The effects of di-D-fructofuranose-1,2':2,3'-dianhydride (DFA III) administration on human intestinal microbiota

Innovative application of a novel and thermostable inulin fructotransferase from Arthrobacter sp. ISL-85 to fructan inulin in burdock root to improve nutrition

Inulin fructotransferase converts prebiotic polysaccharide inulin to difructose anhydride III, known for its numerous beneficial physiological effects. While previous studies focused on using inulin extracts under optimal conditions, this study delves into the enzyme's behavior when dealing with more complex food materials, inulin-rich burdock root, which possesses greater nutritional value but may influence the enzymatic reaction. An inulin fructotransferase from Arthrobacter sp. ISL-85 was identified and characterized, which has the highest activity of 783 U mg-1 at pH 6.5 and 65 °C and remains stable even up to 80 °C. When applied to inulin-rich burdock root (pH 4.7) at 80 °C for 2 h, the enzyme yielded 4.1 g of difructose anhydride III, concurrently increasing fructo-oligosaccharides. This study demonstrates the potential of this enzyme as a valuable tool for efficiently processing inulin within whole food materials under high temperatures. Such an approach could pave the way for enhancing nutrition and promoting health benefits.

Innovative application of a novel di-D-fructofuranose 1,2':2,3'-dianhydride hydrolase (DFA-IIIase) from Duffyella gerundensis A4 to burdock root to improve nutrition

Burdock is native to Europe and Asia and rich in many functional ingredients, including biomacromolecule polysaccharide inulin. The prebiotic fructan inulin can provide energy to organisms via several pathways. One pathway is that inulin fructotransferase (IFTase) first converts inulin to III-type difructose anhydride (DFA-III), which has many beneficial physiological functions. Then, DFA-III is hydrolyzed to inulobiose, which is a Fn-type prebiotic fructo-oligosaccharide, via difructose anhydride hydrolase (DFA-IIIase). However, there has been no study on the application of IFTase or DFA-IIIase to process burdock to increase DFA-III or inulobiose. Moreover, only five DFA-IIIases have been reported to date and all of them are from the Arthrobacter genus. Whether other microbes except for the Arthrobacter genus can utilize DFA-III through DFA-IIIase is unknown. In this work, a DFA-IIIase from Duffyella gerundensis A4 (D. gerundensis A4), abbreviated as DgDFA-IIIase, was identified and characterized in detail. DgDFA-IIIase is a bifunctional enzyme, that is, besides its hydrolytic ability to DFA-III, it has the same catalytic ability as IFTase to inulin. The enzyme was applied to the burdock root aiming at inulin and DFA-III, and inulobiose was produced with an increase in Gn-type fructo-oligosaccharide. The work verifies that microorganisms of the non-Arthrobacter genus also have the potential ability to use DFA-III by DFA-IIIase, and DFA-IIIase is feasible to increase functional substances of burdock root instead of IFTase and endo-inulinase, which paves the way for the production of functional food utilizing the polysaccharide inulin to improve nutrition and health.

Metabolomic study of human tissue and urine in clear cell renal carcinoma by LC-HRMS and PLS-DA

Renal cell carcinoma (RCC) is the most prevalent and lethal malignancy of the kidney. Despite all the efforts made, no tissue biomarker is currently used in the clinical management of patients with kidney cancer. A search for possible biomarkers in urine for clear cell renal cell carcinoma (ccRCC) has been conducted. Non-targeted metabolomic analyses were performed on paired samples of surgically removed renal cancer and normal tissue, as well as on urine samples. Extracts were analyzed by liquid chromatography/high-resolution mass spectrometry (LC-HRMS). Hydroxybutyrylcarnitine, decanoylcarnitine, propanoylcarnitine, carnitine, dodecanoylcarnitine, and norepinephrine sulfate were found in much higher concentrations in both cancer tissues (compared with the paired normal tissue) and in urine of cancer patients (compared with control urine). In contrast, riboflavin and acetylaspartylglutamate (NAAG) were present at significantly higher concentrations both in normal kidney tissue as well as in urine samples of healthy persons. This preliminary study resulted in the identification of several compounds that may be considered potential clear cell renal carcinoma biomarkers. Graphical abstract PLS-DA plot based on LC-MS data for normal and cancer human tissue samples. The aim of this work was the identification of up- and downregulated compounds that could potentially serve as renal cancer biomarkers.

From fructans to difructose dianhydrides

Fructans are the polymers of fructose molecules, normally having a sucrose unit at what would otherwise be the reducing terminus. Inulin and levan are two basic types of simple fructan, which contain β-(2, 1) and β-(2, 6) fructosyl-fructose linkage, respectively. Fructans not only can serve as soluble dietary fibers for food industry, but also may be biologically converted into high-value products, especially high-fructose syrup and fructo-oligosaccharides. In recent years, much attention has been focused on production of difructose dianhydrides (DFAs) from fructans. DFAs are cyclic disaccharides consisting of two fructose units with formation of two reciprocal glycosidic linkages. They are expected to have promising properties and beneficial effects on human health. DFAs can be produced from fructans by fructan fructotransferases. Inulin fructotransferase (IFTase) (DFA III-forming) and IFTase (DFA I-forming) catalyze the DFA III and DFA I production from inulin, respectively, and levan fructotransferase (LFTase) (DFA IV-forming) catalyzes the production of DFA IV from levan. In this article, the DFA-producing microorganisms are summarized, relevant studies on various DFAs-producing enzymes are reviewed, and especially, the comparisons of the enzymes are presented in detail.

Comparison of Yacon (Smallanthus sonchifolius) Tuber with Commercialized Fructo-oligosaccharides (FOS) in Terms of Physiology, Fermentation Products and Intestinal Microbial Communities in Rats

The yacon (Smallanthus sonchifolius) tuber was examined with regard to its prebiotic effects compared with commercialized fructo-oligosaccharides (FOS). A feed containing 10% yacon tuber, which is equivalent to 5% commercialized FOS in terms of the amount of fructo-oligosaccharides (GF2, GF3 and GF4), was administrated to rats for 28 days. The yacon diet changed the intestinal microbial communities beginning in the first week, resulting in a twofold greater concentration of cecal short-chain fatty acids (SCFAs). The SCFA composition differed, but the cecal pH in rats fed yacon tuber was equal to that in rats fed FOS. Serum triglycerides were lower in rats fed yacon compared with rats fed FOS and the control diet. Cecal size was greater with the yacon tuber diet compared with the control diet. The abundant fermentation in the intestines created a selective environment for the intestinal microbiota, which included Lactobacillus acidophilus, Bifidobacterium pseudolongum, Bifidobacterium animalis and Barnesiella spp. according to identification with culture-independent analysis, 16S rRNA gene PCR-DGGE combined with cloning and sequencing. Barnesiella spp. and B. pseudolongum were only found in the rats fed the yacon diet, while L. acidophilus and B. animalis were found in abundance in rats fed both the yacon and FOS diets. The genus Barnesiella has not previously been reported to be associated with yacon or FOS fermentation. We concluded that the physiological and microbiological effects of the yacon tuber were different from those of FOS. Differences in cecal size, blood triglycerides and microbial community profiles including their metabolites (SCFAs) between the yacon tuber and FOS were shown to be more greatly affected by the yacon tuber rather than FOS.

Application of sequence-dependent electrophoresis fingerprinting in exploring biodiversity and population dynamics of human intestinal microbiota: what can be revealed?

Sequence-dependent electrophoresis (SDE) fingerprinting techniques such as denaturing gradient gel electrophoresis (DGGE) have become commonplace in the field of molecular microbial ecology. The success of the SDE technology lays in the fact that it allows visualization of the predominant members of complex microbial ecosystems independent of their culturability and without prior knowledge on the complexity and diversity of the ecosystem. Mainly using the prokaryotic 16S rRNA gene as PCR amplification target, SDE-based community fingerprinting turned into one of the leading molecular tools to unravel the diversity and population dynamics of human intestinal microbiota. The first part of this review covers the methodological concept of SDE fingerprinting and the technical hurdles for analyzing intestinal samples. Subsequently, the current state-of-the-art of DGGE and related techniques to analyze human intestinal microbiota from healthy individuals and from patients with intestinal disorders is surveyed. In addition, the applicability of SDE analysis to monitor intestinal population changes upon nutritional or therapeutic interventions is critically evaluated.

Bacterial, archaeal, and eukaryal diversity in the intestines of Korean people

The bacterial, archaeal, and eukaryal diversity in fecal samples from ten Koreans were analyzed and compared by using the PCR-fingerprinting method, denaturing gradient gel electrophoresis (DGGE). The bacteria all belonged to the Firmicutes and Bacteroidetes phyla, which were known to be the dominant bacterial species in the human intestine. Most of the archaeal sequences belonged to the methane-producing archaea but several halophilic archarea-related sequences were also detected unexpectedly. While a small number of eukaryal sequences were also detected upon DGGE analysis, these sequences were related to fungi and stramenopiles (Blastocystis hominis). With regard to the bacterial and archaeal DGGE analysis, all ten samples had one and two prominent bands, respectively, but many individual-specific bands were also observed. However, only five of the ten samples had small eukaryal DGGE bands and none of these bands was observed in all five samples. Unweighted pair group method and arithmetic averages clustering algorithm (UPGMA) clustering analysis revealed that the archaeal and bacterial communities in the ten samples had relatively higher relatedness (the average Dice coefficient values were 68.9 and 59.2% for archaea and bacteria, respectively) but the eukaryal community showed low relatedness (39.6%).

Change in the ileal bacterial population of turkeys fed different diets and after infection with Salmonella as determined with denaturing gradient gel electrophoresis of amplified 16s ribosomal DNA

Changes in ileal bacterial populations of Salmonella-infected turkeys fed different diets were analyzed by using 16S-V3 PCR denaturing gradient gel electrophoresis. Turkeys raised on litter flooring were fed wheat- and corn-based diets with and without enzyme preparations (XY1 and XY2, respectively) from 0 to 126 d. Preparation XY1 contained exclusively endoxylanase, whereas preparation XY2 contained endoxylanase, protease, and alpha-amylase (Danisco, , Wiltshire, UK). The dietary activity levels of XY1 and XY2 were 2,500 and 650 endo-1,4-beta-xylanase units/kg of feed, respectively. Microbial DNA was extracted from the ileal content of 16-wk-old turkeys, and the 16S rDNA gene was amplified by PCR and analyzed by denaturing gradient gel electrophoresis. Diversity indexes, including richness (number of species, S), evenness (relative distribution of species, EH), diversity (using Shannon's index, H'), and Sorenson's pairwise similarities coefficient (measures the species in common between different habitats, Cs) were calculated. Additionally, diversity indexes were associated with Salmonella prevalence determined from fresh fecal droppings collected from each pen. On the basis of contrast analysis, the wheat-based diets resulted in higher microbial diversity indexes than the corn-based diets (S = 10 vs. 12; EH = 0.9 vs. 0.8; H' = 2.2 vs. 1.9, P < 0.05). Likewise, enzyme supplementation stimulated growth of the microbiota and increased the diversity indexes in comparison with unsupplemented treatments (S = 13 vs. 10; EH = 0.9 vs. 0.8; H' = 2.2 vs. 1.9, P < 0.05). Salmonella prevalence was higher (P < 0.05) at 15 wk in turkeys fed the corn-based diet (Salmonella prevalence = 50%) than in turkeys fed the corn-enzyme (Salmonella prevalence = 13%) and wheat-based (Salmonella prevalence = 0%) dietary treatments. Therefore, contrast analysis showed that birds fed the corn control diet had lower microbiota diversity but higher Salmonella prevalence than birds fed the enzyme-supplemented and wheat-based diets. In contrast, birds fed the wheat-based diets had higher diversity but lower Salmonella prevalence than birds fed the corn-based diets. High dietary nonstarch polysaccharides from wheat and dietary exogenous enzyme supplementation promoted microbial community diversity and apparently discouraged Salmonella colonization through competitive exclusion. Nonstarch polysaccharides and dietary exogenous enzyme supplementation may be practical tools to control enteric pathogens and benefit the intestinal health and food safety of the birds.

Difructose anhydride III promotes absorption of the soluble flavonoid alphaG-rutin in rats

A highly soluble quercetin glycoside, alphaG-rutin, is a glucose adduct of insoluble rutin. We examined the effects of difructose anhydride III (DFAIII; di-D-fructofuranosyl 1,2':2,3'-dianhydride) on intestinal absorption of alphaG-rutin by rat experiments. alphaG-rutin, rutin, quercetin, and the quercetin conjugate appeared in the portal blood after an intubation of alphaG-rutin (100 micromol), DFAIII effected higher portal concentrations of alphaG-rutin in portal cannulated rats. In ligated jejunal and ileal loops of rats, alphaG-rutin, rutin, quercetin, and the quercetin conjugate appeared in the intestinal mesenteric blood at both 30 and 60 min in both loops; the concentration of alphaG-rutin was 1.5-3 times higher when absorbed in the presence DFAIII. In the isolated mucosae of the jejunum and ileum, mucosal-to-serosal passage of alphaG-rutin increased with the addition of 100 micromol of DFAIII. These results indicate that alphaG-rutin is absorbed as the intact form and that DFAIII stimulates its absorption in the small intestine.

Effects of long-term ingestion of difructose anhydride III (DFA III) on intestinal bacteria and bile acid metabolism in humans

Changes in the intestinal microbiota of 10 human subjects with long-term ingestion of 3 g/d difructose anhydride III (DFA III; 4 persons, 2 months; 3 persons, 6 months; and 3 persons, 12 months) were examined by denaturing gradient gel electrophoresis (DGGE). According to the answers to questionnaires, the subjects were divided into two groups (constipated and normal). The DGGE profile was different for every individual and each subject had unique profiles of intestinal microbiota. In the DGGE profiles of constipated subjects, the intensities of bands related to Bacteroides spp. increased. Moreover, the DFA III-assimilating bacteria, Ruminococcus sp. were isolated from subjects who ingested DFA III for 12 months. These strains showed 95% similarity of their 16S rDNA sequences with that of Ruminococcus obeum ATCC 29174(T) (X85101) and produced large amounts of acetic acid. DFA III ingestion for 2 months tended to increase total organic acids in feces, and tended to decrease fecal pH and the secondary bile acid (SBA) ratio in total bile acids. The SBA ratio in total bile acids corresponded to fecal pH. The production of SBA was decreased by low pH in vitro. These results indicated that DFA III ingestion in humans tended to lower intestinal pH, inhibited bile acid 7alpha-dehydroxylation activities and also tended to decrease the SBA ratios in total bile acids. Moreover, as another cause for the decrease in the SBA ratio in total bile acids, it was suggested that the number of bile acid 7alpha-dehydroxylating bacteria were decreased by DFA III ingestion.

Effects of difructose anhydride III (DFA III) administration on bile acids and growth of DFA III-assimilating bacterium Ruminococcus productus on rat intestine

The growth of DFA III-assimilating bacteria in the intestines of rats fed 3% DFA III for 2 weeks was examined. Sixty-four percent of the DFA III intake had been assimilated on day 3 of ingestion, and almost all of the DFA III was assimilated at the end of the experiment. The DFA III-assimilating bacterium, Ruminococcus productus, in DFA III-fed rats was in the stationary state of 10(8)-10(9) cells/g dry feces within a week from 10(6) cells/g dry feces on day 1 of DFA III ingestion. The number of R. productus cells was associated with the amount of DFA III excreted in the feces. The acetic acid produced from DFA III by R. productus lowered the cecal pH to 5.8. In control-fed rats and DFA III-fed rats, 94% of secondary bile acids and 94% of primary bile acids, respectively, were accounted for in the total bile acids analyzed. DFA III ingestion increased the ratio of primary bile acids and changed the composition of fecal bile acids. In conclusion, R. productus assimilated DFA III, produced short chain fatty acids, and the cecal pH was lowered. The acidification of rat intestine perhaps inhibited secondary bile acid formation and decreased the ratio of secondary bile acids. Therefore, it is expected that DFA III may prevent colorectal cancer and be a new prebiotic candidate.

Effects of difructose anhydride III (DFA III) administration on rat intestinal microbiota

The effects of difructose anhydride III (di-D-fructofuranose-1,2':2,3'-dianhydride; DFA III) administration (3% DFA III for 4 weeks) on rat intestinal microbiota were examined using denaturing gradient gel electrophoresis (DGGE). According to DGGE profiles, the number of bacteria related to Bacteroides acidofaciens and uncultured bacteria within the Clostridium lituseburense group decreased, while that of bacteria related to Bacteroides vulgatus, Bacteroides uniformis and Ruminococcus productus increased in DFA III-fed rat cecum. In the cecal contents of DFA III-fed rats, a lowering of pH and an increase in short chain fatty acids (SCFAs), especially acetic acid, were observed. The DFA III-assimilating bacterium, Ruminococcus sp. M-1, was isolated from the cecal contents of DFA III-fed rats. The strain had 98% similarity with R. productus ATCC 27340T (L76595), and mainly produced acetic acid. These results confirmed that the bacteria harmful to host health were not increased by DFA III administration. Moreover, DFA III stimulated the growth of Ruminococcus sp. M-1 producing acetic acid, which may alter the intestinal microbiota towards a healthier composition. It is expected that DFA III would be a new candidate as a prebiotic.