Lactobacillus rhamnosus GG
Lacticaseibacillus rhamnosus GG (ATCC 53103)
The most-studied probiotic strain — best evidence for antibiotic-associated and acute pediatric diarrhea
Evidence tier
Strong
Research weight
Citations
14 verified / 14
Classification
Probiotics
❝
What the evidence says. Multiple high-quality RCTs / meta-analyses with consistent effects.
What is Lactobacillus rhamnosus GG?
Lactobacillus rhamnosus GG (Lacticaseibacillus rhamnosus GG (ATCC 53103)) is a probiotic strain used for prevents antibiotic-associated diarrhea, cutting risk from ~22% to ~12% (rr 0.49); effect significant in children (rr 0.48). NutriDex grades the human evidence as Strong. Lacticaseibacillus rhamnosus GG (ATCC 53103) is the world's most extensively researched probiotic strain. The strongest randomized-trial and meta-analytic evidence supports preventing antibiotic-associated diarrhea (especially in children, RR ~0.48-0.49) and reducing the duration of acute infectious gastroenteritis in children by roughly 0.5-1 day, with effects clearest at high doses (≥10^10 CFU/day) and in rotavirus-positive disease. It also prevents healthcare-associated diarrhea and rotavirus gastroenteritis in hospitalized children and shows benefit for childhood IBS. Notably, two large high-quality 2018 RCTs (NEJM/PECARN and Canadian PERC) found no benefit for outpatient acute gastroenteritis, so the diarrhea-duration effect is real but modest and context-dependent.
Purported Benefits
✓Prevents antibiotic-associated diarrhea, cutting risk from ~22% to ~12% (RR 0.49); effect significant in children (RR 0.48)
✓Shortens acute infectious diarrhea in children by ~0.5-1 day, most clearly with high dose (≥10^10 CFU/day) and rotavirus diarrhea
✓Reduces healthcare-associated (nosocomial) diarrhea in hospitalized children (RR ~0.37) and rotavirus gastroenteritis (RR ~0.49)
✓Improves childhood irritable bowel syndrome — higher responder rate (RR 1.70, NNT 4) for abdominal pain
✓May reduce infantile colic crying time in breastfed infants (one RCT: 104 vs 242 min/day), though evidence is mixed
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Prevents antibiotic-associated diarrheaMeta-analysis of 11 RCTs cuts risk ~22%→12% (RR 0.49); effect significant in children. | Strong | ↑ benefit · moderate | 2 |
| Shortens acute infectious diarrhea in childrenMeta-analysis shows ~0.85-day reduction, but two large 2018 RCTs found no outpatient benefit. | Mixed | ↔ mixed · small | 3 |
| Improves childhood IBS / functional abdominal painMeta-analysis: higher responder rate for IBS pain (RR 1.70, NNT 4); pooled from 3 small RCTs. | Moderate | ↑ benefit · moderate | 1 |
| Reduces necrotizing enterocolitis in preterm infantsStrain-specific meta-analysis (5 RCTs) found reduced NEC ≥Stage II (RR 0.50) but no effect on other outcomes. | Moderate | ↑ benefit · moderate | 1 |
| Reduces infantile colic crying timeSingle small RCT (n=45) showed large crying reduction, but the entry notes evidence is mixed. | Preliminary | ↔ mixed · moderate | 1 |
| Bacteremia risk with indwelling intravascular cathetersWGS-confirmed case report of probiotic bacteremia in a catheterized patient on parenteral nutrition. | Preliminary | ⚠ risk | 1 |
Dosing & Compounds
Typical Dose
Trials commonly use 10^10 CFU/day (range 5×10^9 to ≥10^10 CFU/day); higher doses (≥10^10 CFU/day) are more effective for acute diarrhea. For antibiotic-associated diarrhea, give alongside the antibiotic course (separating from the antibiotic dose by a couple of hours) and continue for the duration of treatment; for acute gastroenteritis, start early and continue 5-7 days.
Active Compounds
Safety & Cautions
Generally well tolerated in healthy children and adults, with no serious adverse events in trials. Caution is warranted in critically ill, immunocompromised, or central-venous-catheter/short-gut patients: documented case reports of L. rhamnosus GG bacteremia/endocarditis, including a WGS-confirmed catheter-associated case. Avoid or use only under specialist guidance in immunosuppression, structural heart disease, indwelling intravascular lines, and compromised gut-barrier states. Not a substitute for oral rehydration in acute diarrhea. Educational only — always check with your doctor or pharmacist before combining Lactobacillus rhamnosus GG with any medicine.
Key Studies ★ 14 studies
Cochrane review
Cochrane (Esmaeilinezhad 2025)
✓ PubMed
Updated Cochrane review of probiotics for preventing Clostridioides difficile-associated diarrhea concluded probiotics may yield a small reduction in CDAD risk (about 1 case prevented per 65 people) with no increase in adverse effects in non-immunocompromised patients on antibiotics.
Systematic review / meta-analysis
Ananthan 2024 (EJCN, strain-specific MA)
✓ Source
Strain-specific systematic review and meta-analysis in preterm infants found single-strain L. rhamnosus GG significantly reduced necrotizing enterocolitis >=Stage II (5 RCTs, n=851, RR 0.50, 95% CI 0.26-0.93, P=0.03), though it did not affect other major outcomes.
Systematic review
Frontiers overview of SRs 2023
✓ Source
Overview of systematic reviews of probiotics for preventing/treating antibiotic-associated diarrhea in children synthesized the evidence base, supporting LGG and S. boulardii among the better-supported strains while flagging variable methodological quality across reviews.
Systematic review / meta-analysis
Szajewska & Kołodziej 2015
✓ PubMed
LGG reduced antibiotic-associated diarrhea from 22.4% to 12.3% (11 RCTs, n=1308, RR 0.49, 95% CI 0.29-0.83); significant in children (5 RCTs, n=445, RR 0.48, 95% CI 0.26-0.89).
Systematic review / meta-analysis (2019 update)
Szajewska et al. 2019
✓ PubMed
In children with acute gastroenteritis, LGG had no effect on stool volume but reduced diarrhea duration (15 RCTs, n=3820, MD -0.85 day, 95% CI -1.15 to -0.56); 18 RCTs, n=4208 total.
Meta-analysis
Horvath et al. 2011
✓ PubMed
For childhood abdominal-pain functional GI disorders, LGG raised treatment responders overall (3 RCTs, n=290, RR 1.31, NNT 7) and in IBS (3 RCTs, n=167, RR 1.70, 95% CI 1.27-2.27, NNT 4).
RCT
PICU AAD RCT 2025 (J Pediatr Pharmacol Ther)
✓ Full text
Prospective double-blind placebo-controlled RCT in critically ill children (<=17 y) on antibiotics >=72 h tested LGG vs placebo for prevention of antibiotic-associated diarrhea in the pediatric ICU (J Pediatr Pharmacol Ther 2025;30(1):47-51).
RCT
Reuterin GG hospitalized RCT 2024 (Microorganisms)
✓ Full text
Single-center open-label RCT in 113 hospitalized adults on antibiotics (>=5 days) found a L. reuteri LMG P-27481 + L. rhamnosus GG ATCC 53103 combination reduced antibiotic-associated diarrhea versus antibiotics alone.
Randomized controlled trial
Pärtty/Italian colic RCT (Nutrients) 2020
✓ Full text
In 45 colicky breastfed infants, LGG (ATCC 53103) 5×10^9 CFU/day for 28 days reduced median daily crying (104 vs 242 min, p<0.001) and fecal calprotectin (p=0.026).
Large double-blind RCT
Schnadower et al. 2018 (PECARN)
✓ Source
In 943 US children with acute gastroenteritis, LGG 10^10 CFU twice daily for 5 days showed no benefit over placebo for moderate-to-severe disease within 14 days.
Randomized placebo-controlled trial
Grüber et al. 2007
✓ PubMed
LGG 5×10^9 CFU twice daily for 12 weeks showed no therapeutic benefit for mild-to-moderate atopic dermatitis in infants aged 3-12 months.
Review
Cantón-Cordeiro 2026
✓ PubMed
Systematic review of the gut-bone axis and potential probiotic intervention pathways for bone health.
Review
Liu 2026
✓ PubMed
Seasonal Affective Disorder and the Microbiota-Gut-Brain Axis: Circadian Disruption, Tryptophan Metabolism, and Psychobiotic Potential of Lacticaseibacillus rhamnosus GG
Case report (whole-genome sequencing)
Salminen-region WGS case report 2022
✓ Full text
L. rhamnosus GG probiotic caused bacteremia in a multi-trauma patient with a central venous catheter on parenteral nutrition, confirmed by WGS, cautioning use with indwelling intravascular catheters.