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Optimization of infant formula with a new type of protein?

In the design of infant formulas, one aim is to optimize the composition to simulate human milk, which is the golden standard for feeding infants. Among other things, this means that you remove part of the milk protein casein, which constitutes 80 percent of the protein content in cow’s milk, but only 40 percent of the protein content in human breast milk. The rest of the protein found in formula is so-called whey protein, which is supposed to be easily digestible compared to casein. In premature infant formula the casein content is removed in order to protect the infant’s gastrointestinal system. However, casein has certain advantages and ensures e.g. increased satiety. In a new cooperation project between the University of Copenhagen and Aarhus University, researchers will examine whether a less processed type of casein may be able to optimize the composition of formula, thus exploiting the advantages of casein in a way that remains gentle to the infants’ gastrointestinal system.

Photo: Colourbox

Within the framework of the CASGUT project – financed via the collaboration Arla Food for Health – researchers from Aarhus University and the University of Copenhagen cooperate to map the role of casein in infant formula. These efforts may eventually result in a revised formula composition.

Traditionally, researchers working with formulas have tried to approach the casein contents in human milk, but still lack documentation as to whether or not this is an optimal solution for infant’s nutrition.

Project participant Stine Brandt Bering – Associate Professor and Head of Section for Comparative Pediatrics and Nutrition at University of Copenhagen – explains:

“Casein is found in the most common formula types available today. In relation to formula for premature infants, the entire casein fraction is removed and replaced with whey protein. However, there is only minor documentation for specific effects, benefits and detrimental effects. When removing the casein in premature infant formula, it is due to a certain nervousness as to coagulation and poor absorption of casein. We assume that whey protein is better. Within the framework of this project, we aim to clarify how casein acts in the gastrointestinal tract of term newborns, both physiologically as well as in relation to nutrition and digestion.”


When eating dairy products, a coagulation process takes place in which casein plays a central role. This process may be important as to how the food passes through the gastro-intestinal tract, how the food is broken down and thus also how food is digested. At the same time the coagulation provides a feeling of satiety, as fluid foods such as milk and formula will be more solid due to the coagulation process.

A new product from Arla Food Ingredients – micellar casein isolate – is a less processed casein, which may prove relevant in infant formula. The reduced processing level may result in less damaged proteins and thus increased nutritional contents. And this project will focus specifically on micellar casein isolate.

Piglets as models for infants

Initial work efforts include model experiments in the laboratory at Aarhus University, comparing different types of bovine milk, formula and human milk, including the coagulation processes in the various milk types. Based on the laboratory results achieved, researchers at the University of Copenhagen will conduct piglet experiments, in which piglets will act as a model of newborn infants.

Stine Brandt Bering will be in charge of these experiments. Piglets will be fed various treatments: Human milk, standard formula, formula in which the casein contents have been replaced with intact micellar casein isolate, and finally a treatment in which the micellar casein isolate has been exposed to so-called hydrolyzation – an enzymatic treatment by means of which the protein has been predigested allowing for an easier uptake. 

Stine Brandt Bering explains:

”The piglet experiments will provide us with new knowledge on the physiological effects of both human milk and infant formula as we have access to samples from the piglets’ stomach and the intestinal tract during the digestion process; samples that are not possible to obtain from infants.”

Professor Lotte Bach Larsen, Department of Food Science at Aarhus University, is CASGUT project manager and she is enthusiastic about the collaboration:

Access to tissue samples provides new knowledge

”At AU we have carried out considerable work efforts in relation to the composition of milk and dairy products, and also what processing does to the quality and nutritional properties of these. However, we have not yet had the opportunity to study samples of stomach content after digesting milk, so this will be new to us. And we are eager to see how far our omics methods will help us map the breakdown of proteins and also study the differences between the breakdown of the various allocations as well as the piglets’ uptake of these.”

The piglets will also be fed marked amino acids in order to observe if any differences exist as to the speed at which it enters the bloodstream, according to which of the four treatments the pigs were given.

The project will not revolutionize the formulas overnight; but the hope is to increase existing knowledge on the function of casein:

”We will gain new knowledge about the nutritional uptake, and hopefully also discover if there are any benefits as to well-being in relation to the function of the gastrointestinal tract in newborn infants, as well as the importance of milk coagulation for the breakdown and uptake of milk components”, Lotte Bach Larsen explains.

Stine Brandt Bering adds: ”This study will provide us with more evidence of the potentials of casein in formulas and increase our knowledge on possible benefits of making formulas even closer to human breast milk. In addition, it will give us an idea of whether it will be interesting to study other casein types in the future.”

The project duration is 3 years and it will start on 1 April 2022.


Casein: Protein structure in milk,” transporter” of e.g. calcium. In cow’s milk, casein constitutes approx. 80 % of the protein content, in human milk only about 40 %.

Micellar casein isolate: Casein micelles isolated from cow’s milk by means of filtration processes.

Omics:  The study of a number of biological markers in an analysis such as e.g. proteomics (proteins) and peptidomics (peptides).





Additional information

We strive to ensure that all our articles live up to the Danish universities' principles for good research communication (scroll down to find the English version on the website). Because of this the article will be supplemented with the following information:

Study type




Arla Food for Health, which is financed by Arla Foods, Arla Foods Ingredients, Aarhus University and the University of Copenhagen

Cooperation partners


Department of Food Science, AU – project management and project participant

Department of Veterinary and Animal Sciences, University of Copenhagen, Denmark (project participant)

.Arla Foods Ingredients

Conflicts of interest

Arla Foods Ingredients participates in the project.

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New project


Contact information of the person making a statement. Typically, the researcher/s who are cited in the article.

Lotte Bach Larsen, Project Manager