Homogenized human milk-based products may be unsafe for premature infants, flags Prolacta Bioscience

28 Mar 2022 --- Human milk-based nutritional products should not be homogenized until the process’s safety and efficacy has been established, according to a paper backed by Prolacta Bioscience. It notes that this process disrupts the milk fat globule, which may lead to premature digestion of bioactive components – with unknown implications for infant health.

“Some newer human milk companies are using homogenization, despite the fact that there is no clinical evidence on the safety and efficacy of homogenized human milk products,” lead author Sarah Reyes, scientific liaison of human milk and clinical research, Prolacta Bioscience, tells NutritionInsight. 

However, homogenization is generally not a common practice for established milk banks or companies producing human milk-based products, adds co-author Dr. Melinda Elliott, neonatologist and chief medical officer, Prolacta Bioscience.Conceptual framework of the potential implications of homogenized human milk-based nutritional products on infants.

No drawbacks to not homogenizing 
Homogenization is a process that evenly disperses two liquids to create a single uniform mixture. Within dairy, this can improve cow milk’s taste, consistency, appearance and shelf life. Dairies also homogenize cow milk to disperse fat droplets and prevent the cream from rising to the top.

However, Reyes notes that the clinical benefits of human milk-based nutritional products only apply to currently available non-homogenized products. 

Elliot asserts that there are no drawbacks to not homogenizing human milk.

“As human milk researchers and medical professionals, it is our opinion that the use of industrial processing techniques such as homogenization, with or without high-heat processing, should be avoided for human milk-based nutritional products until their safety and efficacy have been established.”

Spotlight on milk fat globule
Bioactive components in the milk fat globule like sphingolipids and long-chain polyunsaturated fatty acids (LCPUFAs) are linked with favorable neurological outcomes. However, homogenization may mean that these are digested prematurely, details the paper.

“It is unknown whether these components can be absorbed in a specific portion of the intestine to be used appropriately by the infant,” says Elliot.

“If they are prematurely absorbed, are they used by the baby’s body, or are they excreted? Or are they absorbed at too high a level? None of this is known and needs further study,” adds Reyes. 

They also note that milk fat globule membranes (MFGM) have been proposed to improve immune defense, reduce inflammation, reduce risk of infection and improve gut function. Other potential benefits include supporting infant development, especially in neurodevelopment, microbiome and metabolism.

MFGM is a key ingredient in infant formula, with Arla Foods Ingredients recently launching a dry-blend version. Meanwhile, Milk Specialities’ GlobalNutriPro products for adults and infants also include MGFM, as well as alpha-lactalbumin and lactoferrin.Reyes (left) and Elliott are authors of the paper, now published in Current Developments in Nutrition. 

Maintaining bioactivity
Prolacta Bioscience’s human milk-based nutritional products for premature, critically ill infants have never been homogenized.

However, they are vat pasteurized to ensure pathogen inactivation and the highest level of safety. This is all while retaining as much of the natural bioactivity of the milk as possible.

“Our products retain higher bioactivity than products processed using other methods, including retort sterilization and ultra-high-temperature (UHT) processing,” says Reyes.

Heat has negative impacts
Elliot explains that in practice, high-temperature, short-time (HTST), ultra-high temperature (UHT) and retort sterilization treatment of human milk have all been shown to negatively impact individual and total MFGM ganglioside content, compared with pasteurization.

“On the other hand, both vat and Holder pasteurization have been shown to ensure a safe product that maintains a high level of bioactivity,” she continues.

A comparison of Holder and vat pasteurization with retort sterilization of human milk revealed greater preservation of human milk oligosaccharides (HMOs), protein and fat concentrations. 

This included IgA, IgG, IgM, lactoferrin, lysozyme, alpha-lactalbumin, casein, osteopontin, and alpha-1-antitrypsin proteins with vat or Holder pasteurized samples.

Last year, a separate series of studies found that Prolacta Bioscience’s offerings could reduce the incidence of retinopathy of prematurity. 

By Katherine Durrell