Karen Bannert

Dr. Karen Bannert

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
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FMFatuma Meyer
Fatuma Meyer
KBKaren Bannert
Karen Bannert
Mats L. WieseMats L. Wiese
Mats L. Wiese
SESusanne Esau
Susanne Esau
LSLea F. Sautter
Lea F. Sautter
LVLuzia Valentini
Luzia Valentini
Liver cirrhosis is frequently accompanied by disease-related malnutrition (DRM) and sarcopenia, defined as loss of skeletal muscle mass and function. DRM and sarcopenia often coexist in cirrhotic patients and are associated with increased morbidity and mortality. The clinical manifestation of both comorbidities are triggered by multifactorial mechanisms including reduced nutrient and energy intake caused by dietary restrictions, anorexia, neuroendocrine deregulation, olfactory and gustatory deficits. Maldigestion and malabsorption due to small intestinal bacterial overgrowth, pancreatic insufficiency or cholestasis may also contribute to DRM and sarcopenia. Decreased protein synthesis and increased protein degradation is the cornerstone mechanism to muscle loss, among others mediated by disease- and inflammation-mediated metabolic changes, hyperammonemia, increased myostatin and reduced human growth hormone. The concise pathophysiological mechanisms and interactions of DRM and sarcopenia in liver cirrhosis are not completely understood. Furthermore, most knowledge in this field are based on experimental models, but only few data in humans exist. This review summarizes known and proposed molecular mechanisms contributing to malnutrition and sarcopenia in liver cirrhosis and highlights remaining knowledge gaps. Since, in the prevention and treatment of DRM and sarcopenia in cirrhotic patients, more research is needed to identify potential biomarkers for diagnosis and development of targeted therapeutic strategies.

19 February 2020 in Digestive Diseases and Sciences
Verified
Journal Article
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JRJo Reiner
Jo Reiner
PBPeggy Berlin
Peggy Berlin
JWJakob Wobar
Jakob Wobar
HSHolger Schäffler
Holger Schäffler
KBKaren Bannert
Karen Bannert
MWMaria B Witte
Maria B Witte
Background In short bowel syndrome, epithelial surface loss results in impaired nutrient absorption and may lead to intestinal insufficiency or intestinal failure. Nucleotide oligomerization domain 2 (Nod2) dysfunction predisposes to the development of intestinal failure after intestinal resection and is associated with intestinal barrier defects. Epithelial barrier function is crucial for intestinal absorption and for intestinal adaptation in the short bowel situation. Aims The aim of the study was to characterize the effects of the GLP-2 analogue Teduglutide in the small intestine in the presence and absence of Nod2 in a mouse model of short bowel syndrome. Methods Mice underwent 40% ICR and were thereafter treated with Teduglutide versus vehicle injections. Survival, body weight, stool water, and sodium content and plasma aldosterone concentrations were determined. Intestinal and kidney tissue was examined with light and fluorescence microscopy, Ussing chamber studies and quantitative PCR in wild type and transgenic mice. Results Teduglutide reduced intestinal failure incidence in Nod2 k.o. mice. In wt mice, Teduglutide attenuated intestinal insufficiency as indicated by reduced body weight loss and lower plasma aldosterone concentrations, lower stool water content, and lower stool sodium losses. Teduglutide treatment was associated with enhanced epithelial paracellular pore function and enhanced claudin-10 expression in tight junctions in the villus tips, where it colocalized with sodium–glucose cotransporter 1 (SGLT-1), which mediates Na-coupled glucose transport. Conclusions In the SBS situation, Teduglutide not only maximizes small intestinal mucosal hypertrophy but also partially restores small intestinal epithelial function through an altered distribution of claudin-10, facilitating sodium recirculation for Na-coupled glucose transport and water absorption.

31 October 2022 in Nutrition
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Journal Article
Open access
KBKaren Bannert
Karen Bannert
LSLea Franziska Sautter
Lea Franziska Sautter
Mats L. WieseMats L. Wiese
Mats L. Wiese
FMFatuma Meyer
Fatuma Meyer
LELuise Ehlers
Luise Ehlers
GLGeorg Lamprecht
Georg Lamprecht
Disease-related malnutrition (MN) is common in patients with liver cirrhosis (LC), short bowel syndrome (SBS), and chronic pancreatitis (CP). Different MN risk screening tools and diagnostic criteria of the European Society for Clinical Nutrition and Metabolism (ESPEN) and Global Leadership Initiative on Malnutrition (GLIM) algorithms were analyzed for their diagnostic accuracy and role as specific drivers to diagnose MN in patients with LC, SBS, and CP. A total of 187 patients with LC, SBS, and CP, as well as control patients were prospectively recruited in a multicenter cross-sectional study. MN risk was screened using Nutritional Risk Screening 2002 (NRS-2002), the Malnutrition Universal Screening Tool (MUST), and the Royal Free Hospital Nutritional Prioritizing Tool (RFH-NPT), and diagnosed using the ESPEN, GLIM, and GLIMCRP+ (GLIM incorporating C-reactive protein [CRP] >5 mg/L) algorithms. For each of the individual diagnostic criteria, relative frequency, sensitivity, specificity, as well as positive and negative predictive values were calculated. NRS-2002 was only sensitive in conjunction with ESPEN, while MUST was sensitive additionally with the GLIM algorithm. RFH-NPT worked the best for LC. GLIM and GLIMCRP+ diagnosed MN more frequently than the ESPEN algorithm. Diagnostic criteria were detected at remarkably different relative frequencies starting with reduced food intake/malabsorption and chronic disease/inflammation, followed by weight loss, reduced fat-free mass index, low body mass index, and body mass index <18.5 kg/m². Relative frequencies differed between LC, SBS, and CP. Weight loss in LC and CP and reduced fat-free mass index and food intake in SBS had good diagnostic accuracy, suggesting that these criteria act as specific drivers for MN. RFH-NPT and MUST performed better in conjunction with the GLIM algorithm than NRS-2002. MN was diagnosed more frequently by GLIM than the ESPEN algorithm in LC, SBS, and CP. Individual criteria acted as specific drivers in MN in chronic gastrointestinal diseases.

20 December 2018 in Digestive Diseases and Sciences
Verified
Journal Article
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PBPeggy Berlin
Peggy Berlin
JRJo Reiner
Jo Reiner
JWJakob Wobar
Jakob Wobar
KBKaren Bannert
Karen Bannert
ÄGÄnne Glass
Änne Glass
MWMaria B Witte
Maria B Witte
Short bowel syndrome results from extensive small bowel resection and induces adaptation of the remaining intestine. Ileocecal resection (ICR) is the most frequent situation in humans. Villus hypertrophy is one hallmark of mucosal adaptation, but the functional mechanisms of mucosal adaptation are incompletely understood.

25 May 2023 in Clinical Nutrition
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Journal Article
Open access
KBKaren Bannert
Karen Bannert
CKCathleen Karbe
Cathleen Karbe
RFRobert H. Förster
Robert H. Förster
LSLea F. Sautter
Lea F. Sautter
FMFatuma Meyer
Fatuma Meyer
GLGeorg Lamprecht
Georg Lamprecht
In short bowel syndrome, insufficient absorptive capacity of the remnant bowel may lead to metabolic and nutritional consequences including electrolyte disturbances, severe diarrhea and malnutrition. While intestinal failure requires parenteral nutrition, short bowel patients with intestinal insufficiency (SB/II) have achieved oral autonomy. The aim of this exploratory study was to assess the nutritional, muscular and functional status of orally compensated SB/II patients. 28 orally compensated SB/II patients with a mean of 46 months after termination of parenteral nutrition and 56 age- and sex-matched healthy controls (HC) were compared regarding anthropometric parameters, body composition using bioelectrical impedance analysis, handgrip strength and gait speed, blood parameters as well as nutritional intake and physical activity using validated questionnaires. Malnutrition and sarcopenia were diagnosed according to the criteria of the GLIM or EWGSOP2. SB/II patients had lower body mass index (BMI) and anthropometric parameters than HC but were within the normal weight range. The GLIM algorithm operationally diagnosed malnutrition in 39% (n = 11) of SB/II patients. Reduced skeletal muscle mass index and phase angle were rarely accompanied by a reduction of handgrip strength below cut-off values and the subsequent diagnosis of sarcopenia in SB/II patients (15%, n = 4). Compared to 11% of HC, 37% of SB/II patients had low physical activity level. Female SB/II patients had higher caloric and macronutrient intake. Caloric intake negatively correlated with body weight indicating compensatory hyperphagia in patients with lower body weight. Some of the SB/II patients showed signs of dehydration. Orally compensated SB/II patients are thinner than HC but have mostly normal BMI. Malnutrition is frequently diagnosed but may be overestimated due to the underlying malabsorption and its interplay with hyperphagia. Muscle mass is often reduced but is rarely accompanied by functional impairment leading to sarcopenia diagnosis. Thus, SB/II patients long term after termination of parenteral support may be malnourished but usually do not develop sarcopenia.

Verified
Journal Article
Open access
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MWMaria B Witte
Maria B Witte
JSJohannes Saupe
Johannes Saupe
JRJo Reiner
Jo Reiner
KBKaren Bannert
Karen Bannert
CSClemens Schafmayer
Clemens Schafmayer
PBPeggy Berlin
Peggy Berlin
Ileocecal resection (ICR) is frequently performed in Crohn’s disease (CD). NOD2 mutations are risk factors for CD. Nod2 knockout (ko) mice show impaired anastomotic healing after extended ICR. We further investigated the role of NOD2 after limited ICR. C57B16/J (wt) and Nod2 ko littermates underwent limited ICR including 1–2 cm terminal ileum and were randomly assigned to vehicle or MDP treatment. Bursting pressure was measured on POD 5, and the anastomosis was analyzed for matrix turn-over and granulation tissue. Wound fibroblasts from subcutaneously implanted sponges were used for comparison. The M1/M2 macrophage plasma cytokines were analyzed. Mortality was not different between groups. Bursting pressure was significantly decreased in ko mice. This was associated with less granulation tissue but was not affected by MDP. However, anastomotic leak (AL) rate tended to be lower in MDP-treated ko mice (29% vs. 11%, p = 0.07). mRNA expression of collagen-1α (col1 α), collagen-3α (col3 α), matrix metalloproteinase (mmp)2 and mmp9 was increased in ko mice, indicating increased matrix turn-over, specifically in the anastomosis. Systemic TNF-α expression was significantly lower in ko mice. Ileocolonic healing is impaired in Nod2 ko mice after limited ICR by local mechanisms maybe including local dysbiosis.