Background and aims
Dysbiosis with reduced microbial diversity has been associated with multiple diseases including necrotizing enterocolitis in premature infants. Probiotics may counteract the dysbiosis and hence promote health. The aim of the study was to investigate the effect of probiotic supplementation on the gut microbiome in extremely low birth weight (ELBW; birth weight < 1000g, gestational week <28) infants.
Methods
In a randomized, double-blind, multi-center, placebo-controlled trial, ELBW infants were supplemented with either probiotics (L. reuteri DSM 17938) or placebo from birth to gestational week 36. A total of 551 stool samples were used for profiling the gut microbiota with next generation sequencing at 1, 2, 3 and 4 weeks of age, at gestational week 36 and at 2-years of age.
Results
ELBW infants harbored relatively simple bacterial communities in the gut from birth to gestational week 36. Intake of L. reuteri led to a significant increase of Lactobacillus load and microbial diversity and  during neonatal period and a reduction of Staphylococcus at one week of life. There was no correlation between the increased microbiota diversity and the primary clinical outcomes.
Conclusions
The main finding of this study is that supplementation of L. reuteri DSM 17938, in ELBW preterm infants, affects the microbiome during the neonatal period in terms of altered composition and increased alpha-diversity.

11 - EXTREMELY LOW BIRTH WEIGHT INFANTS SUPPLEMENTED WITH PROBIOTIC LACTOBACILLUS REUTERI DSM 17938 HAD HIGHER GUT MICROBIOTA DIVERSITY DURING THE NEONATAL PERIOD