Extracellular vesicles in human preterm colostrum inhibit infection by human cytomegalovirus in vitro

Breast milk is a complex biofluid that nourishes infants, supports their growth and protects them from diseases. However, at the same time, breastfeeding is a transmission route for human cytomegalovirus (HCMV), with preterm infants being at a great risk of congenital disease. The discrepancy between high HCMV transmission rates and the few reported cases of infants with severe clinical illness is likely due to the protective effect of breast milk. The aim of this study was to investigate the anti-HCMV activity of human preterm colostrum and clarify the role of colostrum-derived extracellular vesicles (EVs). Preterm colostrum samples were collected and the EVs were purified and characterized. The in vitro anti-HCMV activity of both colostrum and EVs was tested against HCMV, and the viral replication step inhibited by colostrum-purified EVs was examined. We investigated the putative role EV surface proteins play in impairing HCMV infection using shaving experiments and proteomic analysis. The obtained results confirmed the antiviral action of colostrum against HCMV and demonstrated a remarkable antiviral activity of colostrum-derived EVs. Furthermore, we demonstrated that EVs impair the attachment of HCMV to cells, with EV surface proteins playing a role in mediating this action. These findings contribute to clarifying the mechanisms that underlie the protective role of human colostrum against HCMV infection

Do different techniques of human milk pasteurization impact the kinetics of peptide release during in vitro dynamic digestion?

IntroductionIn order to minimize the denaturation of bioactive compounds, which is known to affect donor humanmilk (HM) after the mandatory heat treatment (Holder pasteurization at 62.5°C, 30min – HoP), anumber of alternative processing techniques are currently being investigated. Recently, High Temperature-Short Time pasteurization (HTST, 72°C-15s) was found to limit the denaturation of somebioactive components of human milk.ObjectiveThe aim of the study was to investigate whether different types of pasteurization (HoP and HTST)may differently affect peptide release from human milk during preterm infant gastrointestinal digestion,by using a dynamic in vitro systemMethodologyPooled raw HM (RHM) from 5 donors was collected and processed in triplicate according to HoP andHTST. The pasteurized milks and RHM were digested in triplicate using a dynamic in vitro digestionsystem, mimicking the preterm physiology conditions. Samples were collected at different digestiontimes. Peptides from undigested and digested samples were analysed using a Q-Exactive massspectrometer and peptide abundance was subjected to multivariate statistics to unravel specificprofile trends.Main findingsPre-proteolysis occurred mostly on β-casein, from which originated more than 82% of the peptidesfound in undigested milk. During digestion, a differential behaviour between gastric and intestinalpeptide release was found by multivariate statistics. In particular, whereas in the gastric phase thepeptide pattern was more similar for HTST and RHM with respect to HoP, the opposite was found atthe beginning of the intestinal phase, while at the end of digestion no difference was found. Thesedifferences were mostly due to peptides released from β-casein, especially in the gastric phase.Some bioactive peptides from bile salt-stimulated lipase, caseins and lactoferrin presented significantlydifferent abundances between the different samples during intestinal digestion.ConclusionThe results indicate possible consequences of the different pasteurizations on the biological activityof donor’s human milk

Do different techniques of human milk pasteurization impact the kinetics of peptide release during in vitro dynamic digestion?

IntroductionIn order to minimize the denaturation of bioactive compounds, which is known to affect donor humanmilk (HM) after the mandatory heat treatment (Holder pasteurization at 62.5°C, 30min – HoP), anumber of alternative processing techniques are currently being investigated. Recently, High Temperature-Short Time pasteurization (HTST, 72°C-15s) was found to limit the denaturation of somebioactive components of human milk.ObjectiveThe aim of the study was to investigate whether different types of pasteurization (HoP and HTST)may differently affect peptide release from human milk during preterm infant gastrointestinal digestion,by using a dynamic in vitro systemMethodologyPooled raw HM (RHM) from 5 donors was collected and processed in triplicate according to HoP andHTST. The pasteurized milks and RHM were digested in triplicate using a dynamic in vitro digestionsystem, mimicking the preterm physiology conditions. Samples were collected at different digestiontimes. Peptides from undigested and digested samples were analysed using a Q-Exactive massspectrometer and peptide abundance was subjected to multivariate statistics to unravel specificprofile trends.Main findingsPre-proteolysis occurred mostly on β-casein, from which originated more than 82% of the peptidesfound in undigested milk. During digestion, a differential behaviour between gastric and intestinalpeptide release was found by multivariate statistics. In particular, whereas in the gastric phase thepeptide pattern was more similar for HTST and RHM with respect to HoP, the opposite was found atthe beginning of the intestinal phase, while at the end of digestion no difference was found. Thesedifferences were mostly due to peptides released from β-casein, especially in the gastric phase.Some bioactive peptides from bile salt-stimulated lipase, caseins and lactoferrin presented significantlydifferent abundances between the different samples during intestinal digestion.ConclusionThe results indicate possible consequences of the different pasteurizations on the biological activityof donor’s human milk

Do different techniques of human milk pasteurization impact the kinetics of peptide release during in vitro dynamic digestion?

IntroductionIn order to minimize the denaturation of bioactive compounds, which is known to affect donor humanmilk (HM) after the mandatory heat treatment (Holder pasteurization at 62.5°C, 30min – HoP), anumber of alternative processing techniques are currently being investigated. Recently, High Temperature-Short Time pasteurization (HTST, 72°C-15s) was found to limit the denaturation of somebioactive components of human milk.ObjectiveThe aim of the study was to investigate whether different types of pasteurization (HoP and HTST)may differently affect peptide release from human milk during preterm infant gastrointestinal digestion,by using a dynamic in vitro systemMethodologyPooled raw HM (RHM) from 5 donors was collected and processed in triplicate according to HoP andHTST. The pasteurized milks and RHM were digested in triplicate using a dynamic in vitro digestionsystem, mimicking the preterm physiology conditions. Samples were collected at different digestiontimes. Peptides from undigested and digested samples were analysed using a Q-Exactive massspectrometer and peptide abundance was subjected to multivariate statistics to unravel specificprofile trends.Main findingsPre-proteolysis occurred mostly on β-casein, from which originated more than 82% of the peptidesfound in undigested milk. During digestion, a differential behaviour between gastric and intestinalpeptide release was found by multivariate statistics. In particular, whereas in the gastric phase thepeptide pattern was more similar for HTST and RHM with respect to HoP, the opposite was found atthe beginning of the intestinal phase, while at the end of digestion no difference was found. Thesedifferences were mostly due to peptides released from β-casein, especially in the gastric phase.Some bioactive peptides from bile salt-stimulated lipase, caseins and lactoferrin presented significantlydifferent abundances between the different samples during intestinal digestion.ConclusionThe results indicate possible consequences of the different pasteurizations on the biological activityof donor’s human milk

New perspectives on corporate social responsibility

International audienceIntroduction: Donor human milk (DHM) represents the best alternative when mother’s own milk is not available, a common occurrence in Neonatal Intensive Care Units. Heat treatment of DHM is mandatory for safety reasons. Holder pasteurization (HoP, 62.5°C-30’) is recommended by all human milk bank guidelines. Recent studies have demonstrated that HoP affects the digestion profile and behavior of several human milk components. High Temperature-Short Time pasteurization (HTST, 71°C-15’’) is currently under evaluation as a promising alternative technology to limit the denaturation of some biological compounds of raw human milk. The aim of the present work was to assess whether the different types of pasteurization (HoP, HTST) impacted the digestive kinetics of human milk during in vitro dynamic digestion. Materials and Methods: pooled raw HM (RHM) was collected and processed by using the two pasteurization techniques. The pasteurized samples and RHM were digested in vitro using preterm gastrointestinal conditions. Samples were collected at different digestion times. Undigested and digested milks samples were characterized for their particle size distribution (PSD), triglyceride content, protein and amino acid (AA) profiles. Results: during gastric digestion, both pasteurization methods modified PSD, as compared to RHM. Caseins were rapidly hydrolyzed in the gastric phase unlike that for the whey proteins. Lactoferrin was hydrolyzed faster in the pasteurized samples in comparison to RHM, in which lactoferrin was resistant to gastro-intestinal digestion. Heat-treatments, consequently, affected the intestinal release of some AA, and a higher bioaccessibility of AA was found for HTST, as compared to HoP. Concerning lipolysis, at any time of the intestinal digestion phase, the lipolysis of HoP samples was significantly lower (p < 0.05) than in both RHM and HTST samples. Conclusions: this work provides the first important evidences on the differential impact of HoP and HTST pasteurization techniques on bioaccessibility of DHM nutrients and biological compounds, for preterm newborns

Anti-zika virus and anti-usutu virus activity of human milk and its components

The benefits of human milk are mediated by multiple nutritional, trophic, and immunological components, able to promote infant’s growth, maturation of its immature gut, and to confer protection against infections. Despite these widely recognized properties, breast-feeding represents an important mother-to-child transmission route of some viral infections. Different studies show that some flaviviruses can occasionally be detected in breast milk, but their transmission to the newborn is still controversial. The aim of this study is to investigate the antiviral activity of human milk (HM) in its different stages of maturation against two emerging flaviviruses, namely Zika virus (ZIKV) and Usutu virus (USUV) and to verify whether HM-derived extracellular vesicles (EVs) and glycosaminoglycans (GAGs) contribute to the milk protective effect. Colostrum, transitional and mature milk samples were collected from 39 healthy donors. The aqueous fractions were tested in vitro with specific antiviral assays and EVs and GAGs were derived and characterized. HM showed antiviral activity against ZIKV and USUV at all the stages of lactation with no significant differences in the activity of colostrum, transitional or mature milk. Mechanism of action studies demonstrated that colostrum does not inacti-vate viral particles, but it hampers the binding of both flaviviruses to cells. We also demonstrated that HM-EVs and HM-GAGs contribute, at least in part, to the anti-ZIKV and anti-USUV action of HM. This study discloses the intrinsic antiviral activity of HM against ZIKV and USUV and demonstrates the contribution of two bioactive components in mediating its protective effect. Since the potential infectivity of HM during ZIKV and USUV infection is still unclear, these data support the World Health Organization recommendations about breast-feeding during ZIKV infection and could contribute to producing new guidelines for a possible USUV epidemic