Exclusive Human Milk Diet for Extremely Premature Infants: A Novel Fortification Strategy That Enhances the Bioactive Properties of Fresh, Frozen, and Pasteurized Milk Specimens

Abstract

Background: Human milk (HM) fortification has been recommended for the nutritional optimization of very low-birthweight infants. This study analyzed the bioactive components of HM and evaluated fortification choices that could accentuate or attenuate the concentration of such components, with special reference to human milk-derived fortifier (HMDF) offered to extremely premature infants as an exclusive human milk diet. Materials and Methods: An observational feasibility study analyzed the biochemical and immunochemical characteristics of mothers' own milk (MOM), both fresh and frozen, and pasteurized banked donor human milk (DHM), each supplemented with either HMDF or cow's milk-derived fortifier (CMDF). Gestation-specific specimens were analyzed for macronutrients, pH, total solids, antioxidant activity (AA), α-lactalbumin, lactoferrin, lysozyme, and α- and β-caseins. Data were analyzed for variance applying general linear model and Tukey's test for pairwise comparison. Results: DHM exhibited significantly lower (p < 0.05) lactoferrin and α-lactalbumin concentrations than fresh and frozen MOM. HMDF reinstated lactoferrin and α-lactalbumin and exhibited higher protein, fat, and total solids (p < 0.05) in comparison to unfortified and CMDF-supplemented specimens. HMDF had the highest (p < 0.05) AA, suggesting the potential capability of HMDF to enhance oxidative scavenging. Conclusion: DHM, compared with MOM, has reduced bioactive properties, and CMDF conferred the least additional bioactive components. Reinstatement and further enhancement of bioactivity, which has been attenuated through pasteurization of DHM, is demonstrated through HMDF supplementation. Freshly expressed MOM fortified with HMDF and given early, enterally, and exclusively (3E) appears an optimal nutritional choice for extremely premature infants.

Keywords: breastfeeding; donor human milk; donor milk bank; exclusive human milk diet; human milk-derived fortifier; necrotizing enterocolitis; pasteurization.

FIG. 1.

Antioxidant activity of DHM, MOM (fresh and frozen) with HMDF, and CMDF supplementation and commercial preprepared bovine-based formulas expressed as percentage. Values are mean of triplicate measurements with their standard deviations represented by vertical bars. AA, antioxidant activity; CMDF, cow's milk-derived fortifier; DHM, donor human milk; HMDF, human milk-derived fortifier; MOM, mothers' own milk.

FIG. 2.

Reversed-phase HPLC of six milk specimens: PTDHM, PTDHM fortified with CMDF, PTDHM fortified with HMDF, FroMOM-24 weeks fortified with HMDF, FroMOM-24 weeks without fortification and CBPTF-1. CBPTF-1, commercial preprepared term type; CMDF, cow's milk-derived fortifier; FroMOM, frozen mother's own milk; PTDHM, preterm donor human milk; HMDF, human milk-derived fortifier; HPLC, high-performance liquid chromatography.

FIG. 3.

Alpha-lactalbumin content (mg/mL) of DHM and MOM (fresh and frozen) supplemented with HMDF and CMDF and commercial preprepared bovine-based formulas. Values are means of triplicate measurements with their standard deviations represented by vertical bars. Column headed by α-LA content. CMDF, cow's milk-derived fortifier; DHM, donor human milk; HMDF, human milk-derived fortifier; α-LA, α-lactalbumin; MOM, mothers' own milk.

FIG. 4.

Lactoferrin content (mg/mL) of DHM and MOM (fresh and frozen) supplemented with HMDF and CMDF and commercial preprepared bovine-based formulas. Values are means of triplicate measurements with their standard deviations represented by vertical bars. Column headed by Human LF content. CMDF, cow's milk-derived fortifier; DHM, donor human milk; HMDF, human milk-derived fortifier; LF, Lactoferrin; MOM, mothers' own milk.

FIG. 5.

Reducing SDS-PAGE patterns of seven fresh human milk samples “FreMOM” of mothers of infants born at 24, 26, and 28-week gestational ages with or without fortifications. Lane1: FreMOM – 24 weeks. Lane 2: FreMOM – 26 weeks. Lane 3: FreMOM – 26 weeks+CMDF. Lane 4: FreMOM – 26 weeks+HMDF. Lane 5: FreMOM – 28 weeks. Lane 6: FreMOM – 28 weeks+CMDF. Lane 7: FreMOM – 28 weeks+HMDF. Lane 9: Pure human milk-based fortifier “HMDF.” Lane 10: pure bovine-based powder fortifier “CMDF.” Molecular mass markers (10–250 kDa) are in Lane 8. CMDF, cow's milk-derived fortifier; FreMOM, freshly expressed mother's own milk; HMDF, human milk-derived fortifier; SDS-PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis.

FIG. 6.

Reducing SDS-PAGE patterns of fresh and frozen human milk samples of mothers of infants born at 24 and 26-week gestational ages with or without fortifications. Lane1: FreMOM–26 weeks. Lane 2: FreMOM–26 weeks+CMDF. Lane 3: FreMOM–26 weeks+HMDF. Lane 4: FroMOM–26 weeks. Lane 5: FroMOM–26 weeks+CMDF. Lane 6: FroMOM–26 weeks+HMDF. Lane 8: Alpha-Lactalbumin human milk standard. Lane 9: FreMOM–24 weeks. Lane 10: FroMOM–24 weeks. Molecular mass markers (6.5–200 kDa) are in Lane 7. CMDF, cow's milk-derived fortifier; FreMOM, freshly expressed mother's own milk; HMDF, human milk-derived fortifier; SDS-PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis.