Newborn and maternal microbiome overview
This new IN FOCUS collection is dedicated to Maternal and Newborn microbiome. We have prepared and commented a selection of articles published in 2018 or in 2019 about this theme.
Many evidences support the importance of the maternal microbiome in the newborn health. New Important findings have been done during last years in this area. We can now imagine that the newborn microbiome is acquired following a detailed and meticulous plan from whose success depends the health of the newborn, not only during the first years of life but also in the childhood and even later in the adultness. These long-lasting effects of the maternal microbiome transmission and of the newborn microbiome correct shaping along the different steps of the development make more interesting to focus on that. In the light of new knowledge we can say that not only DNA from parents is transmitted to the offspring but also selected bacterial genomes need to be transmitted by the correct via, in the adequate proportion and in the precise developmental step to get that the child grows healthy.
It appears that newborn microbiome is acquired following a highly precise and detailed plan designed to do a selective seed of the most beneficial microbiome for each tissue in each moment of the newborn development.
Different transmission pathways of maternal microbiome to her child participate in this complex process that is yet partially unknown. Antenatal period is one of the discussed possibilities of very selective initial seeding that is under debate. Vaginal via during parturition is another important maternal transmission pathway especially for seeding of the newborn mouth microbiome. Precolostrum and colostrum are the next media for early maternal transmission of selected bacteria. Then, breastfeeding is crucial for shaping newborn microbiome mainly by means of the milk and indirectly by the type of nutrients that it supplies to the infant and that induce a specific gut flora in the child but also by the direct contact of the newborn with maternal skin and mammary gland.
Human Maternal Oligosaccharides (HMOs) and Immunoglobulin A (IgA) are especially important components of maternal milk involved in the development of a healthy microbiome in the newborn but there are many other milk components that influence neonatal microbiome. HMOs from human milk inhibit the adhesion of microorganisms to the intestinal mucosa to avoid the adhesion of pathogen microorganisms to the intestinal mucosa of the newborn. IgA coated bacteria play a vital role in intestinal homeostasis.
The results of the analysis of different cohorts support that vaginally delivered newborns have a different microbiome that those delivered by caesarian section. The lack of maternal seeding of the neonatal mouth microbiome could be a possible cause involved in these differences.
Some of the questions about which are centered the selected articles are the following:
The newborn microbiome
- What is a healthy microbiota of the newborn?
- Predominance of Bifidobacterium in the gut microbiome of the newborn
Breast milk microbiome
- Breast milk microbiome characterization
- Maternal IgA and the newborn microbiome
- Maternal breast milk metabolome and microbiome.
Selective maternal seeding of the newborn microbiome
- How newborn’s skin and mucosal surfaces are seeded with microorganisms from the mother
- Whether intrauterine environment is sterile or not
- Differences in the microbiome between newborns delivered by caesarian section and those vaginally delivered
- The intestinal dysbiosis frequently observed in preterm infants
- The seeding during vaginal delivery and via breastfeeding
- Microbiota of human precolostrum and its potential role as a source of bacteria to the infant mouth.
- Mother-to-child strain bacterial transmission events
- Breastfeeding as a key mechanism to transmit maternal microbes to the newborn
Maternal microbiome and child illness
- Cervicovaginal microbiota and local immune response as determinants of the risk of spontaneous preterm delivery.
- Links between the composition of the maternal microbiome and subsequent risk of childhood illnesses: infection, asthma, allergy, autoimmunity, and metabolic diseases such as obesity and diabetes
- Immune system development and microbial colonization during early life
- Neuroimmune development and microbiome: the microbiota-mediated gut–brain axis in the newborn
- Maternal microbiota in pregnancy and early life and prevention of diseases
How drugs and toxics exposure and diet during pregnancy affect the newborn
- The association of maternal diet during pregnancy with the infant gut microbiome
- How maternal exposure to toxics during pregnancy affects the newborn microbiome
- Prenatal antibiotic exposure and childhood asthma
- Prenatal antibiotic exposure and childhood obesity
- Whether prophylactic antibiotics have some impact on gut microbiota colonization or in antibiotic susceptibility of the gut bacteria in the newborn