The infant is first exposed to bacteria in utero from the placenta during gestation, then at the time of birth, is colonized with rich and diverse microorganisms from maternal sites, including the maternal lower genital tract, feces and/or skin, from milk feeds as well as from the general environment. The microorganisms contribute to the development of the neonatal oral microbiota that will then colonies the remainder of the gastrointestinal tract (GIT). The GIT microbiota has been shown to have many important roles in producing the infant’s innate and adaptive immune system, conferring protection against attacks from pathogenic microbes
In newborn child’s saliva high levels of the metabolites, xanthine and hypoxanthine are present, which are substrates of xanthine oxidase (XO), an enzyme that is highly abundant in breast milk. When neonatal saliva mixed with breastmilk during feeding, hydrogen peroxide (H2O2) at concentrations up to 100 micromolar are formed, and this, in turn, activates the ‘lactoperoxidase system’ (LPO) in milk to further produce other reactive oxygen species (ROS) and reactive nitrogen species (RNS). The creation of these ROS and RNS was affirmed to have in vitro antibacterial action.
The mixture of breastmilk and saliva has been shown to play a vital role in shaping the healthy oral microbiota during the first few months of life, but this also has significant implications for premature or sick babies who are fed via a tube.
The newborn baby’s gut microbiota is a highly powerful community that is continuously shaped during the 1st days of life, with nutrition being among the most relevant drivers for its composition.
In this situation of the microbial trend among mother and child, the baby’s mouth is unavoidably involved, being the commit transition point for the milk to reach the gastrointestinal tract. The oral microbiota is a well-defined portion of the human microbiome.
During breastfeeding, the infant’s saliva responds with breastmilk to deliver reactive oxygen species, while at the same time giving growth-promoting nucleotide precursors. Milk thus plays a nutritional role in mammals, collaborating with newborn’s saliva to produce a strong mixture of stimulatory and inhibitory metabolites that regulate early oral-and consequently gut-microbiota.
Human milk confers unique nutritional and non-nutritional benefits, enhancing a child’s growth and development, as well as overall health, not only in early life but also for the long-term and offering prevention against some diseases. An epigenetic mechanism is a biochemical alteration to the DNA that does not change the sequence but does influence gene expression. These epigenetic alterations are extraordinarily affected by nature and are heritable. The major epigenetic forms are DNA methylation, histone change, and chromatin remodelling.
Four main diseases and disorders that breast milk may epigenetically protect against:
- Inflammatory Bowel Disease: This may be clarified by the gut microbiota which can be modified by numerous components in early age. At the point when babies are breastfed, human bosom drain parts advance more advantageous gut microorganisms, which control the statement of qualities engaged with assimilation, obstruction capacity, and generation of secretory IgA (sIgA). sIgA is the most copious class of counteracting agent in our living being and assumes a vital job in the resistant capacity of mucous layers and security against pathogenic living beings.
- Disorders of the Immune System: Breast feeding has been appeared to help anticipate diseases and other resistant related sicknesses, especially gastrointestinal contaminations and intense otitis media, regardless of whether the kid has hereditary diseases. Human milk contains oligosaccharides which advance more beneficial gut microorganisms which assume a main role in epigenetically programming the new-born child’s safe phenotype and contamination defencelessness.
- Obesity and Related Disorders: obesity is a multifactorial disease – it’s the result of the interaction between genetics, environment and individual lifestyles, including feeding practices during the early ages of life. Babies fed with artificial formula can develop intestinal dysbiosis which leads to an unhealthy epigenetic expression. It is well known that gut microbiota has an important role in human metabolism – an unbalanced microbiota would be a risk factor for a child developing obesity.
- Cancer: Benefits of breastfeeding are not only limited to the breastfed child. Mothers can have a deep and relevant impact on their own health just by nursing their babies. Scientists have proposed several mechanisms that might explain this positive effect of nursing in breast-cancer risk reduction, such as hormonal changes breast cancer prevention via epigenetic mechanisms, which specific components of human milk are involved.