Specific Nutritional Requirements Research Articles

Nutritional Modulation of Insulin Resistance in the True Carnivorous Cat: A Review

Cats are strict carnivores that rely on nutrients in animal tissues to meet their specific and unique nutritional requirements. In their natural habitat, cats consume prey high in protein with moderate amounts of fat and minimal carbohydrates in contrast to commercial diets, which are sometimes moderate to high in carbohydrates. This change in diet has been accompanied by a shift from an outdoor environment to an indoor lifestyle and decreased physical activity, because cats no longer need to hunt to obtain food. This transformation of the lifestyle of cats is thought to be responsible for the recent increase in incidence of obesity, insulin resistance, and diabetes mellitus in domestic cats. At first, an overview of the evolutionary physiological adaptations of carbohydrate digestion in the feline digestive tract and of the hepatic carbohydrate and protein metabolism reflecting the true carnivorous nature of cats is given. Secondly, this literature review deals with nutritional modulation of insulin sensitivity, focusing on dietary macronutrients, carbohydrate sources, and dietary fiber for prevention and treatment of insulin resistance.

Biological and Nutritional Aspects of Human Milk in Feeding of Preterm Infants

Breastfeeding and human milk are the normative standards for feeding and nutrition of both term and pre-term infants. Fresh mother’s own milk is recognized as the optimal choice for feeding all newborns, including preterm and very low birth weight infants. Evidence documents short and long-term metabolic, immunologic and neurodevelopmental advantages of breastfeeding when compared to formula. Moreover, benefits of breastfeeding on psychological and relational aspects have to be considered. Currently, human milk supplementation is usually performed to meet the specific nutritional requirements of preterm infants. When mother’s milk is unavailable or in short supply, donor milk represents the best alternative, although some nutritional elements are inactivated by the necessary pasteurization process. Aim of this review is to briefly summarize the main biological and nutritional factors that contribute to the beneficial effects of human milk feeding for preterm infants.

The Great Portion Debate

The Great Portion Debate

Additive and interactive effects of nutrient classes on longevity, reproduction, and diet consumption in the Queensland fruit fly (Bactrocera tryoni)

Insect lifespan is often closely linked to diet, and diet manipulations have been central to studies of ageing. Recent research has found that lifespan for some flies is maximised on a very low yeast diet, but once all yeast is removed, lifespan drops precipitously. Although effects of yeast availability on lifespan are commonly interpreted in terms of protein, yeast is a complex mix of nutrients and provides a rich source of vitamins, minerals and sterols. Elucidating which components of yeast are involved in this lifespan drop provides insights into more specific nutritional requirements and also provides a test for the commonplace interpretation of yeast in terms of protein. To this end, we fed Queensland fruit flies (Bactrocera tryoni) one of eight experimental diets that differed in the nutrient group(s) found in yeast that were added to sucrose: none, vitamins, minerals, amino acids, cholesterol, vitamin+mineral+cholesterol (VMC), vitamin+mineral+cholesterol+amino acids (VMCA), and yeast. We measured survival rates and egg production in single sex and mixed sex cages, as well as nutrient intake of individual flies. We found that the addition of minerals increased lifespan of both male and female flies housed in single sex cages by decreasing baseline mortality. The addition of just amino acids decreased lifespan in female flies; however, when combined with other nutrient groups found in yeast, amino acids increased lifespan by decreasing both baseline mortality and age-specific mortality. Flies on the yeast and VMCA diets were the only ones to show significant egg production. We conclude that the drop in lifespan observed when all yeast is removed is explained by missing micronutrients (vitamins, minerals and cholesterol) as well as the absence of protein in females, whereas minerals alone can explain the pattern for males. These results indicate a need for caution when interpreting effects of dietary yeast as effects of protein.

Estimation of the dietary nutrient profile of free-roaming feral cats: possible implications for nutrition of domestic cats

Cats are strict carnivores and in the wild rely on a diet solely based on animal tissues to meet their specific and unique nutritional requirements. Although the feeding ecology of cats in the wild has been well documented in the literature, there is no information on the precise nutrient profile to which the cat's metabolism has adapted. The present study aimed to derive the dietary nutrient profile of free-living cats. Studies reporting the feeding habits of cats in the wild were reviewed and data on the nutrient composition of the consumed prey items obtained from the literature. Fifty-five studies reported feeding strategy data of cats in the wild. After specific exclusion criteria, twenty-seven studies were used to derive thirty individual dietary nutrient profiles. The results show that feral cats are obligatory carnivores, with their daily energy intake from crude protein being 52 %, from crude fat 46 % and from N-free extract only 2 %. Minerals and trace elements are consumed in relatively high concentrations compared with recommended allowances determined using empirical methods. The calculated nutrient profile may be considered the nutrient intake to which the cat's metabolic system has adapted. The present study provides insight into the nutritive, as well as possible non-nutritive aspects of a natural diet of whole prey for cats and provides novel ways to further improve feline diets to increase health and longevity.

Demand feeding and welfare in farmed fish

Following the development of demand-feeding systems, many experiments have been conducted to explore feeding motivation and feed intake in farmed fish. This work aims to review a selection of studies in the field, focusing on three key factors, related to demand feeding and fish welfare. Firstly, we outline how demand feeders should be considered when developing feed management strategies for improving welfare in production conditions. Secondly, via laboratory demand-feeding experiments, we show self-feeding activities depend not only on feeding motivation and social organisation, but also on individual learning capacity and risk-taking behaviour. Thirdly, we report encouraging results demonstrating that when presented with two or more self-feeders containing complementary foods, fish select a diet according to their specific nutritional requirements, suggesting that demand feeders could be used to improve welfare by allowing fish to meet their nutritional needs.

Nutritional requirements of freshwater ornamental fish: a review

The knowledge of nutritional requirements in ornamental fish species is essential to improve the productive development; however, the nutritional information of these species is scarce and sometimes this information is extrapolated from results obtained from nonornamental fish species. In ornamental fish, a correct formulation of the diet improve the nutrient digestibility and supply the metabolic needs, reducing the maintenance cost and at the same time the water pollution. Inert food such as meal powder, flakes, milk powder, bovine heart and liver, tubifex worms, as well as live food including Artemia sp., rotifers and Moina have been used extensively in ornamental fish feeding with a diverse range of nutritional values and productive properties. In contrast with farmed fish, skin pigmentation is a mandatory characteristic in ornamental fish and the use of dietary supplements with carotenoids is recommended. The aim of this document is to review the specific nutritional requirements which are indispensable to improve economical and productive potential of freshwater ornamental fish. Key words: Aquarium fish, carotenoids, energy, lipids, ornamental fish, protein, vitamins. (Sources: AIMS, CAB).

Large variations in antioxidant capacity and contents of Hungarian sour and sweet cherry cultivars

Sour cherry (Prunus cerasus L.) cultivars grown in Hungary are of local origin while most sweet cherry cultivars in Hungary are introduced from other countries.A great phenotypic variability is displayed by both species. In the present study, we analyzed 10 sour and 9 sweet cherry cultivars for their antioxidant capacity, total polyphenolics (TPC) and total anthocyanin (TMAC) contents. In general, sour cherries showed higher levels of antioxidant capacity, TPC and TMAC. The anthocyanin contents varied from 0.16 to 6.85 and 1.41 to 127.56 mg/100 g for sweet and sour cherries, respectively. However, TMAC generally seems to have a limited influence on the antioxidant capacity of cherries.An amarelletype sour cherry, ‘Pipacs 1’ showed the highest antioxidant capacity (21.21mmolAA/l) and TPC (44.07mgGA/l) in contrast to its lowanthocyanin content. The detected diversity presents a choice that can satisfy different consumer preferences, and meet specific nutritional requirements.

Fortification of maternal milk for very low birth weight (VLBW) pre-term neonates

Human milk is the best food for all neonates; however, in pre-term infants, especially those with a very low birth weight, it may lead to insufficient intake of protein and energy. The use of fortified human milk produces adequate growth in premature infants and satisfies the specific nutritional requirements of these babies. To improve the nutritional management of pre-term infants ≤ 35 weeks’ gestational age, an individualised human milk fortification system based on the analysis of maternal milk was evaluated.

Main quality attributes and antioxidants in Hungarian sour cherries: identification of genotypes with enhanced functional properties

SummarySour cherry (Prunus cerasus L.) cultivars native to Hungary and some of them grown worldwide, display great phenotypic variability. Eleven sour cherry cultivars were analysed for their main quality attributes including fruit weight, soluble solid content, acidity, pH, specific sugars (glucose and fructose), antioxidant capacity as well as total polyphenolic (TPC), total anthocyanin (TMAC) and vitamin C contents. Results showed wide variation in both fruit quality and antioxidant parameters of Hungarian sour cherries. The anthocyanin contents varied from 11.3 to 93.5 mg/100 g. An amarelle‐type cultivar, ‘Pipacs 1’ showed the highest antioxidant capacity (21.85 mmol AA L−1), TPC (49.04 mg GA L−1) and vitamin C (8.98 mg/100 g) content. Key enzymes in anthocyanin biosynthesis were expressed in both yellow‐coloured flesh and red skin of ‘Pipacs 1’ fruits at all ripening stages. The detected diversity presents a choice that can satisfy different consumer preferences, and meet specific nutritional requirements.

Metabolic Response and Nutritional Support in Traumatic Brain Injury: Evidence for Resistance to Renutrition

Abstract Traumatic brain injury (TBI) is one of the most severe injuries encountered in intensive care units. TBI patients exhibit protein wasting and gastrointestinal dysfunction, which may be risk factors for a septic state. Specific nutritional support may be required for these patients, and we hypothesize that standard nutritional support does not allow restoration of the nutritional state of TBI patients. A well-validated rat model of TBI by fluid percussion was used. Rats were randomized into three groups: healthy rats receiving standard chow diet ad libitum (AL), rats sustaining TBI and receiving standard chow diet (TBI), and rats sustaining TBI and receiving a standard enteral diet (TBI-EN) for 4 days. TBI in rats was characterized by anorexia, body weight loss (AL: +15 +/- 5 g versus TBI: -11 +/- 4 g and TBI-EN: -8 +/- 4 g; p < 0.05), decrease in nitrogen balance (AL: 2.9 +/- 0.2 g versus TBI: 1.0 +/- 0.2 g and TBI-EN: 0.2 +/- 0.2 g, p < 0.05) associated with decrease in muscular protein content (extensor digitorum longus [EDL]: AL: 36 +/- 2 mg versus TBI: 26 +/- 3 mg and TBI-EN: 28 +/- 2 mg; p < 0.05), and intestinal atrophy (ileum: AL: 673 +/- 42 mg versus TBI: 442 +/- 23 mg and TBI-EN: 377 +/- 27 mg; p < 0.05). Interestingly, standard enteral nutrition was not effective in restoring any of these parameters. This work confirms that TBI is associated with profound nutritional alterations and has a major impact on nitrogen metabolism and on intestinal trophicity. It also demonstrates that using standard enteral nutrition cannot reverse this phenomenon. Thus, developing new nutritional strategies to cover TBI patients' specific nutritional requirements appears mandatory.

A specific nutritional requirement for pyrimidines in rudimentary mutants of Drosophila melanogaster.

A nutritional requirement for pyrimidines in rudimentary mutants of Drosophila melanogaster is reported. It is suggested that the rudimentary mutation causes a block in one of the first two steps of pyrimidine biosynthesis, and the evidence for a relationship between pyrimidine metabolism and the pleiotropic effects of the rudimentary gene is discussed.

Intraspecific Strategic Responses of African Elephants to Temporal Variation in Forage Quality

ABSTRACT Mammalian herbivores adopt foraging strategies to optimize nutritional trade‐offs against restrictions imposed by body size, nutritional requirements, digestive anatomy, physiology, and the forage resource they exploit. Selective or generalist feeding strategies scale with body size across species. However, within species, where constraints should be most similar, responses to limitation have rarely been examined. We used African elephants (Loxodonta Africana) to test for changes in seasonal diet quality of individuals of differing body size and sex through measurement of fecal nitrogen and phosphorus. We measured physiological stress response of these age and sex classes to seasonal change by fecal glucocorticoid metabolite levels (i.e., stress hormones). Large body size increased tolerance to lower‐quality forage. Adult males and females exhibited divergent trends; females had higher diet quality than males, irrespective of body size. When limited by forage availability or quality during the dry season, diet quality declined across all body sizes, but weaned calves ingested a higher‐quality diet than larger‐bodied adults. On release from restriction during the wet season, weaned calf nitrogen concentrations were consistently high and stress hormone levels decreased, whereas adult female phosphorus levels were highest and less variable and stress hormone levels were unchanged. The ability to adjust forage quality is an important strategy used to ensure adequate nutritional intake according to body size limitations. Although body size is a key determining factor of dietary differences between adult elephants, foraging strategies are also driven by specific nutritional requirements, which may override the body size effects driving foraging decisions in some cases. The diversity of intraspecific response highlights ecologically segregated entities within a species and should be a concern for population management planning, particularly for threatened species. Fecal diet quality and stress hormone analysis could provide an early and sensitive indicator for monitoring age and sex class responses to resource restriction in high‐density elephant populations.

A method for the identification of proteins secreted by lactic acid bacteria grown in complex media

Lactic acid bacteria (LAB) are known for their special nutritional requirements, being usually cultured in complex media to achieve optimal growth. In this paper, a protocol based on trichloroacetic acid precipitation of peptides and proteins is presented. The method has been tested on four probiotic LAB strains grown in De Man Rogosa Sharpe (MRS) broth, a complex medium that is often used for the culture of such bacteria. This protocol allowed the detection of 19 proteins after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, 10 of them being successfully identified by tandem MS. Thereafter, the 10 were found to be secreted or surface associated by bioinformatic means. In conclusion, this work supplies a method for the identification of proteins secreted by LAB, allowing discrimination between the proteins present in the MRS and those produced by probiotic LAB.

Decolorization of organic dyes by Irpex lacteus in a laboratory trickle‐bed biofilter using various mycelium supports

AbstractBACKGROUND: Dyes used in textile industries and released to their wastewaters are serious ecological problems as they are hard to degrade by common means used in wastewater treatment plants. White‐rot fungi can biodegrade textile dyestuffs using their extracellular enzyme system. However, it is difficult to keep them in functional form in conventional wastewater treatment systems, because of their specific nutritional and physiological requirements. Selection of a suitable bioreactor type and mode of operation are crucial for successful implementation of white rot fungi in waste water treatment processes.RESULTS: Both Remazol Brilliant Blue R (RBBR) and Reactive Orange 16 (RO16) were decolorized efficiently in the trickle‐bed reactor. A degree of decolorization exceeding 80% was achieved within 2 days with all mycelium carriers and both dyes. In reactors packed with plastic kitchen scourers and luffa sponge slices the decolorization degree reached 90% within 2 days. The initial rate of decolorization of RBBR dye was notably higher than the rate of RO16 decolorization. The lowest liquid hold‐up value (1–1.5%) was achieved in the reactor packed with the plastic kitchen scourers, the largest hold‐up value (3–5%) was observed in the reactor filled with luffa sponge. The longest mean retention time, 430 s, was achieved in the reactor with the luffa carrier at a liquid flow rate of 6.81 cm3 min−1; the shortest mean retention times (10–20 s) were achieved in the reactor filled with the plastic kitchen scourers. Broad liquid residence time distributions were observed in tracer experiments at all volumetric flow rates.CONCLUSIONS: The ability of I. lacteus to secrete laccase and manganese peroxidase enzymes in a trickle‐bed bioreactor with three mycelium carriers was proved and quantified experimentally. The decolorization capability of the I. lacteus mycelium was only marginally influenced by the kind of carrier used. Basic operational characteristics of the reactor—residence times, axial dispersion and liquid hold‐up—were determined at various liquid flow rates. Copyright © 2009 Society of Chemical Industry

Metabolic Diversity in Campylobacter jejuni Enhances Specific Tissue Colonization

Campylobacter jejuni is a leading cause of foodborne illness in industrialized countries. This pathogen exhibits significant strain-to-strain variability, which results in differences in virulence potential and clinical presentations. Here, we report that acquisition of the capacity to utilize specific nutrients enhanced the ability of a highly pathogenic strain of C. jejuni to colonize specific tissues. The acquisition of a gene encoding a gamma-glutamyltranspeptidase enabled this strain to utilize glutamine and glutathione and enhanced its ability to colonize the intestine. Furthermore, the acquisition of a DNA segment, which added a sec-dependent secretion signal to an otherwise cytoplasmic asparaginase, allowed this pathogen to utilize asparagine and to more efficiently colonize the liver. Our results reveal that subtle genetic changes in a bacterial pathogen result in significant changes in its ability to colonize specific tissues. In addition, these studies revealed remarkably specific nutritional requirements for a pathogen to effectively colonize different tissues.

Phosphoproteomic analysis of Leishmania donovani pro‐ and amastigote stages

Following transmission to the vertebrate host, the protozoan parasite Leishmania donovani differentiates into the pathogenic amastigote stage that is adapted for intracellular survival. This developmental transition is induced by environmental factors including elevated temperature and acidic pH and is likely transduced by signaling cascades involving protein kinases and their downstream phosphoprotein substrates. These signaling networks are highly adapted to the specific nutritional and physiological requirements of the organism and thus studying Leishmania phosphorylation may allow important insight into the parasite-specific biology. We used a gel-based approach to investigate qualitative and quantitative changes of the phosphoproteome of the major L. donovani life cycle stages. Phosphoproteins were purified by immobilized metal affinity chromatography (IMAC), separated by IEF and SDS-PAGE using pH 4-7 IPG immobiline strips, revealed by fluorescent multiplex staining, and identified by MALDI-MS and MS/MS. Our analysis allowed us to establish a first repertoire of the Leishmania phosphoproteome and to identify phosphoproteins implicated in stress- and heat shock response, RNA/protein turnover, metabolism, and signaling.

P034 A MODEL OF INFECTIOUS COMPLICATIONS IN HEAD-INJURY RATS: PRELIMINARY RESULTS

Rationale: Infectious complications are observed in patients who have sustained head injury, and are responsible for 10 25% of observed mortality. It is likely, but not proven, that sepsis modifies the specific nutritional requirements in trauma. The aim of this work was to develop a model of infectious complications in headinjury rats using E. coli-Xen 14 with a stable copy of the lux operon. This allows evaluation of infection behaviour by optical imaging. Methods: Male SD rats were randomized into three groups: AL (healthy rats, n = 9), HI (head-injury rats (Day 0) fed a standard enteral nutrition, Sondalis® HP, n = 10), HI-EC (HI rats (Day 0) + single enteral bolus of E. coli, 1.3×109/rat (Day 2), n = 9). Bacterial proliferation was evaluated with a cooled CCD camera at T+2 and T+6 h after E. coli challenge. Blood was sampled to determine amino acid concentrations. At Day 10, muscles were removed and weighed. Results are expressed as means ± SEM except for luminescence (median [min-max] in arbitrary units). Statistics: ANOVA + Fisher test or Wilcoxon test (for luminescence). Results: HI was associated with body weight loss, muscle atrophy and plasma amino acid disturbances, in particular GLN depletion (AL 919±37 vs. HI 647±25 and HIEC 717±20mmol/l, p < 0.05). The luminescence signal visualized was observed at T+2h (34778 [1617 2918810]), and significantly decreased at T+6 h (0 [0 847922], p < 0.05). Bacterial challenge was associated with specific alterations of sulphur plasma amino acids (CYS: AL 53±2 vs. HI-EC 46±2, p < 0.05; MET: AL 55±2 vs. HIEC 47±1mmol/l, p < 0.05) and ALA (AL 512±41 vs. HI-EC 395±29mmol/l, p < 0.05). Conclusion: Preliminary results suggest that HI with infectious complications leads to specific metabolic alterations. A disease-based diet should be tested in this model.

APPLICATION OF ANTIOXIDANTS DURING SHORT‐PATH DISTILLATION OF STRUCTURED LIPIDS

ABSTRACT A specific structured lipid was produced from sunflower oil and caprylic acid. The antioxidative effect of adding α‐tocopherol, ascorbyl palmitate or citric acid (each in three different concentrations) was investigated before and after the purification process (short‐path distillation), and was compared with a control without addition of antioxidant. The oxidative status and stability were characterized by peroxide and anisidine values, secondary volatile oxidation products and induction period. The antioxidants affected the oxidative status compared with the control: citric acid was prooxidative at low concentrations, but antioxidative at high concentrations. Addition of ascorbyl palmitate had an antioxidative effect at all concentrations employed. α‐Tocopherol showed less antioxidative activity compared with ascorbyl palmitate and citric acid, and its efficacy was slightly decreased with increasing concentration. Combinations of citric acid with ascorbyl palmitate were tested in a later part of the study. No additive or synergistic effect was found between citric acid and ascorbyl palmitate. PRACTICAL APPLICATIONSProduction of structured lipids (SLs) provides unique possibilities to design fats that can meet specific nutritional requirements. The desirednutritional quality of the lipid may be negatively influenced by production parameters, e.g., due to oxidation. Addition of antioxidants before purification of the lipid, as described in the present article, can improve the oxidative status of the final product compared with a product devoid of added antioxidants. This is also known from the deodorization process. The storage stability of the SL and its nutritional quality is therefore expected to be considerably improved compared with a lipid to which no antioxidant is added.

Chemical composition and in vitro starch digestibility of pigmented corn tortilla

AbstractBACKGROUND: Tortillas were prepared from two (blue and regular white) maize varieties and compared with regard to chemical composition and in vitro starch digestibility, i.e., available starch (AS), total (RS) and retrograde (RRS) resistant starch contents, amylolysis rate and predicted glycemic index (pGI). The impact of cold storage (4 °C) on digestibility was also investigated.RESULTS: Despite its higher protein and lipid contents, pigmented tortilla exhibited lower AS content than the white product. AS in both types of tortilla decreased during the first 2 days of storage, and remained stable thereafter. Blue tortilla had lower RS content (21 g kg−1 dry matter basis) than the white tortilla (30 g kg−1 dry matter basis). RS values were slightly higher in 2 day‐stored tortillas than in their fresh counterparts. Although the RRS content in recently made white tortillas was greater than in the colored preparation, stored blue tortillas exhibited double RRS values compared with freshly baked samples. α‐Amylolysis of blue tortilla was slower than in the white sample. Consequently, blue tortilla exhibited a lower pGI value. pGI for the white tortilla decreased upon cold storage, a change that was not be observed for the colored preparation.CONCLUSION: Starch digestibility characteristics of blue tortilla make it suitable for people with special nutritional or metabolic requirements. Copyright © 2007 Society of Chemical Industry