Revista de histología molecular y fisiología médica

Microbial Diversity of Human milk and Infants

Abstract

Omnia Badr

A wide variety of microbial communities found in human milk have positive benefits on health, including colonisation and gut development in young children. In this study, we described the bacterial communities in the Egyptian mother-infant pairs throughout the first year of life while they were breastfed normally. Forty-one isolates were chosen for probiotic potential out of one hundred isolates. The physical and biochemical profiles of the chosen isolates were created. Based on the 16S rRNA gene sequence and phylogenetic trees between the isolates' sequence and the closest sequences in the database, the taxonomic evidence of these isolates was examined. The isolates were identified as belonging to three genera: Lactobacillus, Enterococcus and Lactococcus based on taxonomic and biochemical evidence. With a high incidence of its many species, the genus Lactobacillus was the most prevalent one in samples of human milk and faeces (Lacticaseibacillus paracasei, Lactobacillus delbrueckii, Lactiplantibacillus plantarum, Lactobacillus gasseri and Lacticaseibacillus casei). Interestingly, BlastN and Jalview alignment findings showed that six isolates had poor identity ratios with database sequences (less than 95%). The distinct physiological, biochemical and probiotic characteristics of these isolates substantiated this differentiation. The isolate L. delbrueckii, ASO 100, which had the best probiotic and antibacterial characteristics and the lowest identity ratio, is highly likely to be a new species. Probiotic tests and ultrastructural analysis were performed on nine isolates and the results showed that these isolates had a high potential for use as preventative and therapeutic agents in the treatment of intestinal pathogens due to their antibiotic resistance and antibacterial activity as well as their high probiotic characteristics.