In Vivo Assessment of Antioxidant Potential of Human Milk Treated by Holder Pasteurization or High Hydrostatic Pressure Processing: A Preliminary Study on Intestinal and Hepatic Markers in Adult Mice

Abstract

Preterm infants are highly susceptible to oxidative stress due to an imbalance between endogenous oxidant and antioxidant systems. In addition, these newborns are frequently fed with donor milk (DM) treated by Holder pasteurization (HoP) at 62.5 °C for 30 min, which is known to alter numerous heat-sensitive factors, including some antioxidants. High hydrostatic pressure (HHP) processing was recently proposed as an innovative method for the treatment of DM. The present study aimed to measure the redox balance of HoP- and HHP-DM and to study, in vivo, the effects of HoP- and HHP-DM on the gut and liver. H2O2, vitamin A and vitamin E (α- and γ-tocopherols) concentrations, as well as the total antioxidant capacity (TAC), were measured in raw-, HoP- and HHP-DM. The gene expression level of antioxidant systems and inflammatory response were quantified in the ileum and liver of adult mice after 7 days of oral administration of HoP- or HHP-DM. HoP reduced the γ-tocopherol level, whereas HHP treatment preserved all vitamins close to the raw milk level. The milk H2O2 content was reduced by HHP but not by HoP. The total antioxidant capacity of DM was reduced after HHP processing measured by PAOT-Liquid® technology but was unaffected after measurement by ORAC assay. In mice, HHP-DM administration induced a stimulation of antioxidant defenses and reduced some inflammatory markers in both the ileum and liver compared to HoP-DM treatment. Our preliminary study suggests that the HHP processing of DM may better protect preterm infants from gut and liver pathologies compared to HoP, which is currently used in most human milk banks.

The Sterilization of Human Milk by Holder Pasteurization or by High Hydrostatic Pressure Processing Leads to Differential Intestinal Effects in Mice

“…These mice also had an increased expression of some ileal tight junctions ( Ocln , Cdh1 ) and an augmented expression of the intestinal mucin Muc2 . Interestingly, in a recent study of our group, we showed that HHP-DM mice also displayed a stimulated antioxidant defense and a reduced expression of inflammatory markers in the ileum, compared with HoP-treated mice [ 19 ]. It is now well shown that the intestinal barrier function is strongly regulated by the redox homeostasis [ 20 ].…”

New alternatives to holder pasteurization in processing donor milk in human milk banks

“…Many authors have shown significant decrease in bioactive factors in milk following HoP compared with HPP. Thus, immunoglobulins ( 42 , 43 , 50 ), lactoferrin ( 42 , 44 , 48 , 50 ), lysozyme ( 43 , 44 , 50 ), lipase activity ( 24 , 44 , 45 , 50 , 51 , 53 ) and many hormones ( 54 , 57 ) are largely affected by HoP.…”

“…Studies comparing mice fed HoP- and HPP-treated milk showed a loss of antioxidant defenses and an increase of inflammatory markers in animals fed HoP-treated milk ( 54 ).…”

Fresh Parent’s Own Milk for Preterm Infants: Barriers and Future Opportunities

“…While macronutrients are not impacted much through pasteurization, there is some evidence that they may reduce preterm infant fat absorption [8]. Additionally, heat treatment and cold storage impact many bioactive components of fresh human milk [9][10][11]; see Figure 1. Therefore, it is vital to recognize and consider the potential biological benefits of fresh parent's own milk on infant health and development.…”