of participants were responders. This is compared to 25% in the placebo group. However, this difference was not statistically significant (P = 0.467).
Per domain analysis on the IBS-QOL showed greater improvement in nearly all domains for patients treated with the probiotic combination (both high and low doses) compared to those treated with a placebo. This difference was statistically significant in the Mental Health domain (P = 0.030).
Gut-related anxiety, measured with the VSI scale, also improved more in patients treated with the probiotic combination. For the high dose group, there was a 10 ± 2 score increment, and for the low dose group, there was a 14 ± 2 score increment (P = 0.015 vs placebo for the low dose), compared to a 7 ± 1 score increment in the placebo group. We calculated an effect size of 0.42 for the high dose gut-related anxiety improvement, but unlike the study authors, we found this result to be statistically nonsignificant. For the low dose, we calculated a Cohen’s d of 1.00 and found this result to be statistically significant.
Interestingly, the improvement in gut-related anxiety took longer to become evident compared to IBS-related quality of life. The significant differences emerged only after six weeks of treatment, whereas no differences were observed between the treatment groups at three weeks (VSI score increments after three weeks were 6 ± 2, 7 ± 2, and 6 ± 1 for the high dose, low dose, and placebo groups, respectively).
After three weeks of treatment, all patient groups experienced an improvement in their IBS Quality of Life (IBS-QoL) scores. Statistically significant differences between the treatment groups were noted both at three and six weeks (P = 0.012 and P = 0.008, respectively). Specifically, after three weeks, the mean score increase was 18 ± 2 for the high-dose probiotic group (P = 0.017 vs placebo), 17 ± 3 for the low-dose group (P = 0.071 vs placebo), and 12 ± 2 for the placebo group.
The differences became even more pronounced after six weeks. Both the high-dose (18 ± 3) and low-dose (22 ± 4) probiotic groups showed significantly greater improvements in IBS-QoL compared to the placebo group (9 ± 3), with P-values of 0.041 and 0.023, respectively. There was no significant difference between the high and low probiotic doses (P = 0.392).
A post hoc analysis revealed that a significantly larger number of patients treated with probiotics (both high and low doses) showed a good response to the treatment, defined as an improvement of ≥15 points (P = 0.009). Additionally, the number of patients showing some improvement (defined as an improvement of >10 points) was significantly higher in the probiotic groups compared to the placebo group (P = 0.038). Despite the fivefold difference in probiotic concentration between the high and low doses, there was no observed difference in their effect on IBS-QoL by the end of the study.
All study results were derived from a population of individuals with IBS-D.
For further details about the effects on stool consistency, please refer to the bowel habits cell. All participants in the study, which included only IBS-M (Mixed Irritable Bowel Syndrome) and IBS-D (Irritable Bowel Syndrome with Diarrhea) patients, were recruited during a diarrheal phase of their illness.
Probiotic treatment: 44.4% of patients reported a positive change in their stool consistency. This result is statistically significant, with a strong effect size (Cohen’s d = 3.3; p < 0.05).
Probiotic plus antispasmodic treatment: Combining probiotics with an antispasmodic seemed to work even better, with 57.9% of patients experiencing improvement. This combination had an even larger effect size (Cohen’s d = 4.38; p < 0.05), indicating a stronger impact.
Placebo: In contrast, only 16.7% of patients in the placebo group reported any improvement, highlighting the effectiveness of the other treatments.
Probiotic treatment: 38.9% of patients reported a reduction in abdominal pain (Cohen’s d = 1.33; p < 0.05).
Probiotic plus antispasmodic treatment: 57.9% of patients experienced a reduction in pain (Cohen’s d = 2.36; p < 0.05).
The IBS-QoL (Irritable Bowel Syndrome Quality of Life) response rates, based on an ITT (intention-to-treat) analysis, were as follows:
Probiotic treatment: 50.0% of patients showed a positive response (Cohen’s d = 0.69; p = 0.04).
Probiotic plus antispasmodic treatment: 68.4% of patients experienced improvement (Cohen’s d = 0.84; p < 0.05).
The study population was composed entirely of individuals diagnosed with either IBS-M (mixed IBS) or IBS-D (diarrhea-predominant IBS), all of whom were in the diarrheal phase of their condition.