Inulin-type fructans with different degrees of polymerization improve lipid metabolism but not glucose metabolism in rats fed a high-fat diet under energy restriction.

BACKGROUND: Inulin-type fructan ameliorates metabolic diseases associated with obesity in animals. However, relatively little information is available on the comparative effects of inulins with different degree of polymerization (DP) on the lipid or glucose metabolism. AIM: The objective of this study was to investigate the effect of inulins with various DP on metabolic disorders associated with obesity in rats fed a high-fat diet under food restriction. METHODS: Rats were fed a high-fat diet supplemented with 5 % inulin-GR (Raftiline GR), inulin-Tokachi (Tokachi), or inulin-HP (Raftiline HP) without cellulose for 28 days at normal energy intakes or 14.5 % energy restriction. RESULTS: Under food restriction, the dietary inulin-Tokachi (mean DP 15) and -HP (mean DP 24), but not -GR (mean DP 10), reduced (p < 0.05) the serum cholesterol and triglyceride levels, and liver triglyceride concentration in rats, compared to the control diet. The cecal neutral steroid, bile acid, and propionate concentrations in the Tokachi and HP groups were higher (p < 0.05) than in the CONT group, and the cecal Bifidobacterium count in the Tokachi group was higher (p < 0.05) than in the other groups. CONCLUSIONS: Findings suggest that, depending on DP, dietary supplementation with inulin (DP 15 or DP 24) in rats fed a high-fat diet, regardless of food intake, positively modulates lipid metabolism and fecal microbiota but not glucose metabolism.

Amelioration of D-galactosamine-induced acute liver injury in rats by dietary supplementation with betaine derived from sugar beet molasses.

The effects of betaine supplementation on D-galactosamine-induced liver injury were examined in terms of hepatic and serum enzyme activities and of the levels of glutathione and betaine-derived intermediates. The rats induced with liver injury showed marked increases in serum enzyme activity, but those receiving dietary supplementation of 1% betaine showed enzyme activity levels similar to a control group without liver injury. Administration of betaine also increased both hepatic and serum glutathione levels, even following D-galactosamine injection. The activity of glutathione-related enzymes was markedly decreased following injection of D-galactosamine, but remained comparable to that of the control group in rats receiving 1% betaine. The concentrations of hepatic S-adenosyl methionine and cysteine showed similar trends to that observed for hepatic glutathione levels. These results indicate that 1% betaine has a hepatoprotective effect by increasing hepatic and serum glutathione levels along with glutathione-related enzyme activities in rats.

Dietary melibiose regulates th cell response and enhances the induction of oral tolerance.

We examined how dietary melibiose affected the T-helper (Th) cell responses induced by an orally fed antigen in ovalbumin (OVA)-specific T cell receptor transgenic mice (OVA 23-3). Dietary melibiose markedly decreased the Th2 type responses as shown by a significant decrease in the interleukin (IL)-4 production and T cell proliferative response induced by sensitization from the 7-d oral administration of OVA. It was additionally observed that the Th1 type responses tended to decrease. We therefore examined the effect of melibiose feeding on the induction of immunological tolerance induced by the oral administration of an antigen (oral tolerance). The Th cell responses induced in BALB/c mice by subcutaneous immunization with OVA were suppressed by the prior oral administration of OVA. Such responses in the OVA-fed and immunized mice were further diminished by dietary melibiose. These results suggest that dietary melibiose strongly affected the Th cell responses to an ingested antigen, and further demonstrate the potential of melibiose to enhance the induction of oral tolerance.

Structural analysis of novel kestose isomers isolated from sugar beet molasses.

Eight kestose isomers were isolated from sugar beet molasses by carbon-Celite column chromatography and HPLC. GC-FID and GC-MS analyses of methyl derivatives, MALD-TOF-MS measurements and NMR spectra were used to confirm the structural characteristics of the isomers. The (1)H and (13)C NMR signals of each isomer saccharide were assigned using COSY, E-HSQC, HSQC-TOCSY, HMBC and H2BC techniques. These kestose isomers were identified as α-D-fructofuranosyl-(2- > 2)-α-D-glucopyranosyl-(1 < ->2)-ß-D-fructofuranoside, α-D-fructofuranosyl-(2- > 3)-ß-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, α-D-fructofuranosyl-(2- > 4)-ß-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, ß-D-fructofuranosyl-(2- > 4)-ß-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, ß-D-fructofuranosyl-(2- > 3)-α-D-glucopyranosyl-(1 < ->2)-ß-D-fructofuranoside, α-D-fructofuranosyl-(2- > 1)-ß-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside, α-D-fructofuranosyl-(2- > 6)-α-D-glucopyranosyl-(1 < ->2)-ß-D-fructofuranoside, and α-D-fructofuranosyl-(2- > 6)-ß-D-fructofuranosyl-(2 < ->1)-α-D-glucopyranoside. The former five compounds are novel saccharides.

Structural confirmation of novel oligosaccharides isolated from sugar beet molasses.

Eleven oligosaccharides were isolated from sugar beet molasses using carbon-Celite column chromatography and HPLC. The constituent sugars and linkage positions were determined using methylation analysis, MALDI-TOF-MS, and NMR measurements. The configurations of isolated oligosaccharides were confirmed based on detailed NMR analysis. Based on our results, three of the 11 oligosaccharides were novel.

Characteristic intestinal microflora of specific pathogen-free mice bred in two different colonies and their influence on postnatal murine immunocyte profiles.

Cecal microflora of BALB/c mice originating from two different SPF-breeding colonies were compared. The analysis of cultivable bacteria in the ceca showed significantly higher numbers of total bacteria in BALB/cCrSlc (SLC mice) than in BALB/cA Jcl (JCL mice) (p<0.05), which were mainly based on higher numbers and occurrence of Peptococaceae. Bifidobacteria were detected only in SLC mice. Feeding an oligosaccharide, raffinose, to the mice also induced different shifts in the composition of cecal microflora and the concentration of cecal organic acids. In the second experiment, hysterectomy-derived (HD) SLC mice were fostered to SPF lactating SLC mothers, or SPF lactating JCL mice, together with the mother's own natural birth (NB) pups in each isolator. HD mice fostered to SLC-mothers showed significantly higher percentages of T-cell receptor alphabeta cells expressing a CD8alpha homodimer (p<0.05) and a CD8alphabeta heterodimer (p<0.001) in the intraepithelial lymphocytes (IEL) compared with HD mice fostered to JCL-mothers. IEL profiles of HD mice corresponded well to those of NB mice that were breast-fed by the same mothers. Differences in the ratio of B220(+)cells to Thy1.2(+)cells in the splenocytes were also observed as a trend between both HD mice fostered to SLC or JCL mothers (p=0.06). These results suggest that postnatal colonization of various characteristic intestinal microflora derived from SPF-breeding colonies results in differences in development of lymphocyte populations in the intestinal and systemic organs of mice.

Comparison of the effects of longer chain inulins with different degrees of polymerization on colonic fermentation in a mixed culture of Swine fecal bacteria.

The effects of inulin with three different degrees of polymerization (DP) on microbial dietary fiber fermentation were compared in an in vitro simulator of the porcine large bowel. The three inulin isolates had a DP of 15 (from chicory grown in Hokkaido, Japan), and 10 and 24 (from Orafti, Belgium), while cellulose was used as a control. The Lactobacillus level in the DP 10 group at 48 h and bifidobacteria levels in the DP 15 and DP 24 groups at 24 and 48 h were significantly higher than in the carbohydrate-free and cellulose groups. The SCFA concentrations in all the inulin groups were significantly higher than in the carbohydrate-free and cellulose groups at 24 and 48 h. Ammonia nitrogen concentrations in all the inulin groups were significantly lower than those in the carbohydrate-free and cellulose groups at 24 and 48 h. The three different inulin types were fermentable by gut microbiota as indicated by substantial increases in SCFA. In particular, inulin DP 15 exhibited a clear potential to be used as a prebiotic with significant increases in Lactobacillus and Bifidobacterium populations, and concomitantly propionate and butyrate productions than cellulose at the early incubation time. There was a negative correlation between SCFA and ammonia nitrogen concentrations. These results indicate DP 15 product has similar potential as a prebiotic to DP 10 or DP 24 product and showed substantial equivalence to DP 10 and DP 24 products.

Effects of dietary supplementation with betaine on a nonalcoholic steatohepatitis (NASH) mouse model.

The effects of betaine supplementation on non-alcoholic steatohepatitis (NASH) model mice were examined by measuring the accumulation of fat in the livers of NASH model mice compared to a control. Betaine from sugar beets was provided to the model mice as a dietary supplement. After 3 wk of dietary supplementation, there were no significant differences in body weight or liver weight between the groups. However, the liver to body weight ratio in the high-fat diet with betaine (HFB) group was significantly (p<0.05) higher than that in the high-fat diet (HF) group. There were no differences in serum triglyceride (TG) concentrations, AST and ALT activities, or hepatic glutathione concentrations between the groups. Hepatic TG level in the HFB group was significantly (p<0.05) lower than that in the HF group. Hepatic cells obtained from the HF group showed increased occurrence of explosive puff and necrosis as compared with those in the HFB group. Betaine supplementation had an inhibitory effect on fat accumulation in the liver: the Oil red-positive area in the HFB group (0.82 ± 0.85%) was significantly (p<0.001) smaller than that in the HF group (9.06 ± 2.24%). These results indicate the potential of betaine to serve as an agent for amelioration of hepatic steatosis in NASH model mice.

Structural confirmation of oligosaccharides newly isolated from sugar beet molasses.

BACKGROUND: Sugar beet molasses is a viscous by-product of the processing of sugar beets into sugar. The molasses is known to contain sucrose and raffinose, a typical trisaccharide, with a well-established structure. Although sugar beet molasses contains various other oligosaccharides as well, the structures of those oligosaccharides have not been examined in detail. The purpose of this study was isolation and structural confirmation of these other oligosaccharides found in sugar beet molasses. RESULTS: Four oligosaccharides were newly isolated from sugar beet molasses using high-performance liquid chromatography (HPLC) and carbon-Celite column chromatography. Structural confirmation of the saccharides was provided by methylation analysis, matrix-assisted laser desorption/ionaization time of flight mass spectrometry (MALDI-TOF-MS), and nuclear magnetic resonance (NMR) measurements. CONCLUSION: The following oligosaccharides were identified in sugar beet molasses: ß-D-galactopyranosyl-(1- > 6)-ß-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named ß-planteose), α-D-galactopyranosyl-(1- > 1)-ß-D-fructofuranosyl-(2 <-> 1)-α-D-glucopyranoside (named1-planteose), α-D-glucopyranosyl-(1- > 6)-α-D-glucopyranosyl-(1 <-> 2)-ß-D-fructofuranoside (theanderose), and ß-D-glucopyranosyl-(1- > 3)-α-D-glucopyranosyl-(1 <-> 2)-ß-D-fructofuranoside (laminaribiofructose). 1-planteose and laminaribiofructose were isolated from natural sources for the first time.

One-pot conversion of levan prepared from Serratia levanicum NN to difructose anhydride IV by Arthrobacter nicotinovorans levan fructotransferase.

The newly established difructose anhydride IV (DFA IV) production system is comprised of the effective production of levan from sucrose by Serratia levanicum NN, the conversion of the levan into DFA IV by levan fructotransferase from Arthrobacter nicotinovorans GS-9, which is highly expressed in an Escherichiacoli transformant, and a practical purification step. The chemical properties of DFA IV were also investigated.

Industrial production of difructose anhydride III (DFA III) from crude inulin extracted from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase.

A practical, economical, and industrial process for the enzymatic production of difructose anhydride III (DFA III) was investigated for crude inulin prepared from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase. A comparable level of DFA III production to that from commercial inulin was obtained using crude inulin, suggesting the feasibility of this production process.

Gastric colonization of Candida albicans differs in mice fed commercial and purified diets.

It has been difficult to produce persistent colonization by Candida albicans in the gastrointestinal tract of adult mice without the use of antibiotics and immunosuppressants. We hypothesized that diet influences the colonization of C. albicans and tested the hypothesis. BALB/c mice fed either a commercial rodent diet or a nutritionally adequate mixture of purified ingredients were inoculated i.g. with C. albicans (5 x 10(7) cells). Gastrointestinal colonization was examined by fecal culture, tissue culture, and histology. Mice fed the purified diet had a high fecal recovery of C. albicans [5-6log(10) colony forming units (cfu)/g feces] throughout the experimental period (6 wk), and the major site of colonization was the stomach. C. albicans was undetectable in the feces of mice fed the commercial diet 2 wk after inoculation. Immunosuppressants induced systemic dissemination of C. albicans in mice fed the purified diet. The number of lactobacilli and the concentration of organic acids in the stomach were significantly lower in mice fed the purified diet than in those fed the commercial diet. In vitro culture experiments revealed that acetic and lactic acids suppressed the growth of C. albicans. These results suggest that a reduction in lactobacilli in the stomach of mice fed the purified diet contributed to sustained gastric candidiasis. We therefore propose a novel model of sustained gastric candidiasis by a single i.g. inoculation of C. albicans in healthy adult mice fed a purified diet.

Reduction of allergic airway eosinophilia by dietary raffinose in Brown Norway rats.

Oral administration of raffinose, a naturally occurring indigestible oligosaccharide, has reportedly ameliorated atopic dermatitis in human subjects although the mechanism is unknown. The present study investigated the effect of dietary raffinose on allergen-induced airway eosinophilia in ovalbumin-sensitised Brown Norway rats as an atopic disease model. Brown Norway rats were immunised by subcutaneous injection with ovalbumin on day 0 and fed either a control diet or the diet supplemented with raffinose (50 g/kg diet). The rats were exposed to aerosolised ovalbumin on day 20, and broncho-alveolar lavage fluid was obtained on the next day. The number of eosinophils in the fluid was significantly lower in the rats fed the raffinose diet than in those fed the control diet. Dietary raffinose significantly reduced IL-4 and IL-5 mRNA levels in lung tissue and tended to lower ovalbumin-specific Ig E levels. Suppression of eosinophilia by dietary raffinose was still observed in caecectomised and neomycin-administered rats, suggesting little contribution by the colonic bacteria to the effect of raffinose. Intraperitoneal administration of raffinose also suppressed eosinophilia. Significant concentrations of raffinose were detected in portal venous and abdominal arterial plasma after the intragastric administration of raffinose. Overall, the findings suggest that dietary raffinose ameliorates allergic airway eosinophilia at least partly via post-absorptive mechanisms in Brown Norway rats.