Human Milk Samples Research Articles

1H NMR Metabolomics of Chinese Human Milk at Different Stages of Lactation among Secretors and Non-Secretors.

Human milk is an intricate, bioactive food promoting infant health. We studied the composition of human milk samples collected over an 8-month lactation using 1H NMR metabolomics. A total of 72 human breast milk samples were collected from ten Chinese mothers at eight different time points. The concentrations of ten human milk oligosaccharides (HMOs), fucose and lactose were quantified. Six of the mothers were classified as Lewis-positive secretors (Se+Le+) and four as Lewis-positive non-secretors (Se−Le+) based on the levels of 2′-fucosyllactose (2′-FL), lacto-N-fucopentaose (LNFP) II, lactodifucotetraose (LDFT) and lacto-N-neotetraose (LNnT). Acetate, citrate, short/medium-chain fatty acids, glutamine and urea showed a time-dependent trend in relation to the stage of lactation. The concentrations of 2′-FL, 3-FL (3-fucosyllactose), 3′-SL (3′-sialyllactose), LDFT, LNFP I, LNFP II, LNFP III, LNnT, LNT (lacto-N-tetraose), and fucose were statistically different between secretors and non-secretors. A temporal difference of approximately 1–2 months between the development of non-secretor and secretor HMO profiles was shown. The results highlighted the importance of long-term breastfeeding, especially among non-secretors.

Joint analyses of human milk fatty acids, phospholipids, and choline in association with cognition and temperament traits during the first 6 months of life.

Early dietary exposure via human milk nutrients offers a window of opportunity to support cognitive and temperament development. While several studies have focused on associations of few pre-selected human milk nutrients with cognition and temperament, it is highly plausible that human milk nutrients synergistically and jointly support cognitive and behavioral development in early life. We aimed to discern the combined associations of three major classes of human milk nutrients with cognition and temperament during the first 6 months of life when human milk is the primary source of an infant’s nutrition and explore whether there were persistent effects up to 18 months old. The Mullen Scales of Early Learning and Infant Behavior Questionnaires—Revised were used to assess cognition and temperament, respectively, of 54 exclusively/predominantly breastfed infants in the first 6 months of life, whose follow-ups were conducted at 6–9, 9–12, and 12–18 months old. Human milk samples were obtained from the mothers of the participants at less than 6 months of age and analyzed for fatty acids [total monounsaturated fatty acids, polyunsaturated fatty acid, total saturated fatty acid (TSFA), arachidonic acid (ARA), docosahexaenoic acid (DHA), ARA/DHA, omega-6/omega-3 polyunsaturated fatty acids ratio (n-6/n-3)], phospholipids [phosphatidylcholine, phosphatidylethanolamine (PE), phosphatidylinositol (PI), sphingomyelin], and choline [free choline, phosphocholine (PCho), glycerophosphocholine]. Feature selection was performed to select nutrients associated with cognition and temperament. The combined effects of selected nutrients were analyzed using multiple regression. A positive association between the arachidonic acid (ARA) and surgency was observed (p = 0.024). A significant effect of DHA, n-6/n-3, PE, and TSFA concentrations on receptive language (R2 = 0.39, p = 0.025) and the elevated ARA, PCho, and PI with increased surgency (R2 = 0.43, p = 0.003) was identified, suggesting that DHA and ARA may have distinct roles for temperament and language functions. Furthermore, the exploratory association analyses suggest that the effects of human milk nutrients on R.L. and surgency may persist beyond the first 6 months of life, particularly surgency at 12–18 months (p = 0.002). Our study highlighted that various human milk nutrients work together to support the development of cognition and temperament traits during early infancy.

Comparative Investigation of Conventional and Innovative Headspace Extraction Methods to Explore the Volatile Content of Human Milk.

The odor of human milk induces search-like movements and oral activation in newborns, which increases their chances of taking advantage of milk intake and benefits. However, the underlying volatile fraction of human milk remains understudied. This study aimed to devise a simple method to extract a wide range of volatile compounds from small-volume human milk samples. Headspace solid phase micro-extraction (HS-SPME) with a Car/PDMS fiber and dynamic headspace extraction (D-HS) with a Tenax or a trilayer sorbent were tested because of their selective affinity for volatiles. Then, innovative variations of these methods were developed to combine their respective advantages in a one-step extraction: Static headspace with multiple SPME fibers (S-HS-MultiSPME), Dynamic headspace with multiple SPME fibers (D-HS-MultiSPME) and dynamic headspace with multiple SPME fibers and Tenax (D-HS-MultiSPME/Tenax). The extracts were analyzed by gas chromatography coupled with mass spectrometric and flame ionization detection. The relative performances of these methods were compared based on qualitative and semi-quantitative analyses of the chromatograms. The D-HS technique showed good sensitivity for most compounds, whereas HS-SPME favored the extraction of acids. The D-HS-MultiSPME/Tenax identified more than 60 compounds from human milk (some for the first time) and evidence of individual singularities. This method that can be applied to volatilome analysis of any biological fluid should further our understanding of human milk odor.

Application of net analyte signal and principal component regression for rapid simultaneous determination of Levodopa and carbidopa in commercial pharmaceutical formulation and breast (human) milk sample using spectrophotometric method

In this study, a UV–vis spectrophotometric method coupled with net analyte signal (NAS) and principal component regression (PCR) as multivariate calibration methods were used for the simultaneous determination of levodopa (LEV) and carbidopa (CBD) in prepared mixtures, pharmaceutical formulation, and breast milk sample. The mean recovery of the NAS model was 98.10% and 99.60% for LEV and CBD, respectively. Also, the relative standard deviation (RSD%) values were found to be lower than 5.5% and 4% for LEV and CBD, respectively. On the other hand, the mean recovery of LEV and CBD related to the PCR method was obtained at 96.86% and 92.43%, respectively. K-Fold cross-validation was used to estimate the number of components, which was 7 and 3 with a mean square error prediction (MSEP) of 1.50 and 7.14 for LEV and CBD, respectively. The results revealed that the NAS model was better than the PCR model. Additionally, the proposed NAS-based calibration method was successfully developed for the simultaneous analyses of LEV and CBD in a commercial tablet and breast milk.

Possible role of SIRT1 and SIRT3 in post-translational modifications in human breast milk during the neonatal period

We measured free and proteinic concentrations of native and modified amino acids from post-translational modifications (PTMs) and correlated them with the activity of SIRT1 and SIRT3 in the pellet and aqueous phases of human breast milk samples of ten lactating women during the neonatal period. SIRT1 and SIRT3 correlated directly with citrullination, asymmetric dimethylation and glycation of L-arginine, hydroxylation and glycation of L-lysine. SIRT1 and SIRT3 correlated inversely with the hydroxylation of L-proline. SIRT1 and SITR3 tended to correlate inversely with oxidative stress measured as malondialdehyde. Our study suggests that SIRT1 and SIRT3 may modulate PTMs in human breast milk cells.

Sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous determination of seventeen beta blockers

In recent years, examples of drugs responsible for acute drug intoxication in elderly people include benzodiazepines, phenobarbital, digitalis preparations, phenytoin, beta blockers or calcium antagonists, and antidepressants in Japan. Due to the diversity of underlying diseases, the reasons for this include increasing number of prescription medicines due to regular oral medicines themselves interacting, and age-related changes in drug metabolism. Beta blockers for clinical use are employed in the management of a range of disorders, including hypertension, heart failure, arrhythmias, migraine headache and tremor. Beta blockers are prescribed widely and also have a high frequency of accidental ingestion by the elderly people. Cardiovascular drugs (beta blockers) present more serious symptoms of intoxication than the underlying diseases themselves. The aim of this study is to develop and validate a sensitive liquid chromatography–tandem mass spectrometry (LC-MS/MS) with ESI method for the simultaneous determination of seventeen beta blockers (atenolol, carteolol, nadolol, pindolol, timolol, acebutolol, arotinolol, metoprolol, esmolol, celiprolol, labetalol, bisoprolol, propranolol, alprenolol, betaxolol, bevantolol and carvedilol). The extractions of beta blockers in human serum were performed by solid-phase extraction method using Oasis® PRiME HLB column (Waters). LC-MS/MS experiments were performed with a HPLC system, which consisted of Shimadzu LC-20AD pumps, a SIL-20AC autosampler and the 4000 QTRAP mass spectrometer (AB SCIEX). The chromatographic separation was performed on a Mightysil-RP-18 MS column (150 × 2.0-mm i.d., 5 μm). For the gradient elution, two solvents were used: (A) 10 mM acetic ammonium buffer and (B) acetonitrile. The flow rate was 0.20 mL/min and the column and autosampler were maintained at 37 and 4˚C, respectively. The settings of the turbo ion-spray were as follows; curtain gas, N2:40 psi, collision gas, N2:4 psi, collision energy: 27∼41 V, ion-spray voltage: 5500 V, ionization mode: ESI positive, source temperature: 600˚C. Separation and sensitivity for the detection of seventeen beta blockers by LC-MS/MS were sufficient and the precursor [M + H]+ ion was detected in the mass spectrum for each drug. This method had a chromatographic total run time of 15 min. The calibration curves were linear over the concentration range of 20–400 ng/mL for seventeen beta blockers (r = 0.9686∼0.9997). The extraction yields of human serum sample with Oasis® PRiME HLB column were ranged from 66.1 to 93.5%, the precision within 0.07 CV values were acceptable of this method. But the extraction yields of bevantlol (37.5%) and carvedilol (26.2%) were low. Currently, we are experimenting to improve the extraction yields of bevantolol and carvedilol. Phyo Lwin EM, et al (2017, Bioanalysis.) developed a method for the determination of atenolol in human plasma and milk sample by LC-MS/MS. The limits of detection (LOD) and quantification (LOQ) were in the range 1.0 ng/mL and 5.0 ng/mL for atenolol. Our LC-MS/MS with ESI method was able to measure compounds at approximately the same concentrations as the analytical methods of Phyo Lwin EM, et al. In our experiments, LOD and LOQ in the range 0.0034–1.6 ng/mL and were 20 ng/mL for seventeen beta blockers. The presently established method is very useful for simultaneous measurements of beta blockers in human serum by LC-MS/MS in clinical and forensic investigations.

Premature delivery impacts the concentration of plasminogen activators and a plasminogen activator inhibitor and the plasmin activity in human milk.

Background and aimsPlasmin in human milk partially hydrolyzes milk proteins within the mammary gland and may enhance the hydrolysis of milk proteins within the infant’s stomach. This study examined the effects of extremely preterm (EP)-, very preterm (VP)-, and term-delivery on plasmin activity and the concentrations of plasminogen activators [urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA)], plasminogen activator inhibitor type 1 (PAI-1) and the complexes of PAI-1/uPA and PAI-1/tPA in human milk.Materials and methodsHuman milk samples were collected from mothers who delivered extremely preterm infants [24–27 weeks gestational age (GA), n = 20], very preterm infants (28–32 weeks GA, n = 12), and term infants (38–39 weeks GA, n = 8) during 2–72 days postnatally. Plasmin activity was determined using fluorometric substrate assay, whereas concentrations of uPA, tPA, PAI-1, the PAI-1/uPA complex and the PAI-1/tPA complex were quantified by ELISA.ResultsPlasmin activity, uPA and tPA were detected in all human milk samples, PAI-1 and the PAI-1/uPA complex were present in 42.5 and 32.5% of milk samples, respectively, and the PAI-1/tPA complex was not detected. Plasmin activity was correlated negatively with postnatal age and postmenstrual age (PMA) in the VP group and positively with postnatal age in the term group. uPA and tPA concentrations decreased with increasing postnatal age in both EP and VP groups but did not correlate in the term group. uPA concentration was correlated positively with GA in the VP group and tended to be elevated with increasing GA in the combined three groups. In contrast, tPA concentrations were correlated negatively with GA and PMA in the combined three groups (P < 0.008) and with PMA in the EP and VP groups. PAI-1 concentration tended to be correlated positively with postnatal age in the combined three groups. No correlation was detected with the PAI-1/uPA complex.ConclusionPremature delivery impacted the plasmin activity and the concentrations of uPA, tPA, and PAI-1 in human milk. Whether these changes in milk plasminogen activators and inhibitors have a role in balancing the proteolytic digestion of premature infants remains to be investigated.

Comparison of the Effectiveness of Four Commercial DNA Extraction Kits on Fresh and Frozen Human Milk Samples.

For-profit donor human milk organizations have DNA-based proprietary methodology for testing incoming milk for adulteration with other species’ milk. However, there is currently no standardized methodology for extracting DNA from human milk. Microbiome research has shown that DNA purity and quantity can vary depending on the extraction methodology and storage conditions. This study assessed the purity and quantity of DNA extracted from four commercially available DNA extraction kits—including one kit that was developed for human milk. This study was for method validation only. One donor provided a 90 mL human milk sample. The sample was aliquoted into 70 × 1 mL microcentrifuge tubes. Aliquots were randomized into one of three categories: fresh extraction, extraction after freezing, and extraction after purification and storage at room temperature. DNA was analyzed for purity and quantity using a NanoDrop Spectrophotometer. Results confirmed differences in DNA purity and quantity between extraction kits. The Plasma/Serum Circulating DNA Purification Mini Kit (Norgen Biotek, ON, Canada) provided significantly more DNA, and consistent purity as measured by 260/280 and 260/230 ratios. DNA quantity and purity were similar between fresh and frozen human milk samples. These results suggest that DNA purity and quantity is highest and most consistent when extracted from human milk using the Plasma/Serum Circulating DNA Purification Mini Kit amongst the kits tested in this study. Standardized methodology for extracting DNA from human milk is necessary for improvement of research in the field of human milk. To do this, future studies are recommended for optimization of DNA extraction from human milk using larger sample sizes and multiple donor parents.

Dynamic Changes in the Human Milk Metabolome Over 25 Weeks of Lactation.

Human milk (HM) provides essential nutrition for ensuring optimal infant growth and development postpartum. Metabolomics offers insight into the dynamic composition of HM. Studies have reported the impact of lactation stage, maternal genotype, and gestational age on HM metabolome. However, the majority of the studies have considered changes within the first month of lactation or sampled with large intervals. This leaves a gap in the knowledge of progressing variation in HM composition beyond the first month of lactation. The objective of this study was to investigate whether the HM metabolome from mothers with term deliveries varies beyond 1 month of lactation, during the period in which HM is considered fully mature. Human milk samples (n = 101) from 59 mothers were collected at weeks 1–2, 3–5, 7–9, and 20–25 postpartum and analyzed using 1H nuclear magnetic resonance spectroscopy. Several metabolites varied over lactation and exhibited dynamic changes between multiple time points. Higher levels of HM oligosaccharides, cis-aconitate, O-phosphocholine, O-acetylcarnitine, gluconate, and citric acid were observed in early lactation, whereas later in lactation, levels of lactose, 3-fucosyllactose, glutamine, glutamate, and short- and medium-chain fatty acids were increased. Notably, we demonstrate that the HM metabolome is dynamic during the period of maturity.

Microwave Split Ring Resonator Sensor for Determination of the Fluids Permittivity With Measurement of Human Milk Samples

AbstractIn this paper, the human milk dielectric constant by a microwave sensor has been evaluated. The proposed sensor is result of coupling between a simple microstrip line and a split ring resonator and its resonance frequency is 6 GHz. When up to 30 μl of milk are placed on the sensing area on the sensor, it causes the resonance frequency to shift. Six samples of human milk were measured by a network analyzer, then the dielectric constant of the samples were determined, and three similar samples were measured by the built‐in sensor. The proposed microwave sensor has Q‐factor of 38 and its sensitivity is 0.17%. The implemented sensor has acceptable performance compared to previous sensors and it can be used to determine the normal behavior of human milk with a simple method and for this work, it requires to small value of sample for measurement.

Associations of Macronutrient Intake Determined by Point-of-Care Human Milk Analysis with Brain Development among very Preterm Infants.

Point-of-care human milk analysis is now feasible in the neonatal intensive care unit (NICU) and allows accurate measurement of macronutrient delivery. Higher macronutrient intakes over this period may promote brain growth and development. In a prospective, observational study of 55 infants born at <32 weeks’ gestation, we used a mid-infrared spectroscopy-based human milk analyzer to measure the macronutrient content in repeated samples of human milk over the NICU hospitalization. We calculated daily nutrient intakes from unfortified milk and assigned infants to quintiles based on median intakes over the hospitalization. Infants underwent brain magnetic resonance imaging at term equivalent age to quantify total and regional brain volumes and fractional anisotropy of white matter tracts. Infants in the highest quintile of energy intake from milk, as compared with the lower four quintiles, had larger total brain volume (31 cc, 95% confidence interval [CI]: 5, 56), cortical gray matter (15 cc, 95%CI: 1, 30), and white matter volume (23 cc, 95%CI: 12, 33). Higher protein intake was associated with larger total brain (36 cc, 95%CI: 7, 65), cortical gray matter (22 cc, 95%CI: 6, 38) and deep gray matter (1 cc, 95%CI: 0.1, 3) volumes. These findings suggest innovative strategies to close nutrient delivery gaps in the NICU may promote brain growth for preterm infants.

Extraction, Isolation and Identification of Low Molecular Weight Peptides in Human Milk

Human milk contains numerous free low molecular weight peptides (LMWPs), which may play an important role in infant health and growth. The bioactivities of LMWPs are determined by their structures, especially the amino acid sequences. In the present study, 81 human milk samples were collected and purified by cation-exchange solid-phase extraction (SPE). Ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used for the separation and detection of free LMWPs in human milk. A total of 56 LMWPs were identified and quantified. These LMWPs were mainly derived from 3 regions of β-casein, which were the amino acid fragments of 16–40, 85–110, and 205–226. The predominant LMWPs were RETIESLSSSEESITEYK, RETIESLSSSEESITEYKQKVEKVK, ETIESLSSSEESITEYK, TQPLAPVHNPIS, and QPLAPVHNPISV with molecular weights of 2247.9573, 2860.2437, 2091.8591, 1372.7666, and 1271.7212, respectively. The results indicated that the technique based on SPE and UPLC-QTOF-MS might greatly facilitate the analysis of LMWPs in human milk.

Human Milk Antibody Response After Combining Two Different COVID-19 Vaccines: Mix-and-Match.

SARS-CoV-2-specific antibodies are secreted into human milk after women are vaccinated against COVID-19, which might protect the breastfed infant. Due to several reports of severe side-effects of the Oxford-AstraZeneca ChAdOx1 (AZD1222) vaccine against COVID-19, some lactating women followed a heterologous vaccination schedule consisting of the first dose of AZD1222 and a second dose of an mRNA-based vaccine. However, it is unclear whether this generates a significant SARS-CoV-2-specific antibody response in human milk. To quantify the SARS-CoV-2-specific antibody response in human milk of two lactating women receiving a heterologous vaccination schedules: AZD1222 and mRNA-based vaccine (Pfizer-BioNTech [BNT162b2] and Moderna [mRNA-1273]). Both participants collected 16 samples of human milk longitudinally. SARS-CoV-2-specific Immunoglobulin A was measured using an enzyme-linked immunosorbent assay. Based on our results, it could be suggested that heterologous vaccination with AZD1222 and an mRNA-based vaccine can elicit a significant SARS-CoV-2 specific IgA response in human milk.

Broad Cross-Reactive IgA and IgG against Human Coronaviruses in Milk Induced by COVID-19 Vaccination and Infection.

It is currently unclear if SARS-CoV-2 infection or mRNA vaccination can also induce IgG and IgA against common human coronaviruses (HCoVs) in lactating parents. Here we prospectively analyzed human milk (HM) and blood samples from lactating parents to measure the temporal patterns of anti-SARS-CoV-2 specific and anti-HCoV cross-reactive IgA and IgG responses. Two cohorts were analyzed: a vaccination cohort (n = 30) who received mRNA-based vaccines for COVID-19 (mRNA-1273 or BNT162b2), and an infection cohort (n = 45) with COVID-19 disease. Longitudinal HM and fingerstick blood samples were collected pre- and post-vaccination or, for infected subjects, at 5 time-points 14–28 days after confirmed diagnosis. The anti-spike(S) and anti-nucleocapsid(N) IgA and IgG antibody levels against SARS-CoV-2 and HCoVs were measured by multiplex immunoassay (mPlex-CoV). We found that vaccination significantly increased the anti-S IgA and IgG levels in HM. In contrast, while IgG levels increased after a second vaccine dose, blood and HM IgA started to decrease. Moreover, HM and blood anti-S IgG levels were significantly correlated, but anti-S IgA levels were not. SARS2 acute infection elicited anti-S IgG and IgA that showed much higher correlations between HM and blood compared to vaccination. Vaccination and infection were able to significantly increase the broadly cross-reactive IgG recognizing HCoVs in HM and blood than the IgA antibodies in HM and blood. In addition, the broader cross-reactivity of IgG in HM versus blood indicates that COVID-19 vaccination and infection might provide passive immunity through HM for the breastfed infants not only against SARS-CoV-2 but also against common cold coronaviruses.

Simultaneous determination of neutral and acidic human milk oligosaccharides (HMOs) by liquid chromatography with tandem mass spectrometry (LC-MS/MS)

Human milk oligosaccharides (HMOs) are a complex category of glycans present in high abundance in human milk, with its concentration and composition closely associated with infant health. Health benefits of HMOs include growth promotion of beneficial bacteria such as Bifidobacterium and inhibition of pathogenic agent adhesion to epithelial cell receptors. Ideally, the development of a robust, sensitive, and fast quantitative test method for key HMO species in human milk is desired for human clinical studies on HMOs, to further understand their benefits, related mechanisms and synthesis in relation to maternal phenotypes. Quantitative analysis of HMOs in human milk has been challenging due to the complex sample matrix, multiple components of HMOs and structurally similar isomers such as LNT and LNnT. In this study, a method has been successfully developed for the quantification of two pairs of neutral HMOs - namely the 2’-FL, 3-FL pair and LNT, LNnT pair, as well as a pair of acidic HMOs - 3’-SL and 6’-SL. Using ultra high-performance liquid chromatography (UHPLC) system coupled with Waters XevoTM TQ-XS Tandem Mass Spectrometer (LC-MS/MS), these three pairs of HMOs can be resolved either by chromatographic separation or unique fragment ions (MRMs). This analytical method has demonstrated excellent method performance including simple and fast sample preparation, short total run time, simultaneous determination of neutral and acidic HMO species, and unique MRM to separate and quantify the structurally similar isomers such as LNT and LNnT. This developed method was successfully validated and applied for the determination of the six HMOs in eleven individual human milk samples, with further potential to be used as a reference for food product quality control.

Maternal Diet Is Associated with Human Milk Oligosaccharide Profile.

ScopeHuman milk oligosaccharides (HMOs) are complex glycans that are abundant in human milk. The potential impact of a maternal diet on individual HMOs and the association with secretor status is unknown. Thus, this study is aimed to examine the association between maternal diet and HMO profiles.Methods and resultsThis is a cross‐sectional study of the MAMI cohort with 101 human milk samples from healthy mothers. HMO profiling is assessed by quantitative HPLC. Maternal dietary information is recorded through an FFQ, and perinatal factors including the mode of delivery, antibiotic exposure, and breastfeeding practices, are collected. A more significant effect of diet on HMO profiles is observed in secretor mothers than in non‐secretor mothers. (Poly)phenols and fibers, both soluble and insoluble, and several insoluble polysaccharides, pectin, and MUFA are associated with the secretor HMO profiles.ConclusionsMaternal diet is associated with the composition and diversity of HMO in a secretor status‐dependent manner. The relationship between maternal diet and bioactive compounds, including HMOs, which are present in human milk, needs further research due its potential impact on infant development and health outcomes.

Result of measuring insertion loss of three human milk samples

Result of measuring insertion loss of three human milk samples

Caffeine, Paraxanthine, Theophylline, and Theobromine Content in Human Milk.

This study aimed to assess the content of caffeine and its metabolites—paraxanthine, theophylline, and theobromine—in breast milk according to selected factors. Samples of human milk were collected from 100 women living in the east–northeast region of Poland. Information on the consumption of beverages and foods containing caffeine was collected using a 3 day food record. The determination of caffeine and its metabolite content was performed using liquid chromatography–mass spectrometry (LC–MS/MS). This study research showed that more caffeine was found in the milk of women living in cities, with secondary education, aged 34–43, and also in milk from the 3rd and 4th lactation periods (p ≤ 0.05). Factors such as place of residence, level of education, age, and stage of lactation influenced the nutritional choices of breastfeeding women, which had an impact on the level of caffeine and its metabolites in breast milk. A positive correlation was found between the consumption of caffeine with food and drinks and its level in human milk.

House Dust Mite Exposure through Human Milk and Dust: What Matters for Child Allergy Risk?

Allergies are major noncommunicable diseases associated with significant morbidity, reduced quality of life, and high healthcare costs. Despite decades of research, it is still unknown if early-life exposure to indoor allergens plays a role in the development of IgE-mediated allergy and asthma. The objective of this study is to contribute to the identification of early-life risk factors for developing allergy. We addressed whether two different sources of house dust mite Der p 1 allergen exposure during early life, i.e., human milk and dust, have different relationships with IgE levels and asthma outcomes in children. We performed longitudinal analyses in 249 mother–child pairs using data from the PIAMA birth cohort. Asthma symptoms and serum total and specific IgE levels in children were available for the first 16 years of life. Der p 1 levels were measured in human milk and dust samples from infant mattresses. We observed that infant exposure to Der p 1 through human milk was associated with an increased risk of having high levels of serum IgE (top tertile > 150 kU/mL) in childhood as compared to infants exposed to human milk with undetectable Der p 1 [adjusted OR (95% CI) 1.83 (1.05–3.20) p = 0.0294]. The Der p 1 content in infant mattress dust was not associated with increased IgE levels in childhood. The risk of asthma and Der p 1 sensitization was neither associated with Der p 1 in human milk nor with Der p 1 in dust. In conclusion, high levels of IgE in childhood were associated with Der p 1 exposure through human milk but not exposure from mattress dust. This observation suggests that human milk is a source of Der p 1 exposure that is relevant to allergy development and fosters the need for research on the determinants of Der p 1 levels in human milk.

Proteomic Analysis of Human Breast Milk to Reveal Potential Protein Biomarkers for Breast Cancer

Breast cancer (BC), one of the most common cancers, is a leading cause of death for women in the United States. An estimated 1 in 8 women in the United States will develop BC in their lifetime. Early diagnosis and treatment of BC is crucial, and protein biomarkers for this disease could make this possible. Mass spectrometry (MS)‐based proteomic methods are ideal for the investigation of protein biomarkers. This study employs MS‐based proteomics to study the protein differences in human breast milk from women with BC and matched controls. If significant protein dysregulations are revealed, they could be considered potential future protein biomarkers of BC for diagnosis and treatment. In this study, six human breast milk samples were analyzed by performing a 2D‐SDS‐PAGE and further analyzed via nanoLC‐MS/MS. The human breast milk samples consisted of three comparison pairs of BC vs. control. There were one Coomassie blue‐stained gel (6 total gels) and two replicate silver‐stained gels (12 total gels) for each sample of breast milk. The silver‐stained gels were scanned using a laser densitometer and the images were analyzed using Progenesis Same Spots and Progenesis PG240 software. The spot percentages were measured for each dysregulated spot., An in‐gel trypsin digestion was performed for each spot with statistically significant dysregulation. This was followed by nanoLC‐MS/MS, data processing, database search and statistical analysis. The dysregulated proteins found in this study can be investigated as BC biomarkers for future clinical methods for early diagnosis and treatment of BC.