The Development Of Your Baby's Digestive System

The Development Of Your Baby's Digestive System

Before baby enters the world, all of the nutrients necessary for his growth are provided by the placenta. But as soon as your new little one is born, everything changes.

Once the umbilical cord is cut and the placenta is expelled, your newborn’s digestive and excretory systems are suddenly forced to set into action. Being inexperienced in what they do, it also takes time for both systems to ramp up and function properly. This is why it is important for parents understand how immature theirbaby’s digestive system is and how they can best support it during their first few months.

Transitioning From Womb To Birth

Your baby’s stomach is very small (approximately the size of a marble) and his digestive system is not accustomed to ingesting anything other than what was delivered to him through the placenta. This is why babies may lose anywhere up to 10% of their body weight in the first couple of weeks after birth.

The small size of your baby’s stomach is also why he will need frequent feedings, whether that be by formula or breastmilk. Breastmilk is biologically designed to be high in fat during the first few weeks of your baby’s life. This is to ensure that your baby receives enough calories to pack on the pounds.

Another benefit to choosing breastmilk is that your newborn baby’s pancreas is not fully developed. This means that your baby’s body produces significantly reduced levels of digestive enzymes. Breastmilk contains enzymes which help make up for this shortcoming.

After the first several days your baby’s stomach will expand to be about the same size as a ping pong ball. But he will only still be able to hold up to 60 ml at a time.

You may also find that your baby spits up frequently until he is 3 months of age or older. This is because the lower oesophageal sphincter which separates the stomach from the oesophagus is weak and immature.

The Digestive Lining Issue

The digestive system of healthy human children and adults has a layer of mucous which protects the gastrointestinal tract from microbes and other contaminants which may be present in the foods or drinks we consume. Infants have a very thin and immature barrier which puts newborns at a greater risk of infection.

Fortunately, breastmilk has antibodies which help protect your bub until that digestive mucosal lining is fully mature and he is able to produce his own antibodies (this occurs at around six months of age). Studies have also shown that through breastfeeding, your baby can give your body germs so that your immune system can manufacture antibodies for that germ and help protect your baby.

As if that were not enough, breastmilk has also been shown to  help engineer the gut of your baby, and it may have a long lasting impact on his health. The antibody SIgA which is found in breastmilk helps your baby set up the correct community of gut microbes. This helps keep your baby healthier now and it can result in fewer chronic illnesses as he ages.

Why You Should Avoid Solid Foods Until Six Months

Babies may exhibit an interest in the foods you are eating at an early age, but that does not mean that you should give him a taste. Your baby’s digestive system is not fully mature and is not ready for solid foods until he is around six months of age.

  • Your baby’s body is not capable of producing sufficient levels of enzymes to digest starches until approximately six months of age
  • The enzymes that digest complex carbohydrates do not reach sufficient levels until approximately seven months of age
  • Bile salts and lipase (which help digest fat) do not reach full levels until between six to nine months of age

It is also important to recognise that between four to six months of age, infants have something which is known as an “open gut”. This “open gut” allows proteins to pass directly from the small intestine and into the bloodstream.

This process happens to allow antibodies from a mother’s breastmilk to enter the baby’s bloodstream. But the larger molecules from solid foods can also pass through which may cause:

  1. a) Allergies; and/or
  2. b) Illness (molecules can carry pathogens along with them)

How To Support Your Baby’s Digestive Learning Curve

The digestive system has a steep learning curve at birth, and it is important that we as parents help make it as easy on our little ones as possible.

One way to make it easier on new mums is to make sure that the feeding process is as easy as possible. This means:

  • Offering encouraging words of support
  • Making sure she is well hydrated
  • Ensuring that she feels secure in her choice of feeding her baby

Peachymama is proud to support mums, both here in Australia and around the world. Our leading fashions can be found on brand new mums right through to those who are beyond the feeding phase – because our on-trend designs and mum-friendly fabrics reveal – and conceal – all the right curves.

Check out our new arrivals at

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