Lactobacillus rhamnosus GG (LGG)

LGG was long promoted as standard for paediatric acute gastroenteritis – based on older Cochrane Allen 2010 RCTs, ESPGHAN 2014 endorsement and wide clinical practice. Large multicentre RCT Schnadower 2018 (PECARN, NEJM, 943 children with acute gastroenteritis) showed NO effect of LGG 1×10^10 CFU twice daily × 5 days vs placebo on diarrhoea duration, vomiting episodes or outpatient visits. Parallel Canadian Freedman 2018 RCT (NEJM, 886 children with a combined L. rhamnosus R0011 + L. helveticus R0052 probiotic, a different rhamnosus strain, not LGG) was also negative. AGA 2020 does not recommend probiotics in children or adults with acute infectious gastroenteritis. Primary therapy for acute gastroenteritis is oral rehydration (ORS); severe dehydration – intravenous infusion. If LGG was recommended as a substitute for rehydration, consider seeking a second opinion from a paediatrician.

ICD-10: A09 · ICD-11: 1A40

LGG is offered in bacterial vaginosis as «vaginal microbiota restoration after metronidazole» or monotherapy. WHO STI 2021 and IUSTI 2018 list metronidazole 500 mg twice daily × 7 days oral or metronidazole 0.75% vaginal gel × 5 days or clindamycin 2% cream × 7 days first-line for bacterial vaginosis. Probiotics (including LGG and L. crispatus) – option with limited evidence base; small RCTs showed heterogeneous results with adjunct post-antibiotic use to reduce recurrence rates. In women with recurrent BV, STI workup (chlamydia, gonorrhoea, trichomoniasis) and risk factor discussion (new or multiple sexual partners, douching) are mandatory. If LGG was recommended as a metronidazole substitute or without diagnostic confirmation (Amsel criteria or Nugent score), consider seeking a second opinion from a gynaecologist.

ICD-10: N76 · ICD-11: GA02

Lactobacillus rhamnosus GG (LGG) is heavily marketed for immune support and preventing colds, but strain-specific evidence for this claim is weak. A 2022 Cochrane review of probiotics overall suggested a possible drop in URTI episodes, yet the certainty was low to moderate and it pooled many strains rather than LGG alone. Pediatric data are mixed: a 2013 meta-analysis reported reduced infection risk, while a larger 2022 randomized trial in 619 children failed to show a reduction in URTI incidence by prespecified criteria. EFSA has not accepted a cause-and-effect link between LGG and defence against infection, so this benefit cannot be claimed in the EU. No serious harm is documented and adverse events are usually mild and gastrointestinal, so use is a personal choice.

LGG is offered for irritable bowel syndrome as part of multi-strain formulas. ACG 2021 IBS guideline gives a conditional recommendation against routine probiotic use in adult IBS: effect is heterogeneous, strain-specific, evidence low-quality. If a patient must choose between LGG and other options (soluble psyllium fibre, low-FODMAP diet, antispasmodics for IBS-D, rifaximin for IBS-D), LGG is not a priority option. NICE NG61 IBS 2017 states: if a patient decides to try a probiotic – minimum 4 weeks at the manufacturer-recommended dose, with effect assessment at end of course. If LGG was recommended for IBS without discussing diet, psyllium and red flags (weight loss, nocturnal symptoms, bloody stool), consider seeking a second opinion.

ICD-10: K58.8 · ICD-11: DD91.0Z

LGG is offered for travellers diarrhoea prevention. Several RCTs showed moderate episode frequency reductions in tourists to endemic regions (Hilton 1997, Oksanen 1990), but the effect is modest and not consistently reproduced across geographies. ISTM (International Society of Travel Medicine) 2017 for travellers diarrhoea prevention lists food safety, hand hygiene and in risk groups – ciprofloxacin or rifaximin when indicated; probiotics are mentioned as an option with limited evidence base. For established travellers diarrhoea, primary therapy is oral rehydration; for bacterial aetiology – azithromycin or ciprofloxacin. If LGG was recommended as a substitute for oral rehydration or empirical antibiotic in a severe episode with fever and bloody stool, consider seeking a second opinion.

ICD-10: A09 · ICD-11: 1A40

LGG is sold as «natural thrush remedy» in oral and intravaginal capsule forms. There are no quality data on LGG specifically in vulvovaginal candidiasis: small probiotic studies are heterogeneous and mostly involve other Lactobacillus species, with no systematic reviews reaching convincing conclusions. IUSTI 2018 lists fluconazole 150 mg single dose first-line for vulvovaginal candidiasis (or topical clotrimazole/miconazole); for recurrent – fluconazole 150 mg every 3 days × 3 doses + 6-month maintenance therapy. Lactobacilli are not in first-line guideline recommendations. If LGG was recommended as a substitute for antifungal therapy or in recurrent candidiasis without diabetes, HIV and other predisposing factor screening, consider seeking a second opinion from a gynaecologist.

ICD-10: B37.3 · ICD-11: 1F23.10