Considerations in Donor Human Milk Use in Premature Infants

Inherited nongenetic influences on the gut microbiome and immune system

The gut microbiome and the immune system codevelop around the time of birth, well after genetic information has been passed from the parents to the offspring. Each of these "organ systems" displays plasticity. The immune system can mount highly specific adaptive responses to newly encountered antigens, and the gut microbiota is affected by changes in the environment. Despite this plasticity, there is a growing appreciation that these organ systems, once established, are remarkably stable. In health, the immune system rapidly mounts responses to infections, and once cleared, resolves inflammatory responses to return to homeostasis. However, a skewed immune system, such as seen in allergy, does not easily return to homeostasis. Allergic responses are often seen to multiple antigens. Likewise, a dysbiotic gut microbiota is seen in multiple diseases. Attempts to reset the gut microbiota as a therapy for disease have met with varied success. Therefore, how these codeveloping "organ systems" become established is a central question relevant to our overall health. Recent observations suggest that maternal factors encountered both in utero and after birth can directly or indirectly impact the development of the offspring's gut microbiome and immune system. Here, we discuss how these nongenetic maternal influences can have long-term effects on the progeny's health.

Better Control of Holder Pasteurization Results in Higher Retention of Human Milk Lactoferrin, IgA, and Lysozyme

Background: Holder pasteurization is commonly used in milk banks. We previously reported that the pattern of temperature and time may be different according to the pasteurizer used. Aim: The aim of our study was to assess the variances in pasteurization using two different devices: a standard pasteurizer (Past STD) and an optimized pasteurizer (Past OPTI). Methods: Immunoglobulin A (IgA), lactoferrin (LF), and lysozyme (LZ) content were assessed before and after pasteurization of 24 donor human milk samples. The impact of the pasteurization device was evaluated by testing 50- to 200-mL samples. Results: Mean temperature and duration of the plateau were 1.5°C lower and 11 min shorter, respectively, with Past OPTI vs. Past STD. The loss of IgA, LF, and LZ was 17.6, 5.6, and 9.8% lower, respectively, with Past OPTI than with Past STD. Conclusions: Accurate control of temperature enabled better preservation of IgA, LF, and LZ in donor milk. Holder pasteurization should be optimized, and new techniques proposed to treat donor milk should be compared with Holder pasteurization performed with a well-controlled device under realistic conditions.