Bioavailability Of Amino Acids Research Articles

Hydrolyzed collagen supplementation prior to resistance exercise augments collagen synthesis in a dose-response manner in resistance-trained, middle-aged men.

Resistance exercise (RE) increases collagen synthesis in young and older men, while hydrolyzed collagen (HC) ingestion improves this response to RE in a dose-response manner in young men. However, the collagen synthesis response to RE with and without HC in middle-aged men is unknown. Eight resistance-trained men (age: 49±8 years; height: 1.78±0.02m; mass: 90±4kg) took part in this double-blind, crossover design study, and undertook 4×10 repetitions of lower-limb RE at maximum load, after consuming 0g, 15g, or 30g vitamin C-enriched HC. We analyzed venous blood samples for N-terminal propeptide of type 1 pro-collagen (PINP), β-isomerized C-terminal telopeptide of type 1 collagen (β-CTx) and 18 collagen amino acids throughout all three interventions. The serum PINP concentration×time area-under-the-curve (AUC) was higher following 30g (169±28 µg/mL×h) than 15g (134±23 µg/mL×h, P<0.05) HC ingestion, and both 15g and 30g were higher than 0g HC (96±23 µg/mL×h, P<0.05). RE with 0g HC showed no change in serum PINP concentration. The AUCs for glycine, proline, hydroxyproline, alanine, arginine, lysine, serine, leucine, valine and isoleucine were greater with 30g than 15g and 0g HC ingestion (P<0.05), and greater with 15g than 0g HC ingestion (P<0.05). Plasma β-CTx concentration decreased after RE independently of HC dose. Our study suggests connective tissue anabolic resistance to RE in middle-aged men but ingesting 15g HC rescues the collagen synthesis response, and 30g augments that response further. This dose-response is associated with the increased bioavailability of collagen amino acids in the blood, which stimulate collagen synthesis.

Dietary protein splanchnic uptake and digestibility via stable isotope tracers.

Dietary proteins are broken down into peptides across the gastrointestinal tract, with skeletal muscle being a primary deposition site for amino acids in the form of incorporation into, for example, metabolic and structural proteins. It follows that key research questions remain as to the role of amino acid bioavailability, of which protein digestibility and splanchnic sequestration (absorption and utilization) of amino acids are determining factors, impact upon muscle protein synthesis (MPS) in clinical states. Elevated splanchnic amino acid uptake has been implicated in anabolic resistance (i.e. attenuated anabolic responses to protein intake) observed in ageing, though it is unclear whether this limits MPS. The novel 'dual stable isotope tracer technique' offers a promising, minimally invasive approach to quantify the digestion of any protein source(s). Current work is focused on the validation of this technique against established methods, with scope to apply this to clinical and elderly populations to help inform mechanistic and interventional insights. Considerations should be made for all facets of protein quality; digestibility of the protein, absorption/utilization and subsequent peripheral bioavailability of amino acids, and resultant stimulation of MPS. Stable isotope tracer techniques offer a minimally invasive approach to achieve this, with wide-ranging clinical application.

In vitro evaluation of algae and their effect as dietary ingredient on growth, chemical composition and intestinal functionality in juvenile turbot (Scophthalmus maximus)

The objectives of this study were to evaluate the in vitro protein hydrolysis of five algae (Arthrospira sp., Chlorella sp., Tisochrysis sp., Microchloropsis sp. and Ulva rigida) by the digestive proteases of Scophthalmus maximus, and to assess the effect of feeding turbot juveniles on diets supplemented with these algae in a 60-day feeding trial. The in vitro results revealed that algal protein was hydrolysed by turbot digestive proteases. Besides, the quantification of total amino acids released during the in vitro hydrolysis evidenced noticeable amino acid bioavailability, mainly in the case of Arthrospira sp. with up to 42.7% of the amino acids released after 120 min of in vitro hydrolysis. However, the structural characteristics of cell wall of each species influenced the protein accessibility as evidenced by the lower values obtained in Microchloropsis sp. For the in vivo feeding trial, 255 specimens of turbot, with an average initial weight of 26.4 ± 7.6 g, were used, and were fed with diets including 5% and 10% of a blend of the same microalgae tested in vitro (M5 and M10) or U. rigida (U5 and U10), compared to a control feed without algal biomass (CT). At the end of the feeding trial, growth performance and nutrient utilization did not show differences among the experimental groups. In addition, the fish fed with the diets supplemented with algae showed lower lipid oxidation in the muscle, and an improvement in digestive functionality, as the activity of pancreatic and intestinal enzymes increased. The ultrastructural study of the intestinal mucosa revealed an increase in the length of the microvilli and the absorptive surface in fish fed with the algae-supplemented diets, as well as decreased thickness of the lamina propria and the number of goblet cells. These results confirmed that the supplementation of turbot juvenile diets with low percentage of microalgae or U. rigida is appropriate for improving digestive functionality, as well as reducing the oxidation of lipids in the muscle.

Protein Nutrition: Understanding Structure, Digestibility, and Bioavailability for Optimal Health.

This review discusses different protein sources and their role in human nutrition, focusing on their structure, digestibility, and bioavailability. Plant-based proteins, such as those found in legumes, nuts, and seeds, may contain anti-nutritional factors that impact their bioavailability apart from structural and compositional differences from animal proteins. Animal proteins are generally highly digestible and nutritionally superior to plant proteins, with higher amino acid bioavailability. Alternative protein sources are also processed in different ways, which can alter their structure and nutritional value, which is also discussed.

Metabolic availability of amino acids in humans.

Knowledge of amino acid bioavailability and the effect of combining complementary protein sources are required to determine how to best meet an individual's protein and indispensable amino acid needs. Traditionally, protein quality of foods has been assessed using digestibility data. Digestibility may overestimate bioavailability of some amino acids particularly those more susceptible to heat and processing. The indicator amino acid oxidation (IAAO) method has been validated and applied to determine amino acid bioavailability termed metabolic availability of the first limiting amino acid of a proteinaceous food. The metabolic availability of the limiting amino acid in the test protein is determined as a ratio of the indicator amino acid oxidation response to graded intakes of the test protein compared to the indicator response to a reference protein (crystalline amino acid patterned after egg protein). The IAAO method has also been applied to assess the effect of protein complementation directly in humans on the overall protein quality of the diet. The results demonstrate that protein complementation augments the limiting amino acid supply and increases protein synthesis.

246 The effect of trypsin inhibitor unit concentrations from raw soybeans in grower pig performance and protein digestibility

Abstract Soybeans contain two major protease inhibitors, Kunitz trypsin and Bowman-Birk protease inhibitors, both of which are anti-nutritional components that can be directly linked to a reduction in amino acid bioavailability and growth performance in swine. Therefore, the objective of this study was to determine the level at which trypsin inhibitor units (TIU, expressed as TIU/mg of complete feed), coming from raw soybeans, in pig diets result in reduction in growth performance and digestibility. This study used 45 grower gilts initial body weight (BW) = 39.7 ± 2.1 kg] that were individually penned and fed one of five dietary TIU treatments (n = 9 pigs/trt) in a complete randomized design. Diets were representative of a commercial corn-soybean meal diet and formulated to have ranging TIU/mg of complete feed of 0.89, 1.77, 3.55, 6.99, and 11.54 TIU/mg utilizing raw ground soybeans and soybean meal at incremental levels. Analyzed diets contained 0.99, 2.23, 3.07, 6.49, and 9.38 active TIU/mg. Diets were balanced to the same grams of SID Lys:ME of 2.85 and NDF concentration of 7.4% utilizing soybean oil and soybean hulls, respectively. Individual feed intake was recorded throughout, and pig BW were collected on d 0, 21, and 27 to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency gain to feed ratio (G:F). All pigs were placed into metabolism crates on d 21 for 6 d to determine apparent total tract digestibility (ATTD) of nitrogen (N), N excretion and N balance. Growth performance and ATTD data were analyzed with pig as the experimental unit and diet TIU level as a fixed effect using ANOVA, linear, and quadratic contrast models. Overall, ADG decreased as diet TIU increased (1.07, 1.03, 1.02, 0.91, and 0.83 kg/d, respectively, linear P &amp;lt; 0.001). However, no differences in ADFI (P &amp;gt; 0.10) were reported and this resulted in a decrease in G:F (0.48, 0.45, 0.43, 0.41, 0.36, respectively, linear P &amp;lt; 0.001) as dietary TIU concentrations increased from 0.99 to 9.38 TIU/mg. Compared with 0.99 TIU/mg, pigs fed 9.38 TIU/mg had a 9.32% reduction in final BW (68.7 vs. 62.3 kg, linear P &amp;lt; 0.001). Apparent total tract digestibility of N decreased when pigs were fed 9.38 TIU/mg compared with 0.99 and 2.23 TIU/mg (83.26% vs. 90.29% and 89.57%, respectively, P &amp;lt; 0.001). In conclusion, as total trypsin inhibitor units increase in complete feed of grower pigs, digestibility of protein, growth rates and feed efficiency are reduced in a linear manner.

137 Impact of dietary soybean-mediated trypsin inhibitor concentrations on nursery pig performance

Abstract Antinutritional factors associated with soybeans and soy products, such as trypsin inhibitor proteins, have been shown to hinder amino acid bioavailability and, consequently, affect the growth performance of pigs. Thus, our objective was to assess the impact of dietary trypsin inhibitor units (TIU; expressed as TIU/mg of feed) on nursery pig performance and health. Sixty barrows [5.56 ± 0.65 kg body weight (BW), Camborough (1050) x 337, (PIC, Hendersonville, TN)], freshly weaned and 19 to 21 d of age were randomly selected and allotted across six dietary treatments (10 pigs/treatment) in a randomized complete block design. All pigs were individually penned with ad libitum access to water and feed. Diets were administered in two phases directly post-weaning, spanning 14 and 28 d, respectively, and the entire test period extended for 42 d. Within each phase, diets were formulated to be isocaloric, with uniform NDF and SID lysine concentrations. In both phases, TIU were incrementally adjusted by the inclusion of soybean meal, raw ground soybeans, soybean oil, and soyhulls to attain a target TIU/mg feed of 0.5, 1, 2, 3, 4, and 6. All diets were analyzed for active TIU/mg. Pig BW and feed disappearance were measured at the start and end of each phase to compute average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Fecal consistency was assessed daily in phase 1. Pig was the experimental unit and data were analyzed with the effect of diet, including the linear and quadratic contrasts, evaluating dietary TIU levels. The average analyzed TIU/mg over both diet phases were 0.38, 0.54, 1.85, 3.16, 3.90, and 5.79 TIU/mg diet, respectively. Fecal consistency scores did not differ across diets. At the end of phase 1, BW decreased from 8.7 to 6.9 kg as TIU/mg diet increased from 0.38 to 5.79 (linear P &amp;lt; 0.05). Similarly, by d 42, BW decreased from 25.3 to 15.5 kg with the increase in dietary TIU/mg from 0.38 to 5.79 (linear P &amp;lt; 0.0001). Both phase 1 and 2 showed a decrease in average daily gain (ADG) and G:F as TIU increased (linear P &amp;lt; 0.05). ADFI exhibited a decreasing trend in phase 1 (linear P = 0.079) and a decrease in phase 2 (linear P &amp;lt; 0.05) as dietary TIU increased. No quadratic responses were reported for ADG and G:F. Overall, as TIU increased, ADG, ADFI, and G:F were reduced, with 5.79 TIU/mg feed resulting in a decrease of these parameters by 8 to 22% (linear P &amp;lt; 0.01). In conclusion, increasing TIU levels in the diet had detrimental effects on nursery pig performance. The most significant negative impacts on growth, feed intake, and feed efficiency were observed in diets containing 3.16 to 5.79 TIU/mg feed.

Metabolism-dependent secondary effect of anti-MAPK cancer therapy on DNA repair.

Amino acid bioavailability impacts mRNA translation in a codon-dependent manner. Here, we report that the anti-cancer MAPK inhibitors (MAPKi) decrease the intracellular concentration of aspartate and glutamate in melanoma cells. This coincides with the accumulation of ribosomes on codons corresponding to these amino acids and triggers the translation-dependent degradation of mRNAs encoding aspartate- and glutamate-rich proteins, involved in DNA metabolism such as DNA replication and repair. Consequently, cells that survive MAPKi degrade aspartate and glutamate likely to generate energy, which simultaneously decreases their requirement for amino acids due to the downregulation of aspartate- and glutamate-rich proteins involved in cell proliferation. Concomitantly, the downregulation of aspartate- and glutamate-rich proteins involved in DNA repair increases DNA damage loads. Thus, DNA repair defects, and therefore mutations, are at least in part a secondary effect of the metabolic adaptation of cells exposed to MAPKi.

Measuring bioavailability, utilization, and excretion of rumen-protected lysine in lactating cows using an isotope technique

Supplementing a diet with rumen-protected amino acids (AAs) is a common feeding strategy for efficient production. For a cost-effective use of rumen-protected AA, the accurate bioavailability of rumen-protected amino acids should be known and their metabolism after absorption needs to be well understood. The current study determined the bioavailability, absorption, utilization, and excretion of rumen-protected Lys (RP-Lys). Four ruminally cannulated cows in a 4 × 4 Latin square design (12 d for diet adaptation; 5 or 6 d for total collections) received the following treatments: L0, a basal diet; L25, the basal diet and L-Lys infused into the abomasum to provide 25.9 g/d L-Lys; L50, the basal diet and L-Lys infused into the abomasum to provide 51.8 g/d L-Lys; and RPL, the basal diet supplemented with 105 g/d (as-is) of RP-Lys to provide 26.7 g of digestible Lys. During the last 5 or 6 d in each period, 15N-Lys (0.38 g/d) was infused into the abomasum for all cows to label the pool of AA, and the total collection of milk, urine, and feces were conducted. 15N enrichment of samples on d 4 and 5 were used to calculate the bioavailability and Lys metabolism. We used a model containing a fast AA turnover (≤ 5 d) and slow AA turnover pool (> 5 d) to calculate fluxes of Lys. The Lys flux to the fast AA turnover pool (absorbed Lys + Lys from the slow AA turnover pool to fast AA turnover pool) was calculated using 15N enrichment of milk Lys. The flux of Lys from the fast AA turnover pool to milk and urine was calculated using 15N transfer into milk and urine. Then, absorbed Lys was estimated by the sum of Lys flux to milk and urine assuming no net utilization of Lys by body tissues. Duodenal Lys flow was estimated by 15N enrichment of fecal Lys. The bioavailability of RP-Lys was calculated from duodenal Lys flows and Lys absorption for RPL. Increasing Lys supply from L25 to L50 increased Lys utilization for milk by 9 g/d but also increased urinary excretion by 10 g/d. For RPL, absorbed Lys was estimated to be 136 g/d where 28 g of absorbed Lys originated from RP-Lys. In conclusion, 68% of bioavailability was obtained for RP-Lys. The Lys provided from RP-Lys was not only utilized for milk protein (48%) but also excreted in urine (20%) after oxidation.

Effects of heating soybeans on postruminal amino acid bioavailability, performance, and ruminal fermentation in lactating cows.

Soybeans can provide ruminally degradable protein, lipid, and metabolizable amino acid (AA) to lactating dairy cows; however, soy-based trypsin inhibitors can limit protein digestion in nonruminants. Eight ruminally cannulated lactating Holstein cows were used to evaluate the impacts of soy-based trypsin inhibitors on nutrient disappearance, lactation, and plasma AA bioavailability. Treatments were abomasal infusion of 0 or 400g/d casein or a crystalline AA analog of casein with unroasted or roasted soybeans fed at 10% dry matter (DM). Data were analyzed using the MIXED procedure of SAS. Measures of digestion were determined from fecal output determined with acid detergent insoluble ash and urine output determined from measures of urine creatinine. Neither soybean processing (P ≥ 0.20) nor the source of abomasal infusion (P ≥ 0.60) impacted nutrient digestibility. Ruminal ammonia, isobutyrate, and isovalerate were increased (P ≤ 0.01) among cattle consuming unroasted soybeans. Source of infusion did not affect (P ≥ 0.38) ruminal volatile fatty acids or nitrogen metabolism. Ruminal N metabolism was largely unaffected by soybean processing although microbial N efficiency was greater (P < 0.01) among cows fed unroasted soybeans. DM intake and energy-corrected milk were greater (P < 0.01) in cows fed roasted compared to unroasted soybeans. The proportion of fat, protein, lactose, and solids not fat (SNF) in milk did not differ between soybean processing or postruminal AA source, but fat, protein, lactose, and SNF yield was greater (P ≤ 0.01) when cows were fed roasted soybeans because milk yields were greater when cows were fed roasted vs. unroasted soybeans. As expected, infusion of casein or its crystalline AA analog increased plasma essential AA and milk urea nitrogen concentration. The rate of increase in essential AA concentration in plasma was 2.9× greater for casein than for crystalline AA. These data seem to indicate that soy-based trypsin inhibitors have no impacts on postruminal AA bioavailability when fed to cows and that metabolizable protein from casein is greater than from crystalline AA.

Bioavailability of essential amino acids after ingestion of fortified biscuits with a mixture of essential amino acid in healthy subjects

Bioavailability of essential amino acids after ingestion of fortified biscuits with a mixture of essential amino acid in healthy subjects

A review on nutritional quality of animal and plant-based milk alternatives: a focus on protein.

In recent years, the demand of consumers for products rich in protein is of significant growth. Due to its structure in tissues, protein is considered an essential nutrient for maintenance and growth. It is well known that dairy foods differ from plant-based milk alternatives in their composition. In addition to protein content, nutrients in milk and plant-based beverages vary greatly in composition and content, such as: Calcium, fiber and fat. The nutritional quality of dairy protein sources depends on both their amino acid composition and bioavailability. Indeed, dairy products are considered to be excellent sources of proteins with high Digestible Indispensable Amino Acid Score (DIAAS) values varying from 100 to 120. However, plant proteins are considered to have generally lower essential amino acid contents and lower DIAAS values than dairy proteins. For example, pea and rice proteins are known to have medium and lower DIAAS with values of 62 and 47, respectively. The present review is dedicated to study the nutritional quality of animal and plant-based milk alternatives, where a focus on protein composition and amount are determined.

Current advances for in vitro protein digestibility.

Protein is an essential macronutrient in our diet, source of nitrogen and essential amino acids, but the biological utilization of dietary protein depends on its digestibility and the absorption of amino acids and peptides in the gastrointestinal tract. The methods to define the amount and the quality of protein to meet human nutritional needs, such as the Digestible Indispensable Amino Acid Score (DIAAS), require the use of animal models or human studies. These in vivo methods are the reference in protein quality evaluation, but they are expensive and long-lasting procedures with significant ethical restrictions. Therefore, the development of rapid, reproducible and in vitro digestion methods validated with in vivo data is an old demand. This review describes the challenges of the in vitro digestion methods in the evaluation of the protein nutritional quality. In addition to the technical difficulties to simulate the complex and adaptable processes of digestion and absorption, these methods are affected by similar limitations as the in vivo procedures, i.e., analytical techniques to accurately determine bioavailable amino acids and the contribution of the endogenous nitrogen. The in vitro methods used for the evaluation of protein digestibility, with special attention on those showing comparative data, are revised, emphasizing their pros and cons. The internationally harmonized digestion protocol proposed by the INFOGEST network is being adapted to evaluate protein and amino acid digestibility. The inter-laboratory reproducibility of this protocol was demonstrated for dairy products. The in vivo/in vitro comparability results obtained to date with this protocol for several plant and animal sources are promising, but it requires an extensive validation with a wider range of foods and substrates with known in vivo digestibility. These in vitro methods will probably not be applicable to all foods, and therefore, it is important to identify their limitations, not to elude their use, but to apply them within the limits, by using the appropriate standards and references, and always as a complementary tool to in vivo tests to reduce their number.

Influences of Household Processing Methods on Nutritional Composition, Anti-nutritional Factors and Antioxidant Activities of Foxtail Millet

The present investigation aims to study the influence of household processing methods, such as soaking, germination, and steam cooking, on nutritional composition (proximates, amino acids, minerals, and vitamins), antinutrient factors (phytochemicals: tannins, total phenols, phytic acid; enzyme inhibitors: trypsin and α-amylase inhibitors) and antioxidant properties of whole grains of foxtail millet. The contents of total ash (1.42%), fat (3.02 g/100 g), and mineral chromium (12.83 mg/100 g) were found to be high upon soaking. Trypsin inhibitors were reduced from 26.84% (steam cooking) to 12.45% upon soaking. Germination enhanced the contents of protein (11.57 g/100 g), minerals, i.e., Ca (32.48 mg/100 g), P (5.82 mg/100 g), Fe (5.81 mg/100 g), amino acid tyrosine and vitamin B&lt;sub&gt;1&lt;/sub&gt;. A significant decrease in the contents of tannins from 218.93 mg GAE/g (soaking) to 93.93 mg GAE/g), phytic acid from 307.5 mg/g (soaking) to 97.63 mg GAE/g) and α-amylase inhibitors from 35.20% (steam cooking) to 5.61% were recorded upon germination. The TPCs were reduced from 13.63 mg GAE/g (soaking) to 6.81 mg GAE/g upon steam cooking. Germinated grains recorded the highest antioxidant properties based on the scavenging capacity of DPPH (0.59 mg AScE/g), ABTS&lt;sup&gt;+&lt;/sup&gt; (10.77 mg TE/g) radicals and RPA (0.89 mg AScE/g). Overall, different household processing methods altered the composition of nutrients, antinutrients, and antioxidant properties. Germination has enriched the bioavailability of protein, carbohydrates, minerals, amino acids, and antioxidant properties and reduced the anti-nutritional factors, especially phytic acid, tannins, and α- amylase inhibitors.

Enhancing Bioaccessibility of Plant Protein Using Probiotics: An In Vitro Study.

As plant-based diets become more popular, there is an interest in developing innovations to improve the bioaccessibility of plant protein. In this study, seven probiotic strains (Bifidobacterium animalis subsp. lactis B420, B. lactis Bl-04, Lactobacillus acidophilus NCFM, Lacticaseibacillus rhamnosus HN001, Lacticaseibacillus paracasei subsp. paracasei Lpc-37, Lactiplantibacillus plantarum Lp-115, and Lactococcus lactis subsp. lactis Ll-23) were evaluated for their capacity to hydrolyze soy and pea protein ingredients in an in vitro digestion model of the upper gastrointestinal tract (UGIT). Compared to the control digestion of protein without a probiotic, all the studied strains were able to increase the digestion of soy or pea protein, as evidenced by an increase in free α-amino nitrogen (FAN) and/or free amino acid concentration. The increase in FAN varied between 13 and 33% depending on the protein substrate and probiotic strain. The survival of probiotic bacteria after exposure to digestive fluids was strain-dependent and may have affected the strain's capacity to function and aid in protein digestion in the gastrointestinal environment. Overall, our results from the standardized in vitro digestion model provide an approach to explore probiotics for improved plant protein digestion and bioaccessibility of amino acids; however, human clinical research is needed to evaluate the efficacy of probiotics on amino acid absorption and bioavailability in vivo.

Airway metabolic profiling during Streptococcus pneumoniae infection identifies branched chain amino acids as signatures of upper airway colonisation.

Streptococcus pneumoniae is a leading cause of community-acquired pneumonia and bacteraemia and is capable of remarkable phenotypic plasticity, responding rapidly to environmental change. Pneumococcus is a nasopharyngeal commensal, but is responsible for severe, acute infections following dissemination within-host. Pneumococcus is adept at utilising host resources, but the airways are compartmentalised and those resources are not evenly distributed. Challenges and opportunities in metabolite acquisition within different airway niches may contribute to the commensal-pathogen switch when pneumococcus moves from nasopharynx into lungs. We used NMR to characterise the metabolic landscape of the mouse airways, in health and during infection. Using paired nasopharynx and lung samples from naïve animals, we identified fundamental differences in metabolite bioavailability between airway niches. Pneumococcal pneumonia was associated with rapid and dramatic shifts in the lung metabolic environment, whilst nasopharyngeal carriage led to only modest change in upper airway metabolite profiles. NMR spectra derived from the nasopharynx of mice infected with closely-related pneumococcal strains that differ in their colonisation potential could be distinguished from one another using multivariate dimensionality reduction methods. The resulting models highlighted that increased branched-chain amino acid (BCAA) bioavailability in nasopharynx is a feature of infection with the high colonisation potential strain. Subsequent analysis revealed increased expression of BCAA transport genes and increased intracellular concentrations of BCAA in that same strain. Movement from upper to lower airway environments is associated with shifting challenges in metabolic resource allocation for pneumococci. Efficient biosynthesis, liberation or acquisition of BCAA is a feature of adaptation to nasopharyngeal colonisation.

Development of a Rainbow Trout (Oncorhynchus mykiss) Intestinal In Vitro Platform for Profiling Amino Acid Digestion and Absorption of a Complete Diet.

The ever-increasing number and variation of raw materials utilized to provide alternative feed formulations continues to allow for a more sustainable and flexible approach. Testing all these options in vivo is still the most robust and reliable manner to pick the best raw material candidates, but it requires the use of large numbers of animals and is time-consuming and expensive. Therefore, we are developing an in vitro platform that can provide a reliable evaluation of new ingredients. The main aim of this work was to combine an in vitro digestion protocol of extruded, commercially relevant aquafeeds with the exposure of intestinal epithelial cells to the extracted bio-available fraction (BAF). The results show that 250,000 cells/cm2 represents the optimal seeding density and that up to 50% BAF concentration for up to 24 h had no negative effects on the epithelial barrier morphology and function. It is possible to determine amino acid digestibility and bioavailability in all the experimental conditions (with and without BSA, at 25% and 50% dilution) and at all time points (0, 6, and 24 h). However, BAF concentration, the medium used for its dilution, and the length of exposure to the different epithelial cell lines can all influence the results and, therefore, must be selected according to the final aim of the experiment.

PTFS07-04-23 Effects of Consuming Ounce-Equivalent Portions of Animal- vs. Plant-Based Protein Foods on Essential Amino Acids Bioavailability in Young and Older Adults: ACross-Over RCT

PTFS07-04-23 Effects of Consuming Ounce-Equivalent Portions of Animal- vs. Plant-Based Protein Foods on Essential Amino Acids Bioavailability in Young and Older Adults: ACross-Over RCT

Effects of Consuming Ounce-Equivalent Portions of Animal- vs. Plant-Based Protein Foods, as Defined by the Dietary Guidelines for Americans on Essential Amino Acids Bioavailability in Young and Older Adults: Two Cross-Over Randomized Controlled Trials.

The Dietary Guidelines for Americans (DGA) recommends consuming a variety of "Protein Foods" based on "ounce-equivalent" (oz-eq) portions. No study has assessed the same oz-eq portions of animal- vs. plant-based protein foods on essential amino acid (EAA) bioavailability for protein anabolism in young and older adults. We assessed the effects of consuming two oz-eq portions of pork, eggs, black beans, and almonds on postprandial EAA bioavailability in young and older adults. We conducted two investigator-blinded, randomized crossover trials in young (n = 30; mean age ± SD: 26.0 ± 4.9 y) and older adults (n = 25; mean age ± SD: 64.2 ± 6.6 y). Participants completed four testing sessions where they consumed a standardized meal with two oz-eq of either unprocessed lean pork, whole eggs, black beans, or sliced almonds. Blood samples were taken at baseline and 30, 60, 120, 180, 240, and 300 min postprandially. Plasma EAA bioavailability was based on postprandial integrated positive areas under the curve. Participant age did not affect EAA bioavailability among the four protein foods tested. Two oz-eq portions of pork (7.36 g EAA) and eggs (5.38 g EAA) resulted in greater EAA bioavailability than black beans (3.02 g EAA) and almonds (1.85 g EAA) in young and older adults, separately or combined (p < 0.0001 for all). Pork resulted in greater EAA bioavailability than eggs in young adults (p < 0.0001), older adults (p = 0.0007), and combined (p < 0.0001). There were no differences in EAA bioavailability between black beans and almonds. The same "oz-eq" portions of animal- and plant-based protein foods do not provide equivalent EAA content and postprandial bioavailability for protein anabolism in young and older adults.

Muscle Protein Synthesis with a Hybrid Dairy and Plant-Based Protein Blend (P4) Is Equal to Whey Protein in a Murine Ageing Model after Fasting.

P4, a specific combination of dairy proteins (whey and casein) and plant-based protein isolates (pea and soy), has been shown to provide a more balanced amino acid (AA) profile than its single constituent proteins; however, less is known about how this translates to muscle protein synthesis (MPS). The aim of this study was to investigate the effect of P4 compared to whey or casein against fasted control on MPS. C57BL/6J mice, aged 25 months, were fasted overnight, followed by oral gavage of either whey, P4, casein, or water as a fasted control. Thirty minutes after ingestion, puromycin (0.04 µmol∙g-1 bodyweight) was subcutaneously injected; 30-min thereafter, mice were sacrificed. MPS was measured by the SUnSET method, and signalling proteins were determined in the left-tibialis anterior (TA) muscle by the WES technique. AA composition was determined in plasma and right-TA muscle. Dried blood spots (DBS) were analysed for postprandial AA dynamics at 10, 20, 45, 60 min. MPS was 1.6-fold increased with whey (p = 0.006) and 1.5-fold with P4 compared to fasted (p = 0.008), while no change was seen with casein. This was confirmed by a significant increase of phosphorylated/total ratio of 4E-BP1 for both whey (p = 0.012) and P4 (p = 0.001). No changes were observed in p70S6K and mTOR phosphorylation/total ratio with whey or P4. Intramuscular leucine levels were lower for P4 (0.71 µmol∙g dry weight-1) compared to whey (0.97 µmol∙g dry weight-1) (p = 0.0007). Ten minutes postprandial, DBS showed significantly increased blood AA levels of BCAAs, histidine, lysine, threonine, arginine, and tyrosine for P4 versus fasted. In conclusion, a hybrid mix of dairy and plant-based proteins (P4) resulted in a MPS response that was similar to whey protein in aged mice after fasting. This suggests that other anabolic triggers beyond leucine or the well-balanced amino acid profile and bioavailability of the blend benefit stimulation of MPS.