Webinar | Protein digestion in infants: The impact of infant formula processing and milk sourcing

The webinar was held on May 14th, 2020. Watch the recording here:

Due to time limitation, not all questions were answered during the live webinar. As such, the speaker Dr. Tim Lambers addressed them below.

Q: It would be great to understand more about the manufacturing of infant formula and the reasons for single vs double processing.

A: The ‘single process’ relies on a supply of raw milk, by turning liquid milk into a powdered infant formula in a single heating & drying step which, in practice, requires a control of the whole dairy production chain. Other manufactures, although individual differences may occur in the processes they apply, rely on milk protein ingredients such as milk powders and thus apply ‘double processing’ by re-constituting the already heated and dried powders followed by a second heating & spray drying step to produce the final formula product.

Q: If an infant was to begin with exclusive breastfeeding, and switch to formula, it would be interesting to know if similar results to the showcased study in China would still be observed.

A: In this studies formula fed infants were recruited. Participants had to have switched to formula feeding at least 3 weeks prior to and on formula A, B, C or D for at least 1 week before they were considered eligible to participate in the study. Although not tested and controlled separately, it is thus likely that at least a certain proportion of the infants that were included did receive breastmilk after birth.

Q: Is there any correlation on how milk formula with lower glycation affect occurrence /risk of allergy reaction to milk protein?

A: This has not been studied to date.

Q: Since having less blocked lysine is associated with less constipation, is the protein digestibility the main reason for infant constipation?

A: We cannot conclude that a changed protein digestion is the main reason for constipation. Constipation is multifactorial and can be caused by a diverse range of factors. Specific for formula composition also other factors, including for example oligosaccharides, can affect outcomes.

Q: Does Low glycation level have any impact/goodness for adults?

A: This has not been studied directly to date, but based upon the mechanistic studies presented (particular the mechanistic study with adults, Nyakayiru et al Br J Nutr. 2020) protein glycation did affect digestion and lysine absorption. The lowered protein quality as a result of glycation could thus also have an impact for adults, particularly for situation where a high quality protein source is warranted.

Q: The milk protein glycation study results are they expected to be the same for infants as for adults looking at the postprandial plasma EAA concentrations?

A: Postprandial plasma amino acid concentrations of glycated protein sources as presented were determined in adults, not in infants for ethical reasons. However, based upon the discussed in vitro digestion studies that simulated infant digestive conditions, comparable effects on postprandial plasma amino acid concentrations are expected.

Q: Can we assume that IFs which claim to have a lot of added nutrients  may have undergone more processing and have more blocked lysine?

A: No, the number of added (or optional) ingredients is not indicative for the amount of formula processing.

Q: When mothers facing constipation issue for their infant, some of them turned to non-dairy based infant formula. I am not very familiar with plant based infant formula. Do you think that will have less blocked lysine/or if that will solve the constipation problem?

A: All proteins including plant proteins can be affected by glycation as a result of processing. We’ve not determined levels of blocked lysine in plant-based infant formula but manufacturing of plant-based infant formula rely (at least to the largest extend) on plant-based ingredients (‘double processing’ route). Importantly, constipation is multifactorial and can thus be determined by multiple factors.

Q: Will the feed and environment of cows also affect the mineralized casein content in milk?

A: Effects of feed and environment are under investigation.

Q: Why so much research is going on with protein process and not with lipids process in infant formulas eg adding lcp for better digestion?

A: Lipid digestion is another important focus for FrieslandCampina. The focus of this webinar was however on protein digestion and indeed only a few highlights related to lipid digestion and human milk / formula differences were presented in this lecture.

Q: Hi, I would like to ask how do we determine the level of glycation level in formula milk? How to we advise client/patient to choose milk with low glycation level? can we read from food label?

A: The level of protein glycation and/or the processes that were used for manufacturing of the formula cannot be read from the label. Blocked lysine is the preferred measure for determining the level of glycation although other methods have also been described.

Q: Casein with high mineralization associated with lower digestion, does it affect calcium and phosphate absorption as 2/3 of calcium phosphate carried in casein micelle?

A: Effects on calcium or phosphate absorption have not been determined to date. With the current knowledge, no effects on total calcium or phosphate absorption are expected as the proteins will be digested and calcium-phosphate will be released during digestion.

Q: What is the best ratio of casein and whey in IF to help the digestion and the optimal growth?

A: For growth, overall bioavailability and the level of essential amino acids matter most for a protein source. For infant formulas, levels of essential amino acids have been defined by regulatory bodies and demonstrating normal growth is a prerequisite for infant formula. The level of essential amino acids, is amongst others, determined by the whey:casein ratio which most manufactures have aligned with the composition of human milk.

Important note

Breastfeeding is the best nutrition for healthy growth and development of babies. Exclusive breastfeeding for six months is the optimal way of feeding infants. Thereafter infants should receive complementary foods with continued breastfeeding up to two years or beyond. Mothers should receive guidance on proper maternal nutrition in order to help sustain an adequate supply and quality of breast milk. Unnecessary introduction of bottle-feeding, partially or fully, or of other complementary foods and drinks may have a negative impact on breastfeeding, which may be irreversible. Mothers should consult their doctor and consider the social and financial implications before deciding to use breast milk substitutes or if they have difficulty breastfeeding. Usage, preparation and storage instructions of breast milk substitutes or of other complementary foods and drinks should be followed carefully as improper or unnecessary use may pose a health hazard.

About the Speaker

Dr. Tim Lambers (Ph.D. in physiology) is an expert in gut- & digestive physiology and infant nutrition. He has authored and co-authored over 50 journal and conference papers to date. Currently, Dr. Lambers works as a scientist and cluster leader in the Nutritional Sciences team of FrieslandCampina.

Live webinar

Who? Nutrition and health professionals
Costs? This webinar is provided free of charge by FrieslandCampina Institute
Language? English
Duration? 60 minutes

This webinar is accredited by following associations:

  • Singapore Nutrition and Dietetics Association (SNDA)
  • Malaysian Medical Association (MMA)
  • Pending: ADAP (Dutch dietitians)

This webinar will provide an overview of protein digestion in infants:

  • Introduction to infant digestive physiology in relation to human milk and formula protein digestion
    • Effect of protein coagulation & emulsion stability
  • Overview of in vitro and in vivo research methodologies
  • Observations related to digestive differences amongst formula users
  • Effect of milk protein processing
    • Protein denaturation & glycation
  • Effect of milk sourcing
    • Casein mineralization