Anemia in infancy is associated with alterations in systemic metabolism and microbial structure and function in a sex-specific manner: an observational study.

Background: Anemia is a term that describes low hemoglobin concentrations and can result from micronutrient deficiencies, infection, or low birth weight. Early-life anemia, particularly iron-deficiency anemia (IDA) is associated with several negative metabolic, developmental, and cognitive outcomes, some of which persist into adulthood. Objective: The aim of this study was to investigate alterations in systemic metabolism and fecal microbial diversity and functionality associated with anemia and IDA in male and female infants from Iquitos, Peru. Design: Cross-sectional stool and serum samples were collected from 95 infants (53 boys and 42 girls) at 12 mo of age. The fecal microbiome was assessed by using 16S ribosomal RNA gene sequencing, and the fecal and serum metabolomes were quantified using 1H-nuclear magnetic resonance. Results: The prevalence of anemia was 64%, with a greater proportion of anemia in male infants attributed to iron deficiency. Metabolically, anemia was associated with decreased concentrations of tricarboxylic acid cycle metabolites in both sexes (males: succinate, P = 0.031; females: fumarate, P = 0.028). In addition, anemic male infants exhibited significantly lower serum concentrations of several amino acids compared with nonanemic male infants. Although no specific structural or functional differences in the microbiota were observed with anemia in general, likely due the heterogeneity of its etiology, IDA affected the microbiome both structurally and functionally. Specifically, the abundance of butyrate-producing bacteria was lower in IDA subjects of both sexes than in nonanemic, non-iron-deficient subjects of the same sex (females: Butyricicoccus, P = 0.041; males: Coprococcus, P = 0.010; Roseburia, P = 0.027). IDA male infants had higher concentrations of 4-hydroxyphenyllactate (P < 0.001) and putrescine (P = 0.042) than those without IDA, whereas IDA female infants exhibited higher concentrations of leucine (P = 0.011) and valine (P = 0.003). Conclusions: Sexually dimorphic differences associated with anemia and IDA are suggestive of greater mitochondrial dysfunction and oxidative stress in male infants compared with female infants, and alterations in microbial structure and function may further contribute. Differences in metabolic pathways associated with anemia and IDA in each sex point to potential mechanisms for the associated lasting cognitive deficits. This trial is registered at clinicaltrials.gov as NCT03377777.

Bioactive Proteins in Human Milk: Health, Nutrition, and Implications for Infant Formulas.

Breast milk confers many benefits to the newborn and developing infant. There is substantial support for better long-term outcomes, such as less obesity, diabetes, and cardiovascular disease, in breastfed compared with formula-fed infants. More short-term outcomes, such as incidence and duration of illness, nutrient status, and cognitive development during the first year of life also demonstrate benefits of breastfeeding. Several proteins in breast milk, including lactoferrin, α-lactalbumin, milk fat globule membrane proteins, and osteopontin, have been shown to have bioactivities that range from involvement in the protection against infection to the acquisition of nutrients from breast milk. In some cases, bovine counterparts of these proteins exert similar bioactivities. It is possible by dairy technology to add protein fractions highly enriched in these proteins to infant formula.

Clinical Benefits of Milk Fat Globule Membranes for Infants and Children.

The milk fat globule membrane (MFGM) in breast milk contains many bioactive components. Infant formulas traditionally have been devoid of the MFGM fraction, but dairy technology now has made the addition of bovine MFGM technically feasible. We identified 6 double-blinded randomized controlled trials exploring the effects of MFGM supplementation on the diets of infants or children. Results suggest that supplementation is safe and indicate positive effects on both neurodevelopment and defense against infections. MFGM supplementation of infant formula may narrow the gap in cognitive performance and infection rates between breastfed and formula-fed infants. Because of the small number of studies and the heterogeneity of interventions, more high-quality double-blinded randomized controlled trials are needed, with well characterized and clearly defined MFGM fractions, before firm conclusions on the effects of MFGM supplementation on the health and development of infants can be drawn.

Longitudinal changes in lactoferrin concentrations in human milk: a global systematic review.

Lactoferrin is the second most abundant whey protein in human milk and is known for its functional benefits, particularly antimicrobial activities. We report a comprehensive evaluation of the published literature on quantitative changes in lactoferrin in term and preterm human milk through the course of lactation. We also considered methods used to quantify lactoferrin. We critically evaluated 94 articles on human milk with 52 meeting study inclusion criteria (2724 women). A descriptive analysis of the data was performed. Lactoferrin concentration was highest during early lactation and rapidly declined to remain relatively unchanged from 1 month to 2 years of lactation. The unweighted mean of mean (±SEM) concentrations of lactoferrin in early milk (<28 days lactation) was 4.91 ± 0.31 g/L (range of means 0.34-17.94 g/L; median 4.03). For mature milk, the mean of means was 2.10 ± 0.87 g/L (range of means 0.44-4.4 g/L; median 1.91). The majority of data were derived from Europe with fewer studies from Africa and South America. There was a paucity of data on preterm milk. This comprehensive dataset explains in detail the longitudinal changes of lactoferrin concentrations in human milk throughout the world and briefly describes factors that may influence these concentrations.

Non-heme iron as ferrous sulfate does not interact with heme iron absorption in humans.

The absorption of heme iron has been described as distinctly different from that of non-heme iron. Moreover, whether heme and non-heme iron compete for absorption has not been well established. Our objective was to investigate the potential competition between heme and non-heme iron as ferrous sulfate for absorption, when both iron forms are ingested on an empty stomach. Twenty-six healthy nonpregnant women were selected to participate in two iron absorption studies using iron radioactive tracers. We obtained the dose-response curve for absorption of 0.5, 10, 20, and 50 mg heme iron doses, as concentrated red blood cells. Then, we evaluated the absorption of the same doses, but additionally we added non-heme iron, as ferrous sulfate, at constant heme/non-heme iron molar ratio (1:1). Finally, we compare the two curves by a two-way ANOVA. Iron sources were administered on an empty stomach. One factor analysis showed that heme iron absorption was diminished just by increasing total heme iron (P < 0.0001). The addition of non-heme iron as ferrous sulfate did not have any effect on heme iron absorption (P = NS). We reported evidence that heme and non-heme iron as ferrous sulfate does not compete for absorption. The mechanism behind the absorption of these iron sources is not clear.

Calcium does not inhibit the absorption of 5 milligrams of nonheme or heme iron at doses less than 800 milligrams in nonpregnant women.

Calcium is the only known component in the diet that may affect absorption of both nonheme and heme iron. However, the evidence for a calcium effect on iron absorption mainly comes from studies that did not isolate the effect of calcium from that of other dietary components, because it was detected in single-meal studies. Our objective was to establish potential effects of calcium on absorption of nonheme and heme iron and the dose response for this effect in the absence of a meal. Fifty-four healthy, nonpregnant women were selected to participate in 4 iron absorption studies using iron radioactive tracers. We evaluated the effects of calcium doses between 200 and 1500 mg on absorption of 5 mg nonheme iron (as ferrous sulfate). We also evaluated the effects of calcium doses between 200 and 800 mg on absorption of 5 mg heme iron [as concentrated RBC (CRBC)]. Calcium was administered as calcium chloride in all studies and minerals were ingested on an empty stomach. Calcium doses ≥1000 mg diminished nonheme iron absorption by an average of 49.6%. A calcium dose of 800 mg diminished absorption of 5 mg heme iron by 37.7%. In conclusion, we demonstrated an isolated effect of calcium (as chloride) on absorption of 5 mg of iron provided as nonheme (as sulfate) and heme (as CRBC) iron. This effect was observed at doses higher than previously reported from single-meal studies, starting at ~800 mg of calcium.

Efficacy of an MFGM-enriched complementary food in diarrhea, anemia, and micronutrient status in infants.

OBJECTIVE: The aim of the present study was to evaluate the efficacy of a milkfat globule membrane (MFGM)-enriched protein fraction in a complementary food, on diarrhea, anemia, and micronutrient status. SUBJECTS AND METHODS: A randomized, double-blind controlled design to study 550 infants, 6 to 11 months old, who received daily for 6 months a complementary food (40 g/day) with the protein source being either the MFGM protein fraction or skim milk proteins (control). Health and nutritional status of infants were examined monthly in the outpatient clinic; product intake, food patterns, and diarrhea morbidity were assessed by home visits twice per week. Hemoglobin and micronutrient status were measured at 0 and 6 months of intervention. Results are presented as the entire group and as 6 to 8 and 9 to 11 months subgroups. RESULTS: A total of 499 infants completed the study. Global prevalence of diarrhea was 3.84% and 4.37% in the MFGM group and control group, respectively (P < 0.05). Consumption of the MFGM protein fraction reduced episodes of bloody diarrhea (odds ratio 0.54; 95% confidence interval 0.31-0.93, P = 0.025) adjusting for anemia and potable water facilities as covariates. There were no differences between groups in anemia, serum ferritin, zinc, or folate. CONCLUSIONS: Addition of an MFGM-enriched protein fraction to complementary food had beneficial effects on diarrhea in infants and may thus help to improve the health of vulnerable populations.

Bioactive proteins in human milk: mechanisms of action.

Human milk contains a multitude of bioactive proteins, with very diverse functions. Some of these proteins are involved in the synthesis and expression of milk, but the majority appears to have evolved to provide physiological activities in the breast-fed infant. These activities are exerted by a wide variety of mechanisms and have largely been unraveled by in vitro studies. To be active in the gastrointestinal tract, these proteins must be able to resist proteolytic degradation, at least for some time. We have evaluated the human milk proteins lactoferrin, haptocorrin, alpha(1)-antitrypsin, and transforming growth factor -beta in an in vitro digestion model, mimicking the conditions of the infant gastrointestinal milieu. These bioactive proteins are resistant against proteolysis and can remain intact or as larger fragments through passage of the gastrointestinal tract. In vitro digestibility assays can be helpful to assess which human milk proteins can resist proteolysis and to what extent.

Efficacy of rice-based oral rehydration solution containing recombinant human lactoferrin and lysozyme in Peruvian children with acute diarrhea.

OBJECTIVE: To compare glucose and rice-based oral rehydration solution with rice-based oral rehydration solution containing recombinant human lactoferrin and recombinant human lysozyme in diarrhea outcomes. PATIENTS AND METHODS: We conducted a randomized, double-blind controlled trial in children with acute diarrhea and dehydration. One hundred and forty children 5 to 33 months old were block randomized to receive low osmolarity WHO-ORS (G-ORS), rice-based ORS (R-ORS), or rice-based ORS plus lactoferrin and lysozyme (Lf/Lz-R-ORS). Intake and output were monitored for 48 h in the ORU, with continued monitoring through home and clinic follow-up for 14 d. RESULTS: The G-ORS and R-ORS groups did not show any differences in diarrhea outcomes and were therefore combined as the control group. Intent-to-treat analysis showed a significant decrease in duration of diarrhea (3.67 d vs 5.21 d, P = 0.05) in the Lf/Lz-R-ORS group as compared with the control group and a significant increase in the number of children who achieved 48 h with solid stool, 85% vs 69% (P < 0.05). There were no significant differences [corrected] in volume of diarrhea or [corrected] the percentage of children who had a new diarrhea episode after achieving the endpoint. CONCLUSIONS: Addition of recombinant human lactoferrin and lysozyme to a rice-based oral rehydration solution had beneficial effects on children with acute diarrhea.

Iron deficiency, but not anemia, upregulates iron absorption in breast-fed peruvian infants.

Iron absorption in adults is regulated by homeostatic mechanisms that decrease absorption when iron status is high. There are few data, however, regarding the existence of a similar homeostatic regulation in infants. We studied 2 groups of human milk-fed infants using (57)Fe (given as ferrous sulfate without any milk) and (58)Fe (given at the time of a breast-milk feeding) stable isotopes to determine whether healthy infants at risk for iron deficiency would regulate their iron absorption based on their iron status. We studied 20 Peruvian infants at 5-6 mo of age and 18 infants at 9-10 mo of age. We found no effect of infant hemoglobin concentration on iron absorption with 5-6 mo-old infants absorbing 19.2 +/- 2.1% and 9- to 10-mo-old infants absorbing 25.8 +/- 2.6% of the (57)Fe dose. For (58)Fe, 5- to 6-mo-old infants absorbed 42.6 +/- 5.0% and 9 to 10-mo-old infants absorbed 51.9 +/- 10.3%. Following log transformation, iron absorption from (57)Fe (r = -0.61, P = < 0.001) and (58)Fe (r = -0.61, P = < 0.001) were inversely correlated to serum ferritin (S-Ft). For both the (57)Fe and (58)Fe doses, infants with S-Ft <12 mg/L (n = 11) had significantly higher iron absorption than those with S-Ft >12 mg/L. We concluded that iron absorption in infants is related to iron status as assessed by serum ferritin but not hemoglobin concentration. Infants with low iron status upregulate iron absorption from breast milk at both 5-6 and 9-10 mo of age.

Do indicators of maternal iron status reflect placental iron status at delivery?

Indicators of maternal iron (Fe) status were studied in relation to placental Fe (Pl-Fe) status. Placental (Pl) and maternal (M) venous blood samples were obtained from primiparous women (n = 38), with normal delivery at Paroissien Hospital, Argentina. Maternal hemoglobin (M Hb), soluble transferrin receptor (M sTfR) (ELISA) and serum ferritin (M S-Ft) were studied in relation to Pl-Fe, ferritin (Pl-Ft) and transferrin receptor (Pl-TfR). Pl-TfR was measured by dot blot assay, Pl-Ft and M S-Ft by immunoassay (IRMA) and Pl-Fe by atomic absorption spectrometry. Fe status indicators were, respectively, (mean +/- SD): M Hb 113 +/- 16 g/L; M S-Ft 36 +/- 42 microg/L; M sTfR 6.3 +/- 3.1 mg/L; Pl-Fe 170 +/- 56 microg/g placenta; Pl-Ft 33 +/- 18 microg/g placenta; Pl-TfR 18 +/- 18 (range 0-58) microg/g placenta. Pl-Fe, Pl-Ft and Pl-TfR did not correlate to M Hb, M S-Ft and M sTfR. Women with Pl- Fe, Pl-Ft and Pl-TfR above or below the corresponding median values did not show any statistical significant difference in M Hb, M sTfR or M S-Ft values. Pl-Ft concentration was lower in women with Hb < 110 g/L than in women with normal values: 26 +/- 13 vs. 38 +/- 20 microg/g, respectively (p = 0.021). When Pl-TfR, Pl-Ft and Pl-Fe were compared in women with M S-Ft above or below the cut-off point of 10 or 20 microg/L, no significant difference was found for Pl-TfR neither for Pl-Ft nor Pl-Fe. These results suggest that maternal indicators of Fe status, particularly M sTfR and M S-Ft, do not reflect Fe status of the placenta at delivery.

Iron supplements reduce erythrocyte copper-zinc superoxide dismutase activity in term, breastfed infants.

AIM: To investigate whether iron supplements compromise copper status in infants. METHODS: 214 healthy, term, breastfed Swedish and Honduran infants were randomized to (1) iron supplements (1 mg/kg/d) from 4-9 mo of age, (2) iron supplements from 6-9 mo, or (3) placebo. Blood samples were obtained at 4, 6, and 9 mo and analyzed for plasma copper (p-Cu) and, at 9 mo, for copper/zinc-dependent superoxide dismutase (CuZn-SOD) activity. RESULTS: P-Cu increased with infant age. At 9 mo, Honduran infants had significantly higher p-Cu (1.40+/-0.29 vs 1.09+/-0.22 mg/l, p<0.001) and CuZn-SOD activity (1.09+/-0.29 vs 0.93+/-0.21 U/mg Hb, p<0.001) than Swedish infants. Infants receiving iron supplements from 4-9 mo had significantly lower CuZn-SOD at 9 mo of age (0.95+/-0.27 vs 1.08+/-0.24 U/mg Hb, p=0.023) than those receiving placebo. CONCLUSION: There is a physiologic increase in p-Cu during the first 9 mo of life. Differences in copper status between Swedish and Honduran infants may be due to genetic or nutritional differences. Iron supplementation decreases CuZn-SOD activity, probably due to a negative effect on copper status. Possible clinical implications remain to be elucidated.

Effects of chronic copper exposure during early life in rhesus monkeys.

BACKGROUND: Whether infants regulate copper absorption and the potential effects of excess copper in early life remain poorly defined. OBJECTIVE: The objective of the study was to assess copper retention, liver copper content, and liver function in infant rhesus monkeys fed infant formula containing 6.6 mg Cu/L. DESIGN: From birth to 5 mo of age, infant rhesus monkeys were fed formula that was supplemented with copper (0.6 mg Cu/L; n = 5) or not supplemented (n = 4). In all animals, weight and crown-rump length (by anthropometry), hemoglobin, hematocrit, plasma ceruloplasmin activity, and zinc and copper concentrations were measured monthly (birth to 6 mo) and at 8 and 12 mo. When the animals were 1, 5, and 8 mo old, liver copper and metallothionein concentrations, liver histology (by light and electron microscopy), and the number of Kupffer cells were assessed, and 67Cu retention was measured. Liver function was assessed by measurement of plasma alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, and alkaline phosphatase activities and protein, albumin, bilirubin, and blood urea nitrogen concentrations. RESULTS: 67Cu retention was 19.2% and 10.9% after 1 and 5 mo of copper treatment, respectively, compared with approximately 75% in controls at age 2 mo. At age 8 mo, 67Cu retention was 22.9% in copper-treated animals and 31.5% in controls. Liver histology remained normal by light microscopy, with mild ultrastructural signs of cell damage at 5 mo. Liver copper concentration was 4711, 1139, and 498 microg/g dry tissue at 1, 5, and 8 mo, respectively, in copper-treated animals and 250 microg/g at 2 mo in controls. Measurements could not be completed in all animals. CONCLUSIONS: No clinical evidence of copper toxicity was observed. Copper absorption was down-regulated; increases in liver copper content at ages 1 and 5 mo did not result in histologic damage. Ultrastructural changes at age 5 mo could signal early cellular damage.

A multinational study of alpha-lactalbumin concentrations in human milk.

Alpha-lactalbumin, a 14-kD protein, plays a central biochemical role in the mammary gland as the regulatory subunit of lactose synthase, and also plays a nutritional role for the rapidly growing neonate as the protein in highest concentration in human milk. The current study was undertaken to better characterize alpha-lactalbumin concentrations in human milk from a variety of countries. Mature human milk (lactation duration > or =1 month) was collected from at least 50 women from nine different countries on five continents. Alpha-lactalbumin concentration was determined by HPLC. The mean +/- SD for 452 samples was 2.44 +/- 0.64 g/L. The mean value of the samples from the United States was significantly higher than that from any other country, and the mean in Mexico was significantly lower than that from every country except China and Canada. Alpha-lactalbumin concentration decreased with increasing duration of lactation and was positively correlated with total nitrogen. On average, alpha-lactalbumin contributed 16% of the total nitrogen content of human milk and consequently an important part of the amino acid content.

Randomized controlled trial of the effect of daily supplementation with zinc or multiple micronutrients on the morbidity, growth, and micronutrient status of young Peruvian children.

BACKGROUND: Zinc supplements reduce childhood morbidity in populations in whom zinc deficiency is common. In such populations, deficiencies in other micronutrients may also occur. OBJECTIVE: The objective was to determine whether the administration of other micronutrients with zinc modifies the effect of zinc supplementation on children's morbidity and physical growth. DESIGN: Two hundred forty-six children aged 6-35 mo with persistent diarrhea were randomly assigned to 1 of 3 groups to receive a daily supplement of 10 mg Zn alone (Zn; n = 81), zinc plus vitamins and other minerals at 1-2 times recommended daily intakes (Zn+VM; n = 82), or placebo (n = 83) for approximately 6 mo after the diarrhea episode ended. Morbidity information was collected on weekdays. Weight, length, and other anthropometric indicators were measured monthly, and plasma zinc and other indicators of micronutrient status were measured at baseline and 6 mo. RESULTS: Supplement consumption was high ( approximately 90%) in all groups, although slightly more vomiting was reported in the Zn+VM group (P < 0.0001, analysis of variance). The change in plasma zinc from baseline to 6 mo was greater in the 2 zinc groups (6.1, 27.3, and 16.2 micro g/dL in the placebo, Zn, and Zn+VM groups, respectively; P < 0.0001, analysis of variance). The Zn group had fewer episodes of diarrhea, dysentery, and respiratory illness and a lower prevalence of fever and cough than did the Zn+VM group and a lower prevalence of cough than did the placebo group (P = 0.05). No significant effects of supplementation on growth were observed. CONCLUSION: Morbidity was greater after supplementation with zinc plus multivitamins and minerals than it was after supplementation with zinc alone.