Fermentation of Lactobacillus fermentum NB02 with feruloyl esterase production increases the phenolic compounds content and antioxidant properties of oat bran

In this study, strains producing feruloyl esterase were screened by Oxford Cup clear zones method and by evaluating the ability to decompose hydroxycinnamoyl esters. The strain was identified by 16S rDNA molecular biology. The contents of dietary fiber, reducing sugar, water-extractable arabinoxylans, phytic acid, total phenolics, total flavonoid, phenolic compounds composition, microstructure and antioxidant activity in bran before and after fermentation were studied. Eight strains producing feruloyl esterase were screened, among which strain P1 had the strongest ability to decompose hydroxycinnamoyl esters. The strain was identified and named L. fermentum NB02. Compared with unfermented bran, fermented bran exhibited higher contents of soluble dietary fiber, reducing sugar, water-extractable arabinoxylans, total phenolics, total flavonoid, and lower insoluble dietary fiber and phytic acid content. The dense surface structure of bran was destroyed, forming a porous structure. The release of phenolic compounds increased significantly. L. fermentum NB02 fermentation improved the antioxidant capacity of bran.

Oat bran prevents high-fat-diet induced muscular dysfunction, systemic inflammation and oxidative stress through reconstructing gut microbiome and circulating metabolome

Western-type diet characterized by high fat emerges a promoter of skeletal muscle dysfunctions. Oat bran was typically considered a healthy food of premium quality for its abundant dietary fiber. The present study comprehensively explored the effects of a diet rich in oat bran on skeletal muscle disfunctions in high-fat diet (HFD) fed mice. Dietary-fiber-rich oat bran significantly ameliorated HFD-induced skeletal muscle function abnormalities, as evidenced by a phenotype improvement in mice grip strength and endurance treadmill running distance, accompanied with the regulation of muscle functions related gene expressions, namely Fis1, Cytc, Mhy2 and Mhy4. Oat bran suppressed the production of systemic inflammatory cytokines while promoted superoxide dismutase and glutathione. Furthermore, oat bran significantly impacted gut microbiota composition by promoting short chain fatty acids (SCFAs) producers and certain probiotic genera, along with the enhancement of SCFAs. Oat bran also significantly decreased the circulating levels of inflammation-related metabolites and played roles in MAPK signaling, thereafter influencing skeletal muscle functions. Collectively, benefits from integration of biomedical indicators, microbiomics, and metabolomics demonstrates the benefits of oat bran consumption on prevention of HFD-related muscular dysfunctions via alleviating HFD-induced inflammation, gut dysbiosis, and systemic metabolism, pinpointing a novel mechanism underlying the muscle-promoting property of oat bran.

Bioavailability of orange juice (poly)phenols: β-glucan-rich oat bran decreases urinary excretion of flavanone phase II metabolites and enhances excretion of microbiota-derived phenolic catabolites

The impact of β-glucan-rich oat bran on the bioavailability of orange juice (OJ) flavanones was investigated. Volunteers consumed 500 mL of OJ with and without 22 g of oat bran containing 6 g of β-glucan (OB-6). Urine collected 12 h prior to and over a 0-24 h period post-supplementation was analysed by UHPLC-HRMS. Sixteen flavanone metabolites and thirty-nine colon-derived phenolic catabolites were identified and quantified. The major compounds were hesperetin-3'-glucuronide, along with hippuric acids and the C₆-C₃ phenolic acids 3-(3'-hydroxy-4'-methoxyphenyl)hydracrylic acid and 3-(4'-hydroxy-3'-methoxyphenyl)propanoic acid. A marked reduction in the 0-24 h excretion of flavanone metabolites from 29.7 μmol (9.3% recovery) to 9.3 μmol (2.9% recovery), occurred following consumption of OB-6 compared to OJ. This appeared not to be an effect of fiber on the rate of transport in the upper gut. After consumption of OJ there was a 163 ± 15 μmol excretion of colon-derived phenolic catabolites, equivalent to 43% of (poly)phenol intake and following OB-6 intake there was a further significant 30% increase. The β-oat bran in OB-6 contained 5.8 μmol of free and 52 μmol of bound phenolic derivatives compared to 371 μmol of OJ (poly)phenols. The elevated excretion of phenolics after OB-6 consumption appears not to be due to bound phenolics in the bran, rather it is consequence, principally, of a bran-mediated increase in the quantities of flavanones passing from the upper to the lower bowel where they were subjected to microbiota-mediated catabolism. CLINICAL TRIAL REGISTRATION NUMBER: This trial was registered at clinicaltrials.gov as NCT04867655.

The effect of oat bran consumption on gestational diabetes: a randomized controlled clinical trial

BACKGROUND

Gestational diabetes is the most common medical complication in pregnancy, and it has many side effects for the mother and the fetus. The aim of this study was to evaluate the effect of oat bran consumption on gestational diabetes.

METHODS

This study is a randomized clinical trial that was performed on 112 women with gestational diabetes treated with diet. Participants were randomly divided into two groups of 56. Participants in both groups were given a diet for gestational diabetes. In addition to the diet, the intervention group received 30 g of oat bran daily for 4 weeks at lunch and dinner. Tests of fasting blood glucose and two-hour postprandial (2hpp) glucose were taken from both groups: before the intervention, and 2 and 4 weeks after the start of the intervention. Data analysis was performed using SPSS statistical software (version 22) using independent t-test, as well as Chi-square and Mann-Whitney tests. P values less than 0.05 were considered statistically significant.

RESULTS

There was no statistically significant difference between the two groups in terms of mean blood glucose before the intervention, while 2 and 4 weeks after the intervention, mean fasting blood glucose and two-hour postprandial (2hpp) glucose decreased significantly in the intervention group compared with the control group (P < 0.001).

CONCLUSION

Based on the results of this study, the addition of oat bran to the standard diet for pregnant women with gestational diabetes reduced fasting blood glucose and two-hour postprandial (2hpp) glucose. More detailed studies with higher sample sizes are recommended to prove the effectiveness of this valuable dietary supplement.

TRIAL REGISTRATION

IRCT registration number: IRCT20191220045828N1 . Registration date: 2020-04-18. Registered while recruiting.

Inhibitory Effect of Oat Bran Ethanol Extract on Survival and Gemcitabine Resistance of Pancreatic Cancer Cells

Pancreatic cancer (PC) is one of the most aggressive malignancies in the world. Gemcitabine (Gem), a nucleoside pyrimidine analogue, is a first-line chemotherapeutic drug for PC, but the tumor response rate of Gem is very low and resistance to Gem has emerged as a major problem in the treatment of PC. Oat bran, used as animal and human food, has been found to be beneficial to health. In this study, effects of oat bran ethanol extract (OBE) on PC cells and Gem-resistant PC cells were investigated in vitro. OBE decreased cell survival and colony forming ability of PC cells, without any cytotoxicity on the normal pancreatic cells. Flow cytometry analysis and TUNEL assay showed that the OBE reduced G1/S phase transition and induced death in PC cells through AMPK activation and downregulation of JNK. Additionally, OBE could overcome Gem resistance through reduction in RRM1/2 expression and showed synergistic effect by combinatorial treatment with Gem on Gem-resistant PC cells. Additionally, LC-MS data showed that avenacoside A was a component of OBE. Thus, this study elucidated the anti-proliferative effect of OBE and synergistic effect of OBE with Gem on PC cells and Gem-resistant cells.

Composition and content of phenolic acids and avenanthramides in commercial oat products: Are oats an important polyphenol source for consumers?

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Commercial oat products contained ten phenolic acids and three avenanthramides.

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Commercial oats provide 15.79–25.05 mg total phenolic acids in a 40 g serving of oats.

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The concentrations and compositions in the products were broadly similar.

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Major component was ferulic acid (58–78.1%) in all products.

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Oatbran concentrate has the highest levels of phenolic acids and avenanthramides.

Oats contain a range of phenolic acids and avenanthramides which may have health benefits. Analysis of 22 commercial oat products (oat bran concentrate, oat bran, flaked oats, rolled oats and oatcakes) using HPLC-DAD detected eleven bound and thirteen free + conjugated phenolic acids and avenanthramides. The oat products (excluding concentrate) provided between 15.79 and 25.05 mg total phenolic acids (9.9–19.33 mg bound, 4.96–5.72 mg free + conjugated) and between 1.1 and 2 mg of avenanthramides in a 40 g portion while an 11 g portion of oat concentrate provided 16.7 mg of total phenolic acids (15.17 mg bound, 1.53 mg free + conjugated) and 1.2 mg of avenanthramides. The compositions and concentrations of the components in the different products were broadly similar, with the major component being ferulic acid (58–78.1%). The results show that commercial oat products are a source of phenolic acids and avenanthramides for consumers.

Addition of oat bran reduces HDL-C and does not potentialize effect of a low-calorie diet on remission of metabolic syndrome: A pragmatic, randomized, controlled, open-label nutritional trial

OBJECTIVES

It is unclear whether addition of soluble fiber to a low-calorie diet potentializes weight loss and amelioration of metabolic syndrome (MetS). The aim of this study was to analyze the effects of oat bran on prevalence of MetS and associated disorders.

METHODS

A pragmatic, randomized controlled, 6-wk nutritional trial was carried out with 154 outpatients (mean age 47.6 ± 12.6 y of age). The intervention group (n = 83) received a low-calorie diet plus 40 g/d of oat bran; the control group (n = 71) received a low-calorie diet only. MetS parameters and prevalence were calculated and compared (using two-tailed statistical tests) before and after follow-up.

RESULTS

After follow-up, a significant but similar reduction was observed in MetS prevalence (40% reduction, 63% and 64.8% prevalence in intervention and control groups, respectively; P = 0.226), body mass index, body weight, waist circumference, systolic and diastolic blood pressures, triacylglycerides, and blood glucose levels in both groups (P < 0.05). Mean high-density lipoprotein cholesterol (HDL-C) was reduced in the intervention group (43.6 ± 9.6 to 41.2 ± 9.5 mg/dL; P = 0.025), but not in the control group (44.6 ± 10.5 to 44.5 ± 12.1 mg/dL; P = 0.890). There was no significant difference in any of the variables between the groups, although the P-value for HDL-C was almost significant (P = 0.078). Calorie and dietetic fiber intake during the 6-wk period were similar in both groups.

CONCLUSIONS

Daily consumption of oat bran did not potentialize the beneficial effects of a traditional low-calorie diet on the prevalence of MetS and associated disorders. Additionally, it reduced HDL-C.

In vivo effect of two different dietary fiber blends on the milk calcium bioavailability

Milk is a valuable source of dietary calcium and it becomes important to establish whether incorporation of dietary fiber (DF), a health promoting food constituent, would lead to any undesirable impact on the bioavailability of milk calcium or not. The DF fortified spray dried partly skimmed milk powder with prestandardized fiber Blend-I (psyllium husk, oat fiber, MCC, inulin) and fiber Blend-II (psyllium husk, oat bran, wheat fiber and inulin) was subjected to rat-feeding studies to examine the possible effects on the bioavailability of milk calcium. The differences for calcium absorption and retention among diets containing DF Blend-I, DF Blend-II and cellulose (control) were found to be non-significant. It was evident that the milk calcium bioavailability of the diets containing two fiber formulations tested (at the levels studied) was at par with that of control standard diet containing only cellulose as DF. Therefore, it is reasonable to incorporate these DF blends into dairy products, and thereby add value.

Effect of fiber blends, total solids, heat treatment, whey protein concentrate and stage of sugar incorporation on dietary fiber-fortified Kheer

Owing to the proven beneficial role of dietary fiber (DF) on human health, feasibility of incorporating commercially available soluble and insoluble DF preparations into rice-milk-pudding (kheer, a popular Indian delicacy) was studied through process modification. The novel approach of preparing reduced fat DF-fortified-kheer (DFFK) by developing liquid/cream phase and particulate/rice phase separately, and subsequently blending the two was developed. The major processing variables studied were total solids (TS) in the liquid phase, type of fiber blend, flavor-simulation through heat treatment or added whey protein, and the presence of sugar in water for pre-cooking of rice. Reduced fat DFFK made from three different pre-standardized fiber blends was quite acceptable to the sensory panel (overall rating 7.5). With increasing TS in milk up to 16.5%, sensory acceptability of DFFK increased. There was a small but perceivable improvement in the flavour of DFFK when precooking of rice was carried out in sweetened water. Reduced fat DFFK from different fiber blends was found to be reasonably close to conventional kheer. DFFK prepared from Blend-I provided 3.31 g dietary fiber/100 kcal (suitable for the claim "High-in-Fiber") with 38.71% Reduced-Fat. With the developed process of fortification of kheer with DF, it is possible to reduce fat (and thus calories) to cater to the needs of consumers seeking good health.

Identification of peptides, metal binding and lipid peroxidation activities of HPLC fractions of hydrolyzed oat bran proteins

The aim of this study was to evaluate metal binding and antioxidant activities of hydrolyzed oat bran proteins followed by the determination of peptide sequences. Protamex oat bran protein hydrolysates (OBPH) were separated by reverse-phase HPLC into eight peptide fractions (F1-F8) and their abilities to either chelate metals (Fe²⁺, Ca²⁺) or prevent the oxidation of lipids were investigated. In the Fe²⁺ chelation assay, OBPH had significantly (p < 0.05) higher activity (39.7 %) than the best performed fraction F7 (22.8 %). The second most active was F5 with 12.1 % chelating activity and this was higher than the activity of the tripeptide glutathione (5.8 %) used as control. The two most Fe²⁺ chelating fractions (F5, F7) however had weak calcium binding (0.6-1.0 %) properties at peptide concentration ranging from 0.2 to 1.0 mg/mL. In the lipid peroxidation assay, OBPH and all HPLC fractions prevented the oxidation of linoleic acid. More than 60 peptides mainly derived from globulin and avenin proteins were identified using tandem mass spectrometry.

Effects of oat bran and nutrition counseling on the lipid and glucose profile and anthropometric parameters of hypercholesterolemia patients

BACKGROUND

In order to prevent chronic, non communicable disease, it is essential that lifestyle is modified to include a diet high in fiber.

AIM

To assess the effect oat bran (OB) in conjunction with nutrition counseling (NC) have on lipid and glucose profile, anthropometric parameters,quality of diet, and ingestion of ultraprocessed foods (UPF) and additives in hypercholesterolemia sufferers.

METHOD

This was a 90-day, double-blind, placebo-controlled, block-randomized trial undertaken on 132 men and women with LDL-c ≥ 130 mg/ dL. The participants were sorted into two groups: OB Group (OBG) and Placebo Group (PLG), and were given NC and 40g of either OB or rice flour, respectively. Lipid and glucose profile were assessed, as were the anthropometric data, quality of diet (Diet Quality Index revised for the Brazilian population - DQI-R) and whether or not UPF or additives were consumed.

RESULTS

Both groups showed a significant decrease in anthropometric parameters and blood pressure, as well as a significant reduction in total and LDL cholesterol. There was also an improvement in DQI-R in both groups and a decrease in consumption of UPF. Blood sugar, HOMA-IR and QUICKI values were found to be significantly lower only in the OBG.

CONCLUSION

Our findings in lipid profile and anthropometric parameters signify that NC has a beneficial effect, which is attributable to the improved quality of diet and reduced consumption of UPF. Daily consumption of 40 g of OB was found to be of additional benefit, in decreasing insulin-resistance parameters.

GC-TOF-MS-based serum metabolomic investigations of naked oat bran supplementation in high-fat-diet-induced dyslipidemic rats

The present study aimed to explore the metabolic response of oat bran consumption in dyslipidemic rats by a high-throughput metabolomics approach. Four groups of Sprague-Dawley rats were used: N group (normal chow diet), M group (dyslipidemia induced by 4-week high-fat feeding, then normal chow diet), OL group and OH group (dyslipidemia induced, then normal chow diet supplemented with 10.8% or 43.4% naked oat bran). Intervention lasted for 12weeks. Gas chromatography quadrupole time-of-flight mass spectrometry was used to identify serum metabolite profiles. Results confirmed the effects of oat bran on improving lipidemic variables and showed distinct metabolomic profiles associated with diet intervention. A number of endogenous molecules were changed by high-fat diet and normalized following supplementation of naked oat bran. Elevated levels of serum unsaturated fatty acids including arachidonic acid (Log2Fold of change=0.70, P=.02 OH vs. M group), palmitoleic acid (Log2Fold of change=1.24, P=.02 OH vs. M group) and oleic acid (Log2Fold of change=0.66, P=.04 OH vs. M group) were detected after oat bran consumption. Furthermore, consumption of oat bran was also characterized by higher levels of methionine and S-adenosylmethionine. Pathway exploration found that most of the discriminant metabolites were involved in fatty acid biosynthesis, biosynthesis and metabolism of amino acids, microbial metabolism in diverse environments and biosynthesis of plant secondary metabolites. These results point to potential biomarkers and underlying benefit of naked oat bran in the context of diet-induced dyslipidemia and offer some insights into the mechanism exploration.

Effect of buckwheat flour and oat bran on growth and cell viability of the probiotic strains Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their combination SYNBIO®, in synbiotic fermented milk

Fermented foods have a great significance since they provide and preserve large quantities of nutritious foods in a wide diversity of flavors, aromas and texture, which enrich the human diet. Originally fermented milks were developed as a means of preserving nutrients and are the most representatives of the category. The first aim of this study was to screen the effect of buckwheat flour and oat bran as prebiotics on the production of probiotic fiber-enriched fermented milks, by investigating the kinetics of acidification of buckwheat flour- and oat bran-supplemented milk fermented by Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their 1:1 combination named SYNBIO®. The probiotic strains viability, pH and sensory characteristics of the fermented fiber-enriched milk products, stored at 4 °C for 28 days were also monitored. The results showed that supplementation of whole milk with the tested probiotic strains and the two vegetable substrates results in a significant faster lowering of the pH. Also, the stability of L. rhamnosus IMC 501®, L. paracasei IMC 502® and SYNBIO® during storage at 4 °C for 28 days in buckwheat flour- and oat bran-supplemented samples was remarkably enhanced. The second aim of the study was to develop a new synbiotic product using the best combination of probiotics and prebiotics by promoting better growth and survival and be acceptable to the consumers with high concentration of probiotic strain. This new product was used to conduct a human feeding trial to validate the fermented milk as a carrier for transporting bacterial cells into the human gastrointestinal tract. The probiotic strains were recovered from fecal samples in 40 out of 40 volunteers fed for 4 weeks one portion per day of synbiotic fermented milk carrying about 10(9) viable cells.

Part 2: Rye bran, oat bran and barley fibre

Rye bran, oat bran and barley fibre have been compared as additives in low-fat sausages and meatballs. The water/protein ratio and starch content were constant to allow direct comparisons. Oat bran was the best alternative in low-fat sausages due to its gelling ability upon heating. These sausages exhibited low process (0.9%) and frying losses (10.9%), and high values of firmness (11.0 N) and sensory acceptance. The sausages containing barley fibre, with the highest amount of soluble β-glucan, had high losses (3.8% and 19.6%) and the lowest firmness (4.6 N). Rye bran was suitable in meatballs, probably due to its particulate nature, which is more acceptable in this type of meat product, where the gelling properties are not as important as in sausages. There was no significant difference between the firmness of meatballs containing rye bran (6.1 N) and the reference (7.5 N), after pan-frying. Meatballs with oat bran or barley fibre were less firm (3.6 N and 2.0 N).