In vitro-in vivo Validation of Stimulatory Effect of Oat Ingredients on Lactobacilli.

The prebiotic activity of a commercially available oat product and a novel oat ingredient, at similar ß-glucan loads, was tested using a validated in vitro gut model (M-SHIME®). The novel oat ingredient was tested further at lower ß-glucan loads in vitro, while the commercially available oat product was assessed in a randomised, single-blind, placebo-controlled, and cross-over human study. Both approaches focused on healthy individuals with mild hypercholesterolemia. In vitro analysis revealed that both oat products strongly stimulated Lactobacillaceae and Bifidobacteriaceae in the intestinal lumen and the simulated mucus layer, and corresponded with enhanced levels of acetate and lactate with cross-feeding interactions leading to an associated increase in propionate and butyrate production. The in vitro prebiotic activity of the novel oat ingredient remained at lower ß-glucan levels, indicating the prebiotic potential of the novel oat product. Finally, the stimulation of Lactobacillus spp. was confirmed during the in vivo trial, where lactobacilli abundance significantly increased in the overall population at the end of the intervention period with the commercially available oat product relative to the control product, indicating the power of in vitro gut models in predicting in vivo response of the microbial community to dietary modulation.

Association of whole-grain and dietary fiber intake with cardiometabolic risk in children and adolescents.

BACKGROUND: Diet is known to affect many risk factors of cardiovascular disease (CVD), a leading cause of mortality and morbidity. AIM: The objective of this study was to explore the potential association between whole grain and dietary fiber with CVD risk factors, including metabolic syndrome (MetS) in children and adolescents using National Health and Nutrition Examination Survey (NHANES) 2003-2014. METHODS: Two days of 24-hour recall data from 16,507 children and adolescents age 2-18 years were used to estimate dietary intakes. Continuous MetS scores (cMetS) were computed by aggregating age/sex regressed z-scores of waist circumference, mean arterial blood pressure, high-density lipoprotein-cholesterol, triglycerides, and glucose. Regression analyses were used to assess association of fiber and whole grain intake with cardiometabolic markers including MetS after adjusting for demographic factors. RESULTS: Increasing tertiles of fiber intake were significantly associated with 3% lowered risk MetS in adolescents age 13-18 years. Additionally, increasing intake tertiles of fiber were associated with reduced risk elevated cholesterol (5-11% reduction), elevated diastolic blood pressure (10-23% reduction) in adolescents age 13-18 years, and risk of obesity (3-5% reduction) in children and adolescent age 2-18 years. Increasing tertiles of whole grain intake were only associated with reduced risk of elevated triglycerides (52% risk reduction) in adolescents age 13-18 years. CONCLUSION: The results suggest that intake of dietary fiber was inversely associated with several markers of cardiovascular disease risk including MetS.

The Cholesterol-Lowering Effect of Oats and Oat Beta Glucan: Modes of Action and Potential Role of Bile Acids and the Microbiome.

Consumption of sufficient quantities of oat products has been shown to reduce host cholesterol and thereby modulate cardiovascular disease risk. The effects are proposed to be mediated by the gel-forming properties of oat ß-glucan which modulates host bile acid and cholesterol metabolism and potentially removes intestinal cholesterol for excretion. However, the gut microbiota has emerged as a major factor regulating cholesterol metabolism in the host. Oat ß-glucan has been shown to modulate the gut microbiota, particularly those bacterial species that influence host bile acid metabolism and production of short chain fatty acids, factors which are regulators of host cholesterol homeostasis. Given a significant role for the gut microbiota in cholesterol metabolism it is likely that the effects of oat ß-glucan on the host are multifaceted and involve regulation of microbe-host interactions at the gut interface. Here we consider the potential for oat ß-glucan to influence microbial populations in the gut with potential consequences for bile acid metabolism, reverse cholesterol transport (RCT), short-chain fatty acid (SCFA) production, bacterial metabolism of cholesterol and microbe-host signaling.

Oatmeal-Containing Breakfast is Associated with Better Diet Quality and Higher Intake of Key Food Groups and Nutrients Compared to Other Breakfasts in Children.

Oatmeal is a whole grain (WG) food rich in fiber and other nutrients. The study objective was to compare diet quality and nutrient intake of children consuming oatmeal breakfasts to those of children consuming other breakfasts using the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Dietary intake data from 5876 children aged 2-18 years were divided by breakfast food consumption: oatmeal breakfasts, "Doughnuts, sweet rolls, pastries", "Pancakes, waffles, French toast", "Eggs and omelets", "Ready-to-eat cereal, lower sugar", and "Ready-to-eat cereal, higher sugar" were used to assess diet quality and intake of food groups and nutrients using the USDA Healthy Eating Index-2015 (HEI-2015), Food Patterns Equivalents Database, and Food and Nutrient Database for Dietary Studies, respectively. As compared to consumers of other breakfasts or breakfast skippers, oatmeal consumers had consistently higher diet quality (4-16 points higher HEI 2015 total score, p < 0.05), higher WG intake (0.6-1.6 oz eq. higher, p < 0.05), and higher fiber and magnesium intakes compared to consumers of most other breakfasts or breakfast skippers. The results show that children consuming oatmeal breakfasts have better diet quality and increased intake of key nutrients compared to breakfast skippers and other breakfast consumers and suggest oatmeal may represent an important component of a healthy childhood diet.

Different Oat Ingredients Stimulate Specific Microbial Metabolites in the Gut Microbiome of Three Human Individuals in Vitro.

We used a standardized in vitro simulation of the intestinal environment of three human donors to investigate the effect of six oat ingredients, which were produced by the application of different processing techniques, on the gut microbial community. Fructooligosaccharide was used as the positive control. Consistent changes in pH and gas production, on average -0.4 pH units and +32 kPa, indicated the high fermentability of the oat ingredients, and the resulting increased production of metabolites that are considered as beneficial for human health. These metabolites included acetate and lactate, but mostly propionate (+13.6 mM on average). All oat ingredients resulted in increased bifidobacteria levels with an average increase of 0.73 log. Moreover, a decreased production of proteolytic markers was observed, including branched short-chain fatty acids and ammonium. The results were donor-specific and product-specific. The results suggested an association between the total amounts of dietary fiber and the prebiotic potentials of different ingredients. Furthermore, as mechanical processing of oat products has previously been linked to increased extractability of dietary fibers, the obtained results suggest that different processing techniques might have impacted the potential functional properties of the final ingredients.

Dietary fiber and digestive health in children.

Digestive health is an expanding area in nutrition research due to the interest in how food components such as fiber affect gastrointestinal tolerance, stool form, defecation frequency, transit time, and gut microbial composition and metabolic activity. In children, however, digestive health studies that intervene with dietary fiber are limited due to legal and ethical concerns. To better understand if fiber improves digestive health in children, a literature review was conducted to answer the following research question: What are the effect(s) of fiber-containing foods and/or supplements on digestive health outcomes in children? A search of the PubMed database identified a total of 12 studies that fit the inclusion criteria established for this review. Most of the evidence in children shows beneficial effects of partially hydrolyzed guar gum, glucomannan, and bran on digestive health outcomes; however, the existing evidence is not conclusive. Furthermore, limited data exists on the effect of whole-grain sources of dietary fiber, such as oats. Additional well-designed intervention trials are needed to determine whether outcomes of digestive health such as stool form, gastrointestinal tolerance, and stool frequency are improved by increasing the fiber content of children's diets with whole-grain sources.

Cost-effectiveness of Maintaining Daily Intake of Oat ß-Glucan for Coronary Heart Disease Primary Prevention.

PURPOSE: Oat ß-glucan reduces cholesterol levels and thus reduces the risk for coronary heart disease (CHD). However, its economic impact has not been well studied. We examined the economic impact of daily intake of ≥3 g of oat ß-glucan in primary prevention of CHD in patients receiving statins or no pharmacologic treatment. METHODS: A decision model was developed to compare costs and outcomes associated with lowering cholesterol levels with no pharmacologic treatment and normal diet, no pharmacologic treatment plus ≥3 g/d of oat ß-glucan, and statin therapy plus ≥3 g/d of oat ß-glucan. The population comprised men 45, 55, or 65 years of age with no history of cardiovascular disease and a 10-year risk for CHD of 5%, 7.5%, or 10%. Clinical efficacy data were gathered from meta-analyses; safety data, costs, and utilities were gathered from published literature. Cost per quality-adjusted life years and number of first events were reported. FINDINGS: Maintaining ≥3 g/d of ß-glucan may be cost-effective in men aged 45, 55, and 65 years with 10-year CHD risks of 5.0%, 7.5%, and 10.0% taking no pharmacologic treatment or on statins. It may also reduce first events of myocardial infarction and CHD death. Results are sensitive to oat ß-glucan cost but insensitive to changes in other parameters. Maintaining ≥3 g of oat ß-glucan daily remains cost-effective within plausible range of values. IMPLICATIONS: ß-glucan may be cost-effective for preventing CHD events in middle-aged men with no history of cardiovascular events whose 10-year CHD risk is ≥5%. Maintaining daily ß-glucan intake may have considerable impact on first events.

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B(6), B(12), D, and E.

A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids, and polyphenols. Recommendations are given regarding which methods are most justified for answering bioaccessibility or bioavailability related questions for specific nutrients. The need for more validation studies in which in vivo results are compared to in vitro results is also discussed.

Recommendations for optimization of fortified and blended food aid products from the United States.

Fortified blended foods (FBFs) were introduced into the Food for Peace program (also known as US Public Law 480) in the 1960s. Minimal changes have since been made to their formulations. A Food Aid Quality Enhancement Project to assess the nutritional adequacy of FBFs for vulnerable populations was conducted, and the findings indicate that FBFs do not meet the nutritional needs of infants and young children between the ages of 6 and 24 months. Improvements are also needed for FBFs intended for school-aged children and adults. Two separate products would better meet the varying nutritional needs of diverse groups of beneficiaries. Proposed here is a two-step strategy for better addressing the needs of today's food aid beneficiaries: 1) improving FBFs for general distribution to households, schools, and emergency settings, with potential efficiencies gained in manufacturing and formulation to reduce costs; 2) developing new products for infants and young children, which would deliver the nutrient density required for growth and development.

A new simulation model estimates micronutrient levels to include in fortified blended foods used in food aid programs.

Current micronutrient levels in Public Law 480 fortified blended foods (FBF) may not be appropriate for all food aid beneficiaries, particularly infants and/or young children and pregnant and/or lactating women. A simulation model was developed to determine the micronutrient fortification levels to include in FBF for food aid programs with the goal of reducing the risk of inadequate micronutrient intakes without exceeding the tolerable upper intake level (UL) for any recipient group. For each micronutrient, the age and gender group with the highest daily Recommended Nutrient Intake (RNI) relative to energy requirement was identified and the effect of providing different percentages of that RNI (66, 75, and 100%) was simulated. In this modeling exercise, we also examined consumption of the FBF at 25 (the usual level), 50, and 100% of daily energy requirement. Results indicated that 2 FBF products are needed: a complementary food for age 6-36 mo and a supplementary food for the older groups. Both of the FBF could be fortified to supply at least 75% of the RNI to all groups, without exceeding the UL for most nutrients, if consumed at 25% of the energy requirement. Even if consumed at 50% of energy requirements, mean intakes of most micronutrients would not exceed the UL, although at 100% of the energy requirement, several micronutrients were undesirably high. We conclude that fortifying an FBF to provide 75% of the RNI would be appropriate for most micronutrients, but this level of fortification would not be appropriate for long-term consumption of the FBF at 100% of the energy requirements.