Benefits and risks associated with meat consumption during key life processes and in relation to the risk of chronic diseases

Red meat has been an important part of the diet throughout human evolution. Overall, when included as part of a healthy and varied diet, red meat can provide a rich source of bioavailable essential nutrients and high biological value protein. The present paper discusses the dietary role/impact of red and processed meat, with some reference to the relative effect of white meat, in a range of chronic conditions including iron-deficiency anaemia, cardiovascular diseases (CVD), cancer and dementia. The role of red meat in relation to key physiological conditions such as maintaining skeletal muscle and bone health and during pregnancy is also discussed. The inclusion of lean red meat in a healthy, varied diet may be beneficial during these critical conditions. There is however increasing evidence that red meat and especially processed meat are associated with increased risks of CVD, cancer and dementia whereas white meat is neutral or associated with a lower risk. There now seems little doubt that processed and unprocessed meat should have separate public dietary guidance

Relative bioefficacy of RRR-α-tocopherol versus all-rac-α-tocopherol in in vitro models

The aim of this study was to evaluate the in vitro relative bioefficacy of RRR-α-tocopherol (RRR- α-T) versus all-rac-α-tocopherol (all-rac-α-T) in counteracting the cytotoxic effect induced by H2O2 in Bovine Mammary Epithelium – University of Vermont (BME-UV1) and Madin-Darby Canine Kidney (MDCK) cells. The range of RRR- α-T and all-rac- α-T concentrations selected for the oxidative challenge experiments was 100µM - 1nM. To study the bioefficacy of RRR- α-T and all-rac- α-T, MTT and LDH tests were performed. Cells were pre-incubated for 3 h with  selected a-tocopherol concentrations and then exposed to increasing H2O2 concentrations ranging from 125 to 750µM for the following 24h. Concerning the cell viability, the pre-treatments with 100µM of RRR- α-T and 100µM all-rac-α-T were able to significantly (P<0.05) counteract the effect induced by 750 µM of H2O2 in BME-UV1. In MDCK the pre-treatment with 1nM of all-rac-α-T was able to significantly (P<0.05) reduce the effect of 125 and 150 mM H2O2. In MDCK cells, the pre-incubation with all-rac-α-T determines a significant reduction of the membrane damage, induced by 175 µM of H2O2. In conclusion, RRR-α-T and all-rac-α-T have shown the ability to counteract the oxidative effects of H2O2, however further investigation will help to better understand their specific mechanism of action in vitro.  

Effect of Zinc Oxide and Zinc Chloride on Human and Swine Intestinal Epithelial Cell Lines

Zinc (Zn) salts are often used as nutritional additives in order to promote gut health. The aim of the present study was to assess the effect of two widely used additives in feedstuff, on the intestinal epithelium. In particular, the effect of zinc oxide (ZnO) and zinc chloride (ZnCl2) was investigated in human (INT-407) and porcine (IPI-2I) cell line models. The effect of Zn sources on IPI-21 and INT-407 cell lines was evaluated by a colorimetric viability test using an incubation period of 3 and 24 hours under serum-free conditions. INT407 and IPI-2I showed to be a suitable model of the intestine and a simple tool to investigate the role of Zn supplements. INT407 showed to be the most sensible model to Zn supplements considered, whereas IPI-2I were more resistant. The results of this study contribute to determine the role of zinc in human and swine intestinal epithelium. However, further in vivo experiments may be done to clarify the contribution of Zn supplements in gut health and to improve Zn supplementation in animal feed and in human formulations

Antioxidant and Antimicrobial Activity of Algal and Cyanobacterial Extracts: An In Vitro Study

Algae and cyanobacteria, other than their nutritional value, possess different beneficial properties, including antioxidant and antimicrobial ones. Therefore, they can be considered functional ingredients in animal feed and natural substitutes for antibiotics. The aim of this study was to evaluate the antioxidant and antimicrobial capacity against porcine O138 E. coli of Ascophyllum nodosum, Chlorella vulgaris, Lithotamnium calcareum, Schizochytrium spp. as algal species and Arthrospira platensis as cyanobacteria. The antioxidant capacity was determined by ABTS Radical Cation Decolorization Assay testing at three different concentrations (100%; 75%; 50%). The growth inhibition effect of the extracts at concentrations of 25%, 12.5%, 6%, 3% and 1.5% against porcine O138 E. coli was genetically characterized by PCR to detect the presence of major virulence factors; this was evaluated by following the microdilution bacterial growth method. The ABTS assay disclosed that Ascophyllum nodosum was the compound with the major antioxidant properties (57.75 ± 1.44 percentage of inhibition; p < 0.0001). All the extracts tested showed growth inhibition activity at a concentration of 25%. Among all extracts, A. nodosum was the most effective, showing a significant growth inhibition of E. coli; in particular, the log(10) cells/mL of E. coli used as a control resulted in a significantly higher concentration of 25% and 12.5% after 4 h (8.45 ± 0.036 and 7.22 ± 0.025 log(10) cells/mL, respectively; p < 0.005). This also suggests a dose-dependent relationship between the inhibitory activity and the concentration. Also, a synergistic effect was observed on antioxidant activity for the combination of Ascophyllum nodosum and Lithotamnium calcareum (p < 0.0001). Moreover, to determine if this combination could affect the viability of the IPEC-J2 cells under the normal or stress condition, the viability and membrane integrity were tested, disclosing that the combination mitigated the oxidative stress experimentally induced by increasing the cell viability. In conclusion, the results obtained highlight that the bioactive compounds of algal species are able to exert antioxidant capacity and modulate O138 E. coli growth. Also, the combination of Ascophyllum nodosum and Lithotamnium calcareum species can enhance their bioactivity, making them a promising functional feed additive and a suitable alternative to antibiotics

Proteomic/peptidomic profile and Escherichia coli growth inhibitory effect of in vitro digested soya protein

Plant proteins contain bioactive peptides with functional properties and physiological activities. In the present work, the bioactive peptides produced during in vitro gastrointestinal digestion of soya protein isolate were investigated. Protein samples were subjected to simulated gastrointestinal digestion with a generation of permeate (3 kDa) fractions. The permeate was analysed by nano-liquid chromatography electrospray ionisation tandem mass spectrometry (LC-nano ESI MS/MS) using a shotgun peptidomic approach, and the retentate was further digested with trypsin and analysed using a shotgun proteomic approach. Based on protein profile observed, the retentate was further tested for its potential antimicrobial activity by evaluating the inhibitory effect on E. coli growth. In the present study the peptidomic/ proteomic characterisation of permeate and retentate fractions revealed the presence of bioactive peptides and proteins associated with antioxidant, ACE-inhibitory, anti-hypertensive and antimicrobial activities. The presence of potentially antimicrobial proteins in the retentate fraction is supported by a marked E. coli F18þ growth inhibitory activity of the same fraction. In particular, the growth inhibitory effect was significant from one until six hours of incubation with 0.65–2.6 mg/ml of in vitro digested soya. The obtained data confirmed that soya-based supplements may have potential beneficial effects after human consumption, and they may be recycled for animal nutrition in line with the circular economy concept

In vitro digested milk proteins: Evaluation of angiotensin-1-converting enzyme inhibitory and antioxidant activities, peptidomic profile, and mucin gene expression in HT29-MTX cells

Over the past decades, several studies investigated the health-promoting functions of milk peptides. However, to date many hurdles still exist regarding the widespread use of milk-derived bioactive peptides, as they may be degraded during gastrointestinal digestion. Thus, the aim of our study was to in vitro digest intact whey protein isolate (WPI) and casein proteins (CNP), mimicking in vivo digestion, to investigate their bioactive effects and to identify the potential peptides involved. Whey protein isolate and CNP were digested using a pepsin-pancreatin protocol and ultra-filtered (3-kDa cutoff membrane). A permeate (3 kDa) were obtained. Soy protein was included as a control (CTR). Angiotensin-1-converting enzyme inhibitory (ACE1-I) and antioxidant activity (AOX) were assessed and compared with those observed in undigested proteins and CTR. Furthermore, the permeate was characterized by nano-liquid chromatography electrospray ionization tandem mass spectrometry (LC-nano ESI MS/MS) using a shotgun peptidomic approach, and retentate was further digested with trypsin and analyzed by MS using a shotgun proteomic approach to identify potentially bioactive peptides. Further, the effects of WPI, CNP, and CTR retentate on cell metabolic activity and on mucus production (MUC5AC and MUC2 gene expression) were assessed in intestinal goblet HT29-MTX-E12 cells. Results showed that WPI permeate induced a significant ACE1-I inhibitory effect [49.2 ± 0.64% (SEM)] compared with undigested WPI, CNP permeate, and retentate or CTR permeate (10.40 ± 1.07%). A significant increase in AOX (1.58 ± 0.04 and 1.61 ± 0.02 µmol of trolox AOX equivalents per mg of protein, respectively) upon digestion was found in WPI. Potentially bioactive peptides associated with ACE1-I and antihypertensive effects were identified in WPI permeate and CNP retentate. At specific concentrations, WPI, CNP, and CTR retentate were able to stimulate metabolic activity in HT29-MTX-E12 cells. Expression of MUC5AC was increased by CNP retentate and unaltered by WPI retentate; MUC2 expression was significantly increased by 0.33 mg/g of CNP and reduced by 1.33 mg/g of CNP. Our results confirm that milk proteins may be rich sources of bioactive compounds, with the greatest beneficial potential of CNP at the intestinal goblet cell level

Whey protein lowers blood pressure and improves endothelial function and lipid biomarkers in adults with prehypertension and mild hypertension: results from the chronic Whey2Go randomized 1,2 controlled trial

Background: Cardiovascular diseases (CVDs) are the greatest cause of death globally, and their reduction is a key public-health target. High blood pressure (BP) affects 1 in 3 people in the United Kingdom, and previous studies have shown that milk consumption is associated with lower BP. Objective: We investigated whether intact milk proteins lower 24-h ambulatory blood pressure (AMBP) and other risk markers of CVD. Design: The trial was a double-blinded, randomized, 3-way–crossover, controlled intervention study. Forty-two participants were randomly assigned to consume 2 × 28 g whey protein/d, 2 × 28 g Ca caseinate/d, or 2 × 27 g maltodextrin (control)/d for 8 wk separated by a 4-wk washout. The effects of these interventions were examined with the use of a linear mixed-model ANOVA. Results: Thirty-eight participants completed the study. Significant reductions in 24-h BP [for systolic blood pressure (SBP): −3.9 mm Hg; for diastolic blood pressure (DBP): −2.5 mm Hg; P = 0.050 for both)] were observed after whey-protein consumption compared with control intake. After whey-protein supplementation compared with control intake, peripheral and central systolic pressures [−5.7 mm Hg (P = 0.007) and −5.4 mm Hg (P = 0.012), respectively] and mean pressures [−3.7 mm Hg (P = 0.025) and −4.0 mm Hg (P = 0.019), respectively] were also lowered. Flow-mediated dilation (FMD) increased significantly after both whey-protein and calcium-caseinate intakes compared with control intake [1.31% (P < 0.001) and 0.83% (P = 0.003), respectively]. Although both whey protein and calcium caseinate significantly lowered total cholesterol [−0.26 mmol/L (P = 0.013) and −0.20 mmol/L (P = 0.042), respectively], only whey protein decreased triacylglycerol (−0.23 mmol/L; P = 0.025) compared with the effect of the control. Soluble intercellular adhesion molecule 1 and soluble vascular cell adhesion molecule 1 were reduced after whey protein consumption (P = 0.011) and after calcium-caseinate consumption (P = 0.039), respectively, compared with after control intake. Conclusions: The consumption of unhydrolyzed milk proteins (56 g/d) for 8 wk improved vascular reactivity, biomarkers of endothelial function, and lipid risk factors. Whey-protein supplementation also lowered 24-h ambulatory SBP and DBP. These results may have important implications for public health. This trial was registered at clinicaltrials.gov as NCT02090842

Benefits and Risks Associated with Meat Consumption during Key Life Processes and in Relation to the Risk of Chronic Diseases

Red meat has been an important part of the diet throughout human evolution. Overall, when included as part of a healthy and varied diet, red meat can provide a rich source of bioavailable essential nutrients and high biological value protein. The present paper discusses the dietary role/impact of red and processed meat, with some reference to the relative effect of white meat, in a range of chronic conditions including iron-deficiency anaemia, cardiovascular diseases (CVD), cancer and dementia. The role of red meat in relation to key physiological conditions such as maintaining skeletal muscle and bone health and during pregnancy is also discussed. The inclusion of lean red meat in a healthy, varied diet may be beneficial during these critical conditions. There is however increasing evidence that red meat and especially processed meat are associated with increased risks of CVD, cancer and dementia whereas white meat is neutral or associated with a lower risk. There now seems little doubt that processed and unprocessed meat should have separate public dietary guidance

Evaluation of the Absorption of Methionine Carried by Mineral Clays and Zeolites in Porcine Ex Vivo Permeability Models

Supplemental dietary amino acids (AAs) need to be provided in a form that prevents their degradation along the gastrointestinal tract to guarantee their high bioavailability and bioactivity. In this study, methionine (Met) protected via organo-clay intercalation (natural carriers) has been developed as a sustainable alternative to polymeric coating. Specifically, two different bentonite-zeolite-based mineral clays were tested, Adsorbene (ADS) and BioKi (BIO). Briefly, 1 g of the carrier (ADS or BIO) was contacted with 50 mL of an aqueous solution at a pH of 3.0, 5.8, and 8.9. Solid-liquid separation was conducted. The released Met in the liquid phase was analysed by Chemical Oxygen Demand, while residual Met in the solid phase was analysed by Fourier Transform Infra-Red (FT-IR) spectroscopy. The effect of Met-ADS complex on cell viability was tested on IPEC-J2 cells incubated 3 h with Met-ADS 2.5 mM. Jejunum segments obtained by entire male pigs (Swiss Large White, body weight 100 ± 5 kg) were used as ex vivo models to compare the absorption of 2.5 mM Met released by ADS with 2.5 mM free Met and its influence on epithelial integrity in perfusion Ussing chambers. The carriers released a very low amount of Met and Met-BIO interaction was stronger than Met-ADS. The maximum release of Met was at pH 3, with 3% and 6% of Met release from Met-BIO and Met-ADS, respectively. Cell viability experiments revealed that Met-ADS did not alter cell metabolic activity. No differences in Met absorption and intestinal epithelial integrity were observed ex vivo between free Met and Met-ADS. This study provided new insights into the release of Met from natural clays such as ADS and BIO, the safety of its use in the porcine intestine and the ability of ADS-released Met to absorb to the same extent as the free Met in porcine jejunum