Mu Q, Tavella VJ, Luo XM. Frontiers in Microbiology. 2018;9:757. doi:10.3389/fmicb.2018.00757
Background & Rationale
Amid rising antibiotic resistance and interest in non-drug approaches to gut and immune health, this review examines Lactobacillus reuteri, a well-characterised probiotic species that colonises the human gastrointestinal tract, urinary tract, skin, and breast milk. The authors note that L. reuteri abundance in humans has declined in recent decades alongside a rise in inflammatory disease incidence. The review consolidates evidence on how L. reuteri may confer benefit, via antimicrobial metabolites, immune modulation, and gut barrier support, and summarises clinical evidence across various conditions.
Study Design
This is a narrative review, not a primary trial. The authors synthesise in vitro and human clinical data from published literature, several studies being randomised, double-blind, and placebo-controlled at the individual level. The review covers L. reuteri’s probiotic properties (colonisation, metabolite production, microbiota and immune modulation, neuromodulation, barrier function) and clinical applications in early-life disorders, lupus, obesity, neurodevelopmental conditions, and stress-related infection. No meta-analysis is performed; findings are reported descriptively.
Patient Population
As a review, no single population is described. Cited human data span infants (including preterm and Caesarean-born), children, adolescents, healthy adults, postmenopausal and pregnant women, H. pylori patients, overweight adults, type 2 diabetics, cystic fibrosis patients, and IBD patients. Strains include DSM 17938, ATCC 55730, ATCC PTA 6475, RC-14, and NCIMB 30242, with effects noted as often strain-specific.
Key Findings
In H. pylori infection, several trials reported reduced pathogen load, improved dyspepsia, and fewer antibiotic side effects, though one found no added benefit over triple therapy. L. reuteri DSM 17938 shortened acute diarrhoea duration in children, and most infant colic trials showed reduced crying, though some found no effect, attributed to differences in dose, age, and baseline microbiota. In atopic dermatitis, supplementation improved eczema severity, reduced GI symptoms, and lowered intestinal permeability (lactulose:mannitol ratio). A trial of strain JBD301 reduced body weight in overweight adults over 12 weeks, while formula-fed infants showed no increased weight gain. In type 2 diabetes, three months of DSM 17938 did not significantly alter gut microbiota. In cystic fibrosis, DSM 17938 reduced Proteobacteria and increased Firmicutes abundance. In IBD, a yoghurt containing L. reuteri RC-14 was linked to anti-inflammatory changes in blood.
Discussion
L. reuteri was generally well tolerated across studies in adults, children, infants, and an HIV-infected population, with doses up to 2.9×10⁹ CFU/day reported safe, and no serious adverse events attributed to supplementation. The authors attribute inconsistent findings, particularly for colic and obesity, to variation in strain, dose, duration, and population characteristics. Mechanistic antimicrobial, immunomodulatory, and barrier effects offer plausible rationale, though causal proof from clinical data alone is not claimed.
Authors’ Conclusions
The authors note that declining L. reuteri abundance coincides with rising inflammatory disease rates, while acknowledging causality is unproven. They suggest boosting L. reuteri colonisation, via supplementation or prebiotics, may be a relatively safe strategy for preventing or treating inflammatory disease, locally and systemically. Given strain-dependent effects, combining multiple strains may enhance benefit. Limitations include strain specificity and reliance on heterogeneous studies rather than unified trial design.
Reference
Mu Q, Tavella VJ, Luo XM. Role of Lactobacillus reuteri in Human Health and Diseases. Front Microbiol. 2018;9:757. doi:10.3389/fmicb.2018.00757
This Scientific Publication Summary is an objective summary of the published trial for personal and educational use. It does not constitute clinical advice, endorsement of the intervention, or a recommendation to alter clinical practice.