| 1. |
- Chronakis, I S, et al.
(författare)
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Complex formation in aqueous medium of partially hydrolysed oat cereal proteins with sodium stearoyl-2 lactylate (SSL) lipid surfactant and implications for bile acids activity
- 2004
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Ingår i: Colloids and Surfaces B: Biointerfaces. - : Elsevier BV. - 1873-4367 .- 0927-7765. ; 35:3-4, s. 175-184
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Tidskriftsartikel (refereegranskat)abstract
- Sodium stearoyl-2 lactylate (SSL) lipid surfactant molecules specifically bind partially hydrolysed oat proteins in aqueous medium and significantly enhance the dispersion stability of oat cereal preparations. The proposed complexation is composition dependent and a greater understanding of the role of both oat proteins and lipid surfactant in the effect was gained with data from high performance liquid chromatography (HPLC-UV), viscometry and differential scanning micro calorimetry. The effect of the lipid surfactant on the degree of association is primarily governed by the conformational activity of oat protein molecules related to the extent of protein hydrolysed state, as well as protein unfolded and subsequent aggregated structures. SSL does not dissociate oat proteins into subunits or destroy important hydrophobic contacts already stabilising the protein molecules. Although the exact mode of association is unknown, the present study demonstrates that such interactions occur in a specific manner and suggest selectivity of oat proteins for individual fatty acids. The effect of various amounts of bile acids on SSL-oat protein interaction was also investigated, as a first attempt to investigate the role of lipid surfactant molecules in the known cholesterol-lowering action of oat cereal ingredients and to elucidate favourable conditions by which oat cereal can elicit hypocholesterolemic effects. (C) 2004 Elsevier B.V. All rights reserved.
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| 2. |
- Chronakis, I S, et al.
(författare)
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Solid-state characteristics and redispersible properties of powders formed by spray-drying and freeze-drying cereal dispersions of varying (1→3,1→4)--glucan content
- 2004
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Ingår i: Journal of Cereal Science. - : Elsevier BV. - 0733-5210. ; 40:2, s. 183-193
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Tidskriftsartikel (refereegranskat)abstract
- Cereal powders containing 33, 18 and 4% (w/w) (1→3,1→4)--glucan, prepared from cereal suspensions, had distinct differences in surface morphology as observed by scanning electron microscopy, depending both on the drying process (spray- or freeze-drying) and the dietary fibre level. Freeze-drying produced powders with a ‘flake-like’ matrix, without particle formation and similar matrix morphology independent of the (1→3,1→4)--glucan content, in contrast to spray-drying, which gave powders with morphologies that were (1→3,1→4)--glucan-dependent and consisted of aggregated particles and microspheres. Choosing the concentration of (1→3,1→4)--glucans permits control of the particle size and particle size distribution of the spray-dried cereal powders. pH-dependent zeta () potential measurements of re-dissolved powders indicated that the isoelectric point was in the pH range of 3.8–4.8 and that it increased at higher pH as the (1→3,1→4)--glucan content of the powders was decreased from 33 to 4% (w/w). The absolute value of the zeta () potential fell with increasing pH and was largest for the powder dispersion with the lower (1→3,1→4)--glucan content, leading to the greatest dispersion stability. The importance of particle size, net surface charge and (1→3,1→4)--glucan and protein content in controlling the surface activity at the air–water interface of cereal powder dispersions is also discussed. Author Keywords: Spray-drying; Freeze-drying; (1→3,1→4)--glucan; Morphology; Particles; Zeta potential; Surface activity
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| 3. |
- Andersson, Kristina E, et al.
(författare)
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Effects of oats on plasma cholesterol and lipoproteins in C57BL/6 mice are substrain specific.
- 2010
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Ingår i: British Journal of Nutrition. - 1475-2662. ; 103, s. 513-521
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Tidskriftsartikel (refereegranskat)abstract
- Cholesterol-lowering effects of oats have been demonstrated in both animals and human subjects. However, the crucial properties of oat-containing diets that determine their health effects need to be further investigated to optimise their use. A mouse model would be a valuable tool, but few such studies have been published to date. We investigated the effects of oat bran on plasma cholesterol and lipoproteins in two substrains of C57BL/6 mice. Western diet was made atherogenic by the addition of 0.8 % cholesterol and 0.1 % cholic acid. After 4 weeks on atherogenic diet, total plasma cholesterol had increased from 1.86-2.53 to 3.77-4.40 mmol/l. In C57BL/6NCrl mice, inclusion of 27 and 40 % oat bran reduced total plasma cholesterol by 19 and 24 %, respectively, reduced the shift from HDL to LDL+VLDL and caused increased faecal cholesterol excretion. There was no effect of oat bran on plasma levels of the inflammatory markers fibrinogen, serum amyloid A or TNF-alpha. Contrary to findings in C57BL/6NCrl mice, there was no sustained effect of oat bran (27 or 40 %) on plasma cholesterol in C57BL/6JBomTac mice after 4 weeks of feeding. Thus, C57BL/6NCrl mice fed an atherogenic diet are a good model for studies of physiological effects of oats, whereas a substrain derived from C57BL/6J, raised in a different breeding environment and likely possessing functional genetic differences from C57BL/6N, is considerably less responsive to oats. The present finding that two substrains of mice respond differently to oats is of practical value, but can also help to elucidate mechanisms of the cholesterol-lowering effect of oats.
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| 4. |
- Andersson, Kristina E, et al.
(författare)
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Oats (Avena sativa) reduce atherogenesis in LDL-receptor-deficient mice.
- 2010
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; Jul 1, s. 93-99
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The cholesterol-lowering properties of oats, largely ascribed to its contents of soluble fibers, beta-glucans, are well established, whereas effects on atherogenesis are less well elucidated. Oats also contains components with reported antioxidant and anti-inflammatory effects that may affect atherogenesis. In this work we examined effects of oat bran on plasma cholesterol, markers of inflammation, eNOS expression and development of atherosclerosis in LDL-receptor-deficient (LDLr(-/-)) mice. METHODS AND RESULTS: Female LDLr(-/-) mice were fed Western diet+/-oat bran. Two concentrations of oat bran (40 and 27%) were compared regarding effects on plasma lipids. There was a dose-dependent reduction of plasma cholesterol by 42 and 20% with 40 and 27% oat bran, respectively. Both concentrations also lowered plasma triglycerides (by 45 and 33%) and relative levels of plasma LDL+VLDL. The reduction of plasma lipids was accompanied by increased faecal excretion of cholesterol and bile acids. Oat bran (40%) efficiently reduced atherosclerotic lesion area in the descending aorta (-77%) and aortic root (-33%). Plasma levels of fibrinogen and soluble vascular cell adhesion molecule-1 (VCAM-1) were significantly lower, and immunofluorescence of aortic sections revealed a 75% lower expression of VCAM-1 in oat-fed mice. The expression of eNOS protein in the aortic wall was increased in mice fed oat bran. CONCLUSIONS: Oat bran supplemented to a Western diet lowers plasma cholesterol, reduces levels of some inflammatory markers, increases eNOS expression and inhibits atherosclerotic lesion development in LDLr(-/-) mice. It remains to be investigated which components in oats contribute to these effects.
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| 5. |
- Andersson, Kristina E., et al.
(författare)
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Wholegrain oat diet changes the expression of genes associated with intestinal bile acid transport
- 2017
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Ingår i: Molecular Nutrition and Food Research. - : Wiley. - 1613-4125 .- 1613-4133. ; 61:7
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Tidskriftsartikel (refereegranskat)abstract
- Scope: The molecular mechanisms underlying the cholesterol-lowering properties of oats are only partly known. To study possible pathways involved, we investigated gene expressions in the liver and small intestine of mice fed oats. Method and results: Cholesterol and bile acids were analyzed in plasma and feces from LDL-receptor deficient (LDLr-/-) mice fed Western diet with wholegrain oats. A transcriptome analysis of mRNA from liver and jejunum was performed together with quantitative RT-PCR. Oat-fed mice had lower levels of plasma lipids and increased levels of bile acids and cholesterol in feces compared with controls. Two hundred thirty nine genes in jejunum and 25 genes in liver were differentially expressed (FDR corrected p < 0.05). The most affected biological process in jejunum was lipid biosynthesis and regulation. The apical sodium-dependent bile acid transporter (ASBT, Slc10a) and the intracellular bile acid binding protein (Fabp6) were both upregulated, whereas small heterodimer partner-1 (Shp-1) and apolipoprotein CII (Apoc2) were downregulated. Conclusions: Whole oats attenuated responses typically induced by high-fat diet. Increased expression of genes for intestinal bile acid uptake following oat consumption suggests retention in the gut lumen rather than decreased uptake capacity as cause for the increased bile acid excretion and the concomitant reduction of plasma cholesterol.
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| 6. |
- Eussen, Simone R. B. M., et al.
(författare)
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Simultaneous intake of oat bran and atorvastatin reduces their efficacy to lower lipid levels and atherosclerosis in LDLr-/- mice
- 2011
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Ingår i: Pharmacological Research. - : Elsevier BV. - 1096-1186 .- 1043-6618. ; 64:1, s. 36-43
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Tidskriftsartikel (refereegranskat)abstract
- The present study aimed to investigate the effects of separate and simultaneous dietary intake of atorvastatin (ATO) and the soluble fiber oat bran on serum and hepatic lipid levels and the degree of atherosclerosis. Ninety female LDL-receptor-deficient (LDLr-/-) mice were fed a Western-type diet containing either low dose (0.0025%), high dose (0.01%) or no ATO, with or without oat bran (27%) (n = 15 per group) for 16 weeks. Both ATO and oat bran were effective in reducing serum total cholesterol levels (low ATO: -5.48, high ATO: -9.12, oat bran: -3.82 mmol/l, compared to control (no ATO/no oat bran), all p < 0.0001). When oat bran was added to a low dose ATO, the cholesterol-lowering effects of this combination were 50% smaller compared to the low dose ATO diet alone (between-group difference: 2.77 mmol/l, p = 0.002), whereas total cholesterol decreased to a similar extent in the groups fed a high dose ATO, with or without oat bran (between-group difference: 1.10 mmol/l, p = 0.21). Serum LDL- and HDL-cholesterol, triglycerides, hepatic lipid levels and atherosclerotic lesion development showed a similar pattern. In conclusion, the efficacy of oat bran and atorvastatin to lower lipid levels and atherosclerosis is reduced after simultaneous intake. We hypothesize that oat bran inhibits the intestinal absorption of atorvastatin, and consequently its cholesterol-lowering effects. The effects are likely dependent on the type of statin and dietary fiber, and on the relative timing of intake of the statin and the dietary fiber. Future studies should focus on these aspects to provide further insight into the exact mechanism of this food-drug interaction. (C) 2011 Elsevier Ltd. All rights reserved.
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| 7. |
- Huang, Fang, et al.
(författare)
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A mixture of Nordic berries improves cognitive function, metabolic function and alters the gut microbiota in C57Bl/6J male mice
- 2023
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Ingår i: Frontiers in Nutrition. - 2296-861X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Our diets greatly influence our health. Multiple lines of research highlight the beneficial properties of eating berries and fruits. In this study, a berry mixture of Nordic berries previously identified as having the potential to improve memory was supplemented to young C57Bl/6J male mice to investigate effects on cognition function, metabolic health, markers of neuroinflammation, and gut microbiota composition. C57Bl/6J male mice at the age of 8 weeks were given standard chow, a high-fat diet (HF, 60%E fat), or a high-fat diet supplemented with freeze-dried powder (20% dwb) of a mixture of Nordic berries and red grape juice (HF + Berry) for 18 weeks ( n = 12 animals/diet group). The results show that supplementation with the berry mixture may have beneficial effects on spatial memory, as seen by enhanced performance in the T-maze and Barnes maze compared to the mice receiving the high-fat diet without berries. Additionally, berry intake may aid in counteracting high-fat diet induced weight gain and could influence neuroinflammatory status as suggested by the increased levels of the inflammation modifying IL-10 cytokine in hippocampal extracts from berry supplemented mice. Furthermore, the 4.5-month feeding with diet containing berries resulted in significant changes in cecal microbiota composition. Analysis of cecal bacterial 16S rRNA revealed that the chow group had significantly higher microbial diversity, as measured by the Shannon diversity index and total operational taxonomic unit richness, than the HF group. The HF diet supplemented with berries resulted in a strong trend of higher total OTU richness and significantly increased the relative abundance of Akkermansia muciniphila, which has been linked to protective effects on cognitive decline. In conclusion, the results of this study suggest that intake of a Nordic berry mixture is a valuable strategy for maintaining and improving cognitive function, to be further evaluated in clinical trials.
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| 8. |
- Huang, Fang, et al.
(författare)
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Cultivation of the gut bacterium Prevotella copri DSM 18205T using glucose and xylose as carbon sources
- 2021
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Ingår i: MicrobiologyOpen. - : Wiley. - 2045-8827. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Prevotella copri DSM18205T is a human gut bacterium, suggested as a next-generation probiotic. To utilize it as such, it is, however, necessary to grow the species in a reproducible manner. Prevotella copri has previously been reported to be highly sensitive to oxygen, and hence difficult to isolate and cultivate. This study presents successful batch cultivation strategies for viable strain inoculations and growth in both serum bottles and a stirred tank bioreactor (STR), without the use of an anaerobic chamber, as long as the cells were kept in the exponential growth phase. A low headspace volume in the STR was important to reach high cell density. P. copri utilized xylose cultivated in Peptone Yeast Xylose medium (PYX medium), resulting in a comparable growth rate and metabolite production as in Peptone Yeast Glucose medium (PYG medium) in batch cultivations at pH 7.2.Up to 5 g/L of the carbon source was consumed, leading to the production of succinic acid, acetic acid, and formic acid, and cell densities (OD620 nm ) in the range 6-7.5. The highest yield of produced succinic acid was 0.63 ± 0.05 g/g glucose in PYG medium cultivations and 0.88 ± 0.06 g/g xylose in PYX medium cultivations.
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| 9. |
- Immerstrand, Tina, et al.
(författare)
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Characterization of the properties of Pediococcus parvulus for probiotic or protective culture use.
- 2010
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Ingår i: Journal of Food Protection. - 0362-028X. ; 73:5, s. 960-966
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Tidskriftsartikel (refereegranskat)abstract
- Pediococcus parvulus 2.6 (previously Pediococcus damnosus 2.6, here confirmed as P. parvulus by 16S DNA sequencing) displayed antibacterial activity toward several bacterial species, including isolates found as contaminants in oats, herein genetically identified as Bacillus cereus. No inhibition of Listeria monocytogenes was found under the conditions used. Antibacterial activity was retrieved after ammonium sulfate or acetone precipitation showed it to be peptide mediated. P. parvulus 2.6 has previously shown good technological properties in oat-based products. This, together with the currently found inhibition of food spoilage microorganisms like B. cereus, makes it suitable as a food protective culture. Survival trials of P. parvulus 2.6 at conditions mimicking the gastrointestinal tract were prompted by previously found cholesterol-lowering effects in humans after consumption of oat products cofermented by using P. parvulus 2.6 and Bifidobacterium spp. Viability was measured with in vitro, gutlike simulations at 37 degrees C. High survival was shown under two of three conditions (gastric juice, bile, and small intestine juice), defined as main obstacles of the gastrointestinal tract. The critical step was bile exposure. At a concentration of 20%, viability was low, but 0.3% bile (mean concentration in the intestine) did not have a major influence on growth. Viability of P. parvulus 2.6 was significantly decreased in gastric juice at pH 1.5 (with pepsin), but it was not significantly affected at pH 2.5, and was also improved at a lower pH in 20% oat milk. Viability was judged sufficient for colonization at gutlike conditions, qualifying the strain for further probiotic studies.
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| 10. |
- Immerstrand, Tina, et al.
(författare)
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Effects of oat bran, processed to different molecular weights of beta-glucan, on plasma lipids and caecal formation of SCFA in mice.
- 2010
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Ingår i: British Journal of Nutrition. - 1475-2662. ; 104:3, s. 364-373
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we evaluated the cholesterol-lowering effects of different oat bran (OB) preparations, differing regarding their peak molecular weight (MWp) of beta-glucans (2348, 1311, 241, 56, 21 or < 10 kDa), in C57BL/6NCrl mice. The diets were designed to be atherogenic (0.8 % cholesterol and 0.1 % cholic acid), and they reflected the Western diet pattern (41 % energy fat). All OB preparations that were investigated significantly reduced plasma cholesterol when compared with a cellulose-containing control diet, regardless of the molecular weight of beta-glucan. Moreover, the difference in viscous properties between the processed OB (from 0.11 to 17.7 l/g) did not appear to play a major role in the cholesterol-lowering properties. In addition, there was no correlation between the molecular weight of beta-glucan and the amount of propionic acid formed in caecum. Interestingly, however, there was a significant correlation between the ratio of (propionic acid+butyric acid)/acetic acid and the MWp of beta-glucans: the ratio increased with increasing molecular weight. The results of the present study suggest that the molecular weights and viscous properties of beta-glucan in oat products may not be crucial parameters for their cholesterol-lowering effects.
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