Research project led by Bailey Hanna, MS, RDN - no affiliate links, ads or sponsored products.
A small randomized placebo-controlled trial investigated the effects of Bacillus coagulans LBSC on adults with IBS. Although the study reported some therapeutic benefits, several methodological flaws severely limited our ability to make a confident assessment, leading to the disqualification of this study.
Key Issues Identified:
Conclusion: Despite the promising reported results, the study’s methodological flaws make it difficult to assess the clinical relevance of Bacillus coagulans LBSC for treating IBS. Further well-designed studies are needed to evaluate its efficacy.
Key Takeaway: The one study for Bacillus coagulans LBSC has been disqualified from our database due to poor evidence quality. We do not recommend this probiotic at this time.
Dosing Instructions:
None
References:
There is insufficient evidence demonstrating benefits for IBS with this probiotic. Therefore, we do not provide guidance on finding a commercial product containing this strain/blend.
This probiotic has low to moderate quality studies in IBS populations supporting it. View our evidence evaluation framework to learn how we assess the quality of studies.
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Efficacy and safety of Bacillus coagulans LBSC in irritable bowel syndrome
Medicine 2021.100:3(e23641)
ADULTS 18-65 years
The Digestive Symptom Frequency Questionnaire (DSFQ) was used to assess diarrhea and constipation as a combined parameter. Notably, this was not an originally validated parameter in the DSFQ. There was no analysis specific to any IBS subtype.
The probiotic showed a mean relative symptom score improvement of 54.9% from baseline for this combined parameter. The therapeutic gain over placebo was 25.3% (p=0.0027). It’s important to note that the probiotic group had 49.7% higher mean symptom severity scores at baseline compared to the placebo group.
This greater initial severity could potentially skew the results, as the probiotic group had more room for improvement. The combined assessment of diarrhea and constipation makes it unclear if the improvement trend specifically applies to diarrhea.
Additional information about stool consistency indicated a trend towards normalization in individuals with an “Inflammation” stool form (presumed Bristol stool form scale score of 6 or 7, indicative of diarrhea). However, the details available do not confirm if the two individuals with presumed diarrhea at baseline achieved stool normalization or another abnormal stool form by the end of the treatment.
For more details on stool consistency normalization, refer to the notes in the bowel habit satisfaction category.
The Digestive Symptom Frequency Questionnaire (DSFQ) was used to assess diarrhea and constipation together as one parameter. Interestingly, this combined assessment was not part of the DSFQ’s original validation.
The analysis did not differentiate between IBS subtypes. The probiotic treatment led to a notable 54.9% mean symptom score improvement from baseline for this combined parameter, with a therapeutic gain over placebo of 25.3% (p=0.0027).
However, it’s important to note that the probiotic group had 49.7% higher mean symptom severity scores at baseline compared to the placebo group. This greater initial severity might have influenced the results, as there was more potential for improvement in the probiotic group.
The relevance of this improvement trend specifically for constipation remains unclear due to the combined assessment of diarrhea and constipation. Nevertheless, additional information on stool consistency suggests a reduction in constipation severity by the end of treatment.
Initially, the probiotic group had 2 participants with slight constipation and 6 participants who were very constipated. By the end of the treatment, 6 participants had slight constipation, and none were very constipated. This change indicates a trend toward stool normalization and reduced constipation severity.
For more details on stool consistency normalization, refer to the notes in the bowel habit satisfaction section.
Baseline and Post-Treatment Stool Consistency At the study’s outset, only 10.5% (2 of 19 participants) of both the probiotic and placebo groups had what the authors termed “normal” stools, based on the Bristol stool form scale.
By the end of the treatment, this percentage had risen to 63.2% in the probiotic group and 31.5% in the placebo group. The improvement in the probiotic group was statistically significant (P = .0002), unlike the placebo group (P = .1989).
Issues with Terminology A significant issue in the study was the use of descriptive terms instead of the numerical Bristol stool form scale. The terms used included: Inflammation: Presumably type 6 or 7 stools Lacking fiber: Presumably type 5 stools Normal: Presumably type 3 or 4 stools Slight constipation: Presumably type 2 stools Very constipated: Presumably type 1 stools This approach likely led to misclassification, particularly by labeling type 5 stools (“lacking fiber”) as abnormal.
According to the Rome Foundation criteria for IBS subtypes, only stool types 1 and 2 (constipation) and types 6 and 7 (diarrhea) are considered abnormal. Thus, including type 5 as abnormal inflates the baseline percentage of abnormal stools, potentially exaggerating the perceived benefit of the probiotic treatment.
Adjusted Analysis When adjusting for these inconsistencies, the analysis suggests a more moderate effect of probiotics. Specifically, if type 5 stools were considered normal, 47.4% of participants in the probiotic group would have had normal stool consistency at baseline.
The true normalization effect from baseline would then be an additional 21% (n=4 participants), rather than the larger increase initially reported. Therapeutic Gain Adjusting for the misclassification, the relative therapeutic gain of probiotics over placebo for achieving stool normalization is recalculated to be 15.8%.
This adjusted figure provides a more accurate reflection of the probiotics’ efficacy.
The probiotic intervention showed significant improvements in all gastrointestinal symptoms on the DSFQ (both the originally validated symptoms and the additional parameters added by the study authors) compared to the placebo.
Although IBS-SSS scores were collected, the specific point reduction was not reported, making it difficult to compare these results against established Minimum Clinically Important Differences (MCIDs) for this tool.
In the probiotic group, 63.1% of participants reported no symptoms at the end of the treatment period. The relative mean therapeutic gain over placebo for achieving no symptoms was 42.2%, which was statistically significant (P < .0001).
Abdominal pain was evaluated using a Digestive Symptom Frequency Questionnaire (DSFQ). The results showed that the probiotic led to a significant 76.0% improvement in mean symptom scores from baseline.
Additionally, the therapeutic gain over the placebo was 53.2%, with a p-value of less than 0.0001, indicating strong statistical significance. It’s important to note that the probiotic group had 54.3% higher mean symptom severity scores at baseline compared to the placebo group.
This greater disease severity at the start could potentially affect the results, as those in the probiotic group had more room for improvement, which may influence the observed therapeutic gain over the placebo.
The Digestive Symptom Frequency Questionnaire (DSFQ) was used to assess bloating and cramping. However, it’s important to note that cramping was not initially included during the DSFQ validation study, which might have affected the construct validity of this parameter.
The probiotic showed a significant improvement, with a 54.8% mean symptom score reduction for bloating and cramping from baseline. This translates to a 36.5% therapeutic gain over the placebo (p=0.0148).
Interestingly, the probiotic group had 55.6% higher mean symptom severity scores at baseline compared to the placebo group. This greater initial severity could have influenced the results, as the probiotic group had more room for improvement.
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Nausea was evaluated using the Digestive Symptom Frequency Questionnaire (DSFQ). The results showed an impressive 81.9% mean symptom score improvement from baseline when using the probiotic.
Additionally, the therapeutic gain over the placebo was 88.6% (p=0.0031). Similarly, vomiting was assessed via the DSFQ, revealing a 73.4% improvement from baseline and a remarkable 96.4% therapeutic gain over the placebo.
However, it’s important to note that neither nausea nor vomiting were originally included as assessment parameters in the DSFQ validation study. Due to this lack of construct validity, the clinical relevance of these findings remains unclear.
Anxiety levels were measured using the Digestive Symptom Frequency Questionnaire (DSFQ). The results showed that the probiotic led to an impressive 79.7% reduction in anxiety symptom scores. Additionally, there was a 59.1% therapeutic gain over the placebo for this parameter (p=0.0177).
However, it’s important to note that the original, validated version of the DSFQ does not measure anxiety frequency. This misapplication of the DSFQ in the study raises questions about the validity of these findings, making the clinical relevance of the observed changes unclear.
Quality of life (QOL) was assessed using yes or no responses to a range of symptoms: abdominal pain, diarrhea, constipation, bloating and flatulence, vomiting and nausea, perception of mental well-being, and the overall impact on daily life.
These responses were converted into binary numerical data and analyzed using principal component analysis (PCoA). The analysis revealed significant improvements in the probiotic group across various parameters.
Participants reported reduced abdominal pain, diarrhea, constipation, bloating and flatulence, vomiting and nausea, and an enhanced perception of mental well-being and daily life influence.
In contrast, the placebo group experienced either no improvement, mild improvement, or in some cases, worsening symptoms, including unbearable pain.
In this study, headaches were evaluated using a Digestive Symptom Frequency Questionnaire (DSFQ). The results showed that the probiotic led to an 86.7% relative mean symptom score improvement for headaches compared to baseline. The therapeutic gain over placebo was 59.3% (p=0.0003).
However, it’s important to note that the original validated version of the DSFQ did not include headache frequency as a measure. This misapplication of the DSFQ in the study raises concerns about the construct validity of the findings, making the clinical relevance of the reported improvement unclear.
This study was disqualified due to poor evidence quality.