Development of the gut microbiota in southern Indian infants from birth to 6 months: a molecular analysis

Abstract

Acquisition of the gastrointestinal microbiota at birth may have long-term health impacts. We longitudinally characterised major microbial communities in the faeces of a cohort of infants using molecular methods. Faecal samples were prospectively obtained at several time points after birth from eighty-three infants. Real-time PCR using SYBR green and primers targeted at 16S rRNA gene sequences were used to quantify Bifidobacterium, Lactobacillus acidophilus group, Bacteroides–Prevotella group, Enterobacteriaceae, Enterococcus, Clostridium coccoides–Eubacterium rectale group, Clostridium leptum group and Staphylococcus. Microbial community abundance was expressed relative to amplification of sequences conserved universally for domain bacteria. Faecal copy number of 16S rRNA genes increased non-significantly from a mean of 4·1 × 109/g on day 1 to 1·1 × 1010/g on day 4. All microbial communities were detected from day 1 after birth. Enterobacteriaceae and lactobacilli predominated on day 1, while bifidobacteria and staphylocci increased on day 4. Bacteroides–Prevotella and C. coccoides–E. rectale increased by day 180. C. leptum was detected in half of the cohort at birth and in a slightly larger percentage by 6 months. Caesarean section was associated with delayed colonisation by several bacterial communities. Higher socio-economic status was associated with more abundant lactobacilli and Bacteroides–Prevotella at 90 and 180 d. Supplemental feeding was associated with a reduction in Enterobacteriaceae. Microbial colonisation of the gut was well established on the first day of birth, and relative abundance of microbial communities was influenced by mode of delivery, socio-economic status and supplemental feeding. These findings may have relevance to infant nutrition and growth.

The Role of Gut Microbiota and Environmental Factors in Type 1 Diabetes Pathogenesis

“…Several studies have found that the colonization of Lactobacillus, Bifidobacterium, and Bacteroides is delayed or completely absent in infants born via C-section (92,96,106,107) and the lack of exposure to vaginally-derived Lactobacillus species can lead to differences in microbial succession. Subsequent diversity for the major phyla of gut microbiota-Actinobacteria (dominated by Bifidobacterium), Bacteroidetes, and Proteobacteria-is also significantly lower in C-section-delivered infants (92,(107)(108)(109)(110)(111)(112).…”

The infant microbiome development: mom matters

“…Postnatal colonization of the neonatal intestine by Bacteroides and Bifidobacterium spp. is also delayed in babies delivered by C-section [74–76] and these babies have higher levels of intestinal Clostridium difficile [77–80]. While it remains unknown how long the differences in microbial composition introduced by delivery mode persist in the infant, differences in specific microbial species have been observed between C-section- and vaginally delivered babies after 1 month [81], 2 years [82], and even 7 years [83] of life.…”

Birth Mode-Related Differences in Gut Microbiota Colonization and Immune System Development

“…In addition, Huurre et al [20] showed that infants born by Csection harbored lower amounts of total bacteria in their guts at 1 month of age, mainly due to a reduced number of bifidobacteria. Underrepresentation of Bacteroides is also frequently detected in the microbiota of C-section infants surveyed at 3-4 months of age [16,19,[21][22][23]. Longer term studies that have followed microbiota composition in infants during the first 2 years of life have confirmed an association of C-section with delayed colonization of the Bacteroidetes phylum, and with lower total microbial diversity up to 2 years of age [22,24].…”