Newborn immune cells : connection to microbiota, delivery method and intrapartum antibiotic prophylaxis?

Abstract

The susceptibility of newborns to metabolic diseases, allergies, and asthma is linked to the composition of their microbiome and its interactions with their developing immune system. However, the factors that affect newborn immunity before and during birth, and how they are interconnected, are not well understood. Gaining additional knowledge in this area could help us understand the long-term effects of these factors on our health.

The early interactions between the newborn immune system and the microbiota are critical for shaping the gut microbiome and influencing the development of metabolism and the immune system. Factors such as the mode of delivery and the use of antibiotics during childbirth can impact the microbiota in early life and have long-lasting effects on health. The composition of the microbiota in the meconium, the first stool passed after birth, can reflect the fetal gut microbiome and is associated with specific populations of immune cells in cord blood. Bacterial extracellular vesicles found in meconium may also play a role in newborn immunity, but their exact function is still unknown.

This study characterized cord blood immune cells and examined any differences based on the method of birth, antibiotic usage, and maternal obesity. Cord blood immune cells’ response to maternal fecal extracellular vesicles was also investigated. The findings revealed that the method of delivery and antibiotic usage had significant impacts on the populations of immune cells in cord blood. Maternal obesity was also found to be associated with differences in the population of stem cells. Weak correlations were observed between the populations of cord blood immune cells and microbiota markers. Additionally, the proinflammatory response of cord blood immune cells to maternal extracellular vesicles varied depending on the type of stimulation but appeared to increase along with amount of extracellular vesicles.

These findings suggest that early-life events, such as the method of delivery and antibiotic usage, can influence the composition and properties of immune cells in cord blood, potentially affecting long-term health outcomes. Understanding these early interactions between the immune system and the microbiota can provide insights into the development of various diseases and overall health status later in life.