Alterations of Intestinal Microbiome by Antibiotic Therapy in Hospitalized Children.

The administration of antimicrobial agents leads to an ecological imbalance of the host-microorganisms relationship, and it causes a rapid and significant reduction in the microbial diversity. The aim of the current study was to evaluate the impact of antibiotic therapy on intestinal microbiota of children between 3 and 12 years of age. The fecal samples were collected from hospitalized children (n = 31) and from healthy untreated children (n = 30). The presence of bacteria and their quantities were assessed by culture-based methods and quantitative polymerase chain reaction (qPCR). By culture method, in the children receiving antibiotics, a low recovery of Bifidobacterium spp. (54.8%), Bacteroides spp./Parabacteroides spp. (54.8%), Clostridium spp. (35.5%), and Escherichia coli (74.2%) was observed compared with the children without antibiotic therapy (100%, 80%, 63.3%, and 86.6%, respectively). By qPCR, the children receiving antibiotics showed a lower copy number for all microorganisms, except to Lactobacillus spp. (p = 0.0092). In comparison to the nontreated children, the antibiotic-treated children showed a significantly lower copy number of Bifidobacterium spp. (p = 0.0002), Clostridium perfringens (p < 0.0001), E. coli (p = 0.0268), Methanobrevibacter smithii (p = 0.0444), and phylum Firmicutes (p = 0.0009). In conclusion, our results obtained through qualitative and quantitative analyses, demonstrate that antibiotic therapy affect the intestinal microbiome of children.