Human milk contains prebiotic components such as human milk oligosaccharides (HMOs) which help stimulate the growth of beneficial gut microbiota such as bifidobacteria.
Bifidobacteria play a role in the immune system by inhibiting pathogens, and may also protect against allergies in infants.
Both cow and goat milk contain naturally occurring oligosaccharides, albeit at lower concentrations and diversity than human milk. Although, goat milk has four times more oligosaccharides than cow milk, and higher concentrations of fucosylated oligosaccharides and sialyloligosaccharides.
Hence, manufacturers typically add plant-based or synthetic oligosaccharides into cow or goat milk infant formulas to stimulate the effect of HMOs.
In this in-vitro study conducted by the Dairy Goat Co-operative (NZ) and ProDigest BVBA (Belgium), researchers found that cow and goat milk-based formulas without added prebiotics simulated gastrointestinal digestion and colonic fermentation similar to human milk.
Dairy Goat Co-operative (N.Z.) Ltd is a New Zealand farmer owned Co-operative that develops, manufactures and market its own-brand, goat milk nutritional powders for infants and children.
The findings were published in the journal, Frontiers in Nutrition.
The study was conducted in Belgium. Human milk was collected from a mother in Belgium in her third month of lactation.
The cow milk infant formula was made from pasteurised whole cow milk sourced from New Zealand, skim milk powder and whey protein powder. The cow formula used in the study was similar to Dairy Goat Co-operative manufactured formula sold in Asia.
The goat milk infant formula was made from pasteurised whole goat milk. It is the same formula sold by Dairy Goat distribution partners in New Zealand, Australia, Asia and Europe.
Both formulas also contained vegetable oils (high oleic sunflower oil, coconut oil, canola oil, sunflower oil, soybean oil), minerals, marine fish oil (source of DHA), microbial oil (source of arachidonic acid), and vitamins to meet the needs of infants less than 12 months of age.
The formulas were prepared by mixing 6.6 g of powder to 100 mL with water, while the human milk was diluted 1:1 with water.
The reactor setup was an in-vitro model for 3-month-old babies, based on the Simulator of the Human Intestinal Microbial Ecosystem (SHIME).
The most significant finding was that both cow and goat formulas stimulated microbial activity and increased bifidobacteria comparable to human milk, despite the relative absence of oligosaccharides in the formulas.
“It is hypothesised that this was due to naturally-occurring milk fat and milk fat globule membrane (MFGM) within the formulas,” Colin Prosser, chief scientific officer of Dairy Goat Co-operative (NZ) Ltd told NutraIngredients-Asia.
In this study, both cow and goat formulas contained milk fat, but “in the case of the goat formula 50% of total lipids in the formula was from goat milk fat, while the cow formula had 30% milk fat,” Prosser explained. So, the goat formula is expected to contain more MFGM.
All three test products stimulated microbial activity and increased bifidobacteria, which are regarded as beneficial bacteria in infancy.
Bifidobacteriaceae are capable of producing high concentrations of lactate, which is an important metabolite in the human colon environment because it decreases the gut pH and acts as an antimicrobial agent.
Researchers said it was possible that glycoproteins and glycolipids associated with the MFGM may also act as growth substrates for Bifidobacteria and other bacteria to flourish.
They added that further clinical research is needed to study the role of goat milk fat in formulas on the development of the gut microbiota in early life.
Dairy Goat Co-operative has an ongoing research programme studying the attributes and benefits of goat milk infant formula. This includes setting up nutritional trials to investigate gastro-intestinal outcomes in infants.
Prosser explained: “Consideration of the gut microbial activity and community composition in infants should include other compounds in milk and not just focus on the oligosaccharides in formula. In this context use of whole milk offers advantages over milk fractions and substitution with non-milk components.”
One of the limitations of the in vitro dynamic digestive model was that it lacked the full complement of the digestive system. For instance, brush border enzymes such as lactase, were not present and as a result, there was no breakdown of lactose into galactose or glucose.
Source: Frontiers in Nutrition
“Comparison of the Bifidogenic Effects of Goat and Cow Milk-Based Infant Formulas to Human Breast Milk in an in vitro Gut Model for 3-Month-Old Infants”
Authors: Sophie Gallier, et al.