Development of a child's digestive system

ONE of the most joyful experiences in life is when we welcome a baby into this world. Most mothers delight in the experience of nurturing, cuddling, and breastfeeding their little ones. At birth, your baby is dependent on you for almost every single aspect of his life and survival – he cannot walk as his central nervous system has not fully matured nor can he talk as his brain is still developing.

However, your baby is able to fully enjoy the nutritional benefits breast milk provides as his digestive system is mature enough to digest it at the time of his birth.

Gut development

When a foetus is formed in his mother’s womb, three layers of cells gradually develop to become the three main components of his body. The first layer forms the nervous system and sensory organs while the second layer forms his muscular, circulatory, and skeletal systems. The third layer of cells forms the digestive system. Your baby’s intestines start to develop as early as week five of pregnancy.

During the third month of foetal development, the foetus’ stomach cells start to secrete fluid. Waste that forms from the foetus goes through the placenta and into mother’s blood. This means that the digestive system has already started functioning even during the foetal stage.

At birth, your baby’s digestive system is still developing and maturing. At this point, he is not ready to accept other types of food except breast milk.

At about six months, your baby’s digestive system is mature enough to digest more complex and solid food substances, like starch, protein, and fat in a non-milk diet. At this stage, he’s ready to be introduced to solid foods (complementary food). It is recommended that you continue giving your child breast milk as he gradually gets used to eating solid food.

In his early childhood, your child’s digestive system continues to mature. The first two years are the most critical. The gut microflora established during this period can greatly influence your child’s long-term immunity. If your child’s digestive health is poor and he is malnourished at this point, his growth and development will be jeopardised.

Within your baby’s gut

At birth, your baby’s gut is sterile. As soon as you start breastfeeding, bacteria are introduced into your baby’s gut. Mother’s breast milk gas several beneficial bacteria, e.g. bifidobacteria and lactobacillus, which are crucial for your baby’s gut health. The number of bacteria, both the good and bad bacteria, increases rapidly in the baby’s first few days of life.

As your baby grows, his gut microflora established during his first two years stabilises, and it usually maintains a balance until he reaches adulthood.

A healthy gut microflora ecosystem is essential to your baby’s overall health. Babies that don’t have the right balance of gut bacteria are likely to be more prone to colic (gas and pain in the abdomen), and are believed to be at greater risk of developing allergy (e.g. eczema) and asthma when they grow up.

Breastfed vs. bottle-fed

Breastfeeding can help your child achieve optimal growth, development, and health. Studies have suggested that children who are breastfed have significantly fewer gastrointestinal, ear, urinary, and respiratory infections. Breast milk is rich in antibodies and it can better protect your child against infections. Breast milk will also encourage the colonisation of good bacteria in the newborn’s gastrointestinal tract.

Formula fed babies’ gut microflora have been found to be different from breastfed babies. Formula-fed infants tend to have far less bifidobacteria, a bacteria that contributes towards the development of healthy gut microflora. Some studies suggest that there is increased risk of atopic eczema in infants who are given formula milk compared to those who are exclusively breastfed.

Moreover, bifidogenic factors that are found in breast milk help to boost the growth of beneficial bacteria in the gut, which lessens the risk of diarrhoea and other intestinal illnesses. In other words, breast milk keeps the digestive system in good condition.

It is therefore essential to breastfeed babies, especially during the first few days of life. The World Health Organization (WHO) recommends that mothers breastfeed their children exclusively for at least the first six months and continue breastfeeding their child up till the age of two years. In fact, both UNICEF and WHO encourage mother’s to breastfeed up to two years, if possible. This is because children’s immune systems are not as strong yet, so they need more protection, which breast milk can provide.

Care for your child’s digestive health

You might think the digestive system is merely to help us digest food, but the truth is, it plays a much bigger role. Without a healthy digestive system, your child can’t get all the nutrients he needs to grow properly and stay healthy. A problematic gut can affect your child in several ways, including his body weight, nutritional status, immune system, and even his emotions.

Your child’s digestive system is his “food processing machine”. Food must first be adequately broken down and properly absorbed before it can be utilised by his body. If any part of the process goes wrong, your child’s nutritional status is at risk, and when this happens, it may affect his physical as well as cognitive development.

Your child’s digestion affects his metabolic rate, which in turn affects his overall weight. Good digestion helps optimise metabolism. When your child is not properly nourished, it interferes with nutrient breakdown, absorption, and metabolism, which leads to accumulation of toxins in the body.

Your child’s digestive tract lining is also his body’s first line of defence as it acts as a barrier that stops invaders from entering the body. Studies have indicated that a large proportion of the body’s immune cells lies within the gastrointestinal wall.

This makes sense as your digestive tract makes up the largest surface area in your body and is exposed to an enormous amount of food during a lifetime.

So, if you want your child to grow and stay healthy for many years to come, start taking good care of his little tummy now.

Prof Dr Christopher Boey Chiong Meng is a professor of paediatrics and consultant paediatric gastroenterologist. This article is not in any way intended as a substitute for medical attention. When in doubt, please consult your doctor. This article is courtesy of the Malaysian Paediatric Association’s Positive Parenting Digestive Health Initiative and the Malaysian Society of Gastroenterology & Hepatology that is supported by an educational grant from Vitagen Healthy Tummies Programme. For further information, please visit www.mypositiveparenting.org. To know more about children’s digestive health, please contact 03-56211408 or 03-56323301 for a free digestive health booklet by the Malaysian Paediatric Association’s Positive Parenting in collaboration with the Malaysian Society of Gastroenterology & Hepatology.