Exploring the Impact of Extra Virgin Olive Oil on Maternal Immune System and Breast Milk Composition in Rats.

Maternal breast milk plays a key role in providing newborns with passive immunity and stimulating the maturation of an infant's immune system, protecting them from many diseases. It is known that diet can influence the immune system of lactating mothers and the composition of their breast milk. The aim of this study was to establish if a supplementation during the gestation and lactation of Lewis rats with extra virgin olive oil (EVOO), due to the high proportion of antioxidant components in its composition, has an impact on the mother's immune system and on the breast milk's immune composition. For this, 10 mL/kg of either EVOO, refined oil (control oil) or water (REF group) were orally administered once a day to rats during gestation and lactation periods. Immunoglobulin (Ig) concentrations and gene expressions of immune molecules were quantified in several compartments of the mothers. The EVOO group showed higher IgA levels in both the breast milk and the mammary glands than the REF group. In addition, the gene expression of IgA in mammary glands was also boosted by EVOO consumption. Overall, EVOO supplementation during gestation and lactation is safe and does not negatively affect the mother's immune system while improving breast milk immune composition by increasing the presence of IgA, which could be critical for an offspring's immune health.

Human milk oligosaccharides regulate human macrophage polarization and activation in response to Staphylococcus aureus.

Human milk oligosaccharides (HMOs) are present in high numbers in milk of lactating women. They are beneficial to gut health and the habitant microbiota, but less is known about their effect on cells from the immune system. In this study, we investigated the direct effect of three structurally different HMOs on human derived macrophages before challenge with Staphylococcus aureus (S. aureus). The study demonstrates that individual HMO structures potently affect the activation, differentiation and development of monocyte-derived macrophages in response to S. aureus. 6´-Sialyllactose (6'SL) had the most pronounced effect on the immune response against S. aureus, as illustrated by altered expression of macrophage surface markers, pointing towards an activated M1-like macrophage-phenotype. Similarly, 6'SL increased production of the pro-inflammatory cytokines TNF-α, IL-6, IL-8, IFN-γ and IL-1ß, when exposing cells to 6'SL in combination with S. aureus compared with S. aureus alone. Interestingly, macrophages treated with 6'SL exhibited an altered proliferation profile and increased the production of the classic M1 transcription factor NF-κB. The HMOs also enhanced macrophage phagocytosis and uptake of S. aureus. Importantly, the different HMOs did not notably affect macrophage activation and differentiation without S. aureus exposure. Together, these findings show that HMOs can potently augment the immune response against S. aureus, without causing inflammatory activation in the absence of S. aureus, suggesting that HMOs assist the immune system in targeting important pathogens during early infancy.

Working with companies that manufacture breastmilk substitutes: An EAACI position paper.

Breastmilk is the optimal source of nutrition for infants and should ideally be provided exclusively for the first 6 months of life, and alongside complementary food until 2 years of life. However, there are circumstances where a breastmilk substitute (BMS) may be required. This includes maternal and/or child conditions or personal preference. Whilst these circumstances should never be used as an opportunity to promote BMS, healthcare professionals (HCPs) need to have the knowledge of suitable alternatives and should always be guided by scientific and health motives when recommending a BMS. The Task Force 'Milk Formula Industry Sponsorship' from the European Academy of Allergy and Clinical Immunology (EAACI), provides with this publication recommendations for EAACI interactions with the BMS manufacturers and how this will be supervised.

Breast milk-mediated exposure to dioxins and antigen in infancy enhances antigen-specific antibody production capacity in adulthood in mice.

The immune system is sensitive to many chemicals. Among dioxin compounds, 2,3,7,8-tetrachlorodizenzo-p-dioxin (TCDD) is the most toxic environmental pollutant. The effects of perinatal maternal exposure to dioxins may persist into childhood. However, there have been no reports to date on the effects of exposure to dioxins during infancy, when the immune organs are developing. Therefore, we investigated the effects of TCDD and antigen exposure during lactation on immune function, especially antibody production capacity, in adult mice. Beginning the day after delivery, lactating mothers were orally administered TCDD or a mixture of TCDD and ovalbumin (OVA) daily for 4 weeks, until the pups were weaned. At 6 weeks of age, progeny mice were orally administered OVA daily for 10 weeks, while non-progeny mice were orally administered OVA or a mixture of TCDD and OVA daily for 10 weeks. Production of serum OVA-specific IgG was examined weekly. The amount of TCDD transferred from the mother to the progeny via breast milk was determined by measuring TCDD in the gastric contents of the progeny. A trend toward increasing IgA titer was observed in TCDD-treated mice, and production of IgE was observed only in progeny whose mothers were treated with TCDD and OVA. The results suggest that exposure to TCDD and OVA in breast milk can affect immune function in newborns.

Preservation of Anti-SARS-CoV-2 Neutralizing Antibodies in Breast Milk: Impact of Maternal COVID-19 Vaccination and Infection.

Objectives: To investigate specific immunoglobulin A (sIgA), specific immunoglobulin G (sIgG), and neutralizing antibodies (NAbs) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in breast milk and compare immunity in mothers with hybrid immunity (infection and vaccination) versus those solely vaccinated (coronavirus disease [COVID]-naïve). Methods: A longitudinal study was conducted among lactating mothers who received at least two doses of the coronavirus disease 2019 (COVID-19) vaccine or tested positive for SARS-CoV-2. Details of vaccination and infection were collected through questionnaires and interviews. Fifteen milliliters of breast milk samples, self-collected at 1, 3, and 6 months postvaccination or infection, were sent to analysis for sIgA, sIgG, and NAbs using enzyme-linked immunosorbent assay. Results: In total, 119 lactating mothers (202 milk samples) were enrolled; 82 participants had hybrid immunity, and 32 were COVID-19-naïve. Two-thirds received a combination of different vaccines and booster shots. Breast milk retained sIgA, sIgG, and NAbs for up to 6 months post-COVID vaccination or infection. At 3 months, mothers with hybrid immunity had significantly higher sIgA and NAbs compared with COVID-naïve mothers (geometric mean [95% confidence interval (CI)] of sIgA 2.72 [1.94-3.8] vs. 1.44 [0.83-2.48]; NAbs 86.83 [84.9-88.8] vs. 81.28 [76.02-86.9]). No differences in sIgA, sIgG, and NAbs were observed between lactating mothers receiving two, three, or more than or equal to three doses, regardless of hybrid immunity or COVID-naïve status. Conclusion: sIgA, sIgG, and NAbs against SARS-CoV-2 in breast milk sustained for up to 6 months postimmunization and infection. Higher immunity was found in mothers with hybrid immunity. These transferred immunities confirm in vitro protection, supporting the safety of breastfeeding during and after COVID-19 vaccination or infection.

Core fucosylation of maternal milk N-glycans imparts early-life immune tolerance through gut microbiota-dependent regulation in RORγt+ Treg cells.

Milk glycans play key roles in shaping and maintaining a healthy infant gut microbiota. Core fucosylation catalyzed by fucosyltransferase (Fut8) is the major glycosylation pattern on human milk N-glycan, which was crucial for promoting the colonization and dominant growth of Bifidobacterium and Lactobacillus spp. in neonates. However, the influence of core-fucose in breast milk on the establishment of early-life immune tolerance remains poorly characterized. In this study, we found that the deficiency of core-fucose in the milk of maternal mice caused by Fut8 gene heterozygosity (Fut8+/-) resulted in poor immune tolerance towards the ovalbumin (OVA) challenge, accompanied by a reduced proportion of intestinal RORγt+ Treg cells and the abundance of Lactobacillus spp., especially L. reuteri and L. johnsonii, in their breast-fed neonates. The administration of the L. reuteri and L. johnsonii mixture to neonatal mice compromised the OVA-induced allergy and up-regulated the intestinal RORγt+ Treg cell proportions. However, Lactobacillus mixture supplementation did not alleviate allergic responses in RORγt+ Treg cell-deficient mice caused by Rorc gene heterozygosity (Rorc+/-) post OVA challenge, indicating that the intervention effects depend on the RORγt+ Treg cells. Interestingly, instead of L. reuteri and L. johnsonii, we found that the relative abundance of another Lactobacillus spp., L. murinus, in the gut of the offspring mice was significantly promoted by intervention, which showed enhancing effects on the proliferation of splenic and intestinal RORγt+ Treg cells in in vitro studies. The above results indicate that core fucosylation of breast milk N-glycans is beneficial for the establishment of RORγt+ Treg cell mediated early-life immune tolerance through the manipulation of symbiotic bacteria in mice.

Maternal and infant predictors of proinflammatory milk immune activity in Kilimanjaro, Tanzania.

OBJECTIVES: The immune system of milk (ISOM) creates a mother-infant immune axis that plays an important role in protecting infants against infectious disease (ID). Tradeoffs in the immune system suggest the potential for both protection and harm, so we conceive of two dimensions via which the ISOM impacts infants: promotion of protective activity and control of activity directed at benign targets. High variability in ISOM activity across mother-infant dyads suggests investment the ISOM may have evolved to be sensitive to maternal and/or infant characteristics. We assessed predictors of appropriate and misdirected proinflammatory ISOM activity in an environment of high ID risk, testing predictions drawn from life history theory and other evolutionary perspectives. METHODS: We characterized milk in vitro interleukin-6 (IL-6) responses to Salmonella enterica (a target of protective immune activity; N = 96) and Escherichia coli (a benign target; N = 85) among mother-infant dyads in rural Kilimanjaro, Tanzania. We used ordered logistic regression and mixture models to evaluate maternal and infant characteristics as predictors of IL-6 responses. RESULTS: In all models, IL-6 responses to S. enterica increased with maternal age and decreased with gravidity. In mixture models, IL-6 responses to E. coli declined with maternal age and increased with gravidity. No other considered variables were consistently associated with IL-6 responses. CONCLUSIONS: The ISOM's capacities for appropriate proinflammatory activity and control of misdirected proinflammatory activity increases with maternal age and decreases with gravidity. These findings are consistent with the hypothesis that the mother-infant immune axis has evolved to respond to maternal life history characteristics.

Quantitative analysis of pertussis, tetanus, and diphtheria antibodies in sera and breast milk from Tdap vaccinated women using a qualified multiplex assay.

Pertussis (whooping cough) is a reemergent, highly contagious respiratory infection of public health concern. Infants prior to initiation of their primary vaccination series are the most vulnerable to severe infection, and even death. Vaccination during pregnancy is an efficacious means of reducing infection in infants. This approach relies on boosting maternal immunity and passive transfer of antibodies to the infant via placenta and breast milk. Similarly, maternal vaccination post-partum can enhance maternal-infant immunity. To support the analysis of pertussis immunity in the context of maternal-infant immunization, we developed a high throughput multiplex assay for simultaneous quantification of serum IgG antibodies against pertussis vaccine antigens: pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae (FIM2/3), and against tetanus (TT) and diphtheria toxoids (DT), using the Meso Scale Discovery (MSD) platform. The assay was qualified, and specificity, sensitivity, accuracy, precision, linearity, and robustness were demonstrated. The assay was subsequently adapted for quantification of IgG and IgA in breast milk. Applied to a serological survey of pregnant women living in the United States and sub-Saharan Africa, this method revealed differences in magnitude and breadth of antibody profile, consistent with history of vaccination. A longitudinal analysis of Tdap responses in women vaccinated post-partum demonstrated a rapid increase in serum IgG that remained elevated for up to 24 months. Likewise, high levels of vaccine-specific IgA and IgG antibodies were present in breast milk, although they exhibited faster decay. This multiplex MSD assay is a reliable and practical tool for quantification of pertussis, tetanus, and diphtheria antibodies in serum and breast milk in serosurveys or vaccine studies. IMPORTANCE: Pertussis (whooping cough) has reemerged in recent years. Vaccination during pregnancy is an effective approach to prevent illness during the first months of life. We developed a multiplex assay for quantification of pertussis, tetanus, and diphtheria serum antibodies using the Meso Scale Discovery (MSD) platform; the method was qualified, and specificity, precision, accuracy, linearity, and limits of quantification were defined. It was also adapted for quantification of antibodies in breast milk. We successfully determined serostatus in women from different regions and with different vaccination histories, as well as responses to Tdap in blood and breast milk post-partum. This is the first description of a multiplex assay for the quantification of pertussis, tetanus, and diphtheria antibodies in breast milk.

Specific IgA, But Not IgG, in Human Milk From COVID-19-Infected Mothers Neutralizes SARS-CoV-2.

This study highlights the importance of human milk in providing anti-severe acute respiratory syndrome coronavirus 2 immunity to newborns. The highest protective activity of human milk against COVID-19 was found in colostrum from infected mothers. Neutralizing activity was associated with high levels of specific IgA. Depletion of IgA, but not IgG, from milk samples completely abolished the ability of human milk to neutralize severe acute respiratory syndrome coronavirus 2.

Short term Outcomes of COVID-19 Vaccines Among Lactating Mother and Child Dyads in Bangladesh: A Multi-centre, Cross-sectional Study.

INTRODUCTION: The aims of the study are to: (1) determine the short-term reactogenicity of WHO-approved COVID-19 vaccines (i.e., Pfizer-BioNTech, Moderna, Sinovac, Oxford-AstraZeneca, Johnson and Johnson, Covaxin) amongst lactating women and their children, and 2) evaluate lactation-related outcomes following the same vaccines in Bangladesh. METHODS: This was a multi-centre, self-reported, cross-sectional study of lactating woman-child dyads in Bangladesh. Demographics, past medical history, breastfeeding history and clinical outcomes of lactating woman-child dyads at least 7 days after the last dose of vaccine were determined through a structured questionnaire. RESULTS: There were 750 participants from four centres. The mean age of lactating women and children surveyed were 27.6 (SD ± 4.6) years and 10.3 (SD ± 6.7) months, respectively. Majority (81.2%; 608 of 750) received 2 doses of COVID-19 vaccinations while lactating. Almost all (99.9%; 749 of 750) vaccinated lactating women surveyed reported no change in human milk supply. More than half of the participants (56.9%; 373 of 656) reported no symptoms after both doses of COVID-19 vaccines. There were no serious adverse events such as anaphylaxis or hospital admission. Majority of the lactating women (98.9%; 742 of 750) reported that the children whom they breastfed had no symptoms such as fever or cough. DISCUSSION: This large study of lactating woman-child dyads in Bangladesh, who received a diverse range of WHO-approved COVID-19 vaccines, showed no serious short-term adverse effects.

Maternal Immunization During the Second Trimester with BNT162b2 mRNA Vaccine Induces a Robust IgA Response in Human Milk: A Prospective Cohort Study.

BACKGROUND: The human milk antibody response following maternal immunization with the BNT162b2 mRNA vaccine is important for the protection of the infant during infancy. The vaccine-specific antibody response is still unclear at different stages of human milk production, as are the effects of maternal immunization timing on the robustness of the antibody response. OBJECTIVES: The study aimed to assess the antibody response (IgG/IgA/IgM) during various lactation stages and identify the best vaccination timing during pregnancy. METHODS: A prospective cohort study of 73 postpartum women who were administered the BNT162b2 COVID-19 mRNA vaccine during the second or third trimester of pregnancy were recruited. Statistical comparison was conducted using 16 human milk samples from a prepandemic control group. RESULTS: Excluding 11 women, the study included 62 lactating women who were administered the mRNA vaccine during the second or third trimester of pregnancy. A total of 149 samples of human milk were collected at different lactation stages. Our findings reveal that colostrum exhibits significantly higher levels of IgG (95% confidence interval [CI]: 1.3, 9.0; P = 0.023), IgA (95% CI: 55.98, 100.2; P = 0.0034), and IgM (95% CI: 0.03, 0.62; P < 0.0001) compared with mature milk IgG (95% CI: 0.25, 0.43), IgA (95% CI: 9.65, 13.74), IgM (95% CI: 0.03, 0.04). The timing of maternal immunization affected the antibody response. The level of IgA in mature milk was higher when immunization occurred in the second trimester (95% CI: 11.14, 19.66; P = 0.006) than in the third trimester (95% CI: 7.16, 11.49). Conversely, IgG levels in mature milk were higher when immunization occurred during the third trimester (95% CI: 0.36, 0.65; P < 0.0001) than in the second trimester (95% CI: 0.09, 0.38). CONCLUSIONS: Our study provides evidence that administering the mRNA vaccine to pregnant women during the second trimester increases vaccine-specific IgA levels during lactation. Considering the significance of human milk IgA in mucosal tissues and its prevalence throughout lactation, it is reasonable to recommend maternal immunization with the BNT162b2 mRNA vaccine during the second trimester. This trial was registered at the Helsinki Committee of the Tel Aviv Medical Center as clinical trial number 0172-TLV.

Diet-microbe-host interaction in early life.

Breast milk bioactives are important for infant microbiome and immunity.

Anticorpos neutralizantes contra o vírus SARS-coV-2 no sangue e leite humano de lactantes previamente vacinadas / Neutralizing antibodies against the SARS-coV-2 virus in the blood and human milk of previously vaccinated infants

Introdução: Alguns estudos verificaram que a vacinação contra o coronavírus SARS COV-2 induz resposta efetiva de titulação de anticorpos neutralizantes no sangue e leite materno. No entanto, a maioria dos artigos publicados considerou a transferência de imunidade mãe-feto em mulheres recuperadas da COVID-19 e não vacinadas e/ou analisaram leite e/ou sangue isoladamente. Objetivo: Comparar o quantitativo de anticorpos neutralizantes contra o SARS-CoV-2 no leite e no sangue das lactantes vacinadas em relação àquelas não vacinadas. Métodos: Revisão sistemática nas bases de dados Biblioteca Virtual em Saúde, Pubmed, Embase, Web of Science e Scopus de acordo com as diretrizes do PRISMA e registrada no PROSPERO sob o n° CRD42021287554. Foram elegíveis estudos de coorte, caso-controle e transversal que avaliaram a presença de anticorpos neutralizantes contra o SARS-CoV-2 no leite e no sangue de lactantes vacinadas e que tiveram como grupo controle lactantes não vacinadas. Por sua vez, foram excluídos relatos de casos, revisão sistemática com ou sem meta-análise, artigos que analisaram os anticorpos em mulheres infectadas ou não lactantes, e ainda aqueles que não trouxeram nos seus resultados os dados de comparação entre os grupos que receberam ou não a vacina. Foi avaliado o risco de viés de todos os artigos incluídos através da ferramenta de avaliação Newcastle-Ottawa Scale. Resultados: As buscas nas bases de dados identificaram 233 registros. Após a remoção de 128 que estavam duplicados, foram lidos os títulos e resumos de 105 e excluídos 94 destes. Com a leitura na íntegra de 11 artigos, 4 estudos de coorte foram considerados elegíveis e, incluídos nesta revisão sistemática. Os resultados destes estudos apontaram que, após a vacinação com os imunizantes Pfizer-BioNTech e Moderna, as lactantes apresentaram níveis elevados de anticorpos neutralizantes IgG e IgA anti-SARS-CoV-2 tanto no sangue quanto no leite materno, sendo o nível sanguíneo consideravelmente maior. Conclusão: Como ainda não existem vacinas disponíveis para uso em menores de seis meses e as lactantes vacinadas contra o vírus SARS-CoV-2 apresentam maior expressão de anticorpos em relação àquelas não vacinadas, é provável que, além da proteção materna contra COVID-19, a imunização também forneça imunidade neonatal através da amamentação.

Introduction: Some studies have found that vaccination against the SARS-COV-2 coronavirus induces an effective titration response of neutralizing antibodies in blood and breast milk. However, most published articles considered the transfer of mother fetus immunity in women recovered from COVID-19 and not vaccinated and/or analyzed milk and/or blood alone. Objective: To compare the amount of neutralizing antibodies in the milk and blood of vaccinated infants for SARS-CoV-2. Methods: Systematic review in the Virtual Health Library, Pubmed, Embase, Web of Science and Scopus databases in accordance with PRISMA guidelines and registered in PROSPERO under number CRD42021287554. Cohort, case-control and cross-sectional studies that evaluated the presence of neutralizing antibodies against SARS-CoV-2 in the milk and blood of vaccinated infants and that had unvaccinated infants as a control group were eligible. In turn, case reports, systematic review with or without meta-analysis, articles that analyzed antibodies in infected or non-lactating women, and even those that did not bring in their results data for comparison between the groups that received or not the vaccine. The risk of bias of all included articles was assessed using the Newcastle Ottawa Scale assessment tool. Results: Database searches identified 233 records. After removing 128 that were duplicates, the titles and abstracts of 105 were read and 94 were excluded. With the full reading of 11 articles, 4 cohort studies were considered eligible and included in this systematic review. The results of these studies showed that, after vaccination with the immunizers Pfizer-BioNTech and Moderna, the nursing mothers had high levels of anti-SARS-CoV-2 IgG and IgA neutralizing antibodies both in the blood and in breast milk, with the blood level considerably bigger. Conclusion: As there are still no vaccines available for use in infants under six months of age and lactating women vaccinated against the SARS-CoV-2 virus have a higher expression of antibodies compared to those not vaccinated, it is likely that, in addition to maternal protection against COVID-19, immunization also provides neonatal immunity through breastfeeding.

The consequences of COVID-19 and its vaccine on pregnant and lactating mothers.

The single-stranded RNA virus (coronavirus 2019) pandemic has represented a massive influence on health care professionals and communities around the world. This virus is accompanied by a range of respiratory disorders. Morbidity and mortality are in elevation among pregnant mothers. COVID-19 vaccine is considered safe for the majority of the population. Safety concerns were raised toward pregnant mothers and the COVID-19 vaccine. In the present study, data were taken out from relevant manuscripts; from 20th April 2021 to 25th December 2021. In this study, literature reviews from the most comprehensive health database on 100 papers published during 2020 and 2021 were used. This review article aimed to assess the present evidence available in the literature about the possible effect of COVID-19 on pregnant mothers and their fetuses and, to address considerations for maternal COVID-19 vaccine based on the review of existing data to aid in spreading the awareness about the benefits of vaccine that could save lives. In general, COVID-19 vaccines resulted in reducing the ability of virus transmission and patients' hospitalization. COVID-19 vaccines will never cause infection of corona virus. Evidence showed that COVID-19 vaccines from any brand will reduce the mortality and morbidity. However, available data indicated that possible deterioration of the clinical conditions of pregnant mothers infected with COVID-19 cannot be excluded. Primary outcomes did not show clear safety signs among pregnant mothers who received COVID-19 vaccines. This is because pregnant and lactating mothers were excluded from COVID-19 vaccine studies. Thus, data to lead vaccine decision-making are inadequate. More longitudinal follow up studies are necessary to reinforce the safety of the vaccine.

Breastfeeding: Maternally Transferred Allergens in Breast Milk: Protective or Sensitizing?

According to a thorough literature search, the following allergen sources have been associated with allergy symptoms in the exclusively breastfed child: hen's egg, cow's milk, peanut, trout. Subsequently, several studies use the advantage of molecular allergology and investigate the potential transfer of single allergens into breastmilk. This is shown for caseins, whey proteins, gliadin, ovalbumin, ovomucoid, the peanut allergens Ara h 2 and Ara h 6, as well as the inhalant allergens Der p 1 and Blo t 5. It is still a matter of debate whether or not food allergens transferred via breastfeeding to the baby promote allergic sensitization or induce tolerance and via which mechanisms they may shift the immune response to the one or other side. Noteworthy, some breastfed children are described to be sensitized to foods before being exposed to solid foods, and this exposure may have occurred through breastmilk. In the light of these findings the investigation of food allergens transferred from the mother's diet into breastmilk and their impact on sensitization or allergy prevention remains a current topic in research. This review describes breastmilk in its composition and provides data on the identification of food allergens therein including human and mouse studies.

Inhibition of In Vitro Infection of Hepatitis B Virus by Human Breastmilk.

Despite the presence of hepatitis B virus (HBV) in the human breastmilk of mothers infected with HBV, it has been shown that breastfeeding does not increase the risk of mother-to-child transmission (MTCT) of HBV. We tested the hypothesis that human breastmilk may contain active components that bind to HBV and inhibit the infectivity of HBV. The results show that human whey significantly inhibited the binding of the hepatitis B surface antigen (HBsAg) to its antibodies in competitive inhibition immunoassays. The far-western blotting showed that HBsAg bound to a protein of 80 kD in human whey, which was identified as lactoferrin by mass spectrometry. Competitive inhibition immunoassays further demonstrated that both human lactoferrin and bovine lactoferrin bound to HBsAg. Human whey, human lactoferrin, and bovine lactoferrin each significantly inhibited the infectivity of HBV in vitro. Our results indicate that human breastmilk can bind to HBsAg and inhibit the infectivity of HBV, and the active component is lactoferrin. The findings may explain the reason that breastfeeding has no additional risk for MTCT of HBV, although human breastmilk contains HBV. Our study provides experimental evidence that HBV-infected mothers should be encouraged to breastfeed their infants.

Impact of Surfactant Protein-A on Immunomodulatory Properties of Murine and Human Breast Milk.

OBJECTIVES: Human milk reduces the incidence of necrotizing enterocolitis (NEC). Prior studies have demonstrated that exogenous surfactant protein-A (SP-A) modulates intestinal inflammation, reduces NEC-like pathology in SP-A-deficient (SPAKO) pups, and may contribute to breast milk's immunomodulatory potential. We hypothesize that SP-A is present in milk and impacts inflammatory responses in the terminal ileum of neonatal mice. METHODS: Human milk was collected at postpartum days 1-3 and 28. Mouse milk was collected at postpartum days 1-10. SP-A was detected in milk through immunoprecipitation and western blot analysis. The impact of murine wild-type (WT) milk on SPAKO pup ileum was evaluated in a model of intestinal inflammation via cross-rearing experiments. Terminal ileum was evaluated for inflammatory cytokine and toll-like receptor 4 (TLR4) mRNA expression via quantitative real-time RT-PCR. RESULTS: SP-A was detected in human milk and wild type (WT) mouse milk, but not in SPAKO mouse milk. Expression of TLR4, interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α was decreased in SPAKO pups reared with WT dams compared to SPAKO pups reared with SPAKO dams, with a peak effect at day of life 14. When inflammation was induced using a lipopolysaccharide-induced model of inflammation, expression of TLR4, IL-1ß, IL-6, CXCL-1, and TNF-α was significantly lower in SPAKO pups reared with WT dams compared to SPAKO pups reared with SPAKO dams. CONCLUSIONS: SP-A is present in human and murine milk and plays a role in lowering inflammation in murine pup terminal ileum. Both baseline inflammation and induced inflammatory responses are reduced via exposure to SP-A in milk with the effect amplified in inflammatory conditions.