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.