Probiotics and gut health in infants: A preliminary case-control observational study about early treatment with Lactobacillus reuteri DSM 17938.

AIMS: we performed this case-control observational study to evaluate the effects of early administration of Lactobacillus reuteri DSM 17938 on microbial composition in infants' gastrointestinal tract. METHODS: early fecal microbiota composition was analyzed by using selective and differential cultural methods. Genomic DNA from positive Escherichia coli and Cronobacter sakazakii colonies was extracted and DNA was processed by multiplex PCR assay. RESULTS: fecal samples of 30 hospitalized infants who previously received probiotics and 30 not receiving probiotics were analyzed. We find that the two groups showed differences in gut microbial strains composition and richness. Infant treated with probiotics have a lower total anaerobic gram negative counts (p=0.03) and a higher total anaerobic gram-positive counts (p=0.02). Enterobacteriaceae and enterococci were significantly higher (p=0.04) in the control group. No significant differences were observed for total aerobic counts, lactobacilli and bifidobacteria. C. sakazaki was found only in one infant recruited in the control group. Infants not previously treated with probiotics showed a higher colonization by diarrheagenic E. coli (EPEC) (p=0.04). CONCLUSIONS: our findings enhanced our understanding of the effects of probiotics on gut health in pediatric subjects. Early administration of L.reuteri in infancy could improve gut health by reducing pathogens colonization.