Cooking, Digestion, and In Vitro Colonic Fermentation of Nigerian Wholegrains Affect Phenolic Acid Metabolism and Gut Microbiota Composition.

Wholegrains contain both fibre and phenolic acids (PAs), and their gastrointestinal modifications are critical for their bioavailability and bioactivity. We evaluated the modifications on the PA profile and gut microbiota composition of selected Nigerian wholegrains, following cooking and gastrointestinal digestion. Red fonio, red millet, red sorghum, and white corn were cooked, digested, and fermented using an in vitro colonic model. A total of 26 PA derivatives were quantified in soluble and bound fractions using Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis. DNA samples were analysed using 16S rRNA amplicon sequencing to profile the microbiota composition. The results show that cooking and digestion significantly affected the levels of PAs in all grains (p ≤ 0.05) compared to raw grains. Colonic fermentation resulted in a peak of total soluble PAs at 4-6 h for red sorghum and white corn and at 24 h for red millet and red fonio. Enterobacteriaceae genera were the most abundant at 24 h in all grains studied. 3-hydroxybenzaldehyde correlated positively with the relative abundance of Dorea and the mucus-degrader bacteria Akkermansia (p ≤ 0.05), whereas hydroferulic acid and isoferulic acid levels correlated negatively with Oscillospira and Ruminococcus (p ≤ 0.05), respectively. Our data indicate that cooking, digestion, and colonic fermentation affect the release of bound PAs from wholegrains and, consequently, their metabolic conversion. Furthermore, PA fermentation in the gut is associated with potentially relevant changes in the microbiota. This in vitro study provides the basis for the design of an in vivo human intervention study that can confirm the trends herein observed but also assess the impact on health outcomes.

Prevotella abundance and salivary amylase gene copy number predict fat loss in response to wholegrain diets.

Background: Salivary amylase (AMY1) gene copy number (CN) and Prevotella abundance in the gut are involved in carbohydrate digestion in the upper and lower gastrointestinal tract, respectively; and have been suggested as prognostic biomarkers for weight loss among overweight individuals consuming diets rich in fiber and wholegrains. Objective: We hypothesized that Prevotella abundance would be linked to greater loss of body fat after wholegrain consumption among individuals with low AMY1 CN, but not in those with high AMY1 CN. Methods: We reanalyzed data from two independent randomized ad libitum wholegrain interventions (fiber intake ∼33 g/d for 6-8 weeks), to investigate the relationship between baseline Prevotella abundance and body fat loss among healthy, overweight participants stratified into two groups by median AMY1 CN. Individuals with no detected Prevotella spp. were excluded from the main analysis. Results: In both studies, individuals with low AMY1 CN exhibited a positive correlation between baseline Prevotella abundance and fat loss after consuming the wholegrain diet (r > 0.5, P < 0.05), but no correlation among participants with high AMY1 CN (P ≥ 0.6). Following consumption of the refined wheat control diets, there were no associations between baseline Prevotella abundance and changes in body fat in any of the AMY1 groups. Conclusion: These results suggest that Prevotella abundance together with AMY1 CN can help predict fat loss in response to ad libitum wholegrain diets, highlighting the potential of these biomarkers in personalized obesity management.

Non-linear associations between healthy Nordic foods and all-cause mortality in the NOWAC study: a prospective study.

BACKGROUND: The shape of the associations between intake of foods basic in a healthy Nordic diet and long-term health is not well known. Therefore, we have examined all-cause mortality in a large, prospective cohort of women in Norway in relation to intake of: Nordic fruits and vegetables, fatty fish, lean fish, wholegrain products, and low-fat dairy products. METHODS: A total of 83 669 women who completed a food frequency questionnaire between 1996 and 2004 were followed up for mortality until the end of 2018. Cox proportional hazards regression models were used to examine the associations between consumption of the Nordic food groups and all-cause mortality. The Nordic food groups were examined as categorical exposures, and all but wholegrain products also as continuous exposures in restricted cubic spline models. RESULTS: A total of 8 507 women died during the 20-year follow-up period. Nordic fruits and vegetables, fatty fish and low-fat dairy products were observed to be non-linearly associated with all-cause mortality, while higher intake of lean fish and wholegrain products reduced all-cause mortality. Intake levels and hazard ratios (HR) and 95% confidence intervals (CI) associated with lowest mortality were approximately 200 g/day of Nordic fruits and vegetables (HR 0.83 (95% CI: 0.77-0.91)), 10-20 g/day of fatty fish (10 g/day: HR 0.98 (95% CI: 0.94-1.02)) and 200 g/day of low-fat dairy products (HR 0.96 (95% CI: 0.81-1.01)) compared to no consumption. Consumption of fatty fish ≥ 60 g/day compared to no intake statistically significantly increased the mortality (60 g/day: HR 1.08 (95% CI: 1.01-1.16)), as did consumption of low-fat dairy products ≥ 800 g/day compared to no intake (800 g/day: HR 1.10 (95% CI: 1.02-1.20)). After stratification by smoking status, the observed association between Nordic fruits and vegetables and all-cause mortality was stronger in ever smokers. CONCLUSION: The associations between intake of foods basic in healthy Nordic diets and all-cause mortality may be non-linear. Therefore, assumptions of linear associations between traditional Nordic food groups and health outcomes could lead to wrong conclusions in analyses of healthy Nordic diets.

El papel de los cereales en la nutrición y en la salud en el marco de una alimentación sostenible / The role of cereals in nutrition and health for a sustainable diet

En los últimos años se ha puesto en evidencia el impacto de los sistemas alimentarios en la salud humana y en la del planeta. La transición hacia dietas más saludables y sostenibles se postula como una medida necesaria para abordar las crecientes preocupaciones medioambientales y de salud relacionadas con los sistemas actuales de producción y de consumo de los alimentos.Este trabajo revisa los avances recientes para integrar la sostenibilidad en las recomendaciones dietéticas y en las guías alimentarias poniendo en valor el papel de los cereales como la base de patrones dietéticos saludables y sostenibles. Como particularmente importante se analiza un enfoque que propone un mayor apego a las guías alimentarias existentes como un objetivo más realista y factible para mejorar el impacto medioambiental y de salud de los sistemas alimentarios. En este contexto, los cereales tienen un papel clave al ser un pilar fundamental de los patrones dietéticos saludables y sostenibles por su aporte de energía y de nutrientes a nivel global, así como por los diferentes beneficios para la salud que se asocian con un consumo adecuado de cereales integrales y fibra de cereales. (AU)

Over the last years, the impact of food systems on human and planetary health has been appointed. The transition towards more sustainable and healthier diets is postulated as an urgent measure to address the increasing environmental and health concerns related to the current food production and consumption systems.This work reviews recent developments to integrate sustainability into dietary recommendations and food-based dietary guidelines, recognising the role of cereals as the basis for healthy sustainable dietary patterns. It is worth noting that a change in current eating patterns, to achieve greater adherence to existing official dietary guidelines, is proposed as a more realistic and feasible goal to improve the environmental and health impact of food systems. In this context, cereals play a key role as fundamental pillar of healthy and sustainable dietary patterns, due to their energy and nutrient contribution to human diet worldwide, and the different health benefits associated with an adequate intake of grain fibre and wholegrains. (AU)

Influence of the addition of different ingredients on the bioaccessibility of glucose released from rice during dynamic in vitro gastrointestinal digestion.

Rice represents a primary source of carbohydrates in human nutrition. Upon its consumption, the released sugars are mostly absorbed, categorising rice as a high glycemic index food. Addition of ingredients is common practice when cooking rice, which may affect rice digestibility and influence nutrients absorption in the gastrointestinal (GI) tract, enabling a controlled glucose release. In this sense, rice formulations were submitted to a dynamic in vitro GI model, constituted by reactors that simulates peristalsis coupled to filtration membranes, to evaluate carbohydrates hydrolysis and bioaccessibility. Addition of quinoa and wholegrains reduced carbohydrates hydrolysis (i.e. 38.5 ± 5.08% and 57.98 ± 1.91%, respectively) and glucose bioaccessibility (i.e. 25.92 ± 5.70% and 42.56 ± 1.39%, respectively) when compared with brown rice (i.e. 63.86 ± 2.96% hydrolysed and 44.33 ± 1.88% absorbed). Addition of vegetables significantly decreased sample chewiness and resulted in superior hydrolysis (71.75 ± 7.44%) and glucose absorption (51.61 ± 6.25%).

Sources and Determinants of Wholegrain Intake in a Cohort of Australian Children Aged 12-14 Months.

In the first two years of life, exposure to wholegrain foods may help establish life­long consumption patterns associated with reduced risk of chronic disease, yet intake data are lacking for this age group. This cross­sectional analysis aimed to determine intakes and food sources of wholegrains in a cohort of 828 Australian children aged 12-14 months, and to identify determinants of wholegrain intake. Three non­consecutive days of dietary intake data were collected using a 24­h recall and 2­day estimated food record. The multiple source method was used to estimate usual wholegrain intake, and the multivariable general linear model procedure used to identify associations between usual wholegrain intake and socio­demographic determinants. The mean wholegrain intake was 19.5 (±14) g/day, and the major food sources were ready to eat breakfast cereals (40%) breads and bread rolls (26.6%), flours and other cereal grains (9.4%), and commercial infant foods (8.3%). Lower wholegrain intakes were observed for children whose mothers were born in China (p < 0.001) and other Asian countries (p < 0.001), with the exception of India (p = 0.193); those with mothers aged less than 25 years (p = 0.001) and those with two or more siblings (p = 0.013). This study adds to the weight of global evidence highlighting the need to increase children's intake of foods high in wholegrain, including in the first few years of life.

A Review of Plant-based Diets to Prevent and Treat Heart Failure.

Evidence supporting the role of nutrition in heart failure (HF) incidence and severity is growing. A comprehensive search of online databases was conducted using relevant keywords to identify human studies including diet and HF. Several plant-based diets have consistently been associated with decreased HF incidence and severity, notably the Dietary Approaches to Stop Hypertension (DASH) and Mediterranean diets. Several other plant-based dietary patterns, including low-fat diets and the rice diet, also show promise. Higher dietary quality, as assessed using different scores, seems to provide protective qualities. Fruit, vegetables, legumes and wholegrains appear to be beneficial, whereas red/processed meats, eggs and refined carbohydrates appear harmful. Some evidence suggests detrimental effects of dairy products and poultry, but more research is needed. There is observational and interventional evidence that a plant-based diet high in antioxidants, micronutrients, nitrate and fibre but low in saturated/trans fats may decrease the incidence and severity of HF. Potential mechanisms for this include decreased oxidative stress, homocysteine and inflammation levels, as well as higher antioxidant defence and nitric oxide bioavailability with gut microbiome modulation. Well-designed randomised, controlled nutrition intervention trials specific to HF are urgently required.

Replacing carbohydrate with protein and fat in prediabetes or type-2 diabetes: greater effect on metabolites in PBMC than plasma.

BACKGROUND: Active metabolism of peripheral blood mononuclear cells (PBMC) could suggest their suitability for metabolomics studies. This study examined whether reductions in PBMCs and plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) activities induced by dietary intervention affected the overall metabolic profiles of PBMC and plasma. METHODS: Eighty nonobese subjects aged 40-70 years (18.5 ≤ BMI < 30 kg/m(2)) with prediabetes or newly-diagnosed type-2 diabetes were assigned to consume either the usual refined-rice diet (control group, n = 40) or to replace refined rice with whole grains and legumes as carbohydrates (whole-grain group, n = 40) for three meals per day during the 12-week intervention. Fasting PBMC and plasma metabolomes were profiled using UPLC-LTQ-Orbitrap mass spectrometry. RESULTS: After 12 weeks, changes in fasting glucose, HbA1c, HOMA-IR, MDA, ox-LDL, LDL particle size, plasma Lp-PLA2 activity, and PBMC enzyme activity in the whole-grain group were significantly different from those in the control group before and after adjusting for baseline levels. The PBMC levels of L-leucine, oleamide, lysoPC (16:0), and lysoPC (18:0) in the whole-grain group showed greater reductions compared with those of the control group. Changes in plasma metabolites were not significantly different between the two groups. Changes in PBMC Lp-PLA2 activity positively correlated with changes in L-leucine, oleamide, lysoPC (16:0), lysoPC (18:0), glucose, and ox-LDL, and negatively correlated with changes in LDL particle size. CONCLUSIONS: This study showed that dietary intervention in prediabetic or type-2 diabetic patients had a greater effect on PBMC Lp-PLA2 activity and metabolites compared with those of plasma metabolites. TRIAL REGISTRATION: NCT02191644.

Effects of whole-grain cereal foods on plasma short chain fatty acid concentrations in individuals with the metabolic syndrome.

OBJECTIVE: Short chain fatty acids (SCFAs) derived from dietary fiber fermentation by gut microbiota have been identified as one of the mechanisms behind the association between habitual whole-grain intake and a lower risk of cardiometabolic diseases. The aims of the present work are: (1) to evaluate whether a whole-grain wheat-based diet may increase SCFAs concentration, and (2) to identify possible associations between SCFAs and metabolic changes observed after the nutritional intervention. METHODS: Fifty-four subjects participated in the trial. They underwent a 12-wk dietary intervention based on whole-grain or refined cereal products. At baseline and after the intervention, glucose, insulin, triacylglycerol, inflammatory markers (hs-CRP, IL-1 ra, IL-6, and TNF-α), and SCFAs plasma concentrations were evaluated. RESULTS: After the intervention, in the whole-grain group fasting plasma propionate concentrations were higher than at baseline, whereas a reduction was detected in the control group. The absolute changes (end of trial minus baseline) in fasting plasma propionate concentrations were significantly different between the two groups (P = 0.048). The absolute changes of fasting propionate correlated with cereal fiber intake (r = 0.358, P = 0.023), but no significant correlations with clinical outcomes were found. However, postprandial insulin was significantly decreased in the group having the absolute changes of fasting propionate concentration above the median value (P = 0.022 versus subjects with fasting propionate changes below the median value). CONCLUSIONS: A 12-wk whole-grain wheat-based diet increases fasting plasma propionate. This increase correlates with the cereal fiber intake and is associated with lower postprandial insulin concentrations.

Reduction of toxic gliadin content of wholegrain bread by the enzyme caricain.

Increasingly the number of individuals being diagnosed with some form of sensitivity to the proteins in wheat grains represents a cause for concern. Currently, the treatment is dietary withdrawal of gluten, but commercial gluten-free bread presents some undesirable properties. The objective of this study has been to assess the ability of the enzyme caricain (from papaya latex) to detoxify gliadin in whole wheat flour and develop bread suitable for coeliacs and gluten intolerant individuals. Ion exchange chromatography was used to enrich the caricain in papaya latex and an enzyme-linked immunosorbent assay test kit was used for the analysis of gliadin residues in the baked bread. The partially purified enzyme was found to be more effective in reducing gliadin content than the crude papain and the resultant loaves had acceptable crumb and crust characteristics. Caricain appears to be capable of detoxifying gliadin and has the potential to mitigate the problems confronting coeliacs.

A whole-grain cereal-based diet lowers postprandial plasma insulin and triglyceride levels in individuals with metabolic syndrome.

BACKGROUND AND AIM: Until recently, very few intervention studies have investigated the effects of whole-grain cereals on postprandial glucose, insulin and lipid metabolism, and the existing studies have provided mixed results. The objective of this study was to evaluate the effects of a 12-week intervention with either a whole-grain-based or a refined cereal-based diet on postprandial glucose, insulin and lipid metabolism in individuals with metabolic syndrome. METHODS AND RESULTS: Sixty-one men and women age range 40-65 years, with the metabolic syndrome were recruited to participate in this study using a parallel group design. After a 4-week run-in period, participants were randomly assigned to a 12-week diet based on whole-grain products (whole-grain group) or refined cereal products (control group). Blood samples were taken at the beginning and end of the intervention, both fasting and 3 h after a lunch, to measure biochemical parameters. Generalized linear model (GLM) was used for between-group comparisons. Overall, 26 participants in the control group and 28 in the whole-grain group completed the dietary intervention. Drop-outs (five in the control and two in the whole-grain group) did not affect randomization. After 12 weeks, postprandial insulin and triglyceride responses (evaluated as average change 2 and 3 h after the meal, respectively) decreased by 29% and 43%, respectively, in the whole-grain group compared to the run-in period. Postprandial insulin and triglyceride responses were significantly lower at the end of the intervention in the whole-grain group compared to the control group (p = 0.04 and p = 0.05; respectively) whereas there was no change in postprandial response of glucose and other parameters evaluated. CONCLUSIONS: A twelve week whole-grain cereal-based diet, compared to refined cereals, reduced postprandial insulin and triglycerides responses. This finding may have implications for type 2 diabetes risk and cardiovascular disease.