The digestive system of a new born is not yet fully mature. The capacity to digest and absorb nutrients, develops in the early years of life. Many factors can lead to very different digestive problems or discomfort for the infant (e.g. regurgitation, colic and constipation).
Understanding the digestion and bioavailability of macro- and micronutrients is very important in the development of infant formula. A number of ingredients may help improve the digestibility of infant formula.
Galacto-oligosaccharides (GOS) are soluble carbohydrates that are not digested by digestive enzymes but are fermented by the microbiota in the gut32. Consumption of infant formula containing GOS has been shown to result in softer stools and/or a higher frequency of defecation18,33.
Compared to caseins, whey proteins are easier to digest12. They are also referred to as ‘the fast proteins’. It is well known and acknowledged that breast milk contains much higher levels of whey proteins than caseins. The whey: casein ratio changes from 80:20 early in lactation to 50:50 at late lactation12.
When proteins are hydrolysed, they are basically pre-digested and can therefore become easier to digest by the new-born’s digestive system than intact protein34. So, hydrolysates are not only useful for the management of allergies; healthy infants may also benefit from these ingredients.
Milk fat has a triglyceride structure in which most of the sn-2 position is occupied by long-chain saturated fatty acids35-36. A high percentage of long-chain saturated has been shown to positively affect digestibility of fat35-38. The presence of short-chain and medium-chain fatty acids at the sn1/3 position delivers the infant with easily absorbable fatty acids35,39.