Probiotics and carriage of Streptococcus pneumoniae serotypes in Danish children, a double-blind randomized...

Area of Science:

• Microbiology
• Pediatrics
• Immunology

Background:

• Streptococcus pneumoniae carriage is common in young children.
• Understanding carriage dynamics is crucial for preventing invasive pneumococcal disease (IPD).
• Probiotics are explored for their potential impact on respiratory pathogens.

Purpose of the Study:

• To investigate Streptococcus pneumoniae carriage in healthy Danish children aged 8-19 months.
• To assess the efficacy of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis on pneumococcal carriage.
• To analyze risk factors for carriage and compare findings with invasive pneumococcal disease (IPD) data.

Main Methods:

• A double-blind, randomized controlled trial (ProbiComp study) involving 290 children.
• Children received probiotics or placebo for 6 months during daycare enrollment.
• Pneumococci identification and serotyping using optochin sensitivity, bile solubility, and Quellung reaction.

Main Results:

• The overall carriage rate of S. pneumoniae increased from 26.0% at baseline to 67.4% at the end of the intervention.
• No significant difference in pneumococcal carriage was observed between the probiotic and placebo groups (p=0.508).
• Children carried non-vaccine serotypes prevalent in younger children, but not those common in elderly IPD cases.

Conclusions:

• Probiotics Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis did not significantly alter pneumococcal carriage in this cohort.
• Danish children aged 8-19 months primarily carry S. pneumoniae serotypes not associated with high IPD rates in the elderly.
• Other age groups may be more significant reservoirs for pneumococcal serotypes causing IPD in the elderly, warranting further investigation.