Alexander Link

Otto-von-Guericke-Universität Magdeburg | OvGU · Department of Gastroenterology Hepatology and Infectious Diseases

Background Assessment of the disease activity in inflammatory bowel disease (IBD) is essential for adequate treatment management and reliable noninvasive biomarkers for verification of mucosal healing are still needed. MicroRNAs (miRNAs) are differentially expressed in IBD and cancer. We aimed to evaluate the potential of circulating and fecal miRN...

Fusobacterium nucleatum (F. nucleatum) is frequently detected in primary colorectal cancer (CRC) and matching metastasis, and has been linked to a worse prognosis. We investigated the presence of F. nucleatum in gastric cancer (Gc) and gastric preneoplastic conditions of the stomach, and its potential prognostic value in Gc patients. Fusobacterium...

The adaption of gut microbiota (GM) throughout human life is a key factor in maintaining health. Interventions to restore a healthy GM composition may have the potential to improve health and disease outcomes in the elderly. We performed a comprehensive characterization of changes in the luminal and mucosa-associated microbiota composition in elder...

Background: Human gut microbiome composition is influenced by genetics, diet and environmental factors. We investigated the microbial composition in several gastrointestinal (GI) compartments to evaluate the impact of genetics, delivery mode, diet, household sharing and aging on microbial similarity in monozygotic and dizygotic twins. Methods: F...

Introduction: High expression of HOTAIR promotes tumor growth and carries a dismal prognosis for the patient. We investigated the prognostic value of HOTAIR expression in gastric cancer (GC) and systematically delineate the expression in relation to Helicobacter pylori (H. pylori) infection and preneoplastic changes. Methods: HOTAIR expression w...

Helicobacter pylori (H. pylori) infection has been considered as the main causal factor in gastric carcinogenesis, but other bacterial species may also play an important role in pathophysiology of gastric cancer. The aim of the study was to explore the link between gastric cancer prognosis and the mucosal microbial community in tumorous and adjacen...

Background: Helicobacter pylori and the stomach microbiome play a crucial role in gastric carcinogenesis, and detailed characterization of the microbiome is necessary for a better understanding of the pathophysiology of the disease. There are two common modalities for microbiome analysis: DNA (16S rRNA gene) and RNA (16S rRNA transcript) sequencin...

Microbiota research has received an increasing attention for its role in disease development and fungi are considered as one of the key players in the microbial niche. Various sequencing approaches have been applied to uncover the role of fungal community in health and disease; however, little is known on the performance of various primers and comp...

Background Epigenetic modifications in mammalian DNA are commonly manifested by DNA methylation. In the stomach, altered DNA methylation patterns have been observed following chronic Helicobacter pylori infections and in gastric cancer. In the context of epigenetic regulation, the regional nature of the stomach has been rarely considered in detail....

Selenium, ⁷⁹Se, is one of the most critical radionuclides in radioactive waste disposed in future deep geological repositories (DGRs). Here, we investigate the impact of bentonite microbial communities on the allotropic transformation of Se(IV) bioreduction products under DGR relevant conditions. In addition, Se amendment-dependent shifts in the be...

Selenate (Se(VI)) is one of the most soluble and toxic species of Se. Microbial Se(VI) reduction is an efficient tool for bioremediation strategies. However, this process is limited to a few microorganisms, and its molecular basis remains unknown. We present detailed Se(VI)-resistance mechanisms under 50 and 200 mM, in Stenotrophomonas bentonitica...

Pre-clinical studies suggest that circulating oxylipins, i.e., the oxidation products of polyunsaturated fatty acids (PUFAs), modulate gut microbiota composition in mice, but there is no information available in humans. Therefore, this study aimed to investigate the relationship between omega-3 and omega-6 derived oxylipins plasma levels and fecal...

Background Eosinophilic Esophagitis (EoE) has received increasing attention as a disease entity, and it is now recognized as an important disorder of the Upper Gastrointestinal Tract. Topical corticosteroids (tCS) are effective in clinical-pathological remission induction (RI) and remission maintenance (RM) of active EoE. With scoring systems, such...

Objective: Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and its related cardiometabolic diseases; however, whether the gut microbiota might be an efficient stimulus to activate BAT metabolism remains to be ascertained. We aimed to investigate the association of fecal microbiota co...

The colonic mucosa has a complex interaction and is likely the most effective barrier against the numerically more superior microbial community within the gut microbiota. Therefore, it is probably not surprising that colorectal cancer (CRC), one of the largest challenges in gastroenterology and oncology, may be triggered and modulated by gut-microb...

Background Antibiotic susceptibility of Helicobacter pylori to antibiotics may vary among different niches of the stomach. The progression of chronic H. pylori gastritis to atrophy changes intragastric physiology that may influence selection of resistant strains.AimTo study the antibiotic resistance of H. pylori taking the severity of atrophic gast...

Background and aims: Hepatocellular carcinoma (HCC) often develops in patients with alcohol-related cirrhosis (ArC) at an annual risk of up to 2.9%. Some host genetic risk factors have been identified but do not account for the majority of the variance in occurrence. This study aimed to identify novel risk factors for the development of HCC in peop...

Objective Hepatocellular carcinoma (HCC) often develops in patients with alcohol-related cirrhosis at an annual risk of up to 2.5%. Some host genetic risk factors have been identified but do not account for the majority of the variance in occurrence. This study aimed to identify novel susceptibility loci for the development of HCC in people with al...

Four aerobic granular sludge reactors operated in sequential batch mode were implemented to understand the effect of low (7 °C) and high (26 °C) temperature in the removal of pharmaceuticals in the treated effluent. The chemical oxygen demand and nitrogen removal ratio were affected during the startup period in reactors feeding with drugs, but syst...

Objective: To investigate the association of plasma levels of endocannabinoids with fecal microbiota. Methods: Plasma levels of endocannabinoids, anandamide (AEA) and 2-arachidonoylglycerol (2-AG), as well as their eleven analogues, and arachidonic acid (AA), were measured using liquid chromatography-tandem mass spectrometry in 92 young adults....

An aerobic granular biofilm process was operated in a sequential batch reactor for treating nitrate-pollute groundwater at 6 ºC, which was fed with a progressively reduced carbon concentration to understand the nitrate removal efficacy in cold regions by denitrifying microorganisms. The evaluation of the performance reflected a quick granulation pr...

Regulatory changes occurring early in colorectal cancer development remain poorly investigated. Since the majority of cases develop from polyps in the adenoma-carcinoma transition, a search of early molecular features, such as aberrations in miRNA expression occurring prior to cancer development, would enable identification of potentially causal, r...

Background: Gastric cancer (GC) is one of the most frequently diagnosed tumor globally. In most cases, GC develops in a stepwise manner from chronic gastritis or atrophic gastritis (AG) to cancer. One of the major issues in clinical settings of GC is diagnosis at advanced disease stages resulting in poor prognosis. MicroRNAs (miRNAs) are small non...

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) have emerged as leading causes of chronic liver diseases worldwide. ALD and NAFLD share several pathophysiological patterns as well as histological features, while clinically, they are distinguished by the amount of alcohol consumed daily. However, NAFLD coexists with moder...

Here, the spatial distribution of the bacterial flora along the murine alimentary tract was evaluated using high throughput sequencing in wild-type and Tff3-deficient (Tff3KO) animals. Loss of Tff3 was linked to increased dextran sodium sulfate-induced colitis. This systematic study shows the results of 13 different regions from the esophagus to th...

Celiac disease (CeD) is a chronic autoimmune disorder characterized by an intolerance to storage proteins of many grains. CeD is frequently associated with liver damage and steatosis. Bile acid (BA) signaling has been identified as an important mediator in gut–liver interaction and the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Here...

DOI 10.1055/s-0041-1740685 P 1.22 Age-related analysis of transcriptome-wide sequencing of human liver Authors Schreiter Thomas1, Gieseler Robert K.1, Vílchez-Vargas Ramiro2, Jauregui Ruy3, Sowa Jan-Peter1, Klein-Scory Susanne1, Broering Ruth4, Croner Roland S.2, Treckmann Jürgen W.1, Link Alexander2, Canbay Ali1 Institutes 1 University Hospital...

The host genetic background for hepatocellular carcinoma (HCC) is incompletely understood. We aimed to determine if four germline genetic polymorphisms, rs429358 in apolipoprotein E (APOE), rs2642438 in mitochondrial amidoxime reducing component 1 (MARC1), rs2792751 in glycerol‐3‐phosphate acyltransferase (GPAM), and rs187429064 in transmembrane 6...

Citation: Schreiter, T.; Gieseler, R.K.; Vílchez-Vargas, R.; Jauregui, R.; Sowa, J.-P.; Klein-Scory, S.; Broering, R.; Croner, R.S.; Treckmann, J.W.; Link, A.; et al. Transcriptome-Wide Analysis of Human Liver Reveals Age-Related Differences in the Expression of Select Functional Gene Clusters and Evidence for a PPP1R10-Governed 'Aging Cascade'. Ab...

Table S1. Demographic and clinical characteristics of patient groups I and II in order of gender and increasing age. Prior to surgery, all patients tested negative for the hepatitis viruses HAV, HBV, HCV, and HDV as well as HIV-1. All patients underwent surgery before the onset of the COVID-19 pandemic and, thus, were not tested for SARS-CoV-2. Non...

Helicobacter pylori is the most prevalent bacterial infection, affecting half of the world's population, with a high morbidity and mortality rate.1,2 Several invasive and noninvasive testing procedures are available, and their selective use serves the specific needs of diverse clinical scenarios. For gastric cancer prevention, mass screening is nec...

The gastrointestinal (GI) tract is home to a complex and dynamic community of microorganisms, comprising bacteria, archaea, viruses, yeast and fungi. It is widely accepted that human health is shaped by these microbes and their collective microbial genome. This so-called “second genome” plays an important role in normal functioning of the host, con...

Purpose: DNA methylation alterations have emerged as front-runners in cell-free DNA (cfDNA) biomarker development. However, much effort to date has focused on single cancers. In this context, gastrointestinal (GI) cancers constitute the second leading cause of cancer-related deaths worldwide; yet there is no blood-based assay for the early detectio...

Background Distinct fecal microbiota profiles are reported to be associated with various subtypes of IBS. Circulating antibodies to cytolethal-distending-toxin B (CdtB) and vinculin are proposed as biomarkers to identify post-infectious IBS. The aim of our study was to analyze serum levels of anti-CdtB and anti-vinculin antibodies in patients with...

Background Faecal microbiota transplantation (FMT) is an emerging treatment modality, but its current clinical use and organisation are unknown. We aimed to describe the clinical use, conduct, and potential for FMT in Europe. Methods We invited all hospital-based FMT centres within the European Council member states to answer a web-based questionn...

Background and Aims An association between Crohn’s disease (CD) and hepatic steatosis has been reported. However, the underlying mechanisms of steatosis progression in CD are not clear. Among the most effective CD-treatments are agents that inhibit Tumor-Necrosis-Factor (TNF) activity, yet it is unclear why anti-TNFα agents would affect steatosis i...

Background: Regulatory changes occurring early in colorectal cancer development remain poorly investigated. Since the majority of cases develop from polyps in the adenoma-carcinoma pathway, a search of early molecular features, such as aberrations in miRNA expression occurring prior to cancer development, would enable identification of potentially...

Background & Aims The homeostasis of the gastrointestinal epithelium relies on cell regeneration and differentiation into distinct lineages organised inside glands and crypts. Regeneration depends on WNT/β-Catenin pathway activation, but to understand homeostasis and its dysregulation in disease we need to identify the signalling microenvironment g...

Two aerobic granular sludge (AGS) sequential batch reactors were operated at a mild (15 °C) temperature for 180 days. One of those bioreactors was exposed to a mixture of diclofenac, naproxen, trimethoprim, and carbamazepine. The AGS system, operating under pressure from emerging contaminants, showed a decrease in COD, BOD5, and TN removal capacity...

Objectives Hepatocellular carcinoma (HCC) can be diagnosed non-invasively with contrast-enhanced ultrasound (CEUS) in cirrhosis if the characteristic pattern of arterial phase hyperenhancement followed by hypoenhancement is present. Recent studies suggest that diagnosis based on this “hyper-hypo” pattern needs further refinement. This study compare...

Gastric carcinogenesis is associated with alterations of microRNAs (miRNAs) and reversal of these alterations may be a crucial element in cancer prevention. Here we evaluate the influence of H . pylori eradication, low-dose aspirin (LDA), non-steroidal anti-inflammatory drugs (NSAIDs) and proton-pump inhibitors (PPI) on modification of inflammatory...

Background & aims Regular consumption of fast-food (FF) as a form of typical Western style diet is associated with obesity and the metabolic syndrome, including its hepatic manifestation nonalcoholic fatty liver disease. Currently, it remains unclear how intermittent excess FF consumption may influence liver metabolism. The study aimed to character...

Gastric carcinogenesis can be described as a consequence of multilevel molecular alterations that is triggered by a cascade of events. Historically, diet and environmental factors have been identified to substantially contribute to carcinogenesis before the discovery of Helicobacter pylori (H. pylori). But H. pylori infection hasrevolutionized the...

Fatty liver disease (FLD) is one of the prominent diseases which affects the normal functionality of the liver by building vacuoles of fat in the liver cells. FLD is an indicator of imbalance in the metabolic system and could cause cardiovascular diseases, liver inflammation, cirrhosis and furthermore neoplasm. Detection and specification of a FLD...

Background For the first time, transcriptome-wide analysis of human liver has been performed for demonstrating differences between young and old humans, identifying major age-related alterations in hepatic gene expression may pinpoint ontogenetic shifts with important hepatic and systemic consequences, provide novel pharmacogenetic information, and...

Long non-coding RNAs (lncRNA) play an important role in the carcinogenesis of various tumours, including gastric cancer. This study aimed to assess the associations of lncRNA ANRIL, H19, MALAT1, MEG3, HOTAIR single-nucleotide polymorphisms (SNPs) with gastric cancer and atrophic gastritis. SNPs were analyzed in 613 gastric cancer patients, 118 pati...

Background: MicroRNAs (miRNAs) have been suggested as biomarkers for malignant diseases including hepatocellular carcinoma (HCC). Specifically, hsa-miR-21-5p (miR-21) is among the most frequently deregulated miRNA in cancer. The diagnostic and prognostic value of miR-21 has been demonstrated in HCC tissue, mostly in the Asian population. Although...

Background: Fecal microbiota transplantation is an emerging therapeutic option, particularly for the treatment of recurrent Clostridioides difficile infection. Stool banks that organise recruitment and screening of feces donors are being embedded within the regulatory frameworks described in the European Union Tissue and Cells Directive and the te...

In recent years, overexploited industrialization and urbanization activities have led to significant amounts of heavy metals released into the environment. Metal ion contamination of water, especially with toxic metals such as nickel(II) [Ni(II)], which is extensively applied in the electroplating industry, has been a serious problem. The aim of th...

Background and aim: Nonalcoholic fatty liver disease (NAFLD) affects about 25% of the global population, with no reliable noninvasive tests to diagnose nonalcoholic steatohepatitis (NASH) and to differentiate between NASH and nonalcoholic fatty liver (NAFL) (steatosis alone). It is unclear if NAFL and NASH differ in cardiovascular risk for patient...

The potential use of microorganisms in the bioremediation of U pollution has been extensively described. However, a lack of knowledge on molecular resistance mechanisms has become a challenge for the use of these technologies. We reported on the transcriptomic and microscopic response of Stenotrophomonas bentonitica BII-R7 exposed to 100 and 250 μM...

Purpose: In view of high cancer-specificity, DNA methylation alterations have emerged as front-runners in biomarker development, especiy as cell-free DNA (cf-DNA) biomarkers for early detection of cancer. However, much effort to date has focused on developing cancer type-specific biomarkers, but have not explored the possibility of developing a pan...