Date of Award
Selective Evidence-Based Medicine Review
Master of Science in Health Sciences - Physician Assistant
Physician Assistant Studies
OBJECTIVE: The objective of this selective EBM review is to determine whether or not Lactobacillus containing probiotics improve symptoms of gas production in patients with lactose intolerance and lactose maldigestion.
STUDY DESIGN: A systematic review of two randomized, double-blind, placebo controlled, crossover trials (RCTs) and one case series. Each article was published in English after 2010.
DATA SOURCES: Articles were obtained through PubMed and Cochrane Library databases. All articles were published in peer-reviewed journals and selected for their relevance to the clinical question.
OUTCOMES MEASURED: Patient perception of gas production, defined as flatulence and distention or bloating, was measured in each study. Pakdaman et al. (Nutr J. 2016;15(1):56. doi: 10.1186/s12937-016-0172-y) measured flatulence through a 6-hour symptom score requiring patients to rank the symptom on a scale from 0 (no symptoms) to 10 (most severe symptoms). Vitellio et al. (Nutrients. 2019;11(4):886. doi: 10.3390/nu11040886) measured intensity of bloating by a visual analog scale (VAS), which ranged from 0 mm (no perception) to 100 mm (worst possible perception). Almeida et al. (Nutr Clin Pract. 2012;27(2):247-251. doi: 10.1177/0884533612440289) measured flatulence and distension together using this scale 0 = none, 1 = mild, 2 = moderate, and 3 = severe.
RESULTS: The double-blinded RCT by Pakdaman et al. (Nutr J. 2016;15(1):56. doi: 10.1186/s12937-016-0172-y) did not find a statistically significant decrease in flatulence between the treatment and placebo groups (p = 0.770). The flatulence score in the treatment group was 3.16 and 3.21 in the placebo group. Conversely, the double-blinded RCT by Vitellio et al. (Nutrients. 2019;11(4):886. doi: 10.3390/nu11040886) found a reduction in bloating that was statistically significant between the treatment and placebo groups (p = 0.028). The VAS score was 60 for the treatment group and 77 for the placebo group. Finally, the case-series conducted by Almeida et al. (Nutr Clin Pract. 2012;27(2):247-251. doi: 10.1177/0884533612440289) found a small decrease in patient reported flatulence and distension with a mean change of 0.4. However, this change was not found to be statistically significant (p > 0.05).
CONCLUSION: Patients reported a reduction in symptoms of gas production in all studies but the treatment effects were small with the only statistically significant difference seen in Vitellio et al. (Nutrients. 2019;11(4):886. doi: 10.3390/nu11040886). Because of these small treatment effects and lack of statistical significance, the evidence is inconclusive for the efficacy of Lactobacillus at improving symptoms of gas production. Future studies should include larger sample sizes and longer treatment periods with uniform symptomatic measurement across studies.
Godward, Kelsie, "Do lactobacillus containing probiotics improve symptoms of gas production in patients with lactose intolerance and lactose maldigestion?" (2021). PCOM Physician Assistant Studies Student Scholarship. 581.