Supplement analysis backed by scientific evidence · PT

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Moderate evidenceGut health

Lactobacillus Rhamnosus GG

The most-studied probiotic strain in the world, with decent meta-analytic support for antibiotic-associated diarrhoea — but a large, rigorous NEJM trial found it completely ineffective for acute gastroenteritis in children, which should temper expectations considerably.

What the science says

  • No benefit for acute gastroenteritis in children (high-quality trial) Strong evidence

    In a double-blind trial of 971 children aged 3 months to 4 years (Schnadower, NEJM 2018), LGG at 10^10 CFU twice daily for 5 days produced no difference from placebo in moderate-to-severe gastroenteritis outcomes, duration of diarrhoea, vomiting or missed daycare days. This directly contradicts earlier, smaller, lower-quality meta-analyses and is the strongest single piece of evidence on the question.

  • Shortens acute diarrhoea — but mainly in older, lower-quality trials Limited evidence

    A 2019 meta-analysis update found LGG shortened diarrhoea duration by roughly a day, with the effect concentrated in European trials and largely absent in Asian populations and in trials at low risk of bias. Once the large rigorous trials are weighted properly, the benefit shrinks toward nothing; efficacy also appears reduced in rotavirus-vaccinated children.

  • Prevents antibiotic-associated diarrhoea Moderate evidence

    Pooled RCTs support LGG for reducing antibiotic-associated diarrhoea in children and adults, with risk reductions broadly comparable to S. boulardii (relative risk around 0.5) at 10-20 billion CFU/day. This remains its best-supported use.

  • Prevents atopic dermatitis or allergy Limited evidence

    Perinatal LGG showed benefit for eczema prevention in early Finnish trials but failed to replicate in later trials in other populations, and effects on asthma and food allergy have been consistently null. Population-specific at best.

Dosage & safety

Studied dose10^9 to 10^10 CFU (1-10 billion) once or twice daily. Trials for antibiotic-associated diarrhoea used 10-20 billion CFU/day started with the antibiotic and continued 1-2 weeks after. Take bacterial probiotics at least 2 hours apart from an antibiotic dose.
SafetyWell tolerated in healthy people; transient gas and bloating are common in the first days. Documented cases of LGG bacteraemia, endocarditis and liver abscess exist, essentially all in immunocompromised patients, those with central venous catheters, short bowel syndrome, or damaged heart valves — avoid in those groups. Probiotics should not be given to critically ill patients outside a trial: a landmark trial of a Lactobacillus-containing product in severe acute pancreatitis found increased mortality. Product quality varies widely; CFU counts decline with heat and time, so check expiry-dated potency rather than at-manufacture counts.

Scientific references

Where to buy

Swanson Vitamins, Lactobacillus Rhamnosus With FOS, 60 Vegan Capsules

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