Early life colonization of the human gut: microbes matter everywhere

Abstract

Microbes colonising the infant intestine, especially bacteria, are considered important for metabolic and immunological programming in early life, potentially affecting the susceptibility of the host to disease. We combined published data to provide a global view of microbiota development in early life. The results support the concept that the microbiota develops with age in an orchestrated manner, showing common patterns across populations. Furthermore, infants are colonised at birth by specific, selected maternal faecal bacteria and likely their bacteriophages. Therefore, infants are adapted to receiving specific bacterial signals, partly derived from the maternal microbiota, at successive immunological time windows during early development. Birth by caesarean section compromises the initial vertical transmission of microbes whereas antibiotic use shifts the microbiota away from the normal developmental pattern. These disruptions alter the microbial signals that the host receives, potentially affecting child development.

Feeding modes shape the acquisition and structure of the initial gut microbiota in newborn lambs

“…Mounting evidence suggests that the early development of the gut microbiota of newborns is essential for health by maintaining intestinal homeostasis and barrier function, stimulating development of the immune system, contributing to nutrient digestion, and protecting against pathogens (Sekirov et al, 2010;Maynard et al, 2012;Wopereis et al, 2014). The symbiotic microbe-host interactions during the earliest days of life critically determine life-long health (Rautava et al, 2012;Stinson et al, 2017;Korpela and de Vos, 2018). Disruption of the early gut microbiota has been linked to diseases in later life, including obesity, metabolic diseases, inflammatory bowel disease, irritable bowel syndrome, necrotizing enterocolitis, and autoimmune diseases and allergy (Rautava et al, 2012;Christian et al, 2017).…”

Preterm infants harbour diverse Klebsiella populations, including atypical species that encode and produce an array of antimicrobial resistance- and virulence-associated factors

“…The gut microbiota encompasses bacteria, archaea, lower eukaryotes and viruses, with these microbes contributing to host gastrointestinal (GI) and systemic health. Host–microbiome interactions within the intestine are particularly important in neonates, contributing to development of the immune response, establishment of the gut microbiome and protection from infections [1, 2]. Term infants (i.e.…”

“…Term infants (i.e. gestation 37 weeks) are rapidly colonised after exposure to the mother’s microbiota and the environment, with streptococci and Enterobacteriaceae dominating in the initial phases [1], and Bifidobacterium spp. becoming prominent as the infant grows [1].…”

The composition of the perinatal intestinal microbiota in horse

“…The major microbial colonization occurs at birth. Postnatally, the intestinal microbiota goes through a rapid development, with changing bacterial composition, diversity and abundances, before reaching adulthood where the microbiota is relatively stable [8][9][10] . Early exposure to a diverse microbiota promotes the maturation of an immune system which effectively protects from infection while tolerating commensal microbes [11][12][13] .…”