Breast milk fractions solubilize Fe(III) and enhance iron flux across Caco-2 cells

Administration of breast milk cell fractions to neonates with birthweight equal to or less than 1800 g: a randomized controlled trial

Background

Most premature and very low birthweight infants cannot tolerate breast milk feeding in the first few days of life and are deprived of its benefits. This study evaluates the clinical outcomes of administering breast milk cell fractions to neonates with a birthweight of ≤1800 g.

Methods

We conducted a randomized controlled trial on 156 infants in the neonatal intensive care unit of Mahdieh Maternity Hospital in Tehran, Iran, from May 2019 to April 2020. All neonates with a birthweight ≤1800 g were enrolled and divided into intervention and control groups using stratified block randomization. Neonates in the intervention group received the extracted breast milk cell fractions (BMCFs) of their own mother’s milk after being centrifuged in the first 6 to 12 h after birth. The control group received routine care, and breastfeeding was started as soon as tolerated in both groups. Study outcomes were necrotizing enterocolitis (NEC), death, and in-hospital complications.

Results

We divided participants into two groups: 75 neonates in the intervention group and 81 neonates in the control group. The mean birthweight of neonates was 1390.1 ± 314.4 g, and 19 (12.2%) neonates deceased during their in-hospital stay. The incidence of NEC was similar in both groups. After adjustment for possible confounders in the multivariable model, receiving BMCFs were independently associated with lower in-hospital mortality (5 [26.3%] vs. 70 (51.1%]; odds ratio (OR): 0.24; 95% confidence interval [CI] 0.07, 0.86). Also, in a subgroup analysis of neonates with birthweight less than 1500 g, in-hospital mortality was significantly lower in the intervention group (4 [9.5%] vs. 13 [30.2%]; OR: 0.24; 95% CI 0.07, 0.82). There were no differences in major complications such as bronchopulmonary dysplasia and retinopathy of prematurity between the two groups. No adverse effects occurred.

Conclusions

Our research demonstrated a significantly lower mortality rate in neonates (with a birthweight of ≤1800 g) who received breast milk cell fractions on the first day of life. Since this is a novel method with minimal intervention, we are looking forward to developing and evaluating this method in larger studies.

Trial registration

IIranian Registry of Clinical Trials. Registered 25 May 2019, IRCT20190228042868N1.

Comparison of Oral Iron Supplement Formulations for Normalization of Iron Status Following Roux-EN-y Gastric Bypass Surgery: a Randomized Trial

BACKGROUND

The evidence behind recommendations for treatment of iron deficiency (ID) following roux-en-y gastric bypass surgery (RYGB) lacks high quality studies.

SETTING

Academic, United States OBJECTIVE: The objective of the study is to compare the effectiveness of oral iron supplementation using non-heme versus heme iron for treatment of iron deficiency in RYGB patients.

METHODS

In a randomized, single-blind study, women post-RYGB and iron deficient received non-heme iron (FeSO₄, 195 mg/day) or heme iron (heme-iron-polypeptide, HIP, 31.5 to 94.5 mg/day) for 8 weeks. Measures of iron status, including blood concentrations of ferritin, soluble transferrin receptor (sTfR), and hemoglobin, were assessed.

RESULTS

At baseline, the mean ± standard deviation for age, BMI, and years since surgery of the sample was 41.5 ± 6.8 years, 34.4 ± 5.9 kg/m², and 6.9 ± 3.1 years, respectively; and there were no differences between FeSO₄ (N = 6) or HIP (N = 8) groups. Compliance was greater than 94%. The study was stopped early due to statistical and clinical differences between groups. Values before and after FeSO₄ supplementation, expressed as least square means (95% CI) were hemoglobin, 10.8 (9.8, 11.9) to 13.0 (11.9, 14.0) g/dL; sTfR, 2111 (1556, 2864) to 1270 (934, 1737) μg/L; ferritin, 4.9 (3.4, 7.2) to 15.5 (10.6, 22.6) μg/L; and sTfR:ferritin ratio, 542 (273, 1086) to 103 (51, 204); all p < 0.0001. With HIP supplementation, no change was observed in any of the iron status biomarkers (all p > 0.05).

CONCLUSIONS

In accordance with recommendations, oral supplementation using FeSO₄, but not HIP, was efficacious for treatment of iron deficiency after RYGB.

Enzymatic treatment of pork protein for the enhancement of iron bioavailability

The typical intervention for iron-deficiency anaemia is through oral supplementation with iron salts, which have unpleasant side effects. Therefore, there is a need for the development of supplements which will be absorbed more effectively and may have fewer side effects. This study investigated the effects of partially hydrolysed pork proteins on the bioavailability of non-haem iron. The peptides were derived using either pepsin or a combination of bacterial and fungal proteases, and their ability to deliver iron was evaluated in a rat intestine epithelial tissue model. The greatest iron absorption was achieved with peptides hydrolysed by pepsin of low molecular weight (<6-8 kDa). The peptides hydrolysed with bacterial and fungal enzymes may have bound to the iron too strongly, affecting bioavailability. Finally, hydrolysing proteins using pepsin in the presence of iron produces a complex that resulted in more ferritin expression than mixing the peptides with iron after hydrolysis.

Citric acid mediates the iron absorption from low molecular weight human milk fractions

Previously, we have demonstrated increased iron absorption from low molecular weight (LMW) human milk whey fractions. In the present study, we investigated the effect of heat denaturation, zinc (a competitor of iron), duodenal cytochrome b (DcytB) antibody neutralization and citrate lyase treatment on LMW human milk fraction (>5 kDa referred as 5kF) induced ferric iron reduction, solubilization, and uptake in Caco-2 cells. Heat denaturation and zinc inhibited the 5kF fraction induced ferric iron reduction. In contrast, zinc but not heat denaturation abrogated the ferric iron solubilization activity. Despite inhibition of ferric iron reduction, iron uptake in Caco-2 cells was similar from both native and heat denatured 5kF fractions. However, iron uptake was higher from native compared to heat denatured 5kF fractions in the cells preincubated with the DcytB antibody. Citrate lyase treatment inhibited the ferric iron reduction, solubilization, and uptake in Caco-2 cells. These findings demonstrate that citric acid present in human milk solubilizes the ferric iron which could be reduced by other heat labile components leading to increased uptake in intestinal cells.

The lipid fraction of human milk initiates adipocyte differentiation in 3T3-L1 cells

BACKGROUND

The prevalence of childhood obesity has increased worldwide over the past decade. Despite evidence that human milk lowers the risk of childhood obesity, the mechanism is not fully understood.

AIMS

We investigated the direct effect of human milk on differentiation of 3T3-L1 preadipocytes.

STUDY DESIGN AND SUBJECTS

3T3-L1 preadipocytes were treated with donated human milk only or the combination of the standard hormone mixture; insulin, dexamethasone (DEX), and 3-isobututyl-1-methylxanthine (IBMX). Furthermore, the induction of preadipocyte differentiation by extracted lipids from human milk was tested in comparison to the cells treated with lipid extracts from infant formula. Adipocyte differentiation, specific genes as well as formation of lipid droplets were examined.

RESULTS

We clearly show that lipids present in human milk initiate 3T3-L1 preadipocyte differentiation. In contrast, this effect was not observed in response to lipids present in infant formula. The initiation of preadipocyte differentiation by human milk was enhanced by adding the adipogenic hormone, DEX or insulin. The expression of late adipocyte markers in Day 7 adipocytes that have been induced into differentiation with human milk lipid extracts was comparable to those in control cells initiated by a standard adipogenic hormone cocktail.

CONCLUSIONS

These results demonstrate that human milk contains bioactive lipids that can initiate preadipocyte differentiation in the absence of the standard adipogenic compounds via a unique pathway.

Dietary counseling in the management of moderate malnourishment in children

BACKGROUND

Dietary counseling is an integral part of treating malnutrition. A first step toward improving the management of moderate malnutrition is to evaluate dietary messages in current programs and assess their adequacy and effectiveness.

OBJECTIVES

To ascertain current recommendations regarding family foods for the treatment of moderate malnutrition and assess whether these are likely to meet nutritional requirements for rehabilitation; to review the effectiveness of dietary counseling in the management of moderate malnutrition.

METHODS

Information was requested from 10 United Nations agencies or donors, 20 international nongovernmental organizations, 3 pediatric associations, and 6 national programs about the dietary advice they give to caregivers of moderately malnourished children. Adequacy was assessed by comparing dietary recommendations with nutritional requirements. Linear programming was used to identify problem nutrients. A literature search was conducted of studies using family foods for rehabilitating malnourished children.

RESULTS

There was a greater emphasis on providing food supplements for rehabilitation than on utilizing family foods. Dietary recommendations were mostly vague and unlikely to be effective. Those developed by the World Health Organization and the Food and Agriculture Organization for well-nourished children may meet nutritional requirements in moderate malnutrition if the recommendations are made more prescriptive. Zinc and vitamin E emerged as possible problem nutrients. Intervention studies in wasted children suggest that counseling caregivers about family foods can achieve good rates of weight gain.

CONCLUSIONS

Dietary counseling can be effective in managing malnutrition, but it is often weak or absent and should be strengthened. More attention will need to be given to formulating the messages and improving counseling skills.

In Vitro Estimates of Iron Bioavailability in Some Kenyan Complementary Foods

Background

Iron-deficiency anemia is by far the most widespread micronutrient deficiency disease in the world, affecting more than 2 billion people. Although there are multiple causes of anemia, its high prevalence among children—especially in developing countries such as Kenya—is attributed to an inadequate intake of dietary iron.

Objective

The main objective of this study was to assess the amount of bioavailable iron in Kenyan complementary foods and to determine whether strategies such as food diversification using locally available foods would improve the bioavailability of iron from these foods.

Methods

The in vitro iron bioavailability system/ Caco-2 cell model that mirrors the gastric and intestinal digestion of humans was used in this study to estimate the amount of bioavailable iron in the porridges.

Results

The addition of cassava significantly increased the amount of ferritin formation in a cereal-based home recipe from 36.74 to 67.58 ng/mg. The in vitro data suggests that home recipes can provide an equal or greater amount of bioavailable iron as the commercially available nonfortified porridge products. However, in vitro assessment showed that the nonfortified recipes had less bioavailable iron than Cerelac, a commercially available fortified complementary food that provides about 26% of the RDA of iron for infants 6 and 7 months of age per serving ( p < .0001).

Conclusions

In addition to diet diversity, more approaches to address iron inadequacy of complementary foods are required to improve the bioavailability of iron from the Kenyan complementary foods analyzed.

Peptides isolated from in vitro digests of milk enhance iron uptake by caco-2 cells

Milk proteins, during digestion, produce a range of biologically active peptides. Among those are peptides that may enhance iron absorption. The objective of this project was to investigate the effect of isolated milk peptides on iron uptake. Cow's milk, 0% fat, was subjected to a modified in vitro digestion process. The milk digest was further fractionated by gel filtration. All eluted fractions as well as beta-casein synthetic peptides (a tripeptide and a hexapeptide) were subsequently tested for effects on iron uptake with Caco-2 cell monolayers. Fractions of milk digests obtained through Sephadex G-25 gel filtration had a significant enhancing effect on iron uptake in Caco-2 cells compared to nonfractionated milk digests. Two fractions (P = 0) and the hexapeptide (P < 0.0001) enhanced iron uptake by up to 3-fold, whereas others and the tripeptide had no effect. These results suggest that selected peptides produced during the in vitro digestion of milk may enhance iron absorption; however, it remains to be demonstrated whether this effect may be nutritionally significant.

A low-molecular-weight factor in human milk whey promotes iron uptake by Caco-2 cells

The iron bioavailability of human milk (HM) is substantially greater than that of cow's milk (CM), but the factor responsible for this high bioavailability is unknown. This study evaluated the effects of various HM and CM fractions on iron bioavailability. Milk was separated into fat, casein and whey fractions by ultracentrifugation. Whey was further fractionated by ultrafiltration with a 10-kDa membrane to produce a 10-kDa retentate (10kR) and a 10-kDa filtrate (10kF). Samples were prepared by mixing various combinations of the fractions, bringing the samples to prefractionation weight with minimum essential medium (MEM), and adding iron (10 micro mol/L) as ferrous sulfate. Samples were divided into two aliquots: one was subjected to in vitro digestion, the other was not. Bioavailability was assessed by applying the samples to Caco-2 cell monolayers and incubating for 24 h. Ferritin formation in the cells was used as an index of iron uptake. Removing the fat from undigested HM samples doubled the ferritin formation, but removing the whey or casein had no effect. Results with digested HM samples were similar, except that removing the whey decreased ferritin formation by 48%. Removing the fat from digested CM samples had no effect, but removing the casein doubled the ferritin formation. Removing the 10kF from HM reduced ferritin formation by 60%, but removing the 10kR had no effect. These data suggest that a low-molecular-weight factor (<10 kDa) in human milk enhances iron absorption.