Lactobacillus rhamnosus shows some potential benefits for IBS patients, particularly those with diarrhea-predominant IBS, but evidence is limited and mixed. More research is needed to confirm its efficacy.
What the research shows
A high-quality randomized controlled trial (PMID: 22563194) investigated Lactobacillus casei rhamnosus LCR35 in IBS patients and found no significant improvement in overall IBS severity compared to placebo. However, a subgroup with diarrhea-predominant IBS showed clinically relevant symptom improvement with LCR35. Other studies did not specifically evaluate Lactobacillus rhamnosus alone but used multi-strain probiotics including Lactobacillus species, showing some benefits in IBS symptom management. Meta-analyses and trials on other Lactobacillus strains (not rhamnosus) suggest probiotics may help IBS symptoms generally, but strain-specific effects vary and evidence certainty is often low to moderate. Safety profiles are generally good with few adverse events reported.
Best studied probiotic strains
Lactobacillus casei rhamnosus LCR35
Evidence is preliminary and from a small pilot study; larger studies are needed to confirm efficacy.
Who may benefit
Safety
Lactobacillus rhamnosus LCR35 was well tolerated with no significant adverse events reported. Probiotics in general have a good safety profile in IBS patients, including children and adults, with rare mild adverse events.
Limitations
Limited number of studies specifically on Lactobacillus rhamnosus for IBS; small sample sizes in subgroup analyses; mixed results across IBS subtypes; lack of large-scale confirmatory trials; heterogeneity in probiotic strains and formulations; some evidence is low certainty due to risk of bias and inconsistency.
PubMed sources
| Study | Type | Year | PMID |
|---|---|---|---|
| Efficacy and safety profile of LCR35 complete freeze-dried culture in irritable bowel syndrome: a randomized, double-blind study. World journal of gastroenterology |
Randomized Controlled Trial | 2012 | 22563194 |
| Probiotics for management of functional abdominal pain disorders in children. The Cochrane database of systematic reviews |
Meta-analysis | 2023 | 36799531 |
| Efficacy of Probiotics for Irritable Bowel Syndrome: A Systematic Review and Network Meta-Analysis. Frontiers in cellular and infection microbiology |
Meta-analysis | 2022 | 35433498 |
| Two Lactobacilli strains as adjuvant therapy in the management of irritable bowel syndrome: a randomized control trial. Ceska a Slovenska farmacie : casopis Ceske farmaceuticke spolecnosti a Slovenske farmaceuticke spolecnosti |
Randomized Controlled Trial | 2023 | 38195431 |
| Probiotic Blend of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis ssp. Lactis BB-12 in Non-constipated Irritable Bowel Syndrome: A Double-Blind Randomized Placebo-Controlled Trial. Journal of gastroenterology and hepatology |
Randomized Controlled Trial | 2026 | 41255078 |