Alternative Nutritional Strategies Research Articles

A novel botanical formula prevents diabetes by improving insulin resistance

BackgroundType 2 diabetes mellitus (T2DM) is a major risk factor for cardiovascular disease, and the prevalence has increased significantly in recent decades to epidemic proportions in China. Individually, fenugreek (Trigonella foenum graecum) seed, mulberry (Morus alba L.) leaf and American ginseng (Panax quinquefolius) root can improve glycemia in various animal models and humans with impaired glucose metabolism and T2DM. The aim of this study was to design an optimized botanical formula containing these herbal extracts as a nutritional strategy for the prevention of insulin resistance and T2DM.MethodsCell-free α-amylase and α-glucosidase enzyme assays were used to determine inhibitory potential of extracts. Glucose uptake was examined in differentiated human adipocytes using radiolabeled 2-deoxyglucose. Male Sprague Dawley rats were divided and glycemia balanced into 5 groups: two controls (naïve and model) and three doses of the botanical test formula containing standardized fenugreek seed, mulberry leaf and American ginseng extracts (42.33, 84.66 and 169.33 mg/kg BW). Insulin resistance and T2DM was induced by feeding animals a high fat diet and with an alloxan injection. Glucose tolerance was examined by measuring serum glucose levels following an oral glucose load.ResultsFenugreek seed and mulberry leaf dose dependently inhibited α-amylase (IC50 = 73.2 μg/mL) and α-glucosidase (IC50 = 111.8 ng/mL), respectively. All three botanical extracts improved insulin sensitivity and glucose uptake in human adipocytes, which lead to the design of an optimized botanical test formula. In a rat model of insulin resistance and T2DM, the optimized botanical test formula improved fasting serum glucose levels, fasting insulin resistance and the development of impaired glucose tolerance. The reduction in epididymal adipose tissue GLUT4 and PDK1 expression induced by high fat diet and alloxan was blunted by the botanical test formula.ConclusionsA novel botanical formula containing standardized extracts of mulberry leaf, fenugreek seed and American ginseng at a ratio of 1:1.3:3.4 prevented the development of insulin resistance, impaired glucose tolerance and T2DM. Given the rising need for effective non-drug targeting of insulin resistance and progression to T2DM, complementary and alternative nutritional strategies without intolerable side effects could have meaningful impact on metabolic health and diabetes risks.

Going Back to Their Roots: Comanche Trade and Diet Revisited

Abstract Recent studies of eighteenth- and nineteenth-century Comanches have argued that their dependence on bison posed a serious nutritional challenge in the form of a dangerously imbalanced high-protein diet. They contend that this specialization required Comanches to obtain carbohydrates in the form of maize from Spanish-ruled New Mexico and Texas or Native American horticulturalists. This in turn is claimed to have been crucial in structuring Comanche economic and political ties with their neighbors. This article argues instead that the documentary evidence used to support a trade in foodstuffs is weak and that Comanches employed alternative nutritional strategies, including consuming and storing a wide range of wild plants. Prestige and utilitarian goods such as metal tools and weapons, firearms, and items of personal adornment—not food—were the primary motivation for Comanche trade with Europeans.

Does exogenous carbon extend the realized niche of canopy lichens? Evidence from sub‐boreal forests in British Columbia

Foliose lichens with cyanobacterial bionts (bipartite and tripartite) form a distinct assemblage of epiphytes strongly associated with humid microclimatic conditions in inland British Columbia. Previous research showed that these cyano- and cephalolichen communities are disproportionately abundant and species-rich on conifer saplings beneath Populus compared to beneath other tree species. More revealing, lichens with cyanobacterial bionts were observed beneath Populus even in stands that did not otherwise support them. We experimentally test the hypothesis that this association is due to the interception of glucose-rich nectar that is exuded from Populus extra-floral nectaries (EFN). Using CO2 flux measurements and phospholipid fatty acid (PLFA) analysis with experimental applications of 13C6-labeled glucose, we demonstrate that cyano- and cephalolichens have a strong respiratory response to glucose. Lichens treated with glucose had lower net photosynthesis and higher establishment rates than control thalli. Furthermore, lichens with cyanobacterial bionts rapidly incorporate exogenous 13C into lichen fatty acid tissues. A large proportion of the 13C taken up by the lichens was incorporated into fungal biomarkers, suggesting that the mycobiont absorbed and assimilated the majority of applied 13C6 glucose. Our observations suggest that both cyanolichens and cephalolichens may utilize an exogenous source of glucose, made available by poplar EFNs. The exogenous C may enable these lichens to become established by providing a source of C for fungal respiration despite drought-induced inactivity of the cyanobacterial partner. As such, the mycobiont may adopt an alternative nutritional strategy, using available exogenous carbon to extend its realized niche.

A Carnivorous Plant Fed by Its Ant Symbiont: A Unique Multi-Faceted Nutritional Mutualism

Scarcity of essential nutrients has led plants to evolve alternative nutritional strategies, such as myrmecotrophy (ant-waste-derived nutrition) and carnivory (invertebrate predation). The carnivorous plant Nepenthes bicalcarata grows in the Bornean peatswamp forests and is believed to have a mutualistic relationship with its symbiotic ant Camponotus schmitzi. However, the benefits provided by the ant have not been quantified. We tested the hypothesis of a nutritional mutualism, using foliar isotopic and reflectance analyses and by comparing fitness-related traits between ant-inhabited and uninhabited plants. Plants inhabited by C. schmitzi produced more leaves of greater area and nitrogen content than unoccupied plants. The ants were estimated to provide a 200% increase in foliar nitrogen to adult plants. Inhabited plants also produced more and larger pitchers containing higher prey biomass. C. schmitzi-occupied pitchers differed qualitatively in containing C. schmitzi wastes and captured large ants and flying insects. Pitcher abortion rates were lower in inhabited plants partly because of herbivore deterrence as herbivory-aborted buds decreased with ant occupation rate. Lower abortion was also attributed to ant nutritional service. The ants had higher δ15N values than any tested prey, and foliar δ15N increased with ant occupation rate, confirming their predatory behaviour and demonstrating their direct contribution to the plant-recycled N. We estimated that N. bicalcarata derives on average 42% of its foliar N from C. schmitzi wastes, (76% in highly-occupied plants). According to the Structure Independent Pigment Index, plants without C. schmitzi were nutrient stressed compared to both occupied plants, and pitcher-lacking plants. This attests to the physiological cost of pitcher production and poor nutrient assimilation in the absence of the symbiont. Hence C. schmitzi contributes crucially to the nutrition of N. bicalcarata, via protection of assimilatory organs, enhancement of prey capture, and myrmecotrophy. This combination of carnivory and myrmecotrophy represents an outstanding strategy of nutrient sequestration.

Alternative Nutritional Strategies in Protists: Symposium Introduction and a Review of Freshwater Protists that Combine Photosynthesis and Heterotrophy1

The alternative nutritional strategies in protists that were addressed during the symposium by that name at the 2010 annual meeting of the International Society of Protistologists and here in contributed papers, include a range of mechanisms that combine photosynthesis with heterotrophy in a single organism. Often called mixotrophy, these multiple trophic level combinations occur across a broad range of organisms and environments. Consequently, there is great variability in the physiological abilities and relative importance of phototrophy vs. phagotrophy and/or osmotrophy in mixotrophic protists. Recently, research papers addressing ecological questions about mixotrophy in marine systems have been more numerous than those that deal with freshwater systems, a trend that is probably partly due to a realization that many harmful algal blooms in coastal marine systems involve mixotrophic protists. After an introduction to the symposium presentations, recent studies of mixotrophy in freshwater systems are reviewed to encourage continuing research on their importance to inland waters.

Mycorrhizal associations and other means of nutrition of vascular plants: understanding the global diversity of host plants by resolving conflicting information and developing reliable means of diagnosis

A comprehensive appraisal of the mycorrhizal literature provides data for 336 plant families representing 99% of flowering plants, with regard to mycorrhizas and other nutritional adaptations. In total, arbuscular (AM), orchid, ectomycorrhizas (EM) and ericoid mycorrhizas and nonmycorrhizal (NM) roots occur in 74%, 9%, 2%, 1% and 6% of Angiosperm species respectively. Many families of NM plants have alternative nutritional strategies such as parasitism, carnivory, or cluster roots. The remaining angiosperms (8%) belong to families reported to have both AM and NM species. These are designated as NM-AM families here and tend to occur in habitats considered non-conducive to mycorrhizal fungi, such as epiphytic, aquatic, extremely cold, dry, disturbed, or saline habitats. Estimated numbers of species in each category of mycorrhizas is presented with lists of NM and EM families. Evolutionary trends are also summarised by providing data on all clades and orders of flowering and non-flowering vascular plants on a global scale. A case study of Western Australian plants revealed that plants with specialised nutritional modes such as carnivory, cluster roots, or EM were much more diverse in this ancient landscape with infertile soils than elsewhere. Detailed information on the mycorrhizal diversity of plants presented here is linked to a website (mycorrhizas.info) to allow data to remain current. Over a century of research effort has resulted in data on mycorrhizal associations of >10,000 plant species that are of great value, but also somewhat of a liability due to conflicting information about some families and genera. It is likely that these conflicts result in part from misdiagnosis of mycorrhizal associations resulting from a lack of standardisation in criteria used to define them. Families that contain both NM and AM species provide a second major source of inconsistency, but even when these are excluded there is a ∼10% apparent error rate in published lists of mycorrhizal plants. Arbuscules are linked to AM misdiagnosis since they are used less often than vesicles to recognise AM associations in roots and apparently occur sporadically in NM plants. Key issues with the diagnosis of mycorrhizal plants are discussed using the Cyperaceae as a case study. Detailed protocols designed to consistently distinguish AM from endophytic Glomeromycotan Fungus Colonisation (GFC) are provided. This review aims to stimulate debate and provide advice to researchers delving into root biology.

Dynamics of living phytoplankton: Implications for paleoenvironmental reconstructions

Phytoplankton is the dominant primary producer in aquatic ecosystems and is considered a gauge of ecological condition and change. Some phytoplankton groups, namely diatoms, dinoflagellates, and coccolithophores, produce morphological or chemical fossils that can be used for paleoenvironmental reconstruction. This study aims to review the processes that regulate dynamics in living phytoplankton and to highlight how this knowledge is used in paleoecological studies. The distribution patterns of phytoplankton in present-day aquatic ecosystems are shaped by the interplay between processes that regulate cell growth and cell death. Cell growth and cell death are regulated by the internal environment of phytoplankton (e.g., specific environmental tolerances, resource uptake properties, cell size, density and morphology, alternative nutritional strategies such as mixotrophy or N2 uptake, motility, intracellular storage capacities, grazing resistance properties), and by its external environment. The external environment includes variables dependent on the availability of resources (e.g., light intensity, concentration of CO2 and dissolved inorganic macronutrients and micronutrients, availability of living prey in case of mixotrophs) and variables independent of resources (e.g., temperature, salinity, turbulence, ultraviolet radiation, bioactive compounds, activity of grazers, viruses, and eukaryotic parasites). The importance of recently described loss processes, such as grazing by phagotrophic protists, viral lyses, and programmed cell death, is discussed in the context of its potential impact upon phytoplankton vertical fluxes. Examples of the use of different phytoplankton metrics (e.g. abundance, species composition, species morphology, and elemental composition) to infer contemporaneous as well as past environmental and ecological conditions are critically evaluated.

The interaction between threonine level and avilamycin inclusion on piglet performance and diet digestibility post weaning

The increase in the prevalence of post weaning diarrhoea in pigs due to the progressive ban of antibiotic use has necessitated the use of alternative management and nutritional strategies (Le Bellego and Noblet, 2001). During immunological stress, amino acids are redistributed away from protein production towards tissues involved in inflammation and immune response. This can disturb normal body processes, which can in turn induce specific amino acid requirements. Threonine utilization by the gut is higher than that of any other amino acid because it is involved in the synthesis of intestinal mucin. Mucin plays a key role in the defence of the mucosa, however it is indigestible. Thus, when the positive effects of an antimicrobial growth promoter are removed, increased levels of dietary threonine may benefit piglets due to additional reserves of threonine being present to compensate for the portion of dietary threonine that becomes unavailable due to the increased synthesis of intestinal mucin. The objective of the experiment was to investigate the interaction between threonine level and avilamycin inclusion on piglet performance and diet digestibility post weaning.

Alternative nutritional strategies to increase milk yield in dairy cows: a modelling approach

When the ratio between Metabolisable Protein (MP) and Metabolisable Energy (ME) is optimal for a given level of milk output (not constrained by genotype, management or other nutritional factors), further increases in milk output can be obtained by two strategies: Strategy 1. Increased supply of ME and MP (maintaining optimal MP:ME), orStrategy 2. Oversupply of MP (ie MP:ME > optimum)Possible mechanisms underlying Strategy 2 include use of amino acids for gluconeogenesis or oxidation (Oldham, 1994), mobilisation of body energy reserves or, where forage is available ad libitum, increased forage intake (Newbold, 1994). For the purpose of this study, supply of MP above the theoretical optimum was assumed to increase milk protein yield only via the mechanism of increased forage intake.The objective of this study was to evaluate the economic (cost of ration) and environmental (overall efficiency of N use) consequences of increasing milk yield by these two strategies.

Alternative nutritional strategies to increase milk yield in dairy cows: a modelling approach

When the ratio between Metabolisable Protein (MP) and Metabolisable Energy (ME) is optimal for a given level of milk output (not constrained by genotype, management or other nutritional factors), further increases in milk output can be obtained by two strategies: Strategy 1. Increased supply of ME and MP (maintaining optimal MP:ME), orStrategy 2. Oversupply of MP (ie MP:ME > optimum)Possible mechanisms underlying Strategy 2 include use of amino acids for gluconeogenesis or oxidation (Oldham, 1994), mobilisation of body energy reserves or, where forage is available ad libitum, increased forage intake (Newbold, 1994). For the purpose of this study, supply of MP above the theoretical optimum was assumed to increase milk protein yield only via the mechanism of increased forage intake.The objective of this study was to evaluate the economic (cost of ration) and environmental (overall efficiency of N use) consequences of increasing milk yield by these two strategies.

The timing of a moderate nutritional restriction in mid pregnancy and its effect on lamb birth weight and ewe gestation length

Lamb birth weight and ewe gestation length data were collected from a flock of 300-600 parous Border Leicester x Merino ewes over 4 years, as part of a study on nutritional restriction of pregnant ewes. One half of these ewes were nutritionally restricted for a 4-week period commencing 75-95 days post coitus, in order to achieve loss of maternal liveweight and reduction in body fat score to a minimum of 3. The remaining ewes with no nutritional restriction were >6 kg heavier and had a body fat score >0.8 higher at the end of the restriction period. Nutritional restriction affected (P<0.05) birth weight of lambs. With each day's delay in commencing restriction, from day 75 to day 95, gestation length was increased (P<0.001). For each additional day in utero, birth weight was increased by 40-50 g. Restriction and refeeding produced lambs of birth weights and weaning weights indistinguishable from the control ewes, and since there were no apparent disadvantages, mid pregnancy restriction is an alternative nutritional strategy for pregnant ewes.

Income and dietary adequacy in an agricultural community

Although many studies as well as conventional wisdom suggest that increases in income result in improved diet and nutritional status in rural areas of developing countries, several recent studies have failed to demonstrate such a relationship. In this paper the relationships between material wealth and income and dietary strategies are examined for an agricultural community in rural Mexico. A superficial examination focusing on summary indices of dietary adequacy frequently cited in the literature and indices of wealth and income demonstrates a positive relationship between them in this community. However, an examination of the same data emphasizing alternative dietary strategies to achieve nutritional adequacy shows a more complex picture. Increasing income is associated with consumption of purchased foods especially foods of animal origin, and is not associated with the consumption of staple foods produced within the household. Diets dependent on purchased foods do not necessarily meet nutritional needs more adequately than diets which rely on agricultural products and gathered foods. Among the implications of this research are a need for a method of analysis which focuses on alternative nutritional strategies available in particular settings, and a need to reassess the relative importance of income generating activities and subsistence agriculture in areas undergoing agricultural change.