Abstract
Probiotic research is of increasing interest as more evidence of the microbiome’s role in health and disease comes to light, with beneficial alteration of the microbiome with probiotics being desirable. The early establishment of a healthy microbiome in an individual is also of interest. Streptococcus salivarius K12 is an oral probiotic, a bacterium naturally found in humans that has inhibitory activity against numerous pathogens such as Streptococcus pyogenes and Streptococcus agalactiae along with possible beneficial immunomodulation. The main aim of the study was to investigate the transfer of S. salivarius strain K12 from a colonised mother to her baby in the early post-natal period. Nine pregnant women were recruited and dosed with S. salivarius K12 from 37 weeks gestation until 3 weeks post-partum. Saliva samples from the mother and baby, along with breast milk samples, were collected at 1, 2, 4, 8 and 12 weeks post-delivery and tested for S. salivarius inhibitory activity and strain K12 presence.
The results of the study show that most babies acquire similar S. salivarius populations to their mother as soon as one week after birth. Six of the nine babies yielded isolates of the P-type 777 S. salivarius and five of these isolates were established to be strain K12. The mothers in the study showed better colonisation rates (100%) compared to a previous study where the K12 dosing ended at birth (25%), indicating the importance of maintaining probiotic dosing post-partum. More than half of the mothers took antibiotics during the study, which affected colonisation success in baby and mother. The effects of antibiotics on the oral microbiome of mothers and babies needs to be further explored. The incidence of perinatal antibiotic use in a larger population needs to be established, which may further support the value of probiotics in this period.
Screening of a number of candidate probiotic S. salivarius strains against common neonatal pathogens showed that strains K12 and 8618 have strong in vitro inhibitory activity against many of these pathogens, making them excellent probiotic candidates. Of special interest was the inhibitory activity of strain 8618 against Neisseria meningitidis, Moxarella catarrhalis (cause of acute otitis media) and also Mycobacterium bovis.