Page 26 - Petelin, Ana, et al. 2019. Eds. Zdravje otrok in mladostnikov / Health of Children and Adolescents. Proceedings. Koper: University of Primorska Press
P. 26
avje otrok in mladostnikov | health of children and adolescents 24 called gut microbiota has a great impact on nutrient degradation and adsorp-
tion; defense against pathogen microorganisms; immune system; affects gut
health and can greatly influence the functionality and pathophysiology of sev-
eral organs that are anatomically distant from the GI tract (Clemente et al.,
2012). The first years of the child’s life are the most important period for the gut
microbiota development and is greatly influenced by pregnancy (maternal mi-
crobiota, health status, lifestyle), mode of delivery and infancy (genetics, in-
fant diet, family environment, antibiotic treatment) factors (Rodríguez et al.,
2015). In the past years, the composition and role of the gut microbiota have
been studied thoroughly. Although there have been over 50 bacterial phyla de-
scribed to date more than 90% of gut bacteria belong to Bacteroidetes and Fir-
micutes. Firmicutes phyla mainly include Ruminococcus, Clostridium, Lactoba-
cillus, Eubacterium, Faecalibacterium and Roseburia, while in Bacteroides phyla
mainly Prevotella and Xylanibacter genera are present. However, the minority of
species belong to phyla such as Actinobacteria and Proteobacteria (Arumugam
et al., 2011).
The abundance and diversity of human gut microbiota have critical roles
in the maintenance of human health. Various epidemiological studies have
shown a correlation between factors disrupting the gut microbiota during
childhood on one hand with immune and metabolic disorders later in life on
the other (Eggesbo et al., 2003; Huh et al., 2012; Sevelsted et al., 2015). Many ex-
perimental data support long-term health benefits of infant gut microbiota and
its role in health and neurodevelopment (Relman, 2012). These findings have
stimulated the development of strategies to influence the composition, and ac-
tivities of the infant microbiota e.g. by the use of nutraceutical products (e.g.,
probiotics and/or prebiotics).
Development of the infant gut microbiota
It has widely been accepted that the microbial colonization of the newborn
starts during and after birth. Nevertheless, based on the studies of healthy new-
borns the bacteria have been detected in placental tissue (Aagaard et al., 2014)
and in meconium (Gosalbes et al., 2013). This finding increases the evidence of
early microbial contact during the antenatal period. Exposure of the fetal en-
vironment to microbial metabolites and compounds of the maternal microbi-
ota may have an impact on pregnancy outcome and infant development (Ro-
mano-Keeler and Weitkamp, 2015). The development and maturation of gut
microbiota starts after birth and is converged toward an adult-like by the end
of the first 3–5 years of life (Rodríguez et al., 2015; Milani et al., 2017). This dy-
namic process is influenced by various neonatal (mode of delivery, gestation-
al age) and postnatal factors (type of feeding, maternal diet, environment, host
genetics) (Milani et al., 2017).
During delivery and rapidly thereafter, microbiota from the mother and
from the surrounding environment colonize the infant’s gut. During vaginal
delivery there is an extensive transmission of vaginal bacteria to infant gut,
tion; defense against pathogen microorganisms; immune system; affects gut
health and can greatly influence the functionality and pathophysiology of sev-
eral organs that are anatomically distant from the GI tract (Clemente et al.,
2012). The first years of the child’s life are the most important period for the gut
microbiota development and is greatly influenced by pregnancy (maternal mi-
crobiota, health status, lifestyle), mode of delivery and infancy (genetics, in-
fant diet, family environment, antibiotic treatment) factors (Rodríguez et al.,
2015). In the past years, the composition and role of the gut microbiota have
been studied thoroughly. Although there have been over 50 bacterial phyla de-
scribed to date more than 90% of gut bacteria belong to Bacteroidetes and Fir-
micutes. Firmicutes phyla mainly include Ruminococcus, Clostridium, Lactoba-
cillus, Eubacterium, Faecalibacterium and Roseburia, while in Bacteroides phyla
mainly Prevotella and Xylanibacter genera are present. However, the minority of
species belong to phyla such as Actinobacteria and Proteobacteria (Arumugam
et al., 2011).
The abundance and diversity of human gut microbiota have critical roles
in the maintenance of human health. Various epidemiological studies have
shown a correlation between factors disrupting the gut microbiota during
childhood on one hand with immune and metabolic disorders later in life on
the other (Eggesbo et al., 2003; Huh et al., 2012; Sevelsted et al., 2015). Many ex-
perimental data support long-term health benefits of infant gut microbiota and
its role in health and neurodevelopment (Relman, 2012). These findings have
stimulated the development of strategies to influence the composition, and ac-
tivities of the infant microbiota e.g. by the use of nutraceutical products (e.g.,
probiotics and/or prebiotics).
Development of the infant gut microbiota
It has widely been accepted that the microbial colonization of the newborn
starts during and after birth. Nevertheless, based on the studies of healthy new-
borns the bacteria have been detected in placental tissue (Aagaard et al., 2014)
and in meconium (Gosalbes et al., 2013). This finding increases the evidence of
early microbial contact during the antenatal period. Exposure of the fetal en-
vironment to microbial metabolites and compounds of the maternal microbi-
ota may have an impact on pregnancy outcome and infant development (Ro-
mano-Keeler and Weitkamp, 2015). The development and maturation of gut
microbiota starts after birth and is converged toward an adult-like by the end
of the first 3–5 years of life (Rodríguez et al., 2015; Milani et al., 2017). This dy-
namic process is influenced by various neonatal (mode of delivery, gestation-
al age) and postnatal factors (type of feeding, maternal diet, environment, host
genetics) (Milani et al., 2017).
During delivery and rapidly thereafter, microbiota from the mother and
from the surrounding environment colonize the infant’s gut. During vaginal
delivery there is an extensive transmission of vaginal bacteria to infant gut,
