Probiotics and the immunological response to infant vaccinations; a double-blind randomized controlled trial

Area of Science:

• Immunology
• Microbiology
• Pediatrics

Background:

• Infant vaccination is crucial for preventing infectious diseases.
• The gut microbiome may influence vaccine immunogenicity.
• Probiotics are being explored for their potential to modulate immune responses.

Purpose of the Study:

• To investigate the impact of a specific probiotic combination on antibody responses to pneumococcal and pertussis vaccines in Danish infants.
• To assess the effect of probiotics on cytokine production (IL-6 and IFN-γ) in response to bacterial lipopolysaccharide.

Main Methods:

• A randomized controlled trial involving 290 healthy Danish children aged 8-14 months.
• Participants received either a probiotic blend (Bifidobacterium animalis ssp. lactis and Lactobacillus rhamnosus GG) or a placebo for six months.
• Antibody levels against Streptococcus pneumoniae and Bordetella pertussis, and cytokine production (IL-6, IFN-γ) were measured.

Main Results:

• No significant differences were observed in antibody concentrations against S. pneumoniae and B. pertussis between the probiotic and placebo groups.
• The probiotic group exhibited a significantly lower average individual change in IL-6 concentration compared to the placebo group (p=0.024).
• No significant difference was found in IFN-γ concentration between the groups.

Conclusions:

• Probiotic supplementation did not improve the antibody response to pneumococcal or pertussis vaccination in healthy Danish infants.
• The observed reduction in IL-6 suggests a potential immunomodulatory effect of the probiotic intervention, warranting further investigation.