Gestational Age, Birth Method, and Breastfeeding Influence Immune System Development in Early Life

Toddler BreastfeedingAdding to the growing body of research on the importance of gastrointestinal microbiota for good health, a new series of studies presented at the Annual Meeting of the American Academy of Allergy, Asthma & Immunology in Houston, Texas suggests that factors such as gestational age, birth method, and breastfeeding influence the development of the immune system and the susceptibility to asthma and allergies. The findings also support the Hygiene Hypothesis, which argues that early childhood exposure to infectious agents, symbiotic microorganisms, and parasites affects later-life risk of disease.

Says principal research investigator Christine Cole Johnson, Ph.D., MPH, chair of Henry Ford’s Department of Public Health Sciences:

“For years now, we’ve always thought that a sterile environment was not good for babies. Our research shows why. Exposure to these microorganisms, or bacteria, in the first few months after birth actually help stimulate the immune system.

“The immune system is designed to be exposed to bacteria on a grand scale. If you minimize those exposures, the immune system won’t develop optimally.”

The present research consists of six studies that seek to evaluate whether breastfeeding and maternal and birth factors affect the  gut microbiome and allergic and asthma outcomes among children. Using data collected from the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) birth cohort, the researchers analyzed stool samples from infants collected at one month and six months after birth. The purpose of WHEALS is to explore the role of environmental factors and measure biological markers to understand the ways in which allergies and asthma develop early in life.

The researchers additionally investigated whether the gut microbiome affected the development of regulatory T-cells, or Treg, which function to regulate the immune system.

According to the study, gut microbiome patterns vary by maternal race/ethnicity, gestational age at birth, prenatal and postnatal exposure to tobacco smoke, birth method, and presence of pets in the home.

Breastfed babies had distinct microbiome compositions at one month and six months compared to non-breastfed babies. The distinct compositions may influence immune system development. For example, breastfed babies at one month had a decreased risk of developing allergies to pets. Children with asthma who had nighttime coughing or flare-ups had a distinct microbiome composition during the first year of life.

The research also reveals for the first time that gut microbiome composition is associated with increasing Treg cells.

Comments Dr. Johnson on the findings:

“The research is telling us that exposure to a higher and more diverse burden of environmental bacteria and specific patterns of gut bacteria appear to boost the immune system’s protection against allergies and asthma.”

Two other recent studies found that natural birth provides a boost to the immune system because the gut bacteria of babies born vaginally differs from the gut bacteria of babies born via cesarean section and that environmental factors such as birth method and gestation duration may affect the way in which gut bacteria mature.


Breastfeeding May Influence Immune System Development in Early Life:
Breastfeeding, Other Factors Help Shape Immune System Early in Life:

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