State-of-the-art research

Each year, the 15 mill. infants that are born preterm (<37 weeks gestation, 10-15%) have a high mortality (7-10%), and incur high societal costs. Especially those born very preterm (24-32 weeks, 2-3%) have a high risk of developing diseases (e.g. gut and blood infections) and learning disabilities later in life. These long-term problems are still poorly understood because the competences to rescue the most immature infants developed quite recently.

Many of these infants with a Very Low Birth Weight (VLBW) (<1500 g, 2% of all infants) suffer from serious infections (20-30% with late-onset sepsis, LOS) or gut problems (feeding intolerance, necrotizing enterocolitis, NEC). These conditions are worse when infants are not fed MM. Absent or delayed maternal lactation after preterm birth often make DM or IF the only alternatives for nutrients, because long-term use of nutrients via the blood stream (parenteral nutrition, PN) induces further complications.

Still, DM and IF are suboptimal to support the initial growth and gut development in both preterm infants and preterm pigs during the first 1-2 weeks. IF-based fortifiers increase NEC risk in preterm infants when added to MM or DM to increase nutrient density, but better outcomes are found using concentrated DM products. However, such DM-based nutrient fortifiers are difficult and very costly to produce and not widely available.

Our preliminary studies indicate that IF-based fortifiers are also detrimental when added to DM in preterm pigs. On this background, we suggest COL as a novel dietary supplement for preterm infants, used either as the first feed (when MM/DM is insufficient in supply), and/or as a nutrient fortifier (when MM/DM nutrients are inadequate for growth). Bioactive proteins in COL are well preserved after pasteurization and spray-drying, but the refined methods need better documentation, relative to conventional methods.

In preterm pigs, COL is superior to any other milk diet (from cows, pigs or humans), suggesting that species-specificity of milk may not be critical just after preterm birth. The preterm pig models in Denmark are the best models for nutrition studies in preterm infants. They can be used effectively to verify the COL effects after different processing, clinical conditions (e.g. infections) and diet combinations (e.g. MM, PN, DM, IF).