| 1. |
- Berger, Karin, et al.
(författare)
-
Cereal Byproducts Have Prebiotic Potential in Mice Fed a High-Fat Diet
- 2014
-
Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 62:32, s. 8169-8178
-
Tidskriftsartikel (refereegranskat)abstract
- Barley husks, rye bran, and a fiber residue from oat milk production were processed by heat pretreatment, various separation steps, and treatment with an endoxylanase in order to improve the prebiotic potential of these cereal byproducts. Metabolic functions were intended to improve along with improved microbial activity. The products obtained were included in a high-fat mouse diet so that all diets contained 5% dietary fiber. In addition, high-fat and low-fat controls as well as partially hydrolyzed guar gum were included in the study. The soluble fiber product obtained from rye bran caused a significant increase in the bifidobacteria (log copies of 16S rRNA genes; median (25−75 percentile): 6.38 (6.04−6.66) and 7.47 (7.30−7.74), respectively; p < 0.001) in parallel with a tendency of increased production of propionic acid and indications of improved metabolic function compared with high-fat fed control mice. The oat-derived product caused an increase in the pool of cecal propionic (from 0.62 ± 0.12 to 0.94 ± 0.08) and butyric acid (from 0.38 ± 0.04 to 0.60 ± 0.04) compared with the high-fat control, and it caused a significant increase in lactobacilli (log copies of 16S rRNA genes; median (25−75 percentile): 6.83 (6.65−7.53) and 8.04 (7.86−8.33), respectively; p < 0.01) in the cecal mucosa. However, no changes in measured metabolic parameters were observed by either oat or barley products.
|
|
| 2. |
- Berger, Karin, et al.
(författare)
-
Xylooligosaccharides Increase Bifidobacteria and Lachnospiraceae in Mice on a High-Fat Diet, with a Concomitant Increase in Short-Chain Fatty Acids, Especially Butyric Acid
- 2021
-
Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 69:12, s. 3617-3625
-
Tidskriftsartikel (refereegranskat)abstract
- Effects of xylooligosaccharides (XOSs) as well as a mixture of XOS, inulin, oligofructose, and partially hydrolyzed guar gum (MIX) in mice fed a high-fat diet (HFD) were studied. Control groups were fed an HFD or a low-fat diet. Special attention was paid to the cecal composition of the gut microbiota and formation of short-chain fatty acids, but metabolic parameters were also documented. The XOS group had significantly higher cecum levels of acetic, propionic, and butyric acids than the HFD group, and the butyric acid content was higher in the XOS than in the MIX group. The cecum microbiota of the XOS group contained more Bifidobacteria, Lachnospiraceae, and S24-7 bacteria than the HFD group. A tendency of lower body weight gain was observed on comparing the XOS and HFD groups. In conclusion, the XOS was shown to be a promising prebiotic candidate. The fiber diversity in the MIX diet did not provide any advantages compared to the XOS diet.
|
|
| 3. |
- Linares-Pastén, Javier A, et al.
(författare)
-
Novel xylan-degrading enzymes from polysaccharide utilizing loci of Prevotella copri DSM18205
- 2021
-
Ingår i: Glycobiology. - : Oxford University Press (OUP). - 1460-2423. ; 31:10, s. 1330-1349
-
Tidskriftsartikel (refereegranskat)abstract
- Prevotella copri is a bacterium that can be found in the human gastrointestinal tract (GIT). The role of P. copri in the GIT is unclear, and elevated numbers of the microbe have been reported both in dietary fiber-induced improvement in glucose metabolism but also in conjunction with certain inflammatory conditions. These findings raised our interest in investigating the possibility of P. copri to grow on xylan, and identify the enzyme systems playing a role in digestion of xylan-based dietary fibers. Two xylan degrading polysaccharide utilizing loci (PUL10 and 15) were found in the genome, with three and eight glycoside hydrolase (GH) -encoding genes, respectively. Three of them were successfully produced in Escherichia coli: One extracellular enzyme from GH43 (subfamily 12, in PUL10, 60 kDa) and two enzymes from PUL15, one extracellular GH10 (41 kDa), and one intracellular GH43 (subfamily 137 kDa). Based on our results, we propose that in PUL15, GH10 (1) is an extracellular endo-1,4-β-xylanase, that hydrolazes mainly glucuronosylated xylan polymers to xylooligosaccharides (XOS); while, GH43-1 in the same PUL, is an intracellular β-xylosidase, catalyzing complete hydrolysis of the XOS to xylose. In PUL10, the characterized GH43-12 is an arabinofuranosidase, with a role in degradation of arabinoxylan, catalyzing removal of arabinose-residues on xylan.
|
|
