HUMAN BREAST MILK RESEARCH

Breast-milk stem cells may bypass ethical dilemmas

2011-11-14T13:25:00.001-08:00

Embryonic-like stem cells have been isolated from breast milk in large numbers. The discovery raises the possibility of sourcing stem cells for regenerative medicine, without the need to destroy embryos.

Peter Hartmann at the University of Western Australia in Crawley and his colleagues first announced the discovery of stem cells in breast milk in 2008. Now they have grown them in the lab and shown that they can turn into cells representative of all three embryonic germ layers, called the endoderm, mesoderm and ectoderm – a defining property of embryonic stem cells (ESC).

"They can become bone cells, joint cells, fat cells, pancreatic cells that produce their own insulin, liver cells that produce albumin and also neuronal cells," says Foteini Hassiotou, a member of Hartmann's lab team, who led the recent work.

The breast cells also express the majority of protein markers that you would expect to find in ESCs. "What is really amazing is that these cells can be obtained in quite large amounts in breast milk," Hassiotou adds.

She says the stem cells constitute around 2 per cent of cells in breast milk although the number varies according to how long the woman has been producing milk and how full her breasts are. Hassiotou will present the team's work at the 7th International Breastfeeding and Lactation Symposium in Vienna, Austria early next year.

Many remain sceptical, however. "Perhaps there are some mammary gland stem cells that can be coaxed to have a slightly broader potential than normal, but I very much doubt that embryonic-like cells normally exist in the breast," says Robin Lovell-Badge of the National Institute for Medical Research in London. For one thing, you would expect tumours to be more common than they are.

The real test will be to inject these cells into mice and see if they form teratomas – tumours containing tissue or structures derived from all three germ layers. "That's the gold standard for whether you have a true pluripotent cell," says Chris Mason of University College London. Hassitou says they plan to start these tests in the coming weeks.

Embryonic-like stem cells have previously been discovered in amniotic fluid and in the umbilical cord, but this is the first time they have been discovered in an adult. Other adult stems cells exist – such as hematopoietic stem cells, which can generate all types of blood cell and mesenchymal stem cells, which can turn into bone, fat and cartilage cells. But these stem cells cannot generate as many cell types as the breast milk cells apparently can. "If they are truly embryonic, this would be another way of getting stem cells that would not raise ethical concerns," says Mason.

However, even if they do not turn out to be ESCs, these breast milk cells could still have great potential for regenerative medicine. "It might be possible to grow these cells in culture then bank them so that if or when the mother develops some disease later in life, such as diabetes, her cells may be defrosted and differentiated into pancreatic beta cells," says Lyle Armstrong of Newcastle University, UK, although he too, cautions that more tests are needed to determine exactly what these cells are.

The discovery also raises intriguing questions about the role of these cells in breastfed babies. "It has been shown in mice that live immune cells in breast milk pass through the intestinal mucosa into the blood circulation of the pups and engraft in various tissues," says Hassiotou. "If these cells are in human milk and in such high amounts they probably have a role. They might contribute to tissue regeneration and development of the baby or play certain roles if there is a disease."

The team is planning experiments to track what happens to these cells once they get into infants.

New Scientist: November 2011 by Linda Geddes

Lactose-free milk protein-based infant formula: impact on growth and gastrointestinal tolerance in infants

2011-04-03T15:37:00.000-07:00

Abstract
Lactose, the major carbohydrate in human milk and standard milk-based formulas, provides energy for growth in infants. The use of lactose-free milk protein-based infant formulas has increased in the United States. However, clinical studies of their impact on growth, safety, and gastrointestinal tolerance in infants are limited. Thus, a prospective, blinded, randomized clinical trial was conducted in healthy, normal-term infants fed an experimental lactose-free milk protein-based formula (NoLAC; n = 63) versus a standard commercial lactose-containing milk-based formula (LAC; n = 65) for 112 days. Growth (weight, length, and head circumference) was similar and normal in both groups (weight gain: NoLAC = 31.1 ± 0.9 g/day, LAC = 29.4 ± 0.9 g/day, mean ± SEM; P = .895). Serum biochemistries for both groups were within infants' normal reference ranges. Both groups had comparable tolerance but the NoLAC group had softer stools and lower spit-ups. Thus, the study suggests that absence of lactose in milk-based formula does not adversely affect normal growth in term infants.

Lasekan JB, Jacobs J, Reisinger KS, Montalto MB, Frantz MP, Blatter MM.

Abbott Nutrition, Abbott Laboratories, Columbus, OH, USA,

Human breast milk is a rich source of multipotent mesenchymal stem cells

2010-09-15T13:35:00.000-07:00

Abstract
Putative stem cells have been isolated from various tissue fluids such as synovial fluid, amniotic fluid, menstrual blood, etc. Recently the presence of nestin positive putative mammary stem cells has been reported in human breast milk. However, it is not clear whether they demonstrate multipotent nature. Since human breast milk is a non-invasive source of mammary stem cells, we were interested in examining the nature of these stem cells.

In this pursuit, we could succeed in isolating and expanding a mesenchymal stem cell-like population from human breast milk. These cultured cells were examined by immunofluorescent labeling and found positive for mesenchymal stem cell surface markers CD44, CD29, SCA-1 and negative for CD33, CD34, CD45, CD73 confirming their identity as mesenchymal stem cells. Cytoskeletal protein marker analysis revealed that these cells expressed mesenchymal stem cells markers, namely, nestin, vimentin, smooth muscle actin and also manifests presence of E-Cadherin, an epithelial to mesenchymal transition marker in their early passages.

Further we tested the multipotent differentiation potential of these cells and found that they can differentiate into adipogenic, chondrogenic and oesteogenic lineage under the influence of specific differentiation cocktails. This means that these mesenchymal stem cells isolated from human breast milk could potentially be “reprogrammed” to form many types of human tissues. The presence of multipotent stem cells in human milk suggests that breast milk could be an alternative source of stem cells for autologous stem cell therapy although the significance of these cells needs to be determined.

Satish PATKI1, Sachin KADAM2, Vikash CHANDRA2, Ramesh BHONDE2

Impact of breast milk on IQ, brain size and white matter development

2010-01-28T11:45:00.000-08:00

Although observational findings linking breast milk to higher scores on cognitive tests may be confounded by factors associated with mothers' choice to breastfeed, it has been suggested that one or more constituents of breast milk facilitate cognitive development, particularly in preterms. Because cognitive scores are related to head size, we hypothesised that breast milk mediates cognitive effects by affecting brain growth.

We used detailed data from a randomized feeding trial to calculate percentage of breast milk (%EBM) in the infant diet of 50 adolescents. MRI scans were obtained (mean age=15y9m), allowing volumes of total brain (TBV), white and grey matter (WMV, GMV) to be calculated. In the total group %EBM correlated significantly with Verbal IQ (VIQ); in boys, with all IQ scores, TBV and WMV. VIQ was, in turn, correlated with WMV and, in boys only, additionally with TBV. No significant relationships were seen in girls or with grey matter.

These data support the hypothesis that breast milk promotes brain development, particularly white matter growth. The selective effect in males accords with animal and human evidence regarding gender effects of early diet. Our data have important neurobiological and public health implications and identify areas for future mechanistic study.

Infant sex predicts breast milk energy content

2009-11-24T10:40:00.000-08:00

Camille E. Powe 1 *, Cheryl D. Knott 2, Nancy Conklin-Brittain 1

Abstract
During human evolutionary history, and for many around the world, breast milk is the primary source of nutritional energy for infants. Variation in breast milk quality might logically have important effects on infant health, growth, and development, yet the sources of this variation remain largely unelucidated. We quantified nutrient and energy content of breast milk from 25 healthy, well-nourished Massachusetts mothers with infants aged 2-5 months. We examined several potential sources of variation in milk quality, particularly feeding patterns, infant sex, and maternal breast growth during pregnancy.

After controlling for time since last feeding, a known correlate of milk composition, we found that mothers of male infants produced milk that had 25% greater energy content than mothers of female infants (P < 0.001). Change in maternal bra cup size during pregnancy was associated with 16.17 kcal/100 ml greater energy content of milk (P = 0.009), but was not significant after taking infant sex into account. Greater nutritional investment in sons may account for the greater observed growth rates in male compared to female infants.

Funded by:
Harvard College Research Program, Cambridge, Massachusetts
Camille E. Powe 1 *, Cheryl D. Knott 2, Nancy Conklin-Brittain 1
1Department of Anthropology, Harvard University, Cambridge, Massachusetts 02138
2Department of Anthropology, Boston University, Boston, Massachusetts 02115

Protein Content and Fortification of Human Milk Influence Gastroesophageal Reflux in Preterm Infants

2009-08-20T12:16:00.001-07:00

Aceti A, Corvaglia L, Paoletti V, Mariani E, Ancora G, Galletti S, Faldella G.
*Neonatology and Neonatal Intensive Care Unit, S. Orsola-Malpighi Hospital, University of Bologna, Italy dagger"Centro Interdipartimentale di Ricerca sull'Alimentazione Umana, CIRAU," University of Bologna, Italy.

OBJECTIVES:: Preterm human milk (HM) may provide insufficient energy and nutrients and thus may need to be fortified. Our aim was to determine whether fat content, protein content, and osmolality of HM before and after fortification may affect gastroesophageal reflux (GER) in symptomatic preterm infants. METHODS:: Gastroesophageal reflux was evaluated in 17 symptomatic preterm newborns fed naïve and fortified HM by combined pH/intraluminal-impedance monitoring (pH-MII). Human milk fat and protein content was analysed by a near-infrared reflectance analysis. Human milk osmolality was tested before and after fortification. Gastroesophageal reflux indexes measured before and after fortification were compared and were also related to HM fat and protein content and osmolality before and after fortification. RESULTS:: An inverse correlation was found between naïve HM protein content and acid reflux index (RIpH: P = 0.041, rho =-0.501). After fortification, osmolality often exceeded the values recommended for infant feeds; furthermore, a statistically significant (P < 0.05) increase in nonacid reflux indexes was observed. CONCLUSIONS:: Protein content of naïve HM may influence acid GER in preterm infants. A standard fortification of HM may worsen nonacid GER indexes and, due to the extreme variability in HM composition, may overcome both recommended protein intake and HM osmolality. Thus, an individualized fortification, based on the analysis of the composition of naïve HM, could optimize both nutrient intake and feeding tolerance

Nutrient-gene interactions in early life programming: leptin in breast milk prevents obesity later on in life

2009-06-22T08:55:00.001-07:00

Palou A, Sánchez J, Picó C.
Laboratory of Molecular Biology, Nutrition and Biotechnology (Nutrigenomics), University of the Balearic Islands (UIB) and CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Palma de Mallorca, 07122, Spain, andreu.palou@uib.es.

Breast milk is practically the only food eaten during the first months of life in fully breastfed infants and it is assumed to match the nutritional needs during these first months of postnatal life. Breastfeeding compared with infant formula feeding confers protection against several metabolic and physiological changes later on in life and, particularly, against obesity and related medical complications. Recent data from our laboratory, identifying leptin as the first specific compound responsible for these beneficial effects, are reviewed and discussed.

Innate Factors in Human Breast Milk Inhibit Cell-Free HIV-1 but Not Cell-Associated HIV-1 Infection of CD4+ Cells

2009-05-18T13:35:00.000-07:00

From the Departments of *Physiology and daggerMicrobiology and Immunology, Dartmouth Medical School, Lebanon, NH; and double daggerVA Medical Center, White River Junction, VT.

BACKGROUND:: Transmission of HIV from mother to child through breast-feeding remains a global health challenge, particularly in developing countries. Breast milk from an HIV-infected women may contain both cell-free HIV-1 and cell-associated virus; however, the impact of human Breast Milk on HIV infection and replication in CD4 cells remain poorly understood. OBJECTIVES:: In the present study, we evaluated the effects of breast milk in vitro on infection of CD4 cells with cell-free HIV-1, including effects on HIV-1 receptor expression, reverse transcription, integration, and viral transcription. Additionally, we evaluated the ability of breast milk to inhibit cell-associated transmission of HIV-1 from infected CD4 T lymphocytes.

RESULTS:: Our results demonstrate that breast milk potently inhibits infection with cell-free HIV-1 in vitro independently of viral tropism and significantly decreases HIV-1 reverse transcription and integration in CD4 cells. However, the inhibitory effect of breast milk on HIV-1 infection of CD4 cells was lost during extended culture, and direct coculture of HIV-infected CD4 T lymphocytes with susceptible target cells revealed that breast milk was ineffective at blocking cell-associated HIV-1 infection.

CONCLUSIONS:: Our findings suggest that breast milk may provide a protective function against cell-free HIV-1 but may be less effective at blocking infection by cell-associated virus.
J Acquir Immune Defic Syndr. 2009 Apr 2

Automated on-line column-switching HPLC-MS/MS method with peak focusing for measuring parabens, triclosan, and other environmental phenols in human mi

2008-07-15T09:10:00.000-07:00

Parabens (esters of p-hydroxybenzoic acid) and triclosan are widely used as preservatives and antimicrobial agents, respectively, in personal care products, pharmaceuticals, and food processing. Because of their widespread use and potential risk to human health, assessing human exposure to these compounds in breastfed infants is of interest. We developed a sensitive method, using a unique on-line solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry system with peak focusing feature, to measure in human milk the concentrations of five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl parabens), triclosan, and six other environmental phenols: bisphenol A (BPA); ortho-phenylphenol (OPP); 2,4-dichlorophenol; 2,5-dichlorophenol; 2,4,5-trichlorophenol; and 2-hydroxy-4-methoxybenzophenone (BP-3). The method, validated by use of human breast milk pooled samples, shows good reproducibility (inter-day coefficient of variations ranging from 3.5% to 16.3%) and accuracy (spiked recoveries ranging from 84% to 119% at four spiking levels). The detection limits for most of the analytes are below 1 ng mL−1 in 100 μL of milk. We tested the usefulness of the method by measuring the concentrations of these twelve compounds in four human milk samples. We detected methyl paraben, propyl paraben, triclosan, BPA, OPP, and BP-3 in some of the samples tested. The free species of these compounds appear to be the most prevalent in milk. Nevertheless, to demonstrate the utility of these measures for exposure and risk assessment purposes, additional data about sampling and storage of the milk, and on the stability of the analytes in milk, are needed.

ARTICLE

Distribution of polychlorinated biphenyls and organochlorine pesticides in human breast milk from various locations in Tunisia: Levels of contaminatio

2008-07-10T13:05:00.000-07:00

The concentrations of dichlorodiphenytrichloroethane and its metabolites (DDTs), hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), dieldrin, and 20 polychlorinated biphenyls (PCBs) were determined in 237 human breast milk samples collected from 12 locations in Tunisia. Gas chromatography with electron capture detector (GC-ECD) was used to identify and quantify residue levels on a lipid basis of organochlorine compounds (OCs). The predominant OCs in human breast milk were PCBs, p,p′-DDE, p,p′-DDT, HCHs, and HCB. Concentrations of DDTs in human breast milk from rural areas were significantly higher than those from urban locations (p<0.05). With regard to PCBs, we observed the predominance of mid-chlorinated congeners due to the presence of PCBs with high Kow such as PCB 153, 138, and 180. Positive correlations were found between concentrations of OCs in human breast milk and age of mothers and number of parities, suggesting the influence of such factors on OC burdens in lactating mothers. The comparison of daily intakes of PCBs, DDTs, HCHs, and HCB to infants through human breast milk with guidelines proposed by WHO and Health Canada shows that some individuals accumulated OCs in breast milk close to or higher than these guidelines.

ARTICLE

Automated on-line column-switching HPLC-MS/MS method with peak focusing for measuring parabens, triclosan, other environmental phenols in human milk

2008-07-09T14:41:00.000-07:00

Parabens (esters of p-hydroxybenzoic acid) and triclosan are widely used as preservatives and antimicrobial agents, respectively, in personal care products, pharmaceuticals, and food processing. Because of their widespread use and potential risk to human health, assessing human exposure to these compounds in breastfed infants is of interest. We developed a sensitive method, using a unique on-line solid-phase extraction-high performance liquid chromatography-tandem mass spectrometry system with peak focusing feature, to measure in human milk the concentrations of five parabens (methyl-, ethyl-, propyl-, butyl-, and benzyl parabens), triclosan, and six other environmental phenols: bisphenol A (BPA); ortho-phenylphenol (OPP); 2,4-dichlorophenol; 2,5-dichlorophenol; 2,4,5-trichlorophenol; and 2-hydroxy-4-methoxybenzophenone (BP-3). The method, validated by use of breast milk pooled samples, shows good reproducibility (inter-day coefficient of variations ranging from 3.5% to 16.3%) and accuracy (spiked recoveries ranging from 84% to 119% at four spiking levels). The detection limits for most of the analytes are below 1 ng mL−1 in 100 μL of milk. We tested the usefulness of the method by measuring the concentrations of these twelve compounds in four human breast milk samples. We detected methyl paraben, propyl paraben, triclosan, BPA, OPP, and BP-3 in some of the samples tested. The free species of these compounds appear to be the most prevalent in milk. Nevertheless, to demonstrate the utility of these measures for exposure and risk assessment purposes, additional data about sampling and storage of the milk, and on the stability of the analytes in milk, are needed.

ARTICLE

Phthalate Diesters and Their Metabolites in Human Breast Milk, Blood or Serum, and Urine as Biomarkers of Exposure in Vulnerable Populations

2008-07-08T13:28:00.000-07:00

Background. Phthalates may pose a risk for perinatal developmental effects. An important question relates to the choice of suitable biological matrices for assessing exposure during this period.

Objectives. This study was designed to measure the concentrations of phthalate diesters or their metabolites in breast milk, blood or serum, and urine and to evaluate their suitability for assessing perinatal exposure to phthalates.

Methods. In 2001, 2–3 weeks after delivery, 42 Swedish primipara provided breast milk, blood, and urine samples at home. Special care was taken to minimize contamination with phthalates (e.g., use of a special breast milk pump, heat treatment of glassware and needles, addition of phosphoric acid).

Results. Phthalate diesters and metabolites in milk and blood or serum, if detected, were present at concentrations close to the limit of detection. By contrast, most phthalate metabolites were detectable in urine at concentrations comparable to those from the general population in the United States and in Germany. No correlations existed between urine concentrations and those found in milk or blood/serum for single phthalate metabolites. Our data are at odds with a previous study documenting frequent detection and comparatively high concentrations of phthalate metabolites in Finnish and Danish mothers’ milk.

Conclusions. Concentrations of phthalate metabolites in urine are more informative than those in milk or serum. Furthermore, collection of milk or blood may be associated with discomfort and potential technical problems such as contamination (unless oxidative metabolites are measured). Although urine is a suitable matrix for health-related phthalate monitoring, urinary concentrations in nursing mothers cannot be used to estimate exposure to phthalates through milk ingestion by breast-fed infants.

Long-chain polyunsaturated fatty acids in breast milk and early weight gain in breast-fed infants

2008-07-07T14:44:00.000-07:00

The long-chain PUFA (LCPUFA) content of an infant's diet might affect early weight gain. In early trials on supplementation of formula feeding n-3 LCPUFA affected weight gain adversely. n-6 LCPUFA are thought to promote adipose tissue development and might be associated with higher weight gain. We studied the association between the natural n-3 and n-6 LCPUFA content of breast milk of Dutch women and weight and BMI gain of their breast-fed infants in the first year of life. The children in this study were enrolled in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study and were born in 1996–1997 in the Netherlands. Parents reported their child's weight and length in a questionnaire. Of a subgroup of the total population breast-milk samples were collected (n 244). The fatty acid composition of breast milk was determined by GLC and expressed as weight percentages. Linear regression was used for data analysis. Mean gain in weight, length and BMI per week from birth to 1 year of age was 119·5 (sd 16·1) g, 0·48 (sd 0·05) cm and 0·06 (sd 0·03) kg/m2, respectively. The associations between n-6 and n-3 LCPUFA in breast milk, and infant weight, length and BMI gain were weak and inconsistent. The n-3 and n-6 LCPUFA content in breast milk did not affect weight or BMI gain in the first year of life in breast-fed term infants.

28-Day repeated dose oral toxicity of recombinant human apo-lactoferrin or recombinant human lysozyme in rats

2008-07-07T12:34:00.001-07:00

Lactoferrin and lysozyme are important proteins of the human innate immune system. These proteins are found in breast milk and have been associated with improved infant health. Recombinant human apo-lactoferrin (apo-rhLF), 1800 and 180 mg/kg bw/day, and recombinant human lysozyme (rhLZ), 360 and 36 mg/kg bw/day, were orally administered to Wistar rats for 28 days. Apo-rhLF and rhLZ were expressed in rice grain, extracted, purified; the lactoferrin was iron desaturated. The animals were examined for evidence of toxicity; there were no deaths and in-life physical signs were normal. Transient differences in mean food consumption occurred in high dose apo-rhLF and low dose LZ females at week three. There were no biologically significant differences in hematological or clinical chemistry parameters. Necropsy results were normal and microscopic evaluation showed no treatment related changes in animals dosed with 1800 mg/kg/day apo-rhLF or 360 mg/kg/day rhLZ. The results of the 28-day oral administration demonstrate a lack of toxicity of apo-rhLF and rhLZ in rats. There were no treatment related, toxicologically relevant changes in clinical signs, growth, food consumption, hematology, clinical chemistry, organ weight and pathology. The no observed adverse effect level (NOAEL) is greater than 1800 mg/kg/day for apo-rhLF and 360 mg/kg/day for rhLZ.

ARTICLE

Perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA) in human breast milk: Results of a pilot study

2008-07-07T12:29:00.000-07:00

Perfluorinated compounds (PFC) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Because of their global occurrence in different environmental media, their persistence and their potential to bioaccumulate in organisms they are of toxicological and public concern.

In the present study, perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA) were quantified in 70 breast milk samples. Samples were obtained from Leipzig, Germany (38 archived samples), Munich, Germany (19 fresh samples) and Gyor, Hungary (13 frozen samples).

PFOS could be quantified in all 70 samples. The concentration in samples from Germany ranged between 28 and 309 ng/l (median: 119 ng/l). Samples from Hungary showed significantly higher PFOS concentrations (median 330 ng/l, range 96–639 ng/l). In only 11 of 70 samples (16%) PFOA reached the LOQ (200 ng/l); values ranged from 201 to 460 ng/l. If only those samples with PFOA values above the LOQ were considered, we found a significant correlation between the PFOS and PFOA concentrations (r=0.75, p=0.008).

Based on the results of the German sample, we estimated an intake of 0.10 μg PFOS/day (using median) or 0.27 PFOS μg/day (using maximum value) via breast milkfor an infant of 5 kg bodyweight. Our data suggest that fully breastfed infants are unlikely to exceed the recommended tolerable daily intake of PFC. However, more target-oriented studies are needed to identify the amount and time-trend of PFOS and PFOA in maternal blood during pregnancy, after delivery, as well as in the growing infant and in its diet (e.g., breast milk and formula).

ARTICLE