Lactobacillus Rhamnosus
Lactobacillus rhamnosus
TL;DR
Lactobacillus rhamnosus GG is the single most-studied probiotic strain, with solid evidence for preventing antibiotic-associated diarrhea and shortening infectious diarrhea in children — and clear negative trials for acute gastroenteritis in emergency settings.
Ideal For
- Anyone starting a course of antibiotics
- Children with acute infectious diarrhea outside emergency-department settings
- Travellers wanting a modest reduction in traveller's diarrhea risk
Avoid If
- You are severely immunocompromised
- You have a central venous catheter
- You are in intensive care with a compromised gut barrier
Frequently Asked Questions
Overview
Lactobacillus rhamnosus GG (LGG) has been in continuous clinical study since the 1980s, giving it an unusually complete evidence file — including the negative results that most probiotics never generate. The strongest positive signal is prevention of antibiotic-associated diarrhea: Cochrane-level syntheses show meaningful risk reduction in both children and adults when LGG is started alongside the antibiotic. It also modestly shortens acute infectious diarrhea in children, mostly in outpatient and developing-country settings. The honest counterweight is a pair of large, well-run 2018 trials (PECARN and PERC) in North American emergency departments that found LGG no better than placebo for children with acute gastroenteritis. Those results should temper expectations: LGG helps most where the baseline diarrhea burden is high or antibiotic-driven. Evidence for eczema prevention is mixed — early Finnish trials were positive, later replications largely were not. Claims for weight loss, mood and immunity in healthy adults are not supported at a level that justifies daily use.
How It Works
- Adheres tightly to intestinal mucus via SpaCBA pili, allowing transient colonization
- Competitively excludes pathogens and reinforces tight-junction proteins
- Stimulates secretory IgA and modulates dendritic cell signalling
- Produces lactic acid, lowering luminal pH in the colon
Supporting Research7 studies
Administration of a probiotic with peanut oral immunotherapy: a randomized trial
Tang ML, Ponsonby AL, Orsini F +4 more
Combined Lactobacillus rhamnosus plus peanut oral immunotherapy induced possible sustained unresponsiveness in 82.1% versus 3.6% on placebo.
Systematic review with meta-analysis: Lactobacillus rhamnosus GG in the prevention of antibiotic-associated diarrhoea in children and adults
Szajewska H, Kolodziej M
LGG reduced the risk of antibiotic-associated diarrhoea from 22.4% to 12.3% (RR 0.49).
Efficacy of Lactobacillus rhamnosus GG in treatment of acute pediatric diarrhea: A systematic review with meta-analysis
Li YT, Xu H, Ye JZ
LGG significantly reduced the duration of acute diarrhoea in children, with greater effect at doses of 10^10 CFU/day or more.
Lactobacillus rhamnosus GG versus Placebo for Acute Gastroenteritis in Children
Schnadower D, Tarr PI, Casper TC +3 more
Among preschool children with acute gastroenteritis, L. rhamnosus GG did not prevent development of moderate-to-severe gastroenteritis within 14 days.
Multicenter, Randomized, Double-Blind Trial of Probiotics for Acute Gastroenteritis in Children
Freedman SB, Williamson-Urquhart S, Farion KJ
A combined Lactobacillus probiotic did not improve outcomes in children with acute gastroenteritis compared with placebo.
Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial
Kalliomaki M, Salminen S, Arvilommi H
Atopic eczema was diagnosed in 23% of children receiving Lactobacillus GG versus 46% receiving placebo.
Lactobacillus GG in the prevention of gastrointestinal and respiratory tract infections in children who attend day care centers: a randomized, double-blind, placebo-controlled trial
Hojsak I, Snovak N, Abdovic S
LGG reduced the risk of upper respiratory tract infections and of respiratory infections lasting longer than three days.
Safety Information
Potential Side Effects
Bloating and gas in the first few days are typical and self-limiting. Bacteremia is rare and effectively restricted to severely ill or catheterized patients.
Contraindications
Severe immunosuppression, central lines, acute pancreatitis in critical care.
Drug Interactions
- Antibiotics — space doses by 2-3 hours
- Immunosuppressants — discuss with your clinician first
Pregnancy & Breastfeeding
Pregnancy: likely_safe
Breastfeeding: likely_safe
Dosage Guidelines
Dosage Used in Studies
Consult healthcare provider
Forms Compared
Food & Timing
Take with or shortly before a meal; separate from antibiotic doses by at least two hours.
Medical Disclaimer
The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.
Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.