Researcher: Dr. Daniela Barile, UC Davis
• This study investigated the structures, properties, and sources of health-modulating compounds in Procream, also known as whey protein phospholipid concentrate (WPPC), through both in vitro cell cultures and in vivo animal model experiments.
• In vitro experiments with Procream demonstrated that it is a source of prebiotics that enrich beneficial gut bacteria and can also inhibit the growth of pathogenic bacteria.
• In vivo rodent studies suggest Procream supplementation has anti-inflammatory and potentially anti-obesogenic effects.
BACKGROUND AND OBJECTIVE
Procream is an underutilized product in the dairy industry that is produced when whey protein isolate (WPI) undergoes microfiltration to remove fat. This microfiltration process concentrates whey proteins for WPI and leaves a permeate that is rich in phospholipids and bioactive compounds. This study investigated the structures, properties, and sources of health-modulating compounds in Procream through both in vitro cell cultures and in vivo animal model experiments.
METHODS, FINDINGS AND OUTCOMES
To better understand the composition of Procream, the researchers first quantified total fat, total protein, and total solids. A more detailed analysis of the protein profile suggested the presence of various glycoproteins, which are carbohydrate-containing proteins that are involved in many important human physiological processes. To understand the composition of Procream in even more detail, the team conducted glycoproteomic and lipidomic analyses. These approaches quantify the complexity of glycoproteins and lipids by identifying and measuring all the hundreds of different proteins and fats that are present in a sample. An advanced proteomics analysis revealed the presence of 180 unique milk proteins, many of which were glycosylated (having gone through the process by which a carbohydrate is attached to a target macromolecule, typically proteins and lipids) and originated from the milk fat globule (MFG) membrane.
Due to the lack of standardization in Procream production, the researchers took samples from six different manufacturers and analyzed them for chemical composition, protein profiles, and MFG size. They focused specifically on the absolute quantification of several key glycosylated proteins (IgA, IgG, lactoferrin, and GlyCAM1) that are involved in immune function. This analysis revealed significant variation in the glycosylated protein concentrations across manufacturers between 4 to 25 times higher than what is normally found in raw milk samples. The researchers then tested Procream’s ability to selectively grow or inhibit key bacterial strains. The levels of GlyCAM1 in Procream was found to be particularly effective for assisting the growth of select probiotics like bifidobacteria strains, suggesting that Procream’s glycoprotein content may provide a source of prebiotic compounds that can be utilized by beneficial gut microbes.
The researchers also identified antibacterial properties of whole Procream via in vitro studies that showed impaired growth of the pathogens Enterotoxigenic Escherichia coli and Listeria monocytogenes in a dose-dependent manner. To study the biological activity of Procream in vivo, the team conducted research using different rodent models. This first study was on adult mice and helped establish the metabolically relevant dose of Procream. Two Procream concentrations, 1.6% and 4%, were then tested in the context of a whey-based control diet. After 8 weeks, the 1.6% Procream diet reduced the high-fat diet-induced body weight gain and fat mass of the mice but had no effect on food intake. The second study looked at the physiological effects of Procream supplementation in weanling mice on a high-fat diet. Procream supplementation was associated with a significant reduction in lipocalin2, which is a measure of intestinal inflammation, suggesting an anti-inflammatory effect of Procream. In this study on weanling mice, Procream also increased femur length independent of diet, a finding that is interesting considering the links between dairy intake and skeletal growth and development.
The final mouse study investigated whether a higher dose (10%) of Procream supplementation could reduce the cognitive impairment caused by a highfat diet in young rats. For this study, electrodes were implanted on each study animal’s brain. Preliminary findings indicate that the higher dose of Procream may improve memory and novel object recognition compared with rats consuming only the high-fat diet and no Procream.
Procream is a source of bioactive glycoproteins that may provide beneficial gut health effects. Understanding which specific compounds in Procream are key for gut function will help guide the future selection and production of dairy ingredients that can alter the microbiota-gut-brain axis and improve overall health. In vitro experiments found that the compounds in Procream were utilized by most of the bifidobacterial strains tested and could therefore have beneficial effects on gut health. In vivo experiments demonstrated the potential for Procream supplementation to beneficially influence body weight, inflammation, and memory. The researchers suggest combining Procream with select commercial strains of bifidobacteria in future studies to improve the chances of observing health effects.