After analyzing over 40 probiotics across 69 trials, we’ve identified the most promising probiotics for managing bloating and distention in IBS. Our dataset (below) is ordered based on an automated scoring system, which we further refined using additional criteria (below) to select our top choices. Here are the results of our findings. 

Our Top Choice(s)

1. Lactospore

A study in IBS-D participants found that Lactospore significantly reduced bloating symptoms, with a 41.8% reduction in bloating scores (p = 0.0037) and a large effect size of 2.19, indicating a strong impact. This impressive improvement makes Lactospore our #1 choice for reducing bloating. (1)

2. De Simone Formulation

Six studies evaluated the De Simone Formulation for bloating and distention in IBS, yielding generally positive results. Kim HJ et al. 2003 reported a significant reduction in bloating compared to placebo (−13.7 points, p = 0.046, Cohen’s d = 0.84). (2) Guandalini S et al. found a notable decrease in bloating and gas scores (p < 0.001, Cohen’s d = 3.73). (3) Wong R.K. et al. observed a reduction in abdominal distention intensity (p < 0.05, Cohen’s d = 1.28). (4) However, other studies had mixed results. Kim HJ et al. 2005 showed a higher response rate in the De Simone group (46% vs. 33%), but the difference wasn’t statistically significant (p = 0.27). (5) Michail S et al. found no significant changes, though our independent analysis revealed a significant effect with a large effect size (Cohen’s d = 1.63). (6) Tuteja AK et al. reported no significant differences in bloating scores between groups (p = 0.74). (7) Overall, the weighted mean effect size for bloating and distention was 2.14. These findings earned the De Simone Formulation the #2 spot in our rankings for bloating/distention relief.

3. Unique IS-2

Two studies evaluated the effects of Bacillus coagulans Unique IS-2 on bloating, both showing significant improvements. The first study, conducted in children with IBS, found an 80% reduction in bloating over 8 weeks, with scores dropping from 3.0 to 0.6 on a 5-point scale (Cohen’s h = 1.88). (8) The second study, conducted in adults with IBS, reported a 58.8% reduction in bloating, with scores decreasing from 3.4 to 1.4 on a 6-point scale (Cohen’s h = 1.42). (9) These consistent and substantial results earned Bacillus coagulans Unique IS-2 the #3 spot in our rankings for bloating relief.

4. Bio-Kult

In a study involving IBS-D participants, Bio-Kult significantly improved abdominal distention. From month 1 to month 4, participants experienced a 66.5% reduction in distention scores, with a moderate effect size of 0.78 (p < .001). (10) These improvements persisted through the 5-month follow-up, earning Bio-Kult the #4 spot in our rankings for bloating and distention relief.

Honorable Mentions

Paraghurt A randomized, placebo-controlled trial investigated the effects of Paraghurt in adults with IBS. While the study had limitations—such as a small sample size and the lack of clear CFU dosing (only described as “4 tablets per day”)—our independent analysis found that Paraghurt significantly reduced abdominal bloating, with an effect size of 0.84 (p = 0.008). (11) However, due to the unclear dosing information, we’ve included Paraghurt as an honorable mention for bloating relief.

Probio-tec 

In a placebo-controlled trial, participants taking Probio-Tec experienced a significant reduction in bloating, with a 13.0 mm improvement on a 100 mm Visual Analog Scale (VAS), compared to a 3.7 mm reduction in the placebo group (p < 0.01, effect size = 0.61). The benefits persisted one month after treatment (p = 0.03). (12) Probio-Tec has been placed in our honorable mentions because we are unable to confirm that similar commercial products are identical to the formulation and proportions of each strain studied. Additionally, their dosing does not match the studied formulation.

Our Criteria

The probiotics in our full database (below) are automatically ranked based on their 1) effect size for bloating and / or distention relief, followed by 2) effect size for overall IBS symptoms (‘Global IBS Symptoms’), and finally by 3) the quality of evidence from the studies.

For this summary, we selected our top choices based on these rankings, along with the following additional criteria: 

• Evidence Quality Score: We only included probiotics backed by studies with an evidence quality score of 75% or higher.
• Effect Size: Only probiotics that demonstrated a moderate to high effect size (>0.5) for bloating and / or distention relief made the cut.
• Clear Dosing Information: Only probiotics with clear and reliable dosing data were included.
• Commercial Availability: Probiotics needed to be commercially available to consumers.

No Direct Comparisons

It’s important to note that there are no direct comparisons between the probiotics in our database across identical study methods, so we can’t definitively rank one probiotic as superior to another. The probiotics highlighted above have shown promise for bloating and / or distention relief in IBS, but as with all probiotic supplements, always consult your healthcare provider before starting.

*Population values represent the per-protocol population size from studies specifically assessing the above parameters.
*Effect sizes are reported as the weighted mean effect size across studies.

References

1. Majeed, M., Nagabhushanam, K., Natarajan, S. et al. Bacillus coagulans MTCC 5856 supplementation in the management of diarrhea predominant Irritable Bowel Syndrome: a double blind randomized placebo controlled pilot clinical study. Nutr J 15, 21 (2015). https://doi.org/10.1186/s12937-016-0140-6
2. Kim HJ, Camilleri M, McKinzie S, et al. A randomized controlled trial of a probiotic, VSL#3, on gut transit and symptoms in diarrhoea-predominant irritable bowel syndrome. Aliment Pharmacol Ther 2003;17:895–904.
3. Guandalini S, Magazzu G, Chiaro A, et al. VSL#3 improves symptoms in children with irritable bowel syndrome: a multicenter, randomized, placebo-controlled,double-blind, crossover study. J Pediatr Gastroenterol Nutr 2010;51(1):24–30.doi: 10.1097/MPG.0b013e3181ca4d95. 
4. Wong, R.K., Yang, C., Song, GH. et al. Melatonin Regulation as a Possible Mechanism for Probiotic (VSL#3) in Irritable Bowel Syndrome: A Randomized Double-Blinded Placebo Study. Dig Dis Sci 60, 186–194 (2015). https://doi.org/10.1007/s10620-014-3299-8
5. Kim HJ, Vazquez Roque MI, Camilleri M, et al. A randomized controlled trial of a probiotic combination VSL# 3 and placebo in irritable bowel syndrome with bloating. Neurogastroenterol Motil 2005;17(5):687–96. doi: 10.1111/j.13652982.2005.00695.x.
6. Michail S, Kenche H. Gut microbiota is not modified by Randomized, Double-blind, Placebo-controlled Trial of VSL#3 in Diarrhea-predominant Irritable Bowel Syndrome. Probiotics Antimicrob Proteins. 2011 Mar;3(1):1-7. doi: 10.1007/s12602-010-9059-y. PMID: 22247743; PMCID: PMC3255476.
7. Tuteja AK, Talley NJ, Murtaugh MA, Loc-Carrillo CM, Stoddard GJ, Anderson GL. Randomized, Double-Blind Placebo-Controlled Trial to Assess the Effect of Probiotics on Irritable Bowel Syndrome in Veterans With Gulf War Illness. Fed Pract. 2022 Oct;39(10):410-417. doi: 10.12788/fp.0322. Epub 2022 Oct 12. PMID: 36744017; PMCID: PMC9896367.
8. Sudha MR, Jayanthi N, Aasin M, et al. Efficacy of Bacillus coagulans Unique IS2 in treatment of irritable bowel syndrome in children: a double blind, randomised placebo controlled study. Benef Microbes 2018;9(4):563–72. doi: 10.3920/BM2017.0129.
9. Madempudi RS, Ahire JJ, Neelamraju J, et al. Randomized clinical trial: the effect of probiotic Bacillus coagulans Unique IS2 vs. placebo on the symptoms management of irritable bowel syndrome in adults. Sci Rep 2019;9:12210. doi: 10.1038/s41598-019-48554-x. 
10. Ishaque SM, Khosruzzaman SM, Ahmed DS, Sah MP. A randomized placebo-controlled clinical trial of a multi-strain probiotic formulation (Bio-Kult®) in the management of diarrhea-predominant irritable bowel syndrome. BMC Gastroenterol 2018 May 25;18(1):71. [doi: 10.1186/s12876-018-0788-9]
11. Gade J, Thorn P. Paraghurt for patients with irritable bowel syndrome. A controlled clinical investigation from general practice. Scand J Prim Health Care 1989 Mar;7(1):23-6.
12. Jafari E, Vahedi H, Merat S, Momtahen S, Riahi A. Therapeutic effects, tolerability and safety of a multi-strain probiotic in Iranian adults with irritable bowel syndrome and bloating. Arch Iran Med 2014 Jul;17(7):466-70. [doi: 0141707/AIM.003] 

When selecting our top probiotic picks, we ensure they are commercially available and backed by high-quality evidence, with an average score above 75% for the relevant symptom parameters. The probiotics must also demonstrate a moderate to high effect size (>0.5) for these symptoms. If there are more than five candidates, we limit our top picks to the best five based on the effect size for relevant symptoms and Global IBS symptoms, as well as evidence quality. This ensures our recommendations are practical and reliable.

When selecting our top probiotic picks, we ensure they are commercially available and backed by high-quality evidence, with an average score above 75% for the relevant symptom parameters. The probiotics must also demonstrate a moderate to high effect size (>0.5) for these symptoms. If there are more than five candidates, we limit our top picks to the best five based on the effect size for relevant symptoms and Global IBS symptoms, as well as evidence quality. This ensures our recommendations are practical and reliable.