Habitual consumption of high-fibre bread fortified with bean hulls increased plasma indole-3-propionic concentration and decreased putrescine and deoxycholic acid faecal concentrations in healthy volunteers.

Only 6 to 8 % of the UK adults meet the daily recommendation for dietary fibre. Fava bean processing lead to vast amounts of high-fibre by-products such as hulls. Bean hull fortified bread was formulated to increase and diversify dietary fibre while reducing waste. This study assessed the bean hull: suitability as a source of dietary fibre; the systemic and microbial metabolism of its components and postprandial events following bean hull bread rolls. Nine healthy participants (53·9 ± 16·7 years) were recruited for a randomised controlled crossover study attending two 3 days intervention sessions, involving the consumption of two bread rolls per day (control or bean hull rolls). Blood and faecal samples were collected before and after each session and analysed for systemic and microbial metabolites of bread roll components using targeted LC-MS/MS and GC analysis. Satiety, gut hormones, glucose, insulin and gastric emptying biomarkers were also measured. Two bean hull rolls provided over 85 % of the daily recommendation for dietary fibre; but despite being a rich source of plant metabolites (P = 0·04 v. control bread), these had poor systemic bioavailability. Consumption of bean hull rolls for 3 days significantly increased plasma concentration of indole-3-propionic acid (P = 0·009) and decreased faecal concentration of putrescine (P = 0·035) and deoxycholic acid (P = 0·046). However, it had no effect on postprandial plasma gut hormones, bacterial composition and faecal short chain fatty acids amount. Therefore, bean hulls require further processing to improve their bioactives systemic availability and fibre fermentation.

Hemp and buckwheat are valuable sources of dietary amino acids, beneficially modulating gastrointestinal hormones and promoting satiety in healthy volunteers.

PURPOSE: This study evaluated the postprandial effects following consumption of buckwheat, fava bean, pea, hemp and lupin compared to meat (beef); focussing on biomarkers of satiety, gut hormones, aminoacids and plant metabolites bioavailability and metabolism. METHODS: Ten subjects (n = 3 men; n = 7 women; 42 ± 11.8 years of age; BMI 26 ± 5.8 kg/m2) participated in six 1-day independent acute interventions, each meal containing 30 g of protein from buckwheat, fava bean, pea, hemp, lupin and meat (beef). Blood samples were collected during 24-h and VAS questionnaires over 5-h. RESULTS: Volunteers consumed significantly higher amounts of most amino acids from the meat meal, and with few exceptions, postprandial composition of plasma amino acids was not significantly different after consuming the plant-based meals. Buckwheat meal was the most satious (300 min hunger scores, p < 0.05).Significant increase in GLP-1 plasma (AUC, iAUC p = 0.01) found after hemp compared with the other plant-based meals. Decreased plasma ghrelin concentrations (iAUC p < 0.05) found on plant (hemp) vs. meat meal. Several plasma metabolites after hemp meal consumption were associated with hormone trends (partial least squares-discriminant analysis (PLS-DA): 4-hydroxyphenylpyruvic acid, indole 3-pyruvic acid, 5-hydoxytryptophan, genistein and biochanin A with GLP-1, PYY and insulin; 3-hydroxymandelic acid and luteolidin with GLP-1 and ghrelin and 4-hydroxymandelic acid, benzoic acid and secoisolariciresinol with insulin and ghrelin. Plasma branched-chain amino acids (BCAAs), (iAUC, p < 0.001); and phenylalanine and tyrosine (iAUC, p < 0.05) were lower after buckwheat comparison with meat meal. CONCLUSION: Plants are valuable sources of amino acids which are promoting satiety. The impact of hemp and buckwheat on GLP-1 and, respectively, BCAAs should be explored further as could be relevant for aid and prevention of chronic diseases such as type 2 diabetes. Study registered with clinicaltrial.gov on 12th July 2013, study ID number: NCT01898351.

Fruit-Based Beverages Contain a Wide Range of Phytochemicals and Intervention Targets Should Account for the Individual Compounds Present and Their Availability.

Benefits from micronutrients within fruit juice and smoothies are well documented, but fewer studies research the role of phytochemicals. Well-controlled human studies are essential to evaluate their impact, particularly on glucose and lipid regulation but also gastrointestinal health. Planning these studies requires data on the potential molecular targets. Here we report a comprehensive metabolomic (LC-MS) analysis of the phytochemical composition of four commonly consumed beverages, including data on whether they are free to be absorbed early in the gastrointestinal tract or bound to other plant components. Smoothies contained a wide range of phenolics (free and bound), whereas the fruit juices contained higher amounts of fewer compounds. Orange juice was rich in bound hesperidin (1.97 ± 0.39 mg/100 mL) and hydroxycinnamic acids, likely to be delivered to the colon with the potential to have an impact on gut health. Apple juice contained free chlorogenic acid (3.11 ± 1.03 mg/100 mL), phloridzin (0.40 ± 0.03 mg/100 mL), catechin (0.090 ± 0.005 mg/100 mL), and epicatechin (0.38 ± 0.02 mg/100 mL), suggesting potential roles in glucose uptake reduction or positive effects on systemic blood flow. Redox screening established that differences in chemical composition impacted on bioactivity, highlighting the importance of availability from the matrix. This suggests that fruit-based beverage interventions should target specific mechanisms depending on the fruits from which they are comprised and in particular, the availability of the individual constituents.

Availability and dose response of phytophenols from a wheat bran rich cereal product in healthy human volunteers.

SCOPE: Phytophenols present in cereals are metabolised to compounds that could be partly responsible for the reduced risk of chronic diseases and all-cause mortality associated with fibre-rich diets. The bioavailability, form and in vivo concentrations of these metabolites require to be established. MATERIALS AND METHODS: Eight healthy volunteers consumed a test meal containing a recommended dose (40 g) and high dose (120 g) of ready-to-eat wheat bran cereal and the systemic and colonic metabolites determined quantitatively by LC-MS. CONCLUSION: Analysis of the systemic metabolomes demonstrated that a wide range of phytophenols were absorbed/excreted (43 metabolites) within 5 h of consumption. These included 16 of the 21 major parent compounds identified in the intervention product and several of these were also found to be significantly increased in the colon. Not all of the metabolites were increased with the higher dose, suggesting some limitation in absorption due to intrinsic factors and/or the food matrix. Many compounds identified (e.g. ferulic acid and major metabolites) exhibit anti-inflammatory activity and impact on redox pathways. The combination of postprandial absorption and delivery to the colon, as well as hepatic recycling of the metabolites at these concentrations, is likely to be beneficial to both systemic and gut health.

Nutritional and Phytochemical Content of High-Protein Crops.

Sustainable sources of high-protein plants could help meet future protein requirements. Buckwheat, green pea, fava bean, hemp, and lupin were analyzed by proximate analysis and inductively coupled plasma mass spectrometry to determine their macro- and micronutrient contents, and liquid chromatography-mass spectrometry was used to elucidate the phytochemical profiles. The protein contents ranged from 20 to 43% (w/w), and all samples were found to be rich in insoluble fiber: 9-25% (w/w). The selected crops had a favorable micronutrient profile, with phosphorus levels ranging from 2.22 ± 0.05 to 9.72 ± 0.41 g kg-1, while iron levels ranged from 20.23 ± 0.86 to 69.57 ± 7.43 mg kg-1. The crops contained substantial amounts of phytophenolic compounds. In particular, buckwheat was a rich source of pelargonidin (748.17 ± 75.55 mg kg-1), epicatechin (184.1 ± 33.2 mg kg-1), quercetin (35.66 ± 2.22 mg kg-1), caffeic acid (41.74 ± 22.54 mg kg-1), and 3-hydroxyphenylacetic acid (63.64 ± 36.16 mg kg-1); hemp contained p-coumaric acid (84.02 ± 8.10 mg kg-1), cyanidin (58.43 ± 21.01 mg kg-1), protocatechualdehyde (34.77 ± 5.15 mg kg-1), and gentisic acid (31.20 ± 1.67 mg kg-1); and fava bean was the richest source of ferulic acid (229.51 ± 36.58 mg kg-1) and its 5-5' (39.99 ± 1.10 mg kg-1) and 8-5 dimers (58.17 ± 6.68 mg kg-1). Demonstrating that these crops are rich sources of protein, fiber, and phytochemicals could encourage higher consumption and utilization of them as healthy and sustainable ingredients in the food and drink industry.

Nutritional B vitamin deficiency alters the expression of key proteins associated with vascular smooth muscle cell proliferation and migration in the aorta of atherosclerotic apolipoprotein E null mice.

Low B vitamin status is linked with human vascular disease. We employed a proteomic and biochemical approach to determine whether nutritional folate deficiency and/or hyperhomocysteinemia altered metabolic processes linked with atherosclerosis in ApoE null mice. Animals were fed either a control fat (C; 4 % w/w lard) or a high-fat [HF; 21 % w/w lard and cholesterol (0/15 % w/w)] diet with different B vitamin compositions for 16 weeks. Aorta tissue was prepared and global protein expression, B vitamin, homocysteine and lipoprotein status measured. Changes in the expression of aorta proteins were detected in response to multiple B vitamin deficiency combined with a high-fat diet (P < 0.05) and were strongly linked with lipoprotein concentrations measured directly in the aorta adventitia (P < 0.001). Pathway analysis revealed treatment effects in the aorta-related primarily to cytoskeletal organisation, smooth muscle cell adhesion and invasiveness (e.g., fibrinogen, moesin, transgelin, vimentin). Combined B vitamin deficiency induced striking quantitative changes in the expression of aorta proteins in atherosclerotic ApoE null mice. Deregulated expression of these proteins is associated with human atherosclerosis. Cellular pathways altered by B vitamin status included cytoskeletal organisation, cell differentiation and migration, oxidative stress and chronic inflammation. These findings provide new insight into the molecular mechanisms through which B vitamin deficiency may accelerate atherosclerosis.

Expression of cellulosome components and type IV pili within the extracellular proteome of Ruminococcus flavefaciens 007.

BACKGROUND: Ruminococcus flavefaciens is an important fibre-degrading bacterium found in the mammalian gut. Cellulolytic strains from the bovine rumen have been shown to produce complex cellulosome structures that are associated with the cell surface. R. flavefaciens 007 is a highly cellulolytic strain whose ability to degrade dewaxed cotton, but not Avicel cellulose, was lost following initial isolation in the variant 007S. The ability was recovered after serial subculture to give the cotton-degrading strain 007C. This has allowed us to investigate the factors required for degradation of this particularly recalcitrant form of cellulose. METHODOLOGY/PRINCIPAL FINDINGS: The major proteins associated with the bacterial cell surface and with the culture supernatant were analyzed for R. flavefaciens 007S and 007C grown with cellobiose, xylan or Avicel cellulose as energy sources. Identification of the proteins was enabled by a draft genome sequence obtained for 007C. Among supernatant proteins a cellulosomal GH48 hydrolase, a rubrerthyrin-like protein and a protein with type IV pili N-terminal domain were the most strongly up-regulated in 007C cultures grown on Avicel compared with cellobiose. Strain 007S also showed substrate-related changes, but supernatant expression of the Pil protein and rubrerythrin in particular were markedly lower in 007S than in 007C during growth on Avicel. CONCLUSIONS/SIGNIFICANCE: This study provides new information on the extracellular proteome of R. flavefaciens and its regulation in response to different growth substrates. Furthermore it suggests that the cotton cellulose non-degrading strain (007S) has altered regulation of multiple proteins that may be required for breakdown of cotton cellulose. One of these, the type IV pilus was previously shown to play a role in adhesion to cellulose in R. albus, and a related pilin protein was identified here for the first time as a major extracellular protein in R. flavefaciens.

Major phenylpropanoid-derived metabolites in the human gut can arise from microbial fermentation of protein.

SCOPE: Plant secondary metabolites, such as phenolic acids are commonly associated with benefits for human health. Two of the most abundant phenylpropanoid-derived compounds detected in human faecal samples are phenylacetic acid (PAA) and 4-hydroxylphenylacetic acid (4-hydroxyPAA). Although they have the potential to be derived from diets rich in plant-based foods, evidence suggests that these compounds can be derived from the microbial fermentation of aromatic amino acids (AAAs) in the colon. METHODS AND RESULTS: To identify the bacteria responsible, 26 strains representing 25 of the dominant human colonic species were screened for phenyl metabolite formation. Seven strains produced significant amounts of both PAA and 4-hydroxyPAA. These included five out of seven Bacteroidetes (Bacteroides thetaiotaomicron, Bacteroides eggerthii, Bacteroides ovatus, Bacteroides fragilis, Parabacteroides distasonis), and two out of 17 Firmicutes (Eubacterium hallii and Clostridium bartlettii). These species also produced indole-3-acetic acid (IAA), the corresponding tryptophan metabolite, but C. bartlettii showed 100 times higher IAA production than the other six strains. Four strains were further tested and PAA formation was substantially increased by phenylalanine, 4-hydroxyPAA by tyrosine and IAA by tryptophan. CONCLUSION: This study demonstrates that certain microbial species have the ability to ferment all three AAAs and that protein fermentation is the likely source of major phenylpropanoid-derived metabolites in the colon.

Alperujo extract, hydroxytyrosol, and 3,4-dihydroxyphenylglycol are bioavailable and have antioxidant properties in vitamin E-deficient rats--a proteomics and network analysis approach.

SCOPE: Olive products are rich in phenolic compounds, which are natural antioxidants in vitro. We tested the in vivo effects of alperujo, an olive production by-product, as well as hydroxytyrosol and 3,4-dihydroxyphenylglycol (DHPG) isolated from alperujo, on indices and pathways of oxidative and metabolic stress in a vitamin E-deficient rat model. METHODS AND RESULTS: Rats were fed a vitamin E-deficient diet for 10 weeks, followed by this diet supplemented with either 100 mg/kg diet dα-tocopherol, alperujo extract, hydroxytyrosol, or 10 mg/kg diet DHPG, for a further 2 weeks. We detected alperujo phenolics in tissues and blood, indicating they are bioavailable. Alperujo extract partially ameliorated elevated plasma levels of thiobarbituric acid reactive substances and also lowered plasma cholesterol levels, whereas hydroxytyrosol increased plasma triglyceride levels. Proteomics and subsequent network analysis revealed that hepatic mitochondrial aldehyde dehydrogenase (ALDH2), of which protein and activity levels were regulated by dα-tocopherol and olive phenolics, represents a novel central regulatory protein hub affected by the dietary interventions. CONCLUSION: The in vivo free radical scavenging properties of olive phenolics appear relatively modest in our model. But alternative mechanisms, including regulation of ALDH2, may represent relevant antioxidant mechanisms by which dietary olive phenolics could have beneficial impact on cardiovascular health.

Ginger phytochemicals mitigate the obesogenic effects of a high-fat diet in mice: a proteomic and biomarker network analysis.

SCOPE: Natural dietary anti-obesogenic phytochemicals may help combat the rising global incidence of obesity. We aimed to identify key hepatic pathways targeted by anti-obsogenic ginger phytochemicals fed to mice. METHODS AND RESULTS: Weaning mice were fed a high-fat diet containing 6-gingerol (HFG), zerumbone (HFZ), a characterized rhizome extract of the ginger-related plant Alpinia officinarum Hance (high fat goryankang, HFGK) or no phytochemicals (high-fat control, HFC) for 6 wks and were compared with mice on a low-fat control diet (LFC). Increased adiposity in the HFC group, compared with the LFC group, was significantly (p<0.05) reduced in the HFG and HFGK groups without food intake being affected. Correlation network analysis, including a novel residuals analysis, was utilized to investigate relationships between liver proteomic data, lipid and cholesterol biomarkers and physiological indicators of adiposity. 6-Gingerol significantly increased plasma cholesterol but hepatic farnesyl diphosphate synthetase, which is involved in cholesterol biosynthesis was decreased, possibly by negative feedback. Acetyl-coenzyme A acyltransferase 1 and enoyl CoA hydratase, which participate in the ß-oxidation of fatty acids were significantly (p<0.05) increased by consumption of phytochemical-supplemented diets. CONCLUSION: Dietary ginger phytochemicals target cholesterol metabolism and fatty acid oxidation in mice, with anti-obesogenic but also hypercholesterolemic consequences.

Anti-platelet effects of olive oil extract: in vitro functional and proteomic studies.

PURPOSE: Platelets play a key role in haemostasis and wound healing, contributing to formation of vascular plugs. They are also involved in formation of atherosclerosic plaques. Some traditional diets, like the Mediterranean diet, are associated with a lower risk of cardiovascular disease. Components in these diets may have anti-platelet functions contributing to their health benefits. METHODS: We studied the effects of alperujo extract, an olive oil production waste product containing the majority of polyphenols found in olive fruits, through measurement of effects on platelet aggregation and activation in isolated human platelets, and through identification of changes in the platelet proteome. RESULTS: Alperujo extract (40 mg/L) significantly decreased in vitro ADP- (p = 0.002) and TRAP- (p = 0.02) induced platelet activation as measured by the flow cytometry using the antibody for p-selectin (CD62p), but it did not affect the conformation of the fibrinogen receptor as measured by flow cytometry using the antibodies for anti-fibrinogen, CD42a and CD42b. Alperujo extract (100 mg/L) inhibited both collagen- and TRAP-induced platelet aggregation by 5% (p < 0.05), and a combination of hydroxytyrosol and 3,4-dihydroxyphenylglycol were, at least partly, responsible for this effect. Proteomic analysis identified nine proteins that were differentially regulated by the alperujo extract upon ADP-induced platelet aggregation. These proteins represent important mechanisms that may underlie the anti-platelet effects of this extract: regulation of platelet structure and aggregation, coagulation and apoptosis, and signalling by integrin αIIb/ß3. CONCLUSIONS: Alperujo extract may protect against platelet activation, platelet adhesion and possibly have anti-inflammatory properties.

Identification of damaged proteins in human serum using modified Ehrlich's reagent to target protein-bound pyrroles.

Protein-bound pyrroles are a sign of oxidative damage. Here we report a specific method for detecting pyrrole-containing proteins using biotin-labeled Ehrlich's reagent (ER-B). After treatment of either human serum or isolated human serum proteins with various oxidizing agents, damaged, biotin-labeled components could be detected by blotting. Combining the use of ER-B with proteomic techniques allowed human serum proteins susceptible to oxidative damage to be detected and then identified by LC/MS/MS. Identification of such proteins in different human conditions such as obesity, diabetes, and cardiovascular disease should lead to the discovery of new biomarkers and the development of specific assays to monitor health status.