Certain probiotic strains, such as Bacillus coagulans, multispecies probiotics including Bifidobacterium animalis subsp. lactis BB-12, Escherichia coli Nissle 1917, and Lacticaseibacillus rhamnosus GG, have shown evidence of helping alleviate digestive problems, particularly in functional dyspepsia and irritable bowel syndrome (IBS). However, effects vary by strain and condition, and some strains like Lactiplantibacillus plantarum 299v showed no significant benefit in IBS.
What the research shows
High-quality randomized controlled trials support the use of Bacillus coagulans MY01 and Bacillus subtilis MY02 for functional dyspepsia, showing improved symptom response compared to placebo. For IBS, multispecies probiotics containing Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus rhamnosus GG, and others have demonstrated symptom relief and microbiota stabilization. Escherichia coli Nissle 1917 showed benefits mainly in IBS patients with prior gastroenteritis or antibiotic use. Lacticaseibacillus rhamnosus GG also showed symptom improvement in IBS. However, Lactiplantibacillus plantarum 299v did not show significant efficacy in IBS. Some studies suggest probiotics may help with digestive comfort in general populations, but more confirmatory trials are needed. Evidence for probiotics in dyspepsia related to Helicobacter pylori is low and mainly theoretical. Safety profiles are generally good with similar adverse event rates to placebo. Limitations include small sample sizes, heterogeneity of probiotic strains and IBS subtypes, and some open-label or pilot study designs.
Best studied probiotic strains
Bacillus coagulans MY01 and Bacillus subtilis MY02
Effective in functional dyspepsia; studied as spore-forming probiotics.
Bifidobacterium animalis subsp. lactis BB-12 (part of multispecies probiotic)
Used in combination with other strains; benefits mainly in IBS.
Escherichia coli Nissle 1917
Strain-specific benefit in IBS subgroups with altered microflora.
Lacticaseibacillus rhamnosus GG (part of probiotic mixtures)
Often studied as part of multispecies probiotic mixtures.
Who may benefit
Safety
Probiotics studied were generally safe with adverse event rates similar to placebo. Serious adverse events were rare and unlikely related to probiotic use.
Limitations
Many studies have small sample sizes or pilot designs. Probiotic effects are strain-specific and may not generalize across all digestive problems. Some evidence is limited to IBS or functional dyspepsia and may not apply to other digestive conditions. More large-scale, double-blind RCTs are needed to confirm benefits and identify optimal strains and doses.
PubMed sources
| Study | Type | Year | PMID |
|---|---|---|---|
| Efficacy and safety of spore-forming probiotics in the treatment of functional dyspepsia: a pilot randomised, double-blind, placebo-controlled trial. The lancet. Gastroenterology & hepatology |
Randomized Controlled Trial | 2021 | 34358486 |
| Systematic review: Complementary and alternative medicine in the irritable bowel syndrome. Alimentary pharmacology & therapeutics |
Systematic Review | 2006 | 16441466 |
| Clinical trial: multispecies probiotic supplementation alleviates the symptoms of irritable bowel syndrome and stabilizes intestinal microbiota. Alimentary pharmacology & therapeutics |
Randomized Controlled Trial | 2008 | 17919270 |
| Therapeutic Role of Probiotics for the Treatment of Dyspepsia: A Review of the Literature. Neurogastroenterology and motility |
Research Study | 2025 | 40342291 |
| A double-blind placebo-controlled trial to study therapeutic effects of probiotic Escherichia coli Nissle 1917 in subgroups of patients with irritable bowel syndrome. International journal of colorectal disease |
Randomized Controlled Trial | 2012 | 22130826 |
| A probiotic mixture alleviates symptoms in irritable bowel syndrome patients: a controlled 6-month intervention. Alimentary pharmacology & therapeutics |
Randomized Controlled Trial | 2005 | 16128676 |
| Bacterial supplementation in the irritable bowel syndrome. A randomised double-blind placebo-controlled crossover study. Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver |
Randomized Controlled Trial | 2000 | 11515626 |
| Fermented milk containing Bifidobacterium lactis DN-173 010 improved self-reported digestive comfort amongst a general population of adults. A randomized, open-label, controlled, pilot study. Journal of digestive diseases |
Randomized Controlled Trial | 2009 | 19236549 |
| Effects of symbiotic preparations on constipated irritable bowel syndrome symptoms. Acta bio-medica : Atenei Parmensis |
Clinical Trial | 2007 | 17933278 |
| Role of Lactobacillus plantarum 299v versus Placebo in symptomatic improvement of irritable bowel syndrome patients. JPMA. The Journal of the Pakistan Medical Association |
Randomized Controlled Trial | 2022 | 35320214 |