A Gently Processed Skim Milk‐Derived Whey Protein Concentrate for Infant Formula: Effects on Gut Development and Immunity in Preterm Pigs

Abstract

ScopeProcessing of whey protein concentrate (WPC) for infant formulas may induce protein modifications with severe consequences for preterm newborn development. The study investigates how conventional WPC and a gently processed skim milk‐derived WPC (SPC) affect gut and immune development after birth.Methods and resultsNewborn, preterm pigs used as a model of preterm infants were fed formula containing WPC, SPC, extra heat‐treated SPC (HT‐SPC), or stored HT‐SPC (HTS‐SPC) for 5 days. SPC contained no protein aggregates and more native lactoferrin, and despite higher Maillard reaction product (MRP) formation, the clinical response and most gut and immune parameters are similar to WPC pigs. SPC feeding negatively impacts intestinal MRP accumulation, mucosa, and bacterial diversity. In contrast, circulating T‐cells are decreased and oxidative stress‐ and inflammation‐related genes are upregulated in WPC pigs. Protein aggregation and MRP formation increase in HTS‐SPC, leading to reduced antibacterial activity, lactase/maltase ratio, circulating neutrophils, and cytotoxic T‐cells besides increased gut MRP accumulation and expression of TNFAIP3.ConclusionThe gently processed SPC has more native protein, but higher MRP levels than WPC, resulting in similar tolerability but subclinical adverse gut effects in preterm pigs. Additional heat treatment and storage further induce MRP formation, gut inflammation, and intestinal mucosal damage.

Science and Faith to Understand Milk Bioactivity for Infants

“…Processing and storage effects, even from single-step heat pasteurization, are believed to be a key reason why human donor milk remains inferior to a mother’s own milk for preterm infants [ 33 ]. When using preterm pigs as a model for infants, the gut-protective effects of whey protein in formula appeared to decrease as the intensity of heat treatment steps increased [ 6 , 32 , 33 , 36 ], especially when using ultra-high-temperature (UHT) treatments and long storage times to produce ready-to-feed (RTF) liquid formulas [ 30 , 146 ]. While heat damage to the protein fraction is well known, the mechanisms whereby this affects the immature gut are unknown.…”

“…Emphasis is placed on the bioactivity of proteins and peptides, but the health effects of milk may originate from multiple milk constituents and fractions, including carbohydrates, lipids, and micronutrients. Inspiration is gained from the author’s studies on intact milk, milk fractions, or isolated milk proteins in experimental pediatrics [ 3 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. The paper does not provide a review of results from scientific studies, but rather a critical reflection on the scientific methodology and epistemology related to milk bioactivity research.…”