Repletion Diets Research Articles

An Electrolytic Elemental Iron Powder Effectively Regenerates Hemoglobin in Anemic Rats and Is Relatively Well Absorbed When Compared to Ferrous Sulfate Monohydrate.

Elemental iron powders are used as food fortificants to reduce the incidence of iron deficiency anemia. However, many commercially available iron powders are relatively untested in vivo. The purpose of this study was to determine the hemoglobin regeneration efficiency (HRE) and relative iron bioavailability (RBV) of an electrolytic elemental iron powder (EIP), by treating anemic rats with 14 d iron repletion diets fortified with four different concentrations (12, 24, 36, or 48 mg iron/kg diet) of EIP and bakery-grade ferrous sulfate monohydrate (FS; FeSO4•H2O), or no added iron (control); n = 9-12/group. The HRE of FS was significantly higher (p ≤ 0.05) than EIP at each concentration of dietary iron tested. For EIP, the HREs (ratios) of diets containing 12, 24, 36, and 48 mg iron/kg were 0.356, 0.205, 0.197, and 0.163, respectively. For both EIP and FS, HRE was inversely associated with increasing dietary iron. The RBVs (%) of iron from EIP in diets at 12, 24, 36, and 48 mg iron/kg as compared to FS were 64.5, 59.1, 50.6, and 54.3%, respectively. Overall, findings show that at the concentrations of iron tested, EIP has RBVs greater than 50% and is an effective fortification agent to replenish hemoglobin and correct iron deficiency anemia.

Hemoglobin Regeneration Efficiency and Relative Iron Bioavailability of Four Elemental Iron Powders in Rats.

Effective food fortification strategies using elemental iron powders (EIPs) are needed to combat iron deficiency anemia. The purpose of this study was to determine hemoglobin regeneration efficiency (HRE) and relative iron bioavailability (RBV) of four food-grade EIPs (El-Lyte (EL), Hi-Sol (HS), H-325 (H3), and A-131 (A1)) by treating anemic rats with 14 d iron repletion diets (uncooked and cooked), fortified with a 12, 24, or 36 mg iron/kg diet of the EIPs, ferrous sulfate monohydrate (FS, FeSO4•H2O), or no added iron (control), n = 9-12/group. The ability of EL and HS to maintain hemoglobin for 6 weeks on the 6 mg iron/kg diet was also studied. The dissolution rate of iron from the EIPs was measured in hydrochloric acid at pH 1.0. Compared to FS, the EL, HS, and A1 EIPs had >50% overall RBV, with the following order: HS > A1 > EL > H3 (p ≤ 0.05); the effect of cooking was not significant (p > 0.05). Dissolution testing revealed that the mean RBV of the EIPs was positively associated with the percentage of iron solubility. In the 6-week maintenance study, EL and HS maintained hemoglobin as well as FS. Overall, the findings show that at the concentrations of iron tested, these EIPs are effective fortification agents to replenish hemoglobin and correct iron deficiency anemia.

Establishing a Rat Model of Intestinal Heme-iron Absorption

Heme iron, derived from hemoglobin and myoglobin of animal products, is efficiently absorbed and utilized by humans. Despite extensive investigation over the last several decades, the exact mechanism(s) of heme-iron absorption and tissue utilization of absorbed heme are unclear. Mice are frequently used for investigation of iron biology; however, mice do not efficiently utilize dietary iron derived from heme, so development of alternative models is warranted. Rats could more efficiently utilize dietary heme iron, but this has not been rigorously tested. Our initial studies demonstrated that dietary heme (derived from porcine RBCs) could partially correct iron-deficiency anemia (IDA) in rats of one strain (rat strain 1), but not in 2 others. We hypothesized that a heme-iron diet would fully replete strain 1 rats with IDA, at a similar rate to a non-heme iron (NHI) diet. We utilized repletion diets containing 50, 75 or 100 ppm heme iron; a control diet contained 50 ppm NHI. Forty-two, three-week-old, female strain 1 rats were weaned onto a low-iron diet with 3-4 ppm NHI, and then after 2 weeks, rats were repleted with the different diets for 8 days. Rats were housed in overhanging wire bottom stainless steel cages during the low-iron feeding period to prevent coprophagia. Blood was collected from the tail vein at baseline and every 4 days thereafter to track correction of anemia. Outcomes showed that repletion of IDA rats with the 50-ppm heme-iron diet resolved the anemia; however, tissue iron depletion indicated that the rats remained iron deficient. Also, the rate of repletion was slightly slower as compared to rats repleted with the control (50 ppm NHI) diet. With higher dietary heme-iron levels, repletion was as fast, or even faster, than in control rats suggesting that a rat strain was identified that can efficiently assimilate dietary heme iron. Our studies support a role for rats as a genetic model to preferentially mimic human nutritional studies of iron and heme absorption. This investigation was funded by grant DK074867 from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (JFC, PI), and grant DK109717 from NIDDK and the Office of Dietary Supplements (to JFC, PI). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Edible insects prevent changes to brain monoamine profiles from malnourishment in weaned rats

ABSTRACT Background: Childhood malnutrition can have devastating consequences on health, behavior, and cognition. Edible insects are sustainable low cost high protein and iron nutritious foods that can prevent malnutrition. However, it is unclear whether insect-based diets may help prevent changes to brain neurochemistry associated with malnutrition. Materials and Methods: Weanling male Sprague–Dawley rats were malnourished by feeding a low protein-iron diet (LPI, 5% protein and ∼2 ppm Fe) for 3 weeks or nourished by feeding a sufficient protein-iron diet (SPI, 15% protein 20 ppm FeSO4) for the duration of the study. Following 3 weeks of LPI diet, three subsets of the malnourished rats were placed on repletion diets supplemented with cricket, palm weevil larvae, or the SPI diet for 2 weeks, while the remaining rats continued the LPI diet for an additional 2 weeks. Monoamine-related neurochemicals (e.g. serotonin (5-HT), dopamine (DA), norepinephrine) and select monoamine metabolites were measured in the hypothalamus, hippocampus, striatum, and prefrontal cortex using Ultra High-Performance Liquid Chromatography. Results: Five weeks of LPI diets disrupted brain monoamines, most notable in the hypothalamus. Two weeks supplementation with cricket and palm weevil larvae diets prevented changes to measures of 5-HT and DA turnover in the hippocampus and hypothalamus. Moreover, these insect diets prevented the malnutrition-induced imbalance of 5-HT and DA metabolites in the hippocampus, striatum, and hypothalamus. Conclusion: Edible insects such as cricket and palm weevil larvae could be sustainable nutrition intervention to prevent behavioral and cognitive impairment associated abnormal brain monoamine activities that results from early life malnutrition.

Development of bone mineralization and body composition of replacement gilts fed a calcium and phosphorus depletion and repletion strategy

This study investigated the ability of replacement gilts to adapt their calcium and phosphorus utilization and their kinetics in bone mineralization to compensate for modified intake of these nutrients by applying a novel Ca and P depletion and repletion strategy. A total of 24 gilts were fed according to a two-phase feeding program. In the first phase, gilts (60–95 kg BW) were fed ad libitum a depletion diet providing either 60% (D60; 1.2 g digestible P/kg) or 100% (D100; 2.1 g digestible P/kg) of the estimated P requirement. In the second phase, gilts (95–140 kg BW) were fed restrictively (aim: 700–750 g/d BW gain) a repletion diet. Half of the gilts from each depletion diet were randomly assigned to either a control diet or a high-P diet (R100 and R160; with 2.1 and 3.5 g digestible P/kg, respectively) according to a 2 × 2 factorial design, resulting in four treatments: D60-R100, D60-R160, D100-R100 and D100-R160. Dual-energy X-ray absorptiometry was used to measure whole-body bone mineral content (BMC), bone mineral density (BMD) and lean and fat tissue mass on each gilt at 2-week intervals. The depletion and repletion diets, fed for 5 and 8 weeks, respectively, did not influence growth performance. The D60 gilts had a reduced BMC and BMD from the second week onwards and ended (95 kg BW) with 9% lower values than D100 gilts (P < 0.001). During repletion, D60 gilts completely recovered the deficit in bone mineralization from the second and fourth week onwards, when fed R160 (D60-R160 vs D100-R160) or R100 (D60-R100 vs D100-R100) diets, respectively (treatment × time interaction, P < 0.001); thus, the depletion diets did not affect these values at 140 kg BW. These results illustrate the rapid homeostatic counter-regulation capacity of dietary Ca and P, and they show the high potential to limit dietary digestible P concentration by completely excluding the use of mineral phosphates during the depletion phase, representative of the fattening period, without causing any detrimental effects to gilts at mating. The gilts were able to recover their BMC deficit between their selection at 95 kg BW and first mating at 140 kg BW by increasing their dietary Ca and P efficiency. Finally, excess dietary digestible P, requiring increased amounts of mineral phosphates, further increased the gilts’ BMC.

63 Effects of Dietary Calcium and Phosphorus Deficiency on Growth Performance and Subsequent Recovery of Bone Mineralization in Replacement Gilts

Abstract This study was performed to test the hypothesis that after a depletion period that renders replacement gilts more efficient in their use of calcium (Ca) and phosphorus (P), they can recover bone mineralization when fed a repletion diet. To this end, 24 gilts were fed according to a 2-phase feeding program (60–95 kg BW and 95–140 kg BW, respectively), corresponding to the period of depletion and repletion in Ca and P, respectively. The experimental diets for the first phase were a finisher control diet (D100; 2.1 g digestible P/kg) providing 100% of estimated Ca and P requirements or a finisher low-P diet (D60; 1.2 g digestible P/kg) providing 60% of estimated Ca and P requirements. In the second phase, one-half of the gilts from each finisher diet were randomly assigned to either a control (R100) diet or a high-P diet (R160; 3.5 g digestible P/kg) according to a 2 × 2 factorial design, resulting in 4 treatments: D60R100, D60R160, D100R100 and D100R160. Whole-body bone mineral content (BMC) and body composition of pigs were measured on each gilt at 2-week intervals by dual energy X-ray absorptiometry. Diets did not influence the growth performance throughout the experiment. At 95 kg, gilts fed D60 had reduced BMC and BMD (-9% vs D100; P &amp;lt; 0.001). At 140 kg, no significant effect of depletion diets was observed on BMC. These results show the high potential to limit dietary digestible P concentration during the growing period without causing any detrimental effects to gilts at mating, and they confirm the ability of replacement gilts to recover their BMC at 140 kg BW by increasing BMC deposition and their dietary Ca and P efficiency. Finally, high-digestible P content from 95-140 kg BW allowed gilts to increase BMC further, but required the use of dietary phosphates.

Lactobacillus casei CRL431 modulates hemostatic activation induced by protein malnourishment and pneumococcal respiratory infection.

Previously, we demonstrated that Lactobacillus casei CRL431, a well-known immunomodulatory bacterium, beneficially regulates coagulation activation, fibrin formation in lung, and the pro-inflammatory state induced by protein malnourishment and pneumococcal infection. In this study, we deepen in the understanding of the mechanisms involved in the immunoregulatory activity of L. casei CRL431 during a nutritional repletion process by evaluating (a) platelet and endothelial activation, (b) tissue factor (TF) expression, and (c) protease-activated receptor (PAR) activation in an experimental bacterial respiratory infection model in malnourished mice. Our findings demonstrate for the first time that the repletion diet supplemented with L. casei CRL431 was effective to normalize platelet counts in blood, modulate platelet activation and their recruitment into the lung, and regulate local and systemic TF expression and endothelial activation, which were affected by malnourishment. Streptococcus pneumoniae challenge induced local and systemic increase of platelet counts, PARs activation, P-selectin and TF expression, as well as endothelial activation in both well-nourished and malnourished mice. Malnourished animals evidenced the highest alterations of the parameters evaluated while the mice fed with the probiotic bacterium had similar behavior to normal controls but with lower PAR activation in lung. These results demonstrate that supplementation of repletion diet with L. casei CRL431 is effective to modulate alterations induced by malnourishment and pneumococcal infection, restraining coagulation activation, the inflammatory process, and lung damage. These observations contribute to set the basis for the application of probiotic functional foods to modulate the inflammation-hemostasis interactions altered by malnourishment or bacterial respiratory infections. KEY POINTS: • Pneumococcal infection increases pro-coagulant state induced by protein malnourishment. • Repletion with L. casei CRL431 modulates platelet, TF, and endothelial activation. • L. casei CRL431 improves immune-coagulative response in protein malnourishment.

Edible Insects but Not Solanum Torvum Improved Body Composition and Iron Status in Protein and Iron Deficient Rats (P24-007-19)

ObjectivesNutritious underutilized foods (NUFs) such as Solanum torvum (STO) and edible insects are potential sustainable dietary approaches to prevent malnutrition and improve food security. However, little is known about nutrient bioavailability from NUFs. This study determined the effect of STO and insect powders on improving nutritional status of malnourished rats. MethodsMalnutrition was induced in weanling male Sprague-Dawley rats by feeding 5% protein with low Fe (LPI) diet for 21 days. During 14-day repletion, 5 groups of rats (n = 8) were fed the LPI diet supplemented with cricket, palm weevil larvae, STO, cricket + STO and casein + ferrous sulfate (HPI, positive control) while another group remained on the LPI diet (negative control). Repletion diets contained 15% protein and 20 ppm Fe, but palm larvae diet contained only 10 ppm Fe. Body composition was measured by dual X-ray absorptiometry. Hemoglobin (Hb) repletion method was used to compare relative bioavailability (RBV) of the HPI group to the other groups. ResultsCollectively, there were no differences in improved growth rate and body composition measures in groups repleted with edible insects and HPI (P = 0.08). Growth rate was 7.9 times higher in HPI compared to STO and 4.2 times higher in HPI compared to LPI (P < 0.0001). Changes in body composition were similar in STO and LPI but significantly different from HPI. Increase in Hb Fe with cricket (2.00 ± 0.90 mg) and palm weevil larvae (1.17 ± 0.75 mg) was comparable to HPI (1.94 ± 0.74 mg) (P = 0.27). Compared to HPI, there were significant differences in Hb Fe with STO (−0.08 ± 0.37 mg) and LPI (0.55 ± 0.18 mg). When RBV was calculated based on Hb Fe and food intake, RBV was 1.3 for palm weevil larvae but this was not significantly different from HPI (RBV = 1.00) and cricket (RBV = 0.99) (P = 0.83). RBV was similar in STO and LPI, and 100 times lower compared to HPI (P < 0.0001). ConclusionsThough other benefits of STO may be plausible, no nutritional benefits were found in this study, but cricket and palm weevil larvae could be excellent alternative sources of protein and bioavailable Fe and can be sustainable, cheap and locally available foods to prevent malnutrition in humans in countries where they are culturally accepted. Funding SourcesDoris A. Adams endowment funds from the College of Human Sciences at Iowa State University, Ames.

Plasma Response to Deuterium-Labeled Vitamin K Intake Varies by TG Response, but Not Age or Vitamin K Status, in Older and Younger Adults

Phylloquinone is the primary form of vitamin K in the diet and circulation. Large intra- and interindividual variances in circulating phylloquinone have been partially attributed to age. However, little is known about the nondietary factors that influence phylloquinone absorption and metabolism. Similarly, it is not known if phylloquinone absorption is altered by the individual's existing vitamin K status. The purpose of this secondary substudy was to compare plasma response with deuterium-labeled phylloquinone intake in older and younger adults after dietary phylloquinone depletion and repletion. Forty-two older [mean±SD age: 67.2±8.0 y; body mass index (BMI; in kg/m2): 25.4±4.6; n=12 men, 9 women] and younger (mean±SEM age: 31.8±6.6 y; BMI: 25.5±3.3; n=9 men, 12 women) adults were maintained on sequential 28-d phylloquinone depletion (∼10 µg phylloquinone/d) and 28-d phylloquinone repletion (∼500 µg phylloquinone/d) diets. On the 23rd d of each diet phase, participants consumed deuterated phylloquinone-rich collard greens (2H-phylloquinone). Plasma and urinary outcome measures over 72 h were compared by age group, sex, and dietary phase via 2-factor repeated-measures ANOVA. The plasma 2H-phylloquinone area under the curve (AUC) did not differ in response to phylloquinone depletion or repletion, but was 34% higher in older than in younger adults (P=0.02). However, plasma 2H-phylloquinone AUC was highly correlated with the serum triglyceride (TG) AUC (r2=0.45). After adjustment for serum TG response, the age effect on the plasma 2H-phylloquinone AUC was no longer significant. Plasma 2H-phylloquinone response did not differ between phylloquinone depletion and repletion in older and younger adults. The age effect observed was explained by the serum TG response and was completely attenuated after adjustment. Plasma response to phylloquinone intake, therefore, seems to be a predominantly lipid-driven effect and not dependent on existing vitamin K status. More research is required to differentiate the effect of endogenous compared with exogenous lipids on phylloquinone absorption. This trial was registered at clinicaltrials.gov as NCT00336232.

Absorption and Excretion of Vitamin K Varies by Age and Triglycerides: A Metabolic Study in Older and Younger Adults Using Deuterium‐Labeled Collard Greens

Vitamin K is an essential fat‐soluble nutrient, with its most established role as a cofactor in coagulation. Emerging roles in soft tissue calcification have been proposed. However, further progress in understanding absorption and metabolism is needed, including knowledge of the factors influencing the physiologic response to vitamin K. Phylloquinone (PK) is the primary form of vitamin K in the diet and circulation. Large intra‐individual variances in circulating PK exist, and little is known about the dietary and non‐dietary factors that influence PK metabolism.The purpose of this study was to compare absorption efficiency and body retention of PK in older and younger adults following dietary vitamin K depletion and repletion.Forty‐two older (55–80 y; n=21) and younger (18–40 y; n=21) adults were maintained on sequential 28‐day vitamin K depletion (~10 ug PK/day) and vitamin K repletion (~500 ug PK/day) diets. At the end of each phase, subjects were fed deuterated collard greens (2H‐PK) and monitored over 72 hours. Liquid chromatography‐mass spectrometry (LC‐MS) was used to measure labeled and unlabeled PK in plasma and triglyceride‐rich lipoprotein (TRL) fractions, and labeled and unlabeled menadione (a PK metabolite) from 24‐hr urine collections.Absorption efficiency of 2H‐PK did not differ between PK depletion and repletion, but was significantly higher in older adults than in younger adults (p=0.02). 2H‐PK in TRL fractions was correlated with the total 2H‐PK in plasma (r=0.95, p&lt;&lt;0.001), corroborating previous data that PK is primarily transported in circulation associated with triglycerides. Age (p=0.015) and plasma triglycerides (p&lt;0.001) were significant linear predictors of 2H‐PK area under the curve (AUC). Both age and plasma triglycerides retained significance in the multivariate model, and together explained 31.6% of the variance in absorbed plasma 2H‐PK during the depletion period, and 29.9% in the repletion period. Analysis of urinary 2H‐menadione showed no differences in body retention of vitamin K by age, sex, or depletion or repletion.In conclusion, age and circulating triglycerides are determinants of vitamin K absorption efficiency and together explained about 30% of the variance observed in absorbed PK. Body retention of vitamin K did not vary by age, sex, or dietary intake. There is a need to elucidate non‐traditional factors, such as genetics, that may influence absorption and metabolism of vitamin K.Support or Funding InformationStudy supported by the USDA ARS under Cooperative Agreement 58‐1950‐7‐707 and the NIH (5R01DK69341‐4).

Evaluation of iron bioavailability in a mixture of cereals, seeds, and grains ("Human Ration")

Iron bioavailability was evaluated in three mixtures of cereals, seeds, and grains (Human Ration): light, regular, and homemade provided to rats. The animals received an iron depletion diet for 21 days, followed by a repletion diet containing 12 mg·kg-1 of iron for 14 days. The hemoglobin regeneration efficiency and the relative biological value did not differ between the light mixture and control group. The iron bioavailability of the light mixture of cereals, seeds, and grains and the control group were 99.99±27.62 and 80.02±36.63, respectively, while the regular and homemade mixtures of cereals, seeds, and grains showed lower iron bioavailability, 50.12±35.53 and 66.66±15.44, respectively; the iron content of the diet with light cereal mixture light was statistically similar to that of the control (ferrous sulfate 99.99±27.62). The high content of tannin (202.81±19.53 mg·100-1) in the diet with the regular cereal mixture may have contributed to its low iron bioavailability. The higher intake of soluble fiber by the animals fed the light mixture (21.15±0.92 g) was moderately correlated (r=0.5712, p=0.0018) with the concentration of propionate in the caecal bulk (65.49±11.08 µmol/g). The short chain fatty acids produced by soluble fiber fermentation, associated with the low-content of tannin may have improved iron solubility and absorption in the light cereal mixture diet. The iron bioavailability in the light mixture of cereals, seeds, and grains was similar to that of ferrous sulfate.

A multielement trace mineral injection improves liver copper and selenium concentrations and manganese superoxide dismutase activity in beef steers1

Trace minerals (TM) are vital to health and growth of livestock, but low dietary concentrations and dietary antagonists may reduce mineral status and feeder cattle TM status is usually unknown at arrival. The objective of this study was to examine the effect of TM status on response to mineral injection in beef cattle. Forty steers were equally assigned to diets for an 84-d depletion period: control (CON; supplemental Cu, Mn, Se, and Zn) or deficient (DEF; no supplemental Cu, Mn, Se, or Zn plus Fe and Mo as TM antagonists). Lesser liver Cu and Se concentrations (79.0 ± 11.60 and 1.66 ± 0.080 mg/kg DM, respectively) in DEF steers compared with CON steers (228.8 ± 11.60 and 2.41 ± 0.080 mg/kg DM, respectively) on d 71 of depletion indicated mild deficiencies of these TM (P < 0.001). On d 1 of the 85-d repletion period, 10 steers within each dietary treatment were injected with sterilized saline (SAL) or Multimin90 (MM), containing 15, 10, 5, and 60 mg/mL of Cu, Mn, Se, and Zn, respectively, at a dose of 1 mL/68 kg BW. All steers were fed the same repletion diet supplemented with Cu, Mn, Se, and Zn to meet or exceed NRC recommendations. Blood was collected on d 0 and 1, and blood and liver biopsies were collected on d 8, 15, 29, 57, and 85 postinjection. Red blood cell lysate manganese-superoxide dismutase activity was greater in MM (P = 0.02), suggesting incorporation of injectable TM into a biological process. The increase in liver Se in response to MM was greater in CON vs. DEF (P = 0.02), suggesting TM from injection were used rather than stored in DEF steers. Liver Se and Cu (P < 0.05) were elevated through at least d 30 by MM. Dietary TM deficiency decreased neutrophil bacteria killing ability and increased myeloperoxidase (MPO) degranulation (P < 0.04) as measured on d 0, 1, 13, and 14 during the repletion period while injection had no impact. Within CON animals, total MPO was greater in animals that received TM injection, but injection did not affect MPO within DEF steers (P = 0.007). Overall, TM from an injectable mineral were used differently between TM adequate and mildly deficient steers.

Urinary Elimination and Metabolism of Nitrosamines in Different Dietary Protein Wistar Rat Models

It is necessary to establish comparatively whether or not there are differences in the mode of elimination of Nitrosodimethylamine (NDMA) and /or Aflatoxin B1 (AFB1) in urine as between different nutritional states of dietary protein. Four groups of albino wistar rats were fed protein free, normal protein repletion, low protein and high protein diets. NDMA was excreted in urine of rats placed on protein free diet at higher quantity (27.19%) than protein repleted rats (19.35%) and in low protein fed rats at a lower amount (22.82%) than in high protein fed rats (32.68%,) after NDMA was given. There was a lower urinary excretion of NDMA in protein free fed rats (22.18%) than in their protein repleted counterparts (33.77%) and low protein fed rats excreted more NDMA (27.14%) than those placed on high protein (11.79%), after a concurrent dose of NDMA and AFB1. It appears the elimination of NDMA is enhanced by protein free intake compared with normal protein repletion intake while it was reduced by low protein intake as compared to high protein intake. AFB1 increased the elimination of NDMA in normal protein repletion and low protein intakes whereas decreased NDMA elimination was observed for protein free and high protein intakes.

Inflammation–hemostasis relationship in infected malnourished mice: modulatory effect of Lactobacillus casei CRL 431

The coagulation system is considered part of the defense machinery, but its excessive activation can lead to additional damage. We studied the effects of oral administration of Lactobacillus casei CRL 431--a probiotic bacterium--on the activation of coagulation and the relationship with inflammatory parameters during a respiratory infection in malnourished mice. Malnourished Swiss albino mice were nourished with a balanced commercial diet (BCD) for 7 days or BCD with L. casei for the last 2 days (BCD + Lc). BCD, BCD + Lc, malnourished (MNC) and well-nourished controls (WNC) were infected with Streptococcus pneumoniae. Blood and bronchoalveolar lavage samples were obtained at different times post-infection. Malnutrition altered most of the evaluated parameters before and after infection. The repletion diet with supplemental L. casei was the most effective in limiting coagulation activation and normalizing coagulation inhibition mechanisms. These findings will help develop further strategies to reduce the damaging effects of clotting and enhance its beneficial contribution to immune reactions.

Dermal Carotenoids as Measured by Resonance Raman Spectroscopy as a Biomarker of Response to a Fruit/Vegetable Intervention Study

Dermal carotenoid status may have utility as a biomarker for vegetable and fruit consumption. Resonance Raman spectroscopy (RRS) is a valid, non‐invasive method to assess dermal carotenoids as a biomarker of usual vegetable and fruit intake, but has not been evaluated in response to a whole‐diet intervention. Thirteen outpatient subjects who reported a mean intake of 16 mg total carotenoids/day followed a depletion diet (0.76 mg/d) for 6 weeks, and then consumed a controlled repletion diet based upon the Dietary Guidelines for Americans that contained an average of 62 mg carotenoid/d for 8 weeks. RRS measures of the palm were taken at least 2x week during depletion and 5x week during the repletion phase. To model depletion and repletion, the Glimmix procedure in SAS was used and included a linear term for the depletion phase, linear and quadratic terms for the repletion phase, and subject as a random effect. Subjects’ RRS scores decreased by 35 ±12.5% (p&lt;0.001) during depletion and increased by 380 ±180.0% (p&lt;0.001) during repletion. Depletion and repletion slopes did not differ between subjects (p&gt;0.55), despite there being a broad range of baseline values (49% CV). No subject achieved a maximal value during the 8‐week repletion period. RRS is a non‐invasive method that shows great promise as an objective biomarker of response to changes in consumption of carotenoid‐rich foods by individuals.

Immunomodulatory and protective effect of probiotic Lactobacillus casei against Candida albicans infection in malnourished mice

The effect of Lactobacillus casei CRL 431 (Lc), when administered as a supplement to a repletion diet, on the resistance of malnourished mice to Candida albicans infection was studied. Weaned mice were malnourished by being given a protein-free diet (PFD) for 21 days. The malnourished mice were then fed a balanced conventional diet (BCD) for 7 days or BCD for 7 days with supplemental Lc on days 6 and 7 (BCD+Lc). Malnourished (MNC) and well-nourished (WNC) mice were used as controls. At the end of the treatments the mice were infected intraperitoneally with C. albicans. Animals that had received probiotics had improved survival and resistance against this infection compared to those in the BCD and MNC groups. The number and fungicidal activity of phagocytes, and the concentrations of tumor necrosis factor-α, interferon-γ and interleukin-6 (IL-6), increased in blood and infected tissues in all experimental groups, but MNC mice showed lower concentrations than those in the WNC group. BCD and BCD+Lc mice showed higher concentrations of these variables than those in the MNC group, but only the BCD+Lc group presented values similar to the WNC mice. Malnutrition also impaired the production of IL-17 and IL-10 in response to infection. Both repletion treatments normalized IL-17 concentrations, but IL-10 in the BCD+Lc group was significantly higher than in WNC mice. The addition of L. casei to the repletion diet normalized the immune response against C. albicans, allowing efficient recruitment and activation of phagocytes, as well as effective release of pro-inflammatory cytokines. In addition, probiotic treatment induced an increase in IL-10 concentrations, which would have helped to prevent damage caused by the inflammatory response.

Conjugated Linoleic Acid Reduces Hepatic Steatosis and Restores Liver Triacylglycerol Secretion and the Fatty Acid Profile During Protein Repletion in Rats

Protein depletion is associated with hepatic steatosis and decreased circulating triacylglycerol (TAG). Since conjugated linoleic acid (CLA) increases lean body mass, protects against muscle catabolism, and modulates lipid metabolism, the aim of this work was to investigate the effects of CLA with two different amounts of dietary fat on the regulation of plasma and hepatic TAG concentration, and its possible connections with changes in fatty acid (FA) profile in plasma, liver and adipose tissue and hepatic oxidative status during protein repletion. Rats were fed a low protein diet (14days) and then a protein repletion diet (30days), supplemented or not with CLA, containing 7% (w/w) or 20% (w/w) of fat. Hepatic TAG secretion and removal by muscle and adipose tissue lipoprotein lipase, FA profile and liver oxidative status were evaluated. Protein depletion affected hepatic TAG secretion and peripheral removal, decreasing plasma and increasing liver TAG concentration, whereas protein repletion with CLA improved these abnormalities independently of the amount of dietary fat by increasing hepatic TAG secretion. This prevention in the absence of CLA was not observed. CLA was incorporated in plasma and tissues (adipose>liver>plasma, and c9,t11-CLA>t10,c12-CLA), accompanied by alterations in FA composition, mainly in adipose tissue. The hepatic oxidative stress was overcome by protein repletion. CLA had a beneficial impact on TAG metabolism in protein repleted animals, preventing hepatic steatosis through higher hepatic TAG secretion.

Single nucleotide polymorphisms in the phosphatidylethanolamine N‐methyltransferase gene may influence choline requirement

Humans derive the choline they require from their diet and from de novo biosynthesis catalyzed by the enzyme phosphatidylethanolamine N‐methyltransferase (PEMT). In previous studies, we found that pre‐menopausal women were resistant to developing organ dysfunction when consuming a low choline diet as compared to post‐menopausal women and men. Also, we showed that the gene PEMT is estrogen responsive, allowing pre‐menopausal women to form more of their required choline via PEMT. However, some pre‐menopausal women (44%) did develop choline deficiency and we found that they had a haplotype containing an allele for a single nucleotide polymorphism (SNP) in PEMT (rs12325817). To determine whether this effect of the SNP increased with the number of mutant alleles, we recruited 27 pre‐menopausal women with 0, 1 or 2 of the alleles. They were fed a baseline diet containing 550 mg choline/day for 10 days, followed by a choline deficient diet for up to 42 days, and a repletion diet with 850 mg choline for 10 days. Subjects were deemed clinically choline deficient if they developed hepatic steatosis or muscle dysfunction on the low choline diet and if the organ dysfunction disappeared when choline was returned to the diet. We found that 80% of the subjects who were homozygous for the SNP became choline deficient compared to 43% with 1 variant allele, and 13% without the SNP (p=0.02). We conclude that the risk of a pre‐menopausal woman becoming choline deficient is proportional to the allele dose for the SNP rs12325817.This research is supported by grants from NIH‐ DK55865, DK56350 and RR00046.

Effect of reduced dietary calcium concentration and phytase supplementation on calcium and phosphorus utilization in weanling pigs with modified mineral status1

The present study was conducted to assess the effect of 2 dietary Ca concentrations on P and Ca digestive and metabolic utilization in weanling pigs fed diets providing practical concentrations of P, with or without phytase. The responses of pigs fed diets adequate or moderately deficient in Ca and P postweaning were compared. A total of 60 pigs weaned at 28 d of age were used. Two groups of 30 pigs with differing mineral status resulted from a 10-d depletion period, during which the animals received depletion diets (DD) that consisted of corn-soybean meal with either 1.42% Ca and 0.80% P (DD+) or 0.67% Ca and 0.43% P (DD-), designed to achieve the same Ca:digestible P ratio. At the end of the depletion period, a plasma sample was taken from each pig and 12 pigs (6 from each group) were slaughtered for bone assessment to establish the baseline mineral status. The animals fed the DD- diet had signs of P deficiency with reduced plasma P (13%; P < 0.01) and femur ash concentration (8%; P < 0.05), and increased plasma Ca (9%; P < 0.05) and alkaline phosphatase activity (31%; P < 0.01). For the subsequent 25-d period, the remaining 24 pigs from each group were fed 1 of 4 repletion diets: 1) 0.56% P, 1.06% Ca; 2) 0.56% P, 0.67% Ca; 3) diet 1 + 1,000 phytase units (FTU) of Natuphos phytase/kg; and 4) diet 2 + 1,000 FTU of Natuphos phytase/kg. Total feces and urine were collected from d 5 to 11, and a blood sample was taken from each pig at d 11 and 25. The initial moderate P deficiency (DD-) stimulated Ca absorption (5%; P < 0.01), irrespective of the repletion diet, and stimulated P absorption (5%; DD x phytase, P < 0.05), only when the diets contained phytase. At the end of the repletion period, because of these compensatory phenomena, the depleted pigs achieved full recovery of femur DM and ash weight when they received phytase, whereas ash concentration tended to remain reduced by 3% (P = 0.08). Phosphorus digestibility was improved in the diets supplemented with phytase (73.0 vs. 56.0%; P < 0.001), whereas an increase in dietary Ca decreased P digestibility (65.6 vs. 63.4%; P < 0.05). Those 2 effects were independent, indicating that dietary Ca reduced equally P digestibility with and without phytase and did not influence the efficiency of phytase in releasing P in the digestive tract. In pigs fed diets with phytase, however, the reduction of Ca (Ca:P from 1.9 to 1.3) increased urinary P losses 5-fold. Those extra losses were due to a lack of Ca for skeleton ash deposition, resulting in a 4% reduction in femur ash concentration. In the end, reducing the dietary Ca:P from 1.9 to 1.3 in a practical diet containing 0.56% P did not improve the efficiency of phytase in releasing P. Moreover, the reduction in dietary Ca (Ca:P) caused an imbalance between Ca and P that impaired bone mineralization.

Effects of short-term mild calorie restriction diet and renutrition with ruminant milks on leptin levels and other metabolic parameters in mice

Objective The adaptation of an organism to a calorie-restricted diet is characterized by metabolic, endocrine, and immunologic changes. The objective of this study was to determine, in a mouse model, the changes in serum leptin levels in response to short-term mild calorie-restricted and renutrition diets using different ruminant milks. Methods Weaned Swiss albino mice were fed with a mild calorie-restricted diet for 12 d, after which they were renourished with cow, goat, sheep, or buffalo milk for 7 d. Body, thymus, and spleen weights and biochemical, hematologic, and endocrine parameters were evaluated. Results The mild calorie restriction did not significantly modify insulin and leptin levels. The renutrition diets increased insulin levels, being significant ( P < 0.05) only when buffalo and sheep milks were used. Leptin concentrations increased in the control ad libitum (AD) group during the assayed period. After the administration of cow and goat milks, lower leptin levels were observed compared with the control AD group. All repletion diets significantly increased body, thymus, and spleen weights; however, spleen weight did not reach the values observed in the control AD group. Serum glucose and triacylglycerol levels increased after feeding with the renutrition diets. However, serum cholesterol did not increase after the renutrition period. We observed a significant decrease ( P < 0.05) in the leukocyte counts in calorie-restricted mice in comparison with AD mice; after the renutrition period, the leukocyte count did not reach the values for the AD mice. Conclusion This study suggests that a short-term change in diet with a relatively low body weight loss does not significantly affect leptin concentrations in our mouse model. However, the assayed milks could be effectively used as alternative milk sources for weight gain and for the improvement of other metabolic parameters.