Beltsville Human Nutrition Research Center

1. The effect of ammonia concentration on microbial protein production was determined in continuous-culture fermentors charged with ruminal contents obtained from steers fed on either a protein-free purified diet, a maize-based all-concentrate diet, or a forage–concentrate (23:77) diet. Urea was infused into the fermentors to maintain various concentrations of ammonia in the incubating mixtures. 2. Under nitrogen-limiting conditions, microbial protein yield measured as tungstic acid-precipitable N (TAPN) increased linearly with supplementary urea until ammonia started to accumulate in the incubating ingesta. Increasing the ammonia concentration beyond 50 mg NH 3 -N/l had no effect on microbial protein production. 3. The molar proportions of volatile acids produced were not affected by the level of urea supplementation. Total acid production was decreased slightly under N-limiting conditions, but not to the same extent as microbial protein production. 4. Estimated yield of microbial dry matter/mol ATP produced averaged 15·6 when non-limiting N as urea was provided with the purified diet. 5. These results suggest that addition of non-protein N supplements to ruminant rations are warranted only if the prevailing concentration of ruminal ammonia is less than 50 mg NH 3 -N/l ruminal fluid.

Both lipophilic and hydrophilic antioxidant capacities were determined using the oxygen radical absorbance capacity (ORAC(FL)) assay with fluorescein as the fluorescent probe and 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator on over 100 different kinds of foods, including fruits, vegetables, nuts, dried fruits, spices, cereals, infant, and other foods. Most of the foods were collected from four different regions and during two different seasons in U.S. markets. Total phenolics of each sample were also measured using the Folin-Ciocalteu reagent. Hydrophilic ORAC(FL) values (H-ORAC(FL)) ranged from 0.87 to 2641 micromol of Trolox equivalents (TE)/g among all of the foods, whereas lipophilic ORAC(FL) values (L-ORAC(FL)) ranged from 0.07 to 1611 micromol of TE/g. Generally, L-ORAC(FL) values were <10% of the H-ORAC(FL) values except for a very few samples. Total antioxidant capacity was calculated by combining L-ORAC(FL) and H-ORAC(FL). Differences of ORAC(FL) values in fruits and vegetables from different seasons and regions were relatively large for some foods but could not be analyzed in detail because of the sampling scheme. Two different processing methods, cooking and peeling, were used on selected foods to evaluate the impact of processing on ORAC(FL). The data demonstrated that processing can have significant effects on ORAC(FL). Considering all of the foods analyzed, the relationship between TP and H-ORAC(FL) showed a very weak correlation. Total hydrophilic and lipophilic antioxidant capacity intakes were calculated to be 5558 and 166 micromol of TE/day, respectively, on the basis of data from the USDA Continuing Survey of Food Intakes by Individuals (1994-1996).

For 10,000 years pigs and humans have shared a close and complex relationship. From domestication to modern breeding practices, humans have shaped the genomes of domestic pigs. Here we present the assembly and analysis of the genome sequence of a female domestic Duroc pig (Sus scrofa) and a comparison with the genomes of wild and domestic pigs from Europe and Asia. Wild pigs emerged in South East Asia and subsequently spread across Eurasia. Our results reveal a deep phylogenetic split between European and Asian wild boars ∼1 million years ago, and a selective sweep analysis indicates selection on genes involved in RNA processing and regulation. Genes associated with immune response and olfaction exhibit fast evolution. Pigs have the largest repertoire of functional olfactory receptor genes, reflecting the importance of smell in this scavenging animal. The pig genome sequence provides an important resource for further improvements of this important livestock species, and our identification of many putative disease-causing variants extends the potential of the pig as a biomedical model. This study presents the assembly and analysis of the genome sequence of a female domestic Duroc pig and a comparison with the genomes of wild and domestic pigs from Europe and Asia; the results shed light on the evolutionary relationship between European and Asian wild boars. The domestic pig (Sus scrofa) is an important livestock species, its genome shaped by thousands of years of domestication and, latterly, sophisticated breeding practices. A high-quality draft genome sequence for a female domestic Duroc pig is published in this issue of Nature, under the auspices of the Swine Genome Sequencing Consortium. Comparisons of the genomes of wild and domestic pigs shed light on the evolutionary relationship between European and Asian wild boars, and reveal the rapid evolution of genes involved in the immune response and in olfaction. The authors identify many possible disease-causing gene variants, increasing the potential of the pig as a biomedical model, and present a detailed analysis of endogenous porcine retroviruses, knowledge of which is important for the possible use of pigs in xenotransplantation.

Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes. Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function. For example, Tribolium has retained more ancestral genes involved in cell–cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development. Systemic RNA interference in T. castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control. The red flour beetle Tribolium castaneum is a common pest: a type of 'bran bug', it targets cereal products, including grain, flour and rice bran. It is also a commonly used laboratory model, combining the ease of systematic RNA interference experiments such as those used with the nematode worm C. elegans with a biology that is more representative of most insects than even Drosophila. This weeks sees the publication by the Tribolium Genome Sequencing Consortium of the genomic sequence of T. castaneum. This is the first beetle genome to be published, and it will be a valuable resource for insect development studies and pest biology. The beetle Tribolium castaneum is a commonly used laboratory model, combining the ease of systematic RNAi experiments like those in Caenorhabditis elegans, with biology that is more representative of most insects than Drosophila melanogaster. A large consortium has sequenced and analysed the genome of the red flour beetle, creating a resource for biologists everywhere.

Phenolic acids are aromatic secondary plant metabolites, widely spread throughout the plant kingdom. Existing analytical methods for phenolic acids originated from interest in their biological roles as secondary metabolites and from their roles in food quality and their organoleptic properties. Recent interest in phenolic acids stems from their potential protective role, through ingestion of fruits and vegetables, against oxidative damage diseases (coronary heart disease, stroke, and cancers). High performance liquid chromatography (HPLC) as well as gas chromatography (GC) are the two separation techniques reviewed. Extraction from plant matrixes and cleavage reactions through hydrolysis (acidic, basic, and enzymatic) are discussed as are the derivatization reagents used in sample preparation for GC. Detection systems discussed include UV-Vis spectroscopy, mass spectrometry, electrochemical, and fluorometric detection. The most common tandem techniques are HPLC/UV and GC/MS, yet LC/MS is becoming more common. The masses and MS fragmentation patterns of phenolic acids are discussed and tabulated as are the UV absorption maxima.

Anthocyanins (ACNs) are water-soluble plant pigments that have important functions in plant physiology as well as possible health effects. Over 100 common foods were screened for ACNs, and 24 of them were found to contain ACNs. Concentrations of total ACNs varied considerably from 0.7 to 1480 mg/100 g of fresh weight in gooseberry ('Careless' variety) and chokeberry, respectively. Not only does the concentration vary, but the specific anthocyanins present in foods are also quite different. Only six common aglycones, delphinidin, cyanidin, petunidin, pelargonidin, peonidin, and malvidin, were found in all of these foods. However, their sugar moieties and acylation patterns varied from food to food. Results from this study will add to the available data for the USDA Nutrient Database of flavonoids. On the basis of the concentration data and updated food intake data from NHANES 2001-2002, the daily intake of ACNs is estimated to be 12.5 mg/day/person in the United States. Of the different aglycones, cyanidin, delphinidin, and malvidin were estimated to contribute 45, 21, and 15%, respectively, of the total ACN intake. Nonacylated contributed 77% compared to 23% from acylated ACNs.

Social insects are able to mount both group-level and individual defences against pathogens. Here we focus on individual defences, by presenting a genome-wide analysis of immunity in a social insect, the honey bee Apis mellifera. We present honey bee models for each of four signalling pathways associated with immunity, identifying plausible orthologues for nearly all predicted pathway members. When compared to the sequenced Drosophila and Anopheles genomes, honey bees possess roughly one-third as many genes in 17 gene families implicated in insect immunity. We suggest that an implied reduction in immune flexibility in bees reflects either the strength of social barriers to disease, or a tendency for bees to be attacked by a limited set of highly coevolved pathogens.

OBJECTIVE: The objective of this study was to determine whether cinnamon improves blood glucose, triglyceride, total cholesterol, HDL cholesterol, and LDL cholesterol levels in people with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 60 people with type 2 diabetes, 30 men and 30 women aged 52.2 +/- 6.32 years, were divided randomly into six groups. Groups 1, 2, and 3 consumed 1, 3, or 6 g of cinnamon daily, respectively, and groups 4, 5, and 6 were given placebo capsules corresponding to the number of capsules consumed for the three levels of cinnamon. The cinnamon was consumed for 40 days followed by a 20-day washout period. RESULTS: After 40 days, all three levels of cinnamon reduced the mean fasting serum glucose (18-29%), triglyceride (23-30%), LDL cholesterol (7-27%), and total cholesterol (12-26%) levels; no significant changes were noted in the placebo groups. Changes in HDL cholesterol were not significant. CONCLUSIONS: The results of this study demonstrate that intake of 1, 3, or 6 g of cinnamon per day reduces serum glucose, triglyceride, LDL cholesterol, and total cholesterol in people with type 2 diabetes and suggest that the inclusion of cinnamon in the diet of people with type 2 diabetes will reduce risk factors associated with diabetes and cardiovascular diseases.

Essential trace elements are required by man in amounts ranging from 50 micrograms to 18 milligrams per day. Acting as catalytic or structural components of larger molecules, they have specific functions and are indispensable for life. Research during the past quarter of a century has identified as essential six trace elements whose functions were previously unknown. In addition to the long-known deficiencies of iron and iodine, signs of deficiency for chromium, copper, zinc, and selenium have been identified in free-living populations. Four trace elements were proved to be essential for two or more animal species during the past decade alone. Marginal or severe trace element imbalances can be considered risk factors for several diseases of public health importance, but proof of cause and effect relationships will depend on a more complete understanding of basic mechanisms of action and on better analytical procedures and functional tests to determine marginal trace element status in man.

Turmeric is a curry spice that originated from India, which has attracted great interest in recent decades because it contains bioactive curcuminoids (curcumin, demethoxycurcumin, and bisdemethoxycurcumin). Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione), a lipophilic polyphenol may work as an anticancer, antibiotic, anti-inflammatory, and anti-aging agent as suggested by several in vitro, in vivo studies and clinical trials. However, poor aqueous solubility, bioavailability, and pharmacokinetic profiles limit curcumin's therapeutic usage. To address these issues, several curcumin formulations have been developed. However, suboptimal sample preparation and analysis methodologies often hamper the accurate evaluation of bioactivities and their clinical efficacy. This review summarizes recent research on biological, pharmaceutical, and analytical aspects of the curcumin. Various formulation techniques and corresponding clinical trials and in vivo outcomes are discussed. A detailed comparison of different sample preparation (ultrasonic, pressurized liquid extraction, microwave, reflux) and analytical (FT-IR, FT-NIR, FT-Raman, UV, NMR, HPTLC, HPLC, and LC-MS/MS) methodologies used for the extraction and quantification of curcuminoids in different matrices, is presented. Application of optimal sample preparation, chromatographic separation, and detection methodologies will significantly improve the assessment of different formulations and biological activities of curcuminoids.

Background: Crohn’s disease is common in highly industrialised Western countries where helminths are rare and uncommon in less developed areas of the world where most people carry worms. Helminths diminish immune responsiveness in naturally colonised humans and reduce inflammation in experimental colitis. Thus exposure to helminths may help prevent or even ameliorate Crohn’s disease. Aims: The aim of the study was to determine the safety and possible efficacy of the intestinal helminth Trichuris suis in the treatment of patients with active Crohn’s disease. Patients: Twenty nine patients with active Crohn’s disease, defined by a Crohn’s disease activity index (CDAI) ⩾220 were enrolled in this open label study. Methods: All patients ingested 2500 live T suis ova every three weeks for 24 weeks, and disease activity was monitored by CDAI. Remission was defined as a decrease in CDAI to less than 150 while a response was defined as a decrease in CDAI of greater than 100. Results: At week 24, 23 patients (79.3%) responded (decrease in CDAI &gt;100 points or CDAI &lt;150) and 21/29 (72.4%) remitted (CDAI &lt;150). Mean CDAI of responders decreased 177.1 points below baseline. Analysis at week 12 yielded similar results. There were no adverse events. Conclusions: This new therapy may offer a unique, safe, and efficacious alternative for Crohn’s disease management. These findings also support the premise that natural exposure to helminths such as T suis affords protection from immunological diseases like Crohn’s disease.

Rice, a staple food for more than half of the world's population, is grown in >100 countries with 90% of the total global production from Asia. Although there are more than 110,000 cultivated varieties of rice that vary in quality and nutritional content, after post-harvest processing, rice can be categorized as either white or brown. Regional and cultural preferences as well as need for stability during storage and transport are the final determinants of market availability and final consumption. In addition to calories, rice is a good source of magnesium, phosphorus, manganese, selenium, iron, folic acid, thiamin and niacin; but it is low in fiber and fat. Although brown rice is promoted as being "healthier" because of bioactive compounds, including minerals and vitamins not present in white rice after polishing, white rice is more widely consumed than brown. This is for several reasons, including cooking ease, palatability, and shelf life. Polished rice has a higher glycemic load and may impact glucose homeostasis but when combined with other foods, it can be considered part of a "healthy" plate. With the projected increase in the global population, rice will remain a staple. However, it will be important to encourage intake of the whole grain (brown rice) and to identify ways to harness the phytonutrients that are lost during milling. Furthermore, as the world faces environmental challenges, changing demographics and consumer demands, farmers, healthcare providers, food manufacturers and nutritionists must work collaboratively to assure adequate supply, nutritional integrity and sustainability of rice production systems globally.

OBJECTIVE: To compare the diet quality and overweight status of free-living adults, ages 20 years and older, grouped based on their fast food intake status. METHODS: USDA's 1994 to 1996 Continuing Survey of Food Intakes by Individuals (CSFII 1994-1996) data was used. Three separate analyses were conducted: (1) effect of fast food on diet quality of males and females based on day-one data, (2) comparison of dietary and overweight status of adults who ate fast food on one- two- or none of survey days and (3) within-person analysis comparing energy and macronutrient intakes of adults who ate fast food on one of the two survey days. SUDAAN software package was used in pair-wise mean comparisons and regression analyses (alpha = 0.05). RESULTS: At least one in four adults reported eating fast food. The diet of males and females who consumed fast food was high in energy and energy density. Fast food provided more than one-third of the day's energy, total fat and saturated fat; and was high in energy density. Negligible amounts of milk and fruits, but substantially large amounts of non-diet carbonated soft drinks were reported consumed at fast food places. After controlling for age, gender, socio-economic and demographic factors, energy and energy density increased and micronutrient density decreased with frequency of fast food consumption. Adults who reported eating fast food on at least one survey day had higher mean body mass index values than those who did not eat fast food on both survey days. A small, but significant, positive association was seen between fast food consumption and overweight status. Within-person comparisons showed that energy intakes were higher on a fast food day than on a non-fast food day. CONCLUSION: Fast food consumption was associated with a diet high in energy and energy density and low in essential micronutrient density. Frequent fast food consumption may contribute to weight gain.

The flavonoids are plant polyphenols found frequently in fruits, vegetables, and grains. Divided into several subclasses, they include the anthocyanidins, pigments chiefly responsible for the red and blue colors in fruits, fruit juices, wines, and flowers; the catechins, concentrated in tea; the flavanones and flavanone glycosides, found in citrus and honey; and the flavones, flavonols, and flavonol glycosides, found in tea, fruits, vegetables, and honey. Known for their hydrogen-donating antioxidant activity as well as their ability to complex divalent transition metal cations, flavonoids are propitious to human health. Computer-controlled high-performance liquid chromatography (HPLC) has become the analytical method of choice. Many systems have been developed for the detection and quantification of flavonoids across one, two, or three subclasses. A summary of the various HPLC and sample preparation methods that have been employed to quantify individual flavonoids within a subclass or across several subclasses are tabulated in this review.

A physiological compartmental model of alpha-linolenic acid metabolism was derived from the plasma concentration-time curves for d5-18:3n-3, d5-20:5n-3, d5-22:5n-3, and d5-22:6n-3 in eight healthy subjects. Subjects received a 1-g oral dose of an isotope tracer of alpha-linolenate (d5-18:3n-3 ethyl ester) while subsisting on a rigorously controlled beef-based diet. By utilizing the Windows Simulation and Analysis Modeling program, kinetic parameters were determined for each subject. Half-lives and mean transit times of the n-3 fatty acids in the plasma were also determined. The model predicted plasma values for the n-3 fatty acids in good accordance with the measured steady state concentrations and also predicted dietary linolenic acid intake for each subject in accordance with values determined by lipid analysis of the diet. Only about 0.2% of the plasma 18:3n-3 was destined for synthesis of 20:5n-3, approximately 63% of the plasma 20:5n-3 was accessible for production of 22:5n-3, and 37% of 22:5n-3 was available for synthesis of 22:6n-3. The inefficiency of the conversion of 18:3n-3 to 20:5n-3 indicates that the biosynthesis of long-chain n-3 PUFA from alpha-linolenic acid is limited in healthy individuals. In contrast, the much greater rate of transfer of mass from the plasma 20:5n-3 compartment to 22:5n-3 suggests that dietary eicosapentaenoic acid may be well utilized in the biosynthesis of 22:6n-3 in humans.

Chromium is an essential nutrient involved in normal carbohydrate and lipid metabolism. The chromium requirement is postulated to increase with increased glucose intolerance and diabetes. The objective of this study was to test the hypothesis that the elevated intake of supplemental chromium is involved in the control of type 2 diabetes. Individuals being treated for type 2 diabetes (180 men and women) were divided randomly into three groups and supplemented with: 1) placebo, 2) 1.92 micromol (100 microg) Cr as chromium picolinate two times per day, or 3) 9.6 micromol (500 microg) Cr two times per day. Subjects continued to take their normal medications and were instructed not to change their normal eating and living habits. HbA1c values improved significantly after 2 months in the group receiving 19.2 pmol (1,000 microg) Cr per day and was lower in both chromium groups after 4 months (placebo, 8.5 +/- 0.2%; 3.85 micromol Cr, 7.5 +/- 0.2%; 19.2 micromol Cr, 6.6 +/- 0.1%). Fasting glucose was lower in the 19.2-micromol group after 2 and 4 months (4-month values: placebo, 8.8 +/- 0.3 mmol/l; 19.2 micromol Cr, 7.1 +/- 0.2 mmol/l). Two-hour glucose values were also significantly lower for the subjects consuming 19.2 micromol supplemental Cr after both 2 and 4 months (4-month values: placebo, 12.3 +/- 0.4 mmo/l; 19.2 micromol Cr, 10.5 +/- 0.2 mmol/l). Fasting and 2-h insulin values decreased significantly in both groups receiving supplemental chromium after 2 and 4 months. Plasma total cholesterol also decreased after 4 months in the subjects receiving 19.2 micromol/day Cr. These data demonstrate that supplemental chromium had significant beneficial effects on HbA1c, glucose, insulin, and cholesterol variables in subjects with type 2 diabetes. The beneficial effects of chromium in individuals with diabetes were observed at levels higher than the upper limit of the Estimated Safe and Adequate Daily Dietary Intake.

OBJECTIVES: To determine the proportion of youth meeting national recommendations for food group intake and to identify food intake patterns. DESIGN: The US Department of Agriculture's 1989-1991 Continuing Surveys of Food Intakes by Individuals were used to estimate food intake. Intake was determined from 3 days of diet by disaggregating foods into their component ingredients and using weights that correspond to servings. PARTICIPANTS: The sample included 3307 youth, 2 to 19 years of age, living in the 48 conterminous United States. Main Outcome Measures. Mean number of servings and percentage of individuals meeting national recommendations for food group intake according to demographic characteristics, patterns of intake, and nutrient profiles associated with each pattern. RESULTS: Mean numbers of servings per day were below minimum recommendations for all food groups except the dairy group (ages 2 to 11). Percentages of youth meeting recommendations ranged from approximately 30% for fruit, grain, meat, and dairy to 36% for vegetables. Sixteen percent of youth did not meet any recommendations, and 1% met all recommendations. The pattern of meeting all recommendations resulted in nutrient intakes above the recommended dietary allowances and was high in fat. Conversely, meeting none of the recommendations resulted in intakes well below the recommended dietary allowances for some nutrients. Total fat and added sugars averaged 35% and 15% of energy, respectively, and levels were similar among most demographic groups. CONCLUSION: Children and teens in the United States follow eating patterns that do not meet national recommendations. Nutrition education and intervention are needed among US children.

The causes and control of type 2 diabetes mellitus are not clear, but there is strong evidence that dietary factors are involved in its regulation and prevention. We have shown that extracts from cinnamon enhance the activity of insulin. The objective of this study was to isolate and characterize insulin-enhancing complexes from cinnamon that may be involved in the alleviation or possible prevention and control of glucose intolerance and diabetes. Water-soluble polyphenol polymers from cinnamon that increase insulin-dependent in vitro glucose metabolism roughly 20-fold and display antioxidant activity were isolated and characterized by nuclear magnetic resonance and mass spectroscopy. The polymers were composed of monomeric units with a molecular mass of 288. Two trimers with a molecular mass of 864 and a tetramer with a mass of 1152 were isolated. Their protonated molecular masses indicated that they are A type doubly linked procyanidin oligomers of the catechins and/or epicatechins. These polyphenolic polymers found in cinnamon may function as antioxidants, potentiate insulin action, and may be beneficial in the control of glucose intolerance and diabetes.

Innate lymphoid cells (ILCs) are innate counterparts of adaptive T lymphocytes, contributing to host defense, tissue repair, metabolic homeostasis, and inflammatory diseases. ILCs have been considered to be tissue-resident cells, but whether ILCs move between tissue sites during infection has been unclear. We show here that interleukin-25- or helminth-induced inflammatory ILC2s are circulating cells that arise from resting ILC2s residing in intestinal lamina propria. They migrate to diverse tissues based on sphingosine 1-phosphate (S1P)-mediated chemotaxis that promotes lymphatic entry, blood circulation, and accumulation in peripheral sites, including the lung, where they contribute to anti-helminth defense and tissue repair. This ILC2 expansion and migration is a behavioral parallel to the antigen-driven proliferation and migration of adaptive lymphocytes to effector sites and indicates that ILCs complement adaptive immunity by providing both local and distant tissue protection during infection.

Intestinal worm infections characteristically induce T-helper 2 cell (Th2) cytokine production. We reviewed studies performed with mice infected with either of two intestinal nematode parasites, Nippostrongylus brasiliensis or Trichinella spiralis, that evaluate the importance of the Th2 cytokine interleukin-4 (IL-4) and IL-13 in protection against these parasites. These studies demonstrate that while IL-4/IL-13 protect against both parasites by activating signal transducer and activator of transcription 6 (Stat6) through IL-4 receptor alpha (IL-4Ralpha) ligation, Stat6 activation protects against these parasites through different mechanisms. Stat6-dependent gene transcription promotes expulsion of N. brasiliensis solely through effects on non-bone marrow-derived cells that may include enhancement of intestinal smooth muscle contractility, changes in intestinal epithelial cell function, and increased intestinal mucus secretion. In contrast, Stat6 signaling promotes immunity to T. spiralis both through effects on bone marrow-derived cells that can be reproduced by treating mice with IL-4 or IL-13 and through effects on non-bone marrow-derived cells. The former effects appear to include T-cell-dependent induction of intestinal mastocytosis, while the latter sensitize non-bone marrow-derived cells to mast cell-produced mediators. We argue that a limited ability of the host immune system to distinguish among different nematode parasites has led to the evolution of a stereotyped Th2 response that activates a set of effector mechanisms that protects against most intestinal nematode parasites.