Publications by authors named "Alexander G Haslberger"

26 Publications

  • Page 1 of 1

Nutraceutical Approaches of Autophagy and Neuroinflammation in Alzheimer's Disease: A Systematic Review.

Molecules 2020 Dec 18;25(24). Epub 2020 Dec 18.

Department of Nutritional Sciences, University of Vienna, A-1090 Vienna, Austria.

Aging and the emergence of age-associated illnesses are one of the major challenges of our present society. Alzheimer's disease (AD) is closely associated with aging and is defined by increasing memory loss and severe dementia. Currently, there are no therapy options available that halt AD progression. This work investigates three hallmarks of the disease (autophagy, neuroinflammation, and senescence) and systematically analyzes if there is a beneficial effect from three substances derived from food sources, the so called "nutraceuticals" epigallocatechin gallate, fisetin, and spermidine, on these hallmarks. The results imply a positive outlook for the reviewed substances to qualify as a novel treatment option for AD. A combination of nutraceutical substances and other preventive measures could have significant clinical impact in a multi-layered therapy approach to counter AD.
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http://dx.doi.org/10.3390/molecules25246018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7765980PMC
December 2020

Identification of spp. derived from a sheep and cattle slaughterhouse by matrix-assisted laser desorption and ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rDNA sequencing.

J Food Sci Technol 2018 Aug 22;55(8):3232-3240. Epub 2018 Jun 22.

1Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, UZAII;2D541, 1090 Vienna, Austria.

Clostridia are widespread and some of them are serious human pathogens. Identification of spp. is important for managing microbiological risks in the food industry. Samples derived from sheep and cattle carcasses from a slaughterhouse in Iran were analyzed by MALDI-TOF MS using direct transfer and extended direct transfer sample preparation methods and 16S rDNA sequencing. MALDI-TOF MS could identify ten species in 224 out of 240 isolates. In comparison to the 16S rDNA sequencing, correct identification rate of the spp. at the species level by MALDI-TOF MS technique was 93.3%. 16 isolates were not identified by MALDI-TOF MS but 16s rDNA sequencing identified them as , , and species. The most frequently identified species were: (13%), (12.5%), (12%) and (10%). Extended direct transfer method [2.26 ± 0.18 log (score)] in comparison to direct transfer method [2.15 ± 0.23 log (score)] improved spp.

Identification: Using a cut-off score of 1.7 was sufficient for accurate identification of species. MALDI-TOF MS identification scores for spp. decreased with longer incubation time. species predominantly were isolated from carcasses after skinning and evisceration steps in the slaughterhouse. MALDI-TOF MS could be an accurate way to identify species. Moreover, continuous improvement of the database and MALDI-TOF MS instrument enhance its performance in food control laboratories.
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http://dx.doi.org/10.1007/s13197-018-3255-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6046011PMC
August 2018

Counteraction of Oxidative Stress by Vitamin E Affects Epigenetic Regulation by Increasing Global Methylation and Gene Expression of and Dose Dependently in Caco-2 Cells.

Oxid Med Cell Longev 2018 22;2018:3734250. Epub 2018 Mar 22.

Department of Nutritional Sciences, University of Vienna, 1090 Vienna, Austria.

Obesity- or diabetes-induced oxidative stress is discussed as a major risk factor for DNA damage. Vitamin E and many polyphenols exhibit antioxidative activities with consequences on epigenetic regulation of inflammation and DNA repair. The present study investigated the counteraction of oxidative stress by vitamin E in the colorectal cancer cell line Caco-2 under normal (1 g/l) and high (4.5 g/l) glucose cell culture condition. Malondialdehyde (MDA) as a surrogate marker of lipid peroxidation and reactive oxygen species (ROS) was analyzed. Gene expression and promoter methylation of the DNA repair gene () and the () as well as global methylation by were investigated. Results revealed a dose-dependent counteracting effect of vitamin E on HO-induced oxidative stress. Thereby, 10 M vitamin E proved to be more efficient than did 50 M in reducing MDA. Further, an induction of and gene expression was noticed, accompanied by an increase in global methylation. Whether hypomethylation is a cause or effect of oxidative stress is still unclear. In conclusion, supplementation of exogenous antioxidants like vitamin E exhibits beneficial effects concerning oxidative stress as well as epigenetic regulation involved in DNA repair.
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http://dx.doi.org/10.1155/2018/3734250DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5944233PMC
October 2018

EGCG Prevents High Fat Diet-Induced Changes in Gut Microbiota, Decreases of DNA Strand Breaks, and Changes in Expression and DNA Methylation of and in C57BL/6J Male Mice.

Oxid Med Cell Longev 2017 4;2017:3079148. Epub 2017 Jan 4.

Department of Nutritional Sciences, University of Vienna, Vienna, Austria.

Obesity as a multifactorial disorder involves low-grade inflammation, increased reactive oxygen species incidence, gut microbiota aberrations, and epigenetic consequences. Thus, prevention and therapies with epigenetic active antioxidants, (-)-Epigallocatechin-3-gallate (EGCG), are of increasing interest. DNA damage, DNA methylation and gene expression of , , and were analyzed in C57BL/6J male mice fed a high-fat diet (HFD) or a control diet (CD) with and without EGCG supplementation. Gut microbiota was analyzed with quantitative real-time polymerase chain reaction. An induction of DNA damage was observed, as a consequence of HFD-feeding, whereas EGCG supplementation decreased DNA damage. HFD-feeding induced a higher inflammatory status. Supplementation reversed these effects, resulting in tissue specific gene expression and methylation patterns of and . HFD feeding caused a significant lower bacterial abundance. The ratio is significantly lower in HFD + EGCG but higher in CD + EGCG compared to control groups. The results demonstrate the impact of EGCG on the one hand on gut microbiota which together with dietary components affects host health. On the other hand effects may derive from antioxidative activities as well as epigenetic modifications observed on CpG methylation but also likely to include other epigenetic elements.
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http://dx.doi.org/10.1155/2017/3079148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241499PMC
March 2017

The microbial epigenome in metabolic syndrome.

Mol Aspects Med 2017 04 23;54:71-77. Epub 2016 Sep 23.

Department of Nutritional Sciences, University Vienna, Vienna, Austria.

Dietary habits, lifestyle, medication, and food additives affect the composition and functions of the GI microbiota. Metabolic syndrome is already known to be associated with an aberrant gut microbiota affecting systemic low-grade inflammation, which is also outlined by differing epigenetic patterns. Thus, structural changes and compositional evaluation of gut microbial differences affecting epigenetic patterns in metabolic syndrome are of research interest. In the present review we focus on the disparities in the gut microbiota composition of metabolic syndrome and the resulting aberrant profile of bioactive microbial metabolites known to affect epigenetic modifications such as G-protein coupled receptors and inflammatory pathways.
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http://dx.doi.org/10.1016/j.mam.2016.09.003DOI Listing
April 2017

Gut Microbiota of Obese, Type 2 Diabetic Individuals is Enriched in Faecalibacterium prausnitzii, Akkermansia muciniphila and Peptostreptococcus anaerobius after Weight Loss.

Endocr Metab Immune Disord Drug Targets 2016 ;16(2):99-106

Department of Nutritional Sciences, University Vienna, Vienna, Austria, Althanstraße 14; UZA II; 2D542; 1090 Vienna, Austria

Background: Beside the influence of nutritional habits and reduced physical activity, metabolic syndrome is associated with alterations in the structure of gut microbiota influencing the inflammatory immune responses. Gut microbiota and microbial metabolic activities are known to affect the lipid and glucose metabolism, satiety and chronic low-grade inflammation in the metabolic syndrome. The aim of the study was to identify genera or even species affecting host metabolism in obesity and type 2 diabetes beside the common used indicator: Firmicutes/ Bacteroidetes ratio.

Methods: Differences in gut microbiota were investigated in three groups of subjects over a four month intervention period: type 2 diabetics under GLP1-Agonist therapy, obese individuals without established insulin resistance, both receiving nutritional counseling concerning weight reduction, and a lean control group. Collection of fecal samples was accomplished at two time points, before treatment, and after four months of treatment. For identification of bacteria at species-level we used 454 high-throughput sequencing and fragment length polymorphism analysis based on IS-pro (Intergenic-Spacer-profiling). Five bacterial species, two bacterial genera, total bacterial abundance, and the Firmicutes/Bacteroidetes ratio were determined.

Results: Type 2 diabetics showed a higher Firmicutes/Bacteroidetes ratio even with an increase to the second time point (p=0.07). The abundance of B. thetaiotaomicron remained unaffected, whereas B. vulgatus significantly increased in type 2 diabetics (p=0.07) over the study period. Either Alistipes spp. showed an increase in type 2 diabetics between the time points (p=0.06). The abundance of F. prausnitzii (p=0.03) and A. muciniphila (p=0.03) also increased in type 2 diabetics over study period. In addition, the concentration of P. anaerobius (p=0.03) was significantly higher in type 2 diabetics after intervention compared to lean and obese controls.

Conclusion: Our results clearly show a difference in the gut bacterial composition in type 2 diabetics compared to lean controls or obesity. Therefore, the ratio of Fimicutes/Bacteroidetes might only be an indicator, but a detailed view at species level is even more important in regard to distinction of their functions.
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http://dx.doi.org/10.2174/1871530316666160831093813DOI Listing
January 2016

Antibacterial Activity of Carum copticum Essential Oil Against Escherichia Coli O157:H7 in Meat: Stx Genes Expression.

Curr Microbiol 2016 Aug 7;73(2):265-72. Epub 2016 May 7.

Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria.

This work were aimed to (a) determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Carum copticum essential oil (EO) against Escherichia. coli O157:H7 in vitro Trypticase Soy Broth, (TSB) and in ground beef; (b) evaluation of the effect of sub-inhibitory concentrations (sub-MICs) of EO on the growth of bacterium in TSB over 72 h (at 35 °C) and ground beef over 9 days (at 4 °C); and (c) investigation of gene expression involved in Shiga toxins production using relative quantitative real-time PCR method. The MIC in broth and ground beef medium were determined as 0.05 (v/v) and 1.75 % (v/w), respectively. In comparison with control cultures, the EO concentration of 0.03 % in broth caused reduction of colony counting as 1.93, 1.79, and 2.62 log10 CFU ml(-1) after 24, 48, and 72 h at 35 °C, and similarly EO (0.75 %) in ground beef resulted to reduction of colony counting as 1.03, 0.92, 1.48, and 2.12 log10 CFU g (-1) after 2, 5, 7, and 9 days at 4 °C, respectively. An increase and decrease in gene expression were observed as result of EO addition (0.03 %) to broth and (0.5 %) to ground beef was noticed, respectively.
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http://dx.doi.org/10.1007/s00284-016-1048-2DOI Listing
August 2016

Suppression subtractive hybridisation and real-time PCR for strain-specific quantification of the probiotic Bifidobacterium animalis BAN in broiler feed.

J Microbiol Methods 2016 Apr 13;123:94-100. Epub 2016 Feb 13.

University of Vienna, Department of Nutritional Sciences, Althanstraße 14, 1090 Vienna, Austria.

To ensure quality management during the production processes of probiotics and for efficacy testing in vivo, accurate tools are needed for the identification and quantification of probiotic strains. In this study, a strain-specific qPCR assay based on Suppression Subtractive Hybridisation (SSH) for identifying unique sequences, was developed to quantify the strain Bifidobacterium animalis BAN in broiler feed. Seventy potential BAN specific sequences were obtained after SSH of the BAN genome, with a pool of closely related strain genomes and subsequent differential screening by dot blot hybridisation. Primers were designed for 30 sequences which showed no match with any sequence database entry, using BLAST and FASTA. Primer specificity was assessed by qPCR using 45 non-target strains and species in a stepwise approach. Primer T39_S2 was the only primer pair without any unspecific binding properties and it showed a PCR efficiency of 80% with a Cq value of 17.32 for 20 ng BAN DNA. Optimised feed-matrix dependent calibration curve for the quantification of BAN was generated, ranging from 6.28 × 10(3)cfu g(-1) to 1.61 × 10(6)cfu g(-1). Limit of detection of the qPCR assay was 2 × 10(1)cfu g(-1) BAN. Applicability of the strain-specific qPCR assay was confirmed in a spiking experiment which added BAN to the feed in two concentrations, 2 × 10(6)cfu g(-1) and 2 × 10(4)cfu g(-1). Results showed BAN mean recovery rates in feed of 1.44 × 10(6) ± 4.39 × 10(5)cfu g(-1) and 1.59 × 10(4) ± 1.69 × 10(4)cfu g(-1), respectively. The presented BAN-specific qPCR assay can be applied in animal feeding trials, in order to control the correct inclusion rates of the probiotic to the feed, and it could further be adapted, to monitor the uptake of the probiotic into the gastrointestinal tract of broiler chickens.
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http://dx.doi.org/10.1016/j.mimet.2016.02.011DOI Listing
April 2016

Interleukin-6 CpG Methylation and Body Weight Correlate Differently in Type 2 Diabetes Patients Compared to Obese and Lean Controls.

J Nutrigenet Nutrigenomics 2015 10;8(1):26-35. Epub 2015 Jun 10.

Department of Nutritional Sciences, University of Vienna, Vienna, Austria.

Background/aims: Diabetes mellitus type 2 (DMT2) is accompanied by systemic low-grade inflammation with elevated levels of interleukin-6 (IL-6), which is encoded by a gene (IL-6) previously shown to be regulated by DNA methylation. We investigated seven CpG sites in IL-6 in individuals with DMT2, obese individuals and lean controls. Further, the DMT2 group received the glucagon-like peptide 1 agonist liraglutide.

Methods: Blood samples were taken at the beginning of the study and after 4 months. The DNA methylation was assessed using pyrosequencing.

Results: Methylation levels at the CpG sites -664, -628 and +13 at the first sampling time point (T1) and at -666 and -664 at the second sampling time point (T2) correlated negatively with initial body weight in the DMT2 group. We found positive correlations for the obese and the lean control group. In the obese group, CpG +27 methylation at T1 correlated with initial body weight (r = 0.685; p = 0.014). In the lean group, CpG -664 at T1 (r = 0.874; p = 0.005) and CpG -628 at T2 (r = 0.632; p = 0.050) correlated with initial body weight.

Conclusion: These findings are an informative basis for further studies to elucidate epigenetic mechanisms underlying DMT2. Additionally, our results might provide starting points for the development of biomarkers for prevention and therapy strategies.
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http://dx.doi.org/10.1159/000381714DOI Listing
April 2016

Obesity: epigenetic regulation – recent observations.

Biomol Concepts 2015 Jun;6(3):163-75

Genetic and environmental factors, especially nutrition and lifestyle, have been discussed in the literature for their relevance to epidemic obesity. Gene-environment interactions may need to be understood for an improved understanding of the causes of obesity, and epigenetic mechanisms are of special importance. Consequences of epigenetic mechanisms seem to be particularly important during certain periods of life: prenatal, postnatal and intergenerational, transgenerational inheritance are discussed with relevance to obesity. This review focuses on nutrients, diet and habits influencing intergenerational, transgenerational, prenatal and postnatal epigenetics; on evidence of epigenetic modifiers in adulthood; and on animal models for the study of obesity.
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http://dx.doi.org/10.1515/bmc-2015-0009DOI Listing
June 2015

Nutriepigenomics: the role of nutrition in epigenetic control of human diseases.

Curr Opin Clin Nutr Metab Care 2015 Jul;18(4):328-33

aDepartment of Nutritional Sciences, University Vienna, Vienna, Austria bDepartment of Nutrition Science, Purdue University, West Lafaytte, Indiana, USA cDepartment of Gynecology and Obstetrics, Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Ljubljana, Slovenia.

Purpose Of Review: Nutrients or even diets affect the epigenome by lifelong remodeling. Nutritional imbalances are associated with noncommunicable diseases. Thus, nutriepigenomics is a promising field in the treatment of complex human diseases.

Recent Findings: The epigenome is susceptible to changes and can be shaped by nutritional states, especially in prenatal period through transgenerational mechanisms and in early postnatal life when critical developmental processes are taking place. Although more stable, the epigenetic marks in adulthood are also dynamic and modifiable by environmental factors including diet.

Summary: The present review is focused on the most recent knowledge of epigenetically active nutrients/diets including transgenerational inheritance and prenatal predispositions related to increased risk for cancer, metabolic syndrome, and neurodegenerative diseases.
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http://dx.doi.org/10.1097/MCO.0000000000000180DOI Listing
July 2015

Mutation scanning in a single and a stacked genetically modified (GM) event by real-time PCR and high resolution melting (HRM) analysis.

Int J Mol Sci 2014 Oct 31;15(11):19898-923. Epub 2014 Oct 31.

Austrian Agency for Health and Food Safety, Spargelfeldstrasse 191, 1220 Vienna, Austria.

Genetic mutations must be avoided during the production and use of seeds. In the European Union (EU), Directive 2001/18/EC requires any DNA construct introduced via transformation to be stable. Establishing genetic stability is critical for the approval of genetically modified organisms (GMOs). In this study, genetic stability of two GMOs was examined using high resolution melting (HRM) analysis and real-time polymerase chain reaction (PCR) employing Scorpion primers for amplification. The genetic variability of the transgenic insert and that of the flanking regions in a single oilseed rape variety (GT73) and a stacked maize (MON88017×MON810) was studied. The GT73 and the 5' region of MON810 showed no instabilities in the examined regions. However; two out of 100 analyzed samples carried a heterozygous point mutation in the 3' region of MON810 in the stacked variety. These results were verified by direct sequencing of the amplified PCR products as well as by sequencing of cloned PCR fragments. The occurrence of the mutation suggests that the 5' region is more suitable than the 3' region for the quantification of MON810. The identification of the single nucleotide polymorphism (SNP) in a stacked event is in contrast to the results of earlier studies of the same MON810 region in a single event where no DNA polymorphism was found.
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http://dx.doi.org/10.3390/ijms151119898DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4264145PMC
October 2014

Modulation of hyperglycemia and TNFα-mediated inflammation by helichrysum and grapefruit extracts in diabetic db/db mice.

Food Funct 2014 Sep;5(9):2120-8

Department of Nutrition, Food Science and Physiology, University of Navarra, C/Irunlarrea 1, 31008 Pamplona, Navarra, Spain.

Type-2 diabetes is associated with a chronic low-grade systemic inflammation accompanied by an increased production of adipokines/cytokines by obese adipose tissue. The search for new antidiabetic drugs with different mechanisms of action, such as insulin sensitizers, insulin secretagogues and α-glucosidase inhibitors, has directed the focus on the potential use of flavonoids in the management of type-2 diabetes. Thirty six diabetic male C57BL/6J db/db mice were fed a standard diet and randomly assigned into four experimental groups: non-treated control, (n = 8); acarbose (5 mg per kg bw, n = 8); helichrysum (1 g per kg bw, n = 10) and grapefruit (0.5 g per kg bw, n = 10) for 6 weeks. The mRNA expression in pancreas, liver and epididymal adipose tissue was determined by RT-PCR. DNA methylation was quantified in epididymal fat using pyrosequencing. Mice supplemented with helichrysum and grapefruit extracts showed a significant decrease in fasting glucose levels (p < 0.05). A possible mechanism of action could be the up-regulation of liver glucokinase (p < 0.05). The antihyperglycemic effect of both extracts was accompanied by decreased mRNA expression of some proinflammatory genes (monocyte chemotactic protein-1, tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-kappaB) in the liver and epididymal adipose tissue. The CpG3 site of TNFα, located 5 bp downstream of the transcription start site, showed increased DNA methylation in the grapefruit group compared with the non-treated group (p < 0.01). In conclusion, helichrysum and grapefruit extracts improved hyperglycemia through the regulation of glucose metabolism in the liver and reduction of the expression of proinflammatory genes in the liver and visceral fat. The hypermethylation of TNFα in adipose tissue may contribute to reduce the inflammation associated with diabetes and obesity.
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http://dx.doi.org/10.1039/c4fo00154kDOI Listing
September 2014

Effects of short chain fatty acid producing bacteria on epigenetic regulation of FFAR3 in type 2 diabetes and obesity.

Gene 2014 Mar 8;537(1):85-92. Epub 2013 Dec 8.

Department of Nutritional Sciences, University Vienna, Vienna, Austria. Electronic address:

The human gut microbiota and microbial influences on lipid and glucose metabolism, satiety, and chronic low-grade inflammation are known to be involved in metabolic syndrome. Fermentation end products, especially short chain fatty acids, are believed to engage the epigenetic regulation of inflammatory reactions via FFARs (free fatty acid receptor) and other short chain fatty acid receptors. We studied a potential interaction of the microbiota with epigenetic regulation in obese and type 2 diabetes patients compared to a lean control group over a four month intervention period. Intervention comprised a GLP-1 agonist (glucagon-like peptide 1) for type 2 diabetics and nutritional counseling for both intervention groups. Microbiota was analyzed for abundance, butyryl-CoA:acetate CoA-transferase gene and for diversity by polymerase chain reaction and 454 high-throughput sequencing. Epigenetic methylation of the promoter region of FFAR3 and LINE1 (long interspersed nuclear element 1) was analyzed using bisulfite conversion and pyrosequencing. The diversity of the microbiota as well as the abundance of Faecalibacterium prausnitzii were significantly lower in obese and type 2 diabetic patients compared to lean individuals. Results from Clostridium cluster IV and Clostridium cluster XIVa showed a decreasing trend in type 2 diabetics in comparison to the butyryl-CoA:acetate CoA-transferase gene and according to melt curve analysis. During intervention no significant changes were observed in either intervention group. The analysis of five CpGs in the promoter region of FFAR3 showed a significant lower methylation in obese and type 2 diabetics with an increase in obese patients over the intervention period. These results disclosed a significant correlation between a higher body mass index and lower methylation of FFAR3. LINE-1, a marker of global methylation, indicated no significant differences between the three groups or the time points, although methylation of type 2 diabetics tended to increase over time. Our results provide evidence that a different composition of gut microbiota in obesity and type 2 diabetes affect the epigenetic regulation of genes. Interactions between the microbiota and epigenetic regulation may involve not only short chain fatty acids binding to FFARs. Therefore dietary interventions influencing microbial composition may be considered as an option in the engagement against metabolic syndrome.
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http://dx.doi.org/10.1016/j.gene.2013.11.081DOI Listing
March 2014

Vitamin and antioxidant rich diet increases MLH1 promoter DNA methylation in DMT2 subjects.

Clin Epigenetics 2012 Oct 1;4(1):19. Epub 2012 Oct 1.

Department of Nutritional Sciences, University of Vienna, Althanstraße 14, Vienna, 1090, Austria.

Unlabelled:

Background: Oxidative stress may lead to an increased level of unrepaired cellular DNA damage, which is discussed as one risk for tumor initiation. Mismatch repair (MMR) enzymes act as proofreading complexes that maintain the genomic integrity and MMR-deficient cells show an increased mutation rate. One important gene in the MMR complex is the MutL homolog 1 (MLH1) gene. Since a diet rich in antioxidants has the potential to counteract harmful effects by reactive oxygen species (ROS), we investigated the impact of an antioxidant, folate, and vitamin rich diet on the epigenetic pattern of MLH1. These effects were analyzed in individuals with non-insulin depended diabetes mellitus type 2 (NIDDM2) and impaired fasting glucose (IFG).

Methods: In this post-hoc analysis of a randomized trial we analyzed DNA methylation of MLH1, MSH2, and MGMT at baseline and after 8 weeks of intervention, consisting of 300 g vegetables and 25 ml plant oil rich in polyunsaturated fatty acids per day. DNA methylation was quantified using combined bisulfite restriction enzyme analysis (COBRA) and pyrosequencing. MLH1 and DNMT1 mRNA expression were investigated by qRT-PCR. DNA damage was assessed by COMET assay. Student's two-tailed paired t test and one-way ANOVA with Scheffé corrected Post hoc test was used to determine significant methylation and expression differences. Two-tailed Pearson test was used to determine correlations between methylation level, gene expression, and DNA strand break amount.

Results: The intervention resulted in significantly higher CpG methylation in two particular MLH1 promoter regions and the MGMT promoter. DNA strand breaks and methylation levels correlated significantly. The expression of MLH1, DNMT1, and the promoter methylation of MSH2 remained stable. CpG methylation levels and gene expression did not correlate.

Conclusion: This vitamin and antioxidant rich diet affected the CpG methylation of MLH1. The higher methylation might be a result of the ROS scavenging antioxidant rich diet, leading to lower activity of DNA demethylating enzymes. Our results suggest the hypothesis of CpG demethylation via DNA repair enzymes under these circumstances. NIDDM2 and IFG patients benefit from this simple dietary intervention involving epigenetic and DNA repair mechanisms.
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http://dx.doi.org/10.1186/1868-7083-4-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3579724PMC
October 2012

Changes in human fecal microbiota due to chemotherapy analyzed by TaqMan-PCR, 454 sequencing and PCR-DGGE fingerprinting.

PLoS One 2011 14;6(12):e28654. Epub 2011 Dec 14.

Department of Nutritional Sciences, Vienna, Austria.

Background: We investigated whether chemotherapy with the presence or absence of antibiotics against different kinds of cancer changed the gastrointestinal microbiota.

Methodology/principal Findings: Feces of 17 ambulant patients receiving chemotherapy with or without concomitant antibiotics were analyzed before and after the chemotherapy cycle at four time points in comparison to 17 gender-, age- and lifestyle-matched healthy controls. We targeted 16S rRNA genes of all bacteria, Bacteroides, bifidobacteria, Clostridium cluster IV and XIVa as well as C. difficile with TaqMan qPCR, denaturing gradient gel electrophoresis (DGGE) fingerprinting and high-throughput sequencing. After a significant drop in the abundance of microbiota (p = 0.037) following a single treatment the microbiota recovered within a few days. The chemotherapeutical treatment marginally affected the Bacteroides while the Clostridium cluster IV and XIVa were significantly more sensitive to chemotherapy and antibiotic treatment. DGGE fingerprinting showed decreased diversity of Clostridium cluster IV and XIVa in response to chemotherapy with cluster IV diversity being particularly affected by antibiotics. The occurrence of C. difficile in three out of seventeen subjects was accompanied by a decrease in the genera Bifidobacterium, Lactobacillus, Veillonella and Faecalibacterium prausnitzii. Enterococcus faecium increased following chemotherapy.

Conclusions/significance: Despite high individual variations, these results suggest that the observed changes in the human gut microbiota may favor colonization with C. difficile and Enterococcus faecium. Perturbed microbiota may be a target for specific mitigation with safe pre- and probiotics.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0028654PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3237468PMC
August 2012

Quantification of butyryl CoA:acetate CoA-transferase genes reveals different butyrate production capacity in individuals according to diet and age.

FEMS Microbiol Lett 2011 Mar 17;316(2):130-5. Epub 2011 Jan 17.

Department of Nutritional Sciences, University of Vienna, Vienna, Austria.

The gastrointestinal microbiota produces short-chain fatty acids, especially butyrate, which affect colonic health, immune function and epigenetic regulation. To assess the effects of nutrition and aging on the production of butyrate, the butyryl-CoA:acetate CoA-transferase gene and population shifts of Clostridium clusters lV and XlVa, the main butyrate producers, were analysed. Faecal samples of young healthy omnivores (24 ± 2.5 years), vegetarians (26 ± 5 years) and elderly (86 ± 8 years) omnivores were evaluated. Diet and lifestyle were assessed in questionnaire-based interviews. The elderly had significantly fewer copies of the butyryl-CoA:acetate CoA-transferase gene than young omnivores (P=0.014), while vegetarians showed the highest number of copies (P=0.048). The thermal denaturation of the butyryl-CoA:acetate CoA-transferase gene variant melting curve related to Roseburia/Eubacterium rectale spp. was significantly more variable in the vegetarians than in the elderly. The Clostridium cluster XIVa was more abundant in vegetarians (P=0.049) and in omnivores (P<0.01) than in the elderly group. Gastrointestinal microbiota of the elderly is characterized by decreased butyrate production capacity, reflecting increased risk of degenerative diseases. These results suggest that the butyryl-CoA:acetate CoA-transferase gene is a valuable marker for gastrointestinal microbiota function.
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http://dx.doi.org/10.1111/j.1574-6968.2010.02197.xDOI Listing
March 2011

Epigenetic control of estrogen receptor expression and tumor suppressor genes is modulated by bioactive food compounds.

Ann Nutr Metab 2010 18;57(3-4):183-9. Epub 2010 Nov 18.

Department of Nutritional Sciences, University of Vienna, Austria.

Background: The tumor suppressor genes p15(INK)⁴(b) and p16(INK)⁴(a) as well as the estrogen receptor-α (ESR1) gene are abnormally methylated and expressed in colon cancer. The cancer-preventative abilities of several bioactive food components have been linked to their estrogenic and epigenetic activities.

Methods: The effect of folic acid, zebularine, resveratrol, genistein and epigallocatechin-3-gallate (EGCG) on tumor cell growth, promoter methylation of ESR1, p15(INK)⁴(b) and p16(INK)⁴(a) and gene expression of ESR1 and ESR2 was analyzed in Caco-2 cells. Gene expression was measured using real-time PCR, and promoter CpG methylation was assessed using bisulfite conversion and methylation-specific PCR.

Results: After exposure to a high concentration of folic acid (20 μmol/l), enhanced cancer cell growth and concomitant increased methylation of the ESR1 (3.6-fold), p16(INK)⁴(a) and p15(INK)⁴(b) promoters was observed. A lower concentration of folic acid (2 μmol/l) decreased cell growth. The phytoestrogens genistein and resveratrol enhanced expression of ESR1 (genistein 200 μmol/l: 2.1-fold; resveratrol 50 μmol/l: 6.3-fold) and ESR2 (2.6- and 3.6-fold, respectively). Genistein and resveratrol treatment increased promoter methylation of ESR1 (genistein 200 μmol/l: 2.9-fold; resveratrol 50 μmol/l: 1.4-fold). For p16(INK)⁴(a), increased methylation was found after exposure to 10 μmol/l resveratrol, but for p15(INK)⁴(b), decreased methylation was found. Both components showed growth-inhibitory activities. For EGCG, growth inhibition at 100 μmol/l and suppressed promoter methylation of tumor suppressor genes (p16(INK)⁴(a): 0.9-fold; p15(INK)⁴(b): 0.6-fold) was seen.

Conclusions: Our results show that these food compounds regulate ESR and tumor suppressor gene expression by multiple mechanisms including epigenetic processes. An improved understanding of these epigenetic effects could therefore support specific dietary concepts of epigenetic cancer prevention and intervention.
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http://dx.doi.org/10.1159/000321514DOI Listing
March 2011

Characterization of bacteria, clostridia and Bacteroides in faeces of vegetarians using qPCR and PCR-DGGE fingerprinting.

Ann Nutr Metab 2009 27;54(4):253-7. Epub 2009 Jul 27.

Department of Nutritional Sciences, University of Vienna, Vienna, Austria.

Background/aims: This study aimed to investigate the quantitative and qualitative changes of bacteria, Bacteroides, Bifidobacterium and Clostridium cluster IV in faecal microbiota associated with a vegetarian diet.

Methods: Bacterial abundances were measured in faecal samples of 15 vegetarians and 14 omnivores using quantitative PCR. Diversity was assessed with PCR-DGGE fingerprinting, principal component analysis (PCA) and Shannon diversity index.

Results: Vegetarians had a 12% higher abundance of bacterial DNA than omnivores, a tendency for less Clostridium cluster IV (31.86 +/- 17.00%; 36.64 +/- 14.22%) and higher abundance of Bacteroides (23.93 +/- 10.35%; 21.26 +/- 8.05%), which were not significant due to high interindividual variations. PCA suggested a grouping of bacteria and members of Clostridium cluster IV. Two bands appeared significantly more frequently in omnivores than in vegetarians (p < 0.005 and p < 0.022). One was identified as Faecalibacterium sp. and the other was 97.9% similar to the uncultured gut bacteriumDQ793301.

Conclusions: A vegetarian diet affects the intestinal microbiota, especially by decreasing the amount and changing the diversity of Clostridium cluster IV. It remains to be determined how these shifts might affect the host metabolism and disease risks.
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http://dx.doi.org/10.1159/000229505DOI Listing
January 2010

Combined PCR-DGGE fingerprinting and quantitative-PCR indicates shifts in fecal population sizes and diversity of Bacteroides, bifidobacteria and Clostridium cluster IV in institutionalized elderly.

Exp Gerontol 2009 Jun-Jul;44(6-7):440-6. Epub 2009 Apr 17.

Department of Nutritional Sciences, University of Vienna, Austria.

Aims: This study aimed at determining ageing-related shifts in diversity and composition of key members of the fecal microbiota by comparing institutionalized elderly (n = 17, 78-94 years) and young volunteers (n = 17, 18-31 years).

Methods And Results: A combination of molecular methods was used to characterize the diversity and relative abundance of total gastro-intestinal flora, along with relevant subsets within the genera Bacteroides, bifidobacteria and Clostridium cluster IV. The institutionalized elderly harbored significantly higher numbers of Bacteroides cells than control (28.5 +/- 8.6%; 21.4 +/- 7.7%; p = 0.016) but contained less bifidobacteria (1.3 +/- 0.9, 2.7 +/- 3.2%, p = 0.026) and Clostridium cluster IV (26.9 +/- 11.7%, 36.36 +/- 11.26%, p = 0.036). The elderly also displayed less total Bacteria diversity and less diversity with the Clostridium cluster IV (p < 0.016) and Bacteroides.

Conclusion: Despite high individual variations, our analyses indicate the composition of microbiota in the elderly comprises a less diverse subset of young healthy microbiota.

Significance And Impact Of The Study: A better understanding of the individual composition of the human microbiota and the effects of ageing might result in the development of specifically targeted supplementation for elderly citizens in order to support healthy ageing.
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http://dx.doi.org/10.1016/j.exger.2009.04.002DOI Listing
November 2010

Epigenetic regulation of human buccal mucosa mitochondrial superoxide dismutase gene expression by diet.

Br J Nutr 2009 Mar 7;101(5):743-9. Epub 2008 Aug 7.

Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, Vienna, Austria.

The impact of nutrition on the epigenetic machinery has increasingly attracted interest. The aim of the present study was to demonstrate the effects of various diets on methylation and gene expression. The antioxidative enzyme mitochondrial superoxide dismutase (MnSOD) was chosen as the model system because epigenetic regulation has been previously shown in cell lines for this gene. Promoter methylation and gene expression of MnSOD in buccal swabs from three sample groups were analysed. The three groups included: (1) forty vegetarians (aged 20-30 years); (2) age-matched omnivores; (3) elderly omnivores (aged>85 years). A 3-fold increase in the expression of the MnSOD gene was associated with decreased CpG methylation of the analysed promoter region in the vegetarian group compared with the age-matched omnivores group. Expression and promoter methylation of the MnSOD gene in elderly omnivores showed no significant differences compared with younger omnivores. In accordance with previous findings in various tissues, DNA global methylation was found to be significantly higher (30 %) in buccal swabs of younger subjects (independent of the diet), than in those of elderly omnivores. In the control experiment which was designed to verify the findings of the human buccal swab studies, the Caco-2 cell line was treated with zebularine. Results of the control study showed a 6-fold increase of MnSOD expression, an approximately 40 % decreased methylation of specified CpG in the MnSOD promoter and a 50 % reduction of global DNA methylation. These results indicate that diet affects the epigenetic regulation of human MnSOD.
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http://dx.doi.org/10.1017/S0007114508047685DOI Listing
March 2009

DGGE and real-time PCR analysis of lactic acid bacteria in bacterial communities of the phyllosphere of lettuce.

Mol Nutr Food Res 2008 May;52(5):614-23

Department of Nutritional Sciences, University of Vienna, Austria.

Food associated indigenous microbial communities exert antagonistic effects on pathogens and may routinely deliver health relevant microorganisms to the GI tract. By using molecular, culture independent methods including PCR-DGGE of 16S rDNA-coding regions and real-time PCR (RT-PCR) as well as BIOLOG metabolic fingerprinting, microbial communities on lettuce were analyzed in samples from fields, from supermarkets and soil. Amplified 16S rRNA gene sequences (57.7%) could be assigned to species previously reported as typical for the phyllosphere including Pantoea agglomerans, Pseudomonas flavescens, Moraxella spp., and Mycobacterium spp. 71.8% of the sequences obtained represented so far undescribed taxa. Principal component analysis of BIOLOG metabolic profiles indicated a seasonal variation in the lettuce phyllosphere microbial community structure. Various lactic acid bacteria were detected including several Lactobacillus and Leuconostoc species in particular on lettuce from organic farming. By RT-PCR lactobacilli were found with a range of abundances from 1x10(4 )to 1x10(5 )copies/g lettuce. Considering the importance of salad in many diets lettuce may contribute to a constant supply with LAB.
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http://dx.doi.org/10.1002/mnfr.200700158DOI Listing
May 2008

Preanalytic removal of human DNA eliminates false signals in general 16S rDNA PCR monitoring of bacterial pathogens in blood.

Comp Immunol Microbiol Infect Dis 2009 May 7;32(3):207-19. Epub 2008 Feb 7.

Ludwig Boltzmann Institute for Leukemia Research and Hematology, Vienna, Austria.

PCR detection of microbial pathogens in blood from patients is a promising issue for rapid diagnosis of sepsis and early targeted therapy. However, for PCR assays detecting all bacterial groups, broad range primers, in particular the 16S rDNA targeting primers have to be used. Upcoming false signals and reduced sensitivity are a common problem as a consequence of unspecific amplification reactions with the human DNA background. Here we show that, using total DNA extracts from blood, unspecific signals occurred in general 16S rDNA PCRs as a result of the amplification of human sequences. To address this problem, we developed a protocol by which the human background DNA is removed and bacterial DNA is enriched during sample preparation, a method we termed background-free enrichment method (BFEM). In general, we aimed to exclude false signals due to the human background DNA yielded from 16S rDNA PCR, Real-Time-PCR and IGS-PCR analyses. We applied the BFEM to the analysis of blood samples from 22 patients and obtained results similar to standard blood culture methods. The BFEM allows specific and sensitive detection of pathogens in downstream PCR assays and is easy to handle due to the quick sample preparation procedure. Thus, the BFEM contributes to the generation of replicable and more reliable data in general 16S rDNA PCR assays.
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http://dx.doi.org/10.1016/j.cimid.2007.10.005DOI Listing
May 2009

Need for an "integrated safety assessment" of GMOs, linking food safety and environmental considerations.

J Agric Food Chem 2006 May;54(9):3173-80

Vienna Ecology Center, Department for Nutritional Sciences, University of Vienna, Althanstrasse 2, A-1090 Vienna, Austria.

Evidence for substantial environmental influences on health and food safety comes from work with environmental health indicators which show that agroenvironmental practices have direct and indirect effects on human health, concluding that "the quality of the environment influences the quality and safety of foods" [Fennema, O. Environ. Health Perspect. 1990, 86, 229-232). In the field of genetically modified organisms (GMOs), Codex principles have been established for the assessment of GM food safety and the Cartagena Protocol on Biosafety outlines international principles for an environmental assessment of living modified organisms. Both concepts also contain starting points for an assessment of health/food safety effects of GMOs in cases when the environment is involved in the chain of events that could lead to hazards. The environment can act as a route of unintentional entry of GMOs into the food supply, such as in the case of gene flow via pollen or seeds from GM crops, but the environment can also be involved in changes of GMO-induced agricultural practices with relevance for health/food safety. Examples for this include potential regional changes of pesticide uses and reduction in pesticide poisonings resulting from the use of Bt crops or influences on immune responses via cross-reactivity. Clearly, modern methods of biotechnology in breeding are involved in the reasons behind the rapid reduction of local varieties in agrodiversity, which constitute an identified hazard for food safety and food security. The health/food safety assessment of GM foods in cases when the environment is involved needs to be informed by data from environmental assessment. Such data might be especially important for hazard identification and exposure assessment. International organizations working in these areas will very likely be needed to initiate and enable cooperation between those institutions responsible for the different assessments, as well as for exchange and analysis of information. An integrated assessment might help to focus and save capacities in highly technical areas such as molecular characterization or profiling, which are often necessary for both assessments. In the area of establishing international standards for traded foods, such as for the newly created Standards in Trade and Development Facility (STDF), an integrated assessment might help in the consideration of important environmental aspects involved in health and food safety. Furthermore, an established integrated view on GMOs may create greater consumer confidence in the technology.
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http://dx.doi.org/10.1021/jf0511650DOI Listing
May 2006

Codex guidelines for GM foods include the analysis of unintended effects.

Nat Biotechnol 2003 Jul;21(7):739-41

University of Vienna and the World Health Organization FOS Program for Food Safety, Geneva, Switzerland.

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http://dx.doi.org/10.1038/nbt0703-739DOI Listing
July 2003