by Olivia Arena  —

When we think of bacteria, we often think of the type that will leave us calling out sick on a Monday morning, reaching for the tissue box, or grabbing for the cold medicine off the bathroom shelf. However, not all bacteria present themselves in a harmful manner but are there to help. Scientists are becoming more aware of the beneficial properties that bacteria can present for newborns.

During pregnancy, women are encouraged to maintain a healthy diet and lifestyle by exercising regularly and avoiding use of alcohol or excessive amounts of caffeine. Research now suggests that if given the option, women should opt for a vaginal delivery rather than a cesarian section. This is because during a vaginal delivery the newborn infant is coated with commensal bacteria, or “good bacteria” generating a healthy gut-microbiome for the infant. An infant’s gut-microbiome aids in a highly functioning immune system that optimizes the infant’s overall health both initially, and long term.

Bacterial exposure during vaginal vs. cesarean birth

Many of the bacteria that are introduced during vaginal birth are thought to be beneficial. Two of the most common bacteria in a woman’s vaginal tract during delivery are Lactobacillus crispatus and Prevotella. Both commensal bacteria, they coat the newborn in the birth canal, providing the child with a protective layer that acts as a foundation for their immune system. These “good bacteria” will fend off the clustering and potentially invasive pathogens from entering the baby’s undeveloped immune system, gearing it for its initial defense against potential infection.

As many of us are aware, germs in a hospital are about as common as buttered popcorn in a movie theatre. Germs are everywhere, and unfortunately, potentially pathogenic bacteria such as Staphylococcus can be found in abundance in a delivery room. Methicillin-resistant Staphylococcus aureus (MRSA) can be challenging to treat and has been found to be resistant to many antibiotics. Such an infection poses a potentially serious risk to a newborn infant, as their immune system is a shell comparatively to that of a healthy adult’s.

When infants fail to path through the birth canal, they are birthed through cesarian delivery – a surgical procedure that involves an incision in the mother’s abdomen and uterus. This mode of delivery, though can be unavoidable, deprives the newborn of an initial acquaintance with commensal bacteria. Instead, the baby is subjected only to the other surrounding bacteria including the potentially pathogenic bacteria.

Figure 1. From the Nemours Foundation (https://www.nemours.org/), shows MRSA, a skin infection caused by a type of Staphylococcus aureus, a harmful bacterium that can be found in hospitals. MRSA can be challenging to treat and is most often found in those with weak immune systems.

Figure 2. From Nuriel-Ohayon et al. (2016), represents the presence of both ‘good’ and ‘bad’ bacteria associated with mode of delivery. Breast milk is also encouraged, especially for those born by mode of cesarian delivery, as there is a heightened presence of commensal bacteria, compared to a mother who only provides their baby with formula. The green color and arrows represent change in taxonomy, whereas the pink represents general changes, and the orange represents community diversity.

 An infant’s gut-microbiome is crucial to their development and to optimizing their health as they grow and develop through their first few months of life, and even long after into adulthood. A weak immune system can lead to frequent infections and more severe symptoms compared to those with a strong developed immune system, which in a newborns case, could be fatal. Serviceable gut health provides a newborn with high functioning digestion and metabolism of food, a prospering, and a developing immune system. This will also lead to a wealth of neurotransmitters, the chemical messengers that are responsible for transmitting signals from nerve cells to target cells, to condition the infant’s behavior and cognitive function.

Cesarean born infants’ gut microbiome catches up

Research shows that by their first year of life, most babies born by mode of cesarian develop gut-health that matches up to that of a vaginally born infants. That is, the amount of “good” bacteria present in the gut of babies born via cesarian or vaginal can be equally abundant. No matter what mode of delivery, promoting good gut-health gears infants toward a healthy life.

 

References

Nuriel-Ohayon M, Neuman H, Koren O. 2016. Microbial changes during pregnancy, birth, and infancy. Front Microbiol https://doi.org/10.3389/fmicb.2016.01031