Establishment of the bacterial fecal community during the first month of life in Brazilian newborns

Abstract

OBJECTIVE:The establishment of the intestinal microbiota in newborns is a critical period with possible long-term consequences for human health. In this research, the development of the fecal microbiota of a group of exclusively breastfed neonates living in low socio-economic conditions in the city of São Paulo, Brazil, during the first month of life, was studied.METHODS:Fecal samples were collected from ten neonates on the second, seventh, and 30th days after birth. One of the neonates underwent antibiotic therapy. Molecular techniques were used for analysis; DNA was extracted from the samples, and 16S rRNA libraries were sequenced and phylogenetically analyzed after construction. A real-time polymerase chain reaction (PCR) was performed on the samples taken from the 30th day to amplify DNA from Bifidobacterium sp.RESULTS:The primary phylogenetic groups identified in the samples were Escherichia and Clostridium. Staphylococcus was identified at a low rate. Bifidobacterium sp. was detected in all of the samples collected on the 30th day. In the child who received antibiotics, a reduction in anaerobes and Escherichia, which was associated with an overgrowth of Klebsiella, was observed throughout the experimental period.CONCLUSION:The observed pattern of Escherichia predominance and reduced Staphylococcus colonization is in contrast with the patterns observed in neonates living in developed countries.

Anaerobic bacteria in the intestinal microbiota of Brazilian children

“…At some time points, particularly at the second and 12 th months, the copy numbers of Escherichia 16S rRNA were the second highest, consistent with our previous results 8,15. However, due to the presence of Bifidobacterium and Lactobacillus and their protective properties 11 in these childreńs feces, lower values of Escherichia than those observed in the present study were expected.…”

“…The high abundance of E. coli suggests a pattern related to unhygienic conditions, as reported previously in developing countries 34. These results complement analyses of the composition of the gut microbiota in this group of Brazilian breastfed infants living in low socio-economic conditions 8,15 and highlight the influence of both diet and the environment.…”

“…Lactobacillus was detected with low frequency and abundancy, and Bifidobacterium was only detected using qPCR methodology 8,15. qPCR has been widely applied for the quantification of bacterial DNA in different human samples, such as feces 22 and human milk 23, due its specificity and accuracy.…”

“…in neonatal samples, whereas Staphylococcus and Bacteroides spp. were detected at low frequencies and abundances 15. In infants, the microbial community was composed of aerobic species of Bifidobacterium and Clostridium , with a high abundance of facultative anaerobe Escherichia 15.…”

Intestinal Bacterial Colonization in the First 2 Weeks of Life of Nigerian Neonates Using Standard Culture Methods

“…One possible explanation for the absence of Bifidobacteria in our data is that suppression of Bifidobacteria could occur in some instances of predominant growth of gram-negative bacteria and Staphylococcus spp. in neonates (22, 33) or as suggested by Brandt et al (36) and Leke et al (37) that the level of Bifidobacteria was probably under the cultural detection threshold. Another notable negative finding was the absence of Lactobacillus spp.…”