Maternal Microbiota, Early Life Colonization and Breast Milk Drive Immune Development in the Newborn

Abstract

The innate immune system is the oldest protection strategy that is conserved across all organisms. Although having an unspecific action, it is the first and fastest defense mechanism against pathogens. Development of predominantly the adaptive immune system takes place after birth. However, some key components of the innate immune system evolve during the prenatal period of life, which endows the newborn with the ability to mount an immune response against pathogenic invaders directly after birth. Undoubtedly, the crosstalk between maternal immune cells, antibodies, dietary antigens, and microbial metabolites originating from the maternal microbiota are the key players in preparing the neonate’s immunity to the outer world. Birth represents the biggest substantial environmental change in life, where the newborn leaves the protective amniotic sac and is exposed for the first time to a countless variety of microbes. Colonization of all body surfaces commences, including skin, lung, and gastrointestinal tract, leading to the establishment of the commensal microbiota and the maturation of the newborn immune system, and hence lifelong health. Pregnancy, birth, and the consumption of breast milk shape the immune development in coordination with maternal and newborn microbiota. Discrepancies in these fine-tuned microbiota interactions during each developmental stage can have long-term effects on disease susceptibility, such as metabolic syndrome, childhood asthma, or autoimmune type 1 diabetes. In this review, we will give an overview of the recent studies by discussing the multifaceted emergence of the newborn innate immune development in line with the importance of maternal and early life microbiota exposure and breast milk intake.

What Do We Know about the Microbiome in Cystic Fibrosis? Is There a Role for Probiotics and Prebiotics?

“…As mentioned earlier, iatrogenic factors such as antibiotic use can disrupt microbiome progression [ 41 ]. More broadly, early life microbiome disruption has been implicated in the development of autoimmune disease in mouse models [ 244 ], and has been associated with lasting metabolic and autoimmune disease consequences in observational studies [ 245 , 246 , 247 , 248 ].…”

Cow Milk Extracellular Vesicle Effects on an In Vitro Model of Intestinal Inflammation

“…Moreover, milk is essential for infant mammals: it provides nutrition and helps the development of the neonatal gut immune system through maternal immunoglobulin transmission [43,44]. Recently, EVs' described immunomodulation role has also been confirmed in mEVs, accompanied by anti-inflammatory functions [45,46], suggesting a sort of adjuvant activity in the newborn immune system shaping. In fact, mEVs are rich in bioactive molecules such as proteins, lipids, RNAs, and metabolites, which also emerged from our previous studies, known to influence inflammation and the immune system [47][48][49].…”

Baseline Concentrations of Various Immune Biomarkers Determine Their Increase after Consumption of a Postbiotic Based on Cow’s Milk Fermented with Lactobacillus paracasei CBA L74 in Both Newborns and Young Children

“…Another striking feature is the enhanced endocytosis capacity of immature intestinal epithelial cells shortly after birth [23], which might give rise to a sensitization of the appropriate immune cells leading to an upregulation of immune markers. With respect to a difference in development between the innate and the adaptive component of immunity, the observation that the development of the latter starts at birth whereas that of innate immunity already during pregnancy [24] might be of importance here. This timing of the innate component enables the newborn to combat potential pathogens effectively from birth onwards.…”