Infant Digestive System Development

While in utero, your child’s gastrointestinal (GI) tract is considered fully formed at 20 weeks of development. The parts of the GI tract, like the stomach and both intestines, are formed and intact, but they may not be fully functional.2 In fact, while your fetus is developing, their intestine grows by 1,000 times from the 5th week of gestation until the 40th gestational week. The second and third trimesters of pregnancy are crucial for the anatomical and functional development of the GI tract.3 Infant gut immaturity can be seen in premature infants.1

Certain mechanisms within the GI tract aren’t fully functional until later in the gestational period, such as:
  • The large and small intestines aren’t completely differentiated until around the 20th week in utero, but the contractions that move food through the digestive system, called peristalsis, don’t start occurring until the 29th gestational week.2,3
  • The enzymes needed to digest milk or formula may not be produced in a large enough volume.2
  • The ability to coordinate sucking and swallowing is not present until around 33 weeks of gestation.2,3

Immature Gut & Infant Microbiome

It’s important to note that babies with immature GI tracts don’t have anything wrong with their digestive systems; they’re simply not fully functional yet.2 However, infant gut immaturity may negatively influence the normal patterns of gut colonization, potentially subjecting a baby to an abnormal microbiome.3 This can affect the functional and neural development of the GI tract and has an associated risk of further digestive complications.3 Gut microbiota colonization patterns during infancy can interact with a child’s early immune and endocrine systems.1,4

Many studies indicate that breastfed infants have guts that are primarily colonized by Bifidobacterium.4 This infant gut bacteria is thought to be stimulated by the presence of human milk oligosaccharides (HMOs), which are the most abundant carbohydrate component in breast milk.4 There, HMOs act like prebiotics, stimulating the growth of more Bifidobacterium.4 Formula-fed infants tend to have different gut microbes.4 The gut microbiota interacts with the endocrine system, metabolism, and the immune system, providing a foundation for lifelong health.4

Formula to Support a Healthy Gut

Any formula that parents choose to feed their infants can support their little one’s immune system by helping infant gut bacteria flourish. A formula that can help your infant is Enfamil A+® NeuroProTM Gentlease.® It is the ONLY brand with a combination of easy-to-digest proteins, an expert-recommended level of brain-building DHA and our exclusive fibre blend§ with 2’FL HMOs shown to promote softer stools.¶,// It’s also the #1 paediatrician-recommended infant formula.*

Talk to your infant’s healthcare provider about any concerns you may have about an immature gut and what you can do to help your child get the nutrition they need to support their healthy development.