Probiotics are live microbes which, when administered in sufficient amounts, confer a health benefit to the host. According to recent clinical trials, administration of probiotics to very low birth weight infants significantly reduces overall mortality and risk of necrotizing enterocolitis, a devastating inflammatory intestinal disease. The investigators have previously demonstrated that administering probiotics to the lactating mother enhances the immunoprotective properties of breast milk. Despite the promising data, the optimal probiotic intervention is yet to be established. The mechanisms by which probiotics exert their effects remain largely unknown.

This research project is based on the notion that modulation of early microbial contact by probiotics may provide a safe and effective means to improve the health of preterm infants. In particular, the investigators hypothesize that the protective potential of probiotics may be enhanced via breast milk by administering probiotics to the lactating mother. All of the potentially beneficial effects of probiotic bacteria are strain-specific and therefore preliminary laboratory and clinical research with regard to different physiological targets of probiotic intervention should be carried out to guide the design of large-scale clinical trials aiming show clinical efficacy and establish clinical practice. The purpose of this research project is to identify targets for probiotic therapy in premature neonates and to provide insight into the optimal probiotic strains and administration protocol the clinical efficacy of which will subsequently be tested in a randomized controlled trial.

The specific aims of the project are:

1. To determine the effect of maternal consumption of probiotics during lactation on immunomodulatory properties of breast milk in mothers of premature infants. Concentrations of immunomodulatory factors and microbiological properties of breast milk will be measured.
2. To investigate the impact of different probiotic administration protocols on gut microbiota composition in preterm infants. In particular, the issue whether maternal probiotic consumption instead or in addition to probiotics administered to the infant is effective will be elucidated. Different potential probiotic strains will be assessed.
3. To elucidate the impact probiotic bacteria administered to the lactating mother and/or directly to the infant on gut immunophysiology in preterm infants.

Inclusion Criteria:

• premature infant born at <35 weeks gestational age

Exclusion Criteria:

• severe asphyxia
• significant anomalies