MICROBIOME DEVELOPMENT IN BABIES

Written by Lucy Hall

The microbiome is a term we hear more and more, especially in relation to overall health and well-being. It refers to the community of trillions of microorganisms, bacteria, fungi, viruses and other microbes that live in and on the human body. Microorganisms play a critical role in digestion, immunity and even mental health. Part of what makes microbiome development so important for babies is that it lays the ground for their immune system and lifelong health.

Understanding how the microbiome develops in infants can help parents make informed choices about childbirth, feeding and overall care.

The Microbiome at Birth

The baby starts developing a microbiome at birth. When inside the womb, there is almost a completely sterile environment because of protection from outside microorganisms. This means that, in most cases, babies are born without a microbiome. Once a baby is born, babies are exposed to the world around them and that’s where microbial colonisation takes over.

The kind of microbes that originally colonise are determined by the birth of the baby. Babies born vaginally receive their first dose of microbes from their mother’s birth canal, which contains beneficial bacteria that help to seed the baby’s gut and skin microbiomes. These early microbes play an important role because they begin training a baby’s immune system and help protect them against harmful bacteria.

Babies born via caesarean section tend to have a different set of initial microbes. Instead of being exposed to the bacteria in the birth canal, babies delivered via caesarean are often colonised by skin bacteria from the mother, the healthcare workers and the environment in the delivery room. According to some studies, c-section babies have a less diverse microbiome in the first few weeks of life, this may affect how their immune systems develop.

Breastfeeding and the Microbiome

After birth, one of the most important factors influencing the development of a baby’s microbiome is breastfeeding. Breast milk is not just a source of nutrition, it’s also packed with beneficial bacteria and prebiotics which help promote the growth of healthy microbes in the baby’s gut.

Breast milk contains a type of sugar called human milk oligosaccharides (HMOs), which the baby cannot digest. These sugars have a particular purpose, to become food for the good bacteria that live in the infant’s intestines, a species called Bifidobacterium. This good bacteria break down HMOs and help establish a healthy gut microbiome. It has also been suggested that breastfed infants have much higher levels of Bifidobacterium in their intestines and, possibly due to this fact, are less prone to infections, allergic reaction  and other disorders than formula-fed infants.

While breastfeeding provides many benefits for the microbiome, it’s important to acknowledge that not all mothers can breastfeed and formula can also support healthy growth. Advances in formula production have led to the inclusion of prebiotics and probiotics in some formulas to help promote a healthy microbiome.

The Introduction of Solid Foods

The introduction of solid foods starts the diversification of the gut microbiome, another significant turning point. Before solid foods, a baby’s gut microbiome consists of a few important species and is rather simple. The diversity of their microbiome increases with the range of their foods.

Different types of foods introduce new bacteria and nutrients that promote the growth of a more complex microbial community. Fibre rich foods like fruits, vegetables and whole grains are particularly beneficial, as they feed the good bacteria in the gut. A diverse and healthy microbiome is essential for proper digestion, immune function and even mood regulation.

During this time, parents should focus on offering a variety of nutrient dense, whole foods to help nourish their baby’s growing microbiome. Avoiding processed foods and excessive sugar is also important, as these can feed harmful bacteria and disrupt the delicate balance of the microbiome.

The Role of Antibiotics

While antibiotics can be life saving, they have a huge impact on the microbiome. Part of their function is to kill bacteria, however, they are unselective in doing so. This means that while killing the harmful bacteria that may cause an infection, they can also wipe out beneficial bacteria and leave a baby’s microbiome temporarily depleted.

Antibiotic administration during the first months of life results in microbiome changes that could last for a long period of time. Reduced diversity in gut bacteria has been observed in infants exposed to antibiotics in early life and impairs normal immune development. This sometimes leads to an enhanced risk for diseases like asthma, allergies and obesity later in childhood.

While antibiotics are sometimes needed, parents do best when they get in sync with use. If a baby has to take an antibiotic, supplementing their foods or adding supplements will help to replenish the good bacteria in the gut.

Building a Healthy Microbiome Through Lifestyle Includes:

Skin-To-Skin Contact:

In the early days after birth and throughout the first few days of life, holding your infant near facilitates the colonisation of healthy germs by transferring beneficial bacteria from your skin to theirs.

Exposure To Pets And Nature:

Yes hygiene is important, but studies have revealed that babies who have been introduced to pets and the outdoors, in natural environments, have more diversified microbiomes. 

Avoiding Over-Sanitisation:

It’s natural to want to protect your baby from germs, but excessive use of sanitisers and antibacterial products can actually disrupt the microbiome.

The development of microbiome during early life can have an enormous effect on a child’s overall health. Research has demonstrated that the microbiome might have an impact on immune system function, metabolism, and even cognitive development and a healthy system may reduce the  risk of chronic disorders such as obesity, asthma as well as autoimmune diseases in the later stages of life.

The development of a baby’s microbiome is an incredible process that starts at birth and continues throughout childhood. By understanding the factors that can influence microbial health such as birthing methods, breastfeeding, diet and lifestyle, parents are able to take the appropriate steps to promote a healthy and balanced microbiome for their little one. This foundation is essential for supporting their child’s immune system, digestion and well-being as they grow.