Very low-volume interval training improves nonalcoholic fatty liver disease fibrosis score and cardiometabolic health in adults with obesity and metabolic syndrome.

Non-alcoholic fatty liver disease (NAFLD) and cardiometabolic disorders are highly prevalent in obese individuals. Physical exercise is an important element in obesity and metabolic syndrome (MetS) treatment. However, the vast majority of individuals with obesity do not meet the general physical activity recommendations (i.e. 150 min of moderate activity per week). The present study aimed to investigate the impact of a highly time-saving high-intensity interval training (HIIT) protocol (28 min time requirement per week) on NAFLD fibrosis (NFS) and cardiometabolic risk scores in obese patients with MetS and elevated NFS values. Twenty-nine patients performed HIIT on cycle ergometers (5 x 1 min at an intensity of 80 - 95% maximal heart rate) twice weekly for 12 weeks and were compared to a control group without exercise (CON, n = 17). Nutritional counseling for weight loss was provided to both groups. NFS, cardiometabolic risk indices, MetS z-score, cardiorespiratory fitness (VO2max) and body composition were assessed before and after intervention. The HIIT (-4.3 kg, P < 0.001) and CON (-2.3 kg, P = 0.003) group significantly reduced body weight. There were no significant group differences in relative weight reduction (HIIT: -3.5%, CON: -2.4%). However, only the HIIT group improved NFS (-0.52 units, P = 0.003), MetS z-score (-2.0 units, P < 0.001), glycemic control (HbA1c: -0.20%, P = 0.014) and VO2max (+3.1 mL/kg/min, P < 0.001). Decreases in NFS (-0.50 units, P = 0.025) and MetS z-score (-1.4 units, P = 0.007) and the increment in VO2max (3.3 mL/kg/min, P < 0.001) were significantly larger in the HIIT than in the CON group. In conclusion, only 28 min of HIIT per week can elicit significant improvements in NFS and a several cardiometabolic health indices in obese MetS patients with increased NFS grades. Our results underscore the importance of exercise in NAFLD and MetS treatment and suggest that our low-volume HIIT protocol can be regarded as viable alternative to more time-consuming exercise programs.

The amount of liver tissue is essential for accurate histological staging in patients with autoimmune hepatitis.

The gold standard for the evaluation of liver fibrosis is histology. However, the heterogenous distribution of fibrosis limits the sensitivity of histology. The collection of two samples with a 16G needle is therefore recommended to reduce the risk of sampling error. The aim of this study was to investigate whether this standard is also applicable to patients with autoimmune hepatitis (AIH). This retrospective study included patients with AIH, who underwent mini-laparoscopic biopsy at our center between 2011 and 2020 (n = 32). Diagnosis was verified by usage of the simplified AIH score (≥ 6). Patients were categorized into three groups, based on the number of portal fields (PF) in the collected liver tissue (< 10 PF, 10 - 19 PF, ≥ 20 PF). We correlated the histological staging for these groups with the mini-laparoscopic fibrosis score (MLFS). Furthermore, non-invasive methods for the assessment of fibrosis were correlated with the histological staging (acoustic radiation force impulse (ARFI) and FIB-4 score). MLFS correlated well with histological staging (r = 0.649, p = 0.0001). The correlation between MLFS and histology improved with higher numbers of histologically analyzed portal fields (< 10 PF: r = 0.400, p = 0.378; 10 - 19 PF: r = 0.5467, p = 0.023; ≥ 20 PF: r = 0.956, p = 0.0002). The probability of collecting at least 10 or 20 portal fields was dependent on the number and diameter of the samples. For all patients with at least two 16G biopsies, 10 or more PF were available. With three 16G biopsies, at least 20 PF were obtained for all patients. ARFI correlated with MLFS and histological staging only in patients with low/moderate-grade inflammation as defined by ALT < 10xULN (upper limit of normal) (MLFS: r = 0.723; p = 0.004; histology: r = 0.619, p = 0.018). FIB-4 did not correlate with histological staging. The amount of liver tissue obtained by liver biopsy is crucial to minimalize the risk of sampling error and thus underestimation of fibrosis. This study was the first to investigate the amount of liver tissue required for histological staging in AIH. Our data suggest that diagnostic accuracy is likely to be higher with 20 PF compared to the generally recommended 10 PF. We therefore recommend to perform three biopsies with a 16G needle in (suspected) AIH patients. ARFI correlated well with histological staging unless inflammatory activity is high.

Acute gastric lesions induced by the administration of histamine to rats with partial vascular occlusion: evidence for the gastroprotective effect of prostaglandin.

INTRODUCTION: Histamine is not only a potent stimulator of gastric acid secretion, but it also plays a central role in gastroduodenal ulcerogenesis. In the present study we tested the effect of pre-treatment with exogenous prostaglandin E(2) (PGE(2)) in a new rat model of experimental gastric ulcers induced by combination of histamine and gastric ischemia. METHODS: In male Wistar rats, a chronic ischemia of gastric mucosa was induced via the clamping of the left gastric artery and vein (L-AV) in combination with pylorus ligation. The following treatment groups of rats (6 rats/group) were investigated: 1) histamine alone (40 mg/kg twice s.c.); 2) vehicle (saline) followed 30 min later by gastric mucosal L-AV ischemia and pylorus ligation combined with histamine (40 mg/kg twice s.c.) and 3) PGE(2) (5 microg/kg i.g.) followed 30 min later by gastric mucosal L-AV ischemia combined with histamine (40 mg/kg twice s.c.) and pylorus ligation. At 4 hr after the clamping of L-AV and pylorus ligation, the area of gastric lesions and gastric acid secretion was determined. RESULTS: Histamine treatment failed to produce gastric lesions, but when it was combined with ischemia, the widespread gastric lesions in the corpus mucosa, but not in the antrum, were observed. This damaging effect and decrease in the GBF were significantly attenuated by pretreatment with PGE(2). CONCLUSION: The present study demonstrates that gastric hypersecretion induced by histamine in combination with gastric mucosal ischemia results in gastric lesions which progress into chronic gastric ulcers.

Role of melatonin in mucosal gastroprotection against aspirin-induced gastric lesions in humans.

Melatonin and its precursor, l-tryptophan, have been shown to exert gastroprotective effects in animals, but their influence on the gastric damage by aspirin (ASA) in humans has been sparingly investigated. In this study, we designed to determine the effects of melatonin and l-tryptophan on ASA-induced gastric mucosal damage, gastric microbleeding, mucosal generation of prostaglandin E(2), and plasma melatonin, and gastrin levels. Three groups of healthy male volunteers (n = 30) with intact gastric mucosa received daily for 11 days either ASA alone or that combined with melatonin or tryptophan. Gastric blood loss and mucosal damage were evaluated at 3rd, 7th, and 11th days of ASA administration by endoscopy using Lanza score. ASA alone caused a marked rise of gastric damage and gastric blood loss, mainly at day 3rd and 7th, but they were significantly reduced at 11th day. Pretreatment with melatonin or tryptophan remarkably reduced ASA induced gastric lesions and microbleeding. Gastric mucosal generation of PGE(2) was suppressed by about 90% in all subjects treated with ASA alone without or with addition of melatonin or tryptophan. Plasma melatonin was markedly increased after treatment with melatonin or tryptophan plus ASA, but it was also raised significantly after application of ASA alone. Plasma gastrin levels were raised in subjects given melatonin or tryptophan plus ASA, but not in those with ASA alone. We conclude that melatonin and its precursor tryptophan given orally significantly reduce gastric lesions induced by ASA possibly due to (a) direct gastroprotective action of exogenous melatonin or that generated from tryptophan and (b) gastrin released from the gastric mucosa by melatonin or tryptophan.

COVID-19 - more than respiratory disease: a gastroenterologist's perspective.

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV2) outbreak is the most dramatic event since World War II. Originating as a cluster of unexplained cases of pneumonia, it turned out that this viral disease termed COVID-19 is not only a respiratory infection, but a systemic disease associated with a number of extrapulmonary complications. One of the medical disciplines that is strongly affected by this viral infection is gastroenterology. COVID-19 causes in some patients typical symptoms of enteritis such as diarrhea or abdominal pain. There is also evidence that this infection may lead to liver and pancreatic injury. Since the SARS-CoV2 virus was detected in stool, a fecal-oral route of transmission is possible. Moreover, viral receptor angiotensin converting enzyme 2 (ACE2) is highly expressed in the gastrointestinal tract and enables the invasion of the gastrointestinal epithelium as demonstrated in vitro and in vivo. COVID-19 pandemic has an impact on the daily practice and the workflows in endoscopy leading to a dramatic decrease of screening and surveillance procedures. COVID-19 impacts the therapy of patients with inflammatory bowel disease (IBD), particularly those using high doses of corticosteroids, immunosuppressive agents and biologics. Patients with preexisting liver disease, especially metabolic associated liver fatty disease (MALFD) with fibrosis or liver cirrhosis, are at high risk for severe COVID-19. As long as no active vaccine against SARS-CoV2 is available, gastroenterologists have to be aware of these problems that affect their daily routine practice.

Effects of whole-body electromyostimulation exercise and caloric restriction on cardiometabolic risk profile and muscle strength in obese women with the metabolic syndrome: a pilot study.

Obesity, particularly in conjunction with further cardiometabolic risk factors, is associated with an increased risk of cardiovascular disease and mortality. Increased physical activity and dietary modifications are cornerstones of therapeutic interventions to treat obesity and related risk factors. Whole-body electromyostimulation (WB-EMS) has emerged as an innovative, time-efficient type of exercise that can provide positive effects on body composition and muscle strength. However, the impact of WB-EMS on cardiometabolic health in obese individuals with metabolic syndrome (MetS) has yet to be determined. The aim of this pilot study was, therefore, to investigate the feasibility and effects of WB-EMS on cardiometabolic risk markers and muscle strength in obese women diagnosed with MetS. Twenty-nine obese women (56.0 ± 10.9 years, BMI: 36.7 ± 4.6 kg/m2) with the clinical diagnosis of MetS were randomized to either 12 weeks of WB-EMS (n = 15) or an inactive control group (CON, n = 14). Both groups received nutritional counseling (aim: -500 kcal energy deficit/day). WB-EMS was performed 2x/week (20 min/session). Body composition, maximum strength (Fmax) of major muscle groups, selected cardiometabolic risk indices and the metabolic syndrome Z-score (MetS-Z) were determined baseline and after the intervention. WB-EMS was well tolerated and no adverse events occurred. Body weight was significantly reduced in both groups by an average of ~3 kg (P < 0.01). The body fat percentage was only decreased in the WB-EMS group (P = 0.018). Total cholesterol concentrations decreased in the WB-EMS group (P = 0.018) and in CON (P = 0.027). Only the WB-EMS group increased Fmax significantly in all major muscle groups (P < 0.05) and improved the overall cardiometabolic risk score (MetS-Z, P = 0.029). This pilot study indicates that WB-EMS can be considered as a feasible and time-efficient exercise option for improving body composition, muscle strength and cardiometabolic health in obese women with MetS. Moreover, these findings underpin the crucial role of exercise during weight loss interventions in improving health outcomes.

Phase angle and vector analysis from multifrequency segmental bioelectrical impedance analysis: new reference data for older adults.

Phase angle (PA) and bioelectrical impedance vector analysis (BIVA) have been recommended as useful prognostic markers in various clinical settings. However, reference data for older adults measured by the novel segmental multifrequency bioelectrical impedance analysis (SMF-BIA) technique are currently lacking. This study examined 567 (286 men, 281 women) healthy older adults (65 - 97 years) and new SMF-BIA-based PA and BIVA reference values were generated stratified according to gender and 3 age groups (65 - 75 years, 76 - 85 years, > 85 years). Mean PA-values (women: 4.30 ± 0.6°, men: 4.77 ± 0.7°) were significantly lower than those previously reported for a younger reference population. Age and gender were significant determinants of PA and BIVA. PA showed a significant decrease with increasing age in both genders. The greatest changes occurred in the age group > 85 years. Men had higher Pas compared to women (except for the oldest age group), but showed a substantially steeper decline in PA, possibly due to a more pronounced reduction of muscle mass. Compared to published reference data for younger adults, there was a clear downward migration of the BIVA vector points in older adults, indicating an age-related reduction of body cell mass. Accordingly, the equation for the BIVA chart generation was modified by adding the factor age. In conclusion, this is the first study to present SMF-BIA-determined PA and BIVA reference data for healthy subjects aged ≥ 65 years. These data can be used for clinical purposes to identify individuals at increased risk for adverse health events or to monitor treatment responses.

Multicenter analysis of endoclot as hemostatic powder in different endoscopic settings of the upper gastrointestinal tract.

Gastrointestinal bleeding (GIB) still presents a demanding situation with high morbidity and mortality rates; thus hemostatic powders such as EndoClot (EC) have been developed to improve endoscopic armament. The aim of the present study was to determine which indications triggered the application of EC and to assess resulting hemostasis rates. Forty three patients undergoing endoscopical procedures in three hospitals; two tertiary care and one university hospital, were included. EC was applied in 48 endoscopies in 43 patients (27 male, age 65.5 years, range 28 - 92 years) following four different indications. EC was used in active GIB as rescue or first-line therapy giving a short-term and long-term hemostasis in 13/17 patients (76.5%). In the setting of non-active GIB, following conventionally achieved hemostasis or endoscopic interventions, EC was found to prevent bleeding in 19/21 patients (90.4%). EC induced hemostasis in 8/10 patients (80%) with impaired coagulation. EC failures resulted from tumor bleeding, Forrest I lesions or perforated duodenal ulcers. No major adverse events were recorded and one technical failure (2.1%) occurred. EC was applied as first line or salvage treatment in ongoing bleedings with promising results. Furthermore, EC was used after successful hemostasis or following endoscopic interventions to further reduce re-bleeding rates. We saw promising results in all indications, albeit lacking a control group.

Participation of the intestinal microbiota in the mechanism of beneficial effect of treatment with synbiotic Syngut on experimental colitis under stress conditions.

Gut-brain axis plays a central role in the regulation of stress related diseases such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). It is increasingly recognized that stress modulates gut microbiota community structure and activity and represents an important causal factor in dysbiosis. This study was designed to determine the effect of daily treatment with synbiotic (Syngut) containing inulin, Lactobacillus acidophilus, Bifidobacterium lactis W51, Lactobacillus plantarum W21 and Lactococcus lactis applied i.g. at a dose of 50 mg/kg i.g. on the colonic damage and colonic mucosal blood flow in rats with experimentally induced TNBS-colitis that were additionally exposed or not to acute stress (episodes of cold restraint stress every other day before colitis induction). Control rats received daily treatment with vehicle (saline, i.g.) or mesalazine (50 mg/kg-d i.g.), the standard drug recommended in therapy of IBD. At the termination of TNBS colitis, the histologic evaluation of colonic mucosa, mucosal malonyldialdehyde (MDA) level and plasma concentrations of proinflammatory cytokines (TNF-α, IL-1ß) and adipokine adiponectin were assessed. the samples of colonic mucosa not involving colonic lesions and surrounding the flared mucosa were excised for the determination of mRNA expression for proinflammatory biomarkers TNF-α, IL-1ß, IL-10 and COX-2 as well as antioxidazing factors SOD-1 and SOD-2. Finally, the gut microbial profiles were analyzed by 16S rRNA sequencing at phylum, family and genus level. Episodes of cold stress significantly aggravated the course of TNBS colitis, and significantly increased the release of proinflammatory cytokines as well as the significant increase in the MDA concentration has been observed as compared with non-stressed TNBS rats. These changes were followed by the significant fall in the CBF and plasma adiponectin levels and by the overexpression of mRNA of proinflammatory biomarkers. Synbiotic treatment with Syngut significantly reduced the area of colonic lesions observed macroscopically and microscopically in rats with TNBS colitis with or without exposure to cold stress, significantly increased the CBF, normalized plasma adiponectin levels and significantly attenuated the release and colonic expression of proinflammatory cytokines and biomarkers. the analysis of the gut microbiota showed a significant reduction of microbial diversity (Shannon index) in rats with TNBS colitis with or without exposure to stress. The therapy with Syngut failed to significantly affect the alpha diversity. At the phylum level, the significant rise in Proteobacteria has been observed in stressed rats with TNBS colitis and this effects was attenuated by treatment with Syngut. At family level, TNBS colitis alone or in combination with stress led to a significant decrease of SCFA producing bacterial taxa such as Ruminococaceae and Lachnospiraceae and Syngut counteracted this effect. We conclude that: 1) cold stress exacerbates the gastrointestinal inflammation in experimental colitis; 2) the synbiotic therapy with Syngut ameliorates the gut inflammation in rats with TNBS colitis combined with cold stress; 3) the beneficial effect of Syngut is accompanied by increase of anti-inflammatory taxa such as Ruminococaceae and Lachnospiraceae, and 4) the modulation of gut microbiota with Syngut alleviates stress-related intestinal inflammation suggesting a potential usefulness of synbiotic therapy in intestinal disorders accompanied by stress in patients with IBD.

Altered basal and postprandial plasma melatonin, gastrin, ghrelin, leptin and insulin in patients with liver cirrhosis and portal hypertension without and with oral administration of melatonin or tryptophan.

This investigation was designed to assess the effects of oral administration of melatonin (10 mg) and tryptophan (Trp) (500 mg) on fasting and postprandial plasma levels of melatonin, gastrin, ghrelin, leptin and insulin in 10 healthy controls and in age-matched patients with liver cirrhosis (LC) and portal hypertension. Fasting plasma melatonin levels in LC patients were about five times higher (102 +/- 15 pg/mL) than in healthy controls (22 +/- 3 pg/mL). These levels significantly increased postprandially in LC patients, but significantly less so in controls. Treatment with melatonin or L-Trp resulted in a further significant rise in plasma melatonin, both under fasting and postprandial conditions, particularly in LC patients. Moreover, plasma gastrin, ghrelin, leptin and insulin levels under fasting and postprandial conditions were significantly higher in LC subjects than in healthy controls and they further rose significantly after oral application of melatonin or Trp. This study shows that: (a) patients with LC and portal hypertension exhibit significantly higher fasting and postprandial plasma melatonin levels than healthy subjects; (b) plasma ghrelin, both in LC and healthy controls reach the highest values under fasting conditions, but decline postprandially, especially after oral application of melatonin or Trp; and (c) plasma melatonin, gastrin, ghrelin and insulin levels are altered significantly in LC patients with portal hypertension compared with that in healthy controls possibly due to their portal systemic shunting and decreased liver degradation.

Anticoagulant-related gastrointestinal bleeding: a real-life data analysis on bleeding profiles, frequency and etiology of patients receiving direct oral anticoagulants versus vitamin K antagonists.

Vitamin K antagonists (VKA) continue to be the standard of long-term anticoagulation. Direct oral anticoagulants(DOAC) are increasingly used. In many trials DOAC were at least as effective as VKA. In this study we evaluate the bleeding profiles, frequencies and etiologies of patients receiving DOAC versus VKA in a real-life setting. All patients presenting with suspected gastrointestinal bleeding (GIB) in the emergency department of the University Hospital Erlangen in one year were enrolled in this study. They were looked up for the intake of either DOAC (dabigatran, rivaroxaban and apixaban) or VKA. The results showed that 406 patients with suspected GIB were admitted to the emergency unit of the University Hospital Erlangen. In 228 of those patients GIB could be verified (56.2%). Fifty four of those patients (23.7%) were administered either VKA or DOAC. In 35 of those 54 patients (64.8%) GIB was classified as 'major bleeding'. In 27 patients with administration of VKA upper GIB was recorded and lower GIB was detected four times. In 16 patients with administration of DOAC upper GIB was found and lower GIB was found in 7 patients. The presented data do not show higher GIB rates for DOAC (mainly dabigatran and rivaroxaban), but do also not indicate a significantly higher safety of DOAC concerning GIB than VKA. This finding represents a clear contrast to the reduced bleeding rates of DOAC for intracerebral bleeding and other non-GIB events. According to our study, the absolute number of DOAC-associated GIB events is lower than in the VKA group.

Different nutrient intake and prevalence of gastrointestinal comorbidities in women with endometriosis.

Even though endometriosis presents one of the most common gynaecological diseases, the pathogenesis is insufficiently studied. Besides immunologic, inflammatory or oxidative processes, recent studies also suggest an influence of nutrition on disease onset and progression. Because data about the actual nutrient intake of endometriosis patients are scarce, we aimed to examine the actual nutrient intake and potential influencing factors in these women. A total of 156 women with endometriosis (EM) and 52 age-matched controls were included in this retrospective case-control study. All women filled in a validated food frequency questionnaire to acquire the nutrient intake of the past 12 months and a disease-related questionnaire for the determination of disease status, clinical symptoms and comorbidities. Patients with endometriosis suffered significantly more from diet-related comorbidities like food intolerances (25.6% versus 7.7%; P = 0.009) and allergies (57% versus 31%; P < 0.001) compared to controls. Also gastrointestinal symptoms, including constipation, flatulence, pyrosis, diarrhea or frequent defecation, were higher in the EM group (77% versus 29%; P < 0.001). The nutrient intake of patients with endometriosis differed significantly compared to controls with a significantly lower ingestion of organic acids (P = 0.006), maltose (P = 0.0.16), glycogen (P = 0.035), tetradecenoic acid (P = 0.041), methionine (P = 0.046), lysine (P = 0.048), threonine (P = 0.046) and histidine (P = 0.049). The total intake of animal proteins was significantly lower in the EM group compared to the controls (P = 0.047). EM patients showed a decreased intake of vitamin C (P = 0.031), vitamin B12 (P = 0.008) and magnesium (P = 0.043) compared to controls. This study confirms a high association of endometriosis and gastrointestinal disorders accompanied by an altered nutrient intake. A dietary intervention by a professional nutritionist may help to reduce disease burden in the affected women.

Hypoglycemic side effects of sulfonylureas and repaglinide in ageing patients - knowledge and self-management.

Insulinotropic oral antidiabetics (OAD) such as sulfonylureas and (SU) glinides are among the frequently prescribed OAD. Side effects are the potential to induce hypoglycemias and weight gain. The aim was to assess the self-managing skills in case of a hypoglycemic event in an elderly type 2 diabetic patient population. In a 2-year period, 160 hospitalized patients (mean age 77.4 years) under insulinotrophic OAD were interviewed using a standardized questionnaire. Additionally, possible dementia was evaluated by using the Mini-Mental State Examination (MMSE) and the Clock-Drawing Test (CDT). The mean HbA1c was 7.6%. MMSE and CDT did intraindividually correlate well and 23.8% of the patients had moderate dementia (10 - 20 points MMSE), 13.1% had severe dementia (0 - 10 points MMSE) at the time of the survey. When under treatment with a sulfonylurea, only 16.0% of patients were aware of the potential hypoglycemia-inducing side effect. Moreover, only 11.8% of patients treated with a combination of a sulfonylurea and insulin knew this side effect of the OAD. The awareness of the side effects of repaglinide was 21.6% (without insulin therapy) versus 21.4% in the insulin-comedicated group. Only 42.6% of patients treated with sulfonylureas or repaglinide knew how to act in the case of hypoglycemia. Even under comedication with insulin, only in 41.2% of the respondents in the comedicated group knew how to take action if they were to experience hypoglycemia. Our findings raise concerns and demonstrate, that the self-managing skills in an elderly patient group are not good, which may become an increasing problem in an ageing population. The prescription or the re-prescription of insulinotropic OAD needs to be adapted to the current cognitive situation and re-evaluated regularly.

Microbial patterns in patients with histamine intolerance.

Histamine intolerance represents a controversially discussed disorder. Besides an impaired degradation of orally supplied histamine due to diamine oxidase (DAO) deficiency, a deranged gut flora may also contribute to elevated histamine levels. Our aim was to determine the intestinal bacterial composition in patients with proven histamine intolerance in comparison to other food intolerances and healthy controls. A total of 64 participants were included in the study, encompassing 8 patients with histamine intolerance (HIT), 25 with food hypersensitivity (FH), 21 with food allergy and 10 healthy controls (HC). All participants underwent blood testing for total and food-specific immunoglobulin E, plasma histamine and DAO serum activity. Stool samples were used to analyze stool histamine and zonulin levels and bacterial composition by 16s rRNA sequencing. No significant differences in stool histamine levels were observed, but HIT patients showed elevated levels of stool zonulin. Microbiota analysis revealed increased levels of Proteobacteria (5.4%) and a significantly reduced alpha-diversity in the HIT group (P = 0.019). On family level, HC showed a significantly higher abundance of Bifidobacteriaceae compared to other study groups (P = 0.005), with lowest levels in the HIT group (P = 0.036). Also significantly reduced abundances of the genera Butyricimonas (P = 0.026) and Hespellia (P = 0.025) were observed in the HIT patients, whereas Roseburia were significantly elevated (P = 0.021). We concluded that the altered occurrence of Proteobacteria and Bifidobacteriaceae, reduced alpha-diversity as well as elevated stool zonulin levels suggest a dysbiosis and intestinal barrier dysfunction in histamine intolerant patients, which in turn may play an important role in driving disease pathogenesis.

Inhibition of Barret's adenocarcinoma cell growth by simvastatin: involvement of COX-2 and apoptosis-related proteins.

Recent studies demonstrated that inhibitors of 3-hydroxy-3-methylglutaryl coenzyme-A reductase (HMG-CoAR), called "statins", independently of their well known plasma cholesterol lowering effect, exert favourable influence on a diverse range of physiologic processes including endothelial function, oxidant stress and antitumor effect. A number of epidemiological studies demonstrated that statins may have protective effect against cancer. The role of statins in the prevention and therapy of Barrett's adenocarcinoma (BA) has not been investigated so far. The aim of the present study was to analyze: 1) the impact of HMG-CoAR inhibitor, simvastatin, on human BA cell growth and 2) effect of simvastatin on apoptosis related proteins Bax/Bcl-2 and cyclooxygenase-2. BA cells (OE-19 cells) were incubated with simvastatin (1-30 microM). MTT assay was used to determine the antiproliferative effects. The expression of COX-2, Bax and Bcl-2 was analyzed at mRNA and protein level by quantitative RT-PCR and immunoblot. MTT assay demonstrated a significant dose-dependent inhibition of OE-19 cell growth by simvastatin, which also caused a significant reduction in Bcl-2 expression and an increase in Bax expression. In OE-19 cells, the COX-2 expression was detected and significantly increased by the addition of TNFalpha into the medium, however, this effect was significantly attenuated by simvastatin. Our in vitro data demonstrate that statins possess anticancerogenic properties possibly due to the induction of apoptosis and inhibition of COX-2. Clinical trial are necessary to prove the beneficial effects of statins on cancerogenesis in Barrett's esophagus.

Role of melatonin in upper gastrointestinal tract.

Melatonin, an indole formed enzymatically from L-tryptophan, is the most versatile and ubiquitous hormone molecule produced not only in all animals but also in some plants. This review focuses on the role of melatonin in upper portion of gastrointestinal tract (GIT), including oral cavity, esophagus, stomach and duodenum, where this indole is generated and released into the GIT lumen and into the portal circulation to be uptaken, metabolized by liver and released with bile into the duodenum. The biosynthetic steps of melatonin with two major rate limiting enzymes, arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), transforming tryptophan to melatonin, originally identified in pinealocytes have been also detected in entero-endocrine (EE) cells of GIT wall, where this indole may act via endocrine, paracrine and/or luminal pathway through G-protein coupled receptors. Melatonin in GIT was shown to be generated in about 500 times larger amounts than it is produced in pineal gland. The production of melatonin by pineal gland shows circadian rhythm with high night-time peak, especially at younger age, followed by the fall during the day-light time. As a highly lipophilic substance, melatonin reaches all body cells within minutes, to serve as a convenient circadian timing signal for alteration of numerous body functions.. Following pinealectomy, the light/dark cycle of plasma melatonin levels disappears, while its day-time blood concentrations are attenuated but sustained mainly due to its release from the GIT. After oral application of tryptophan, the plasma melatonin increases in dose-dependent manner both in intact and pinealectomized animals, indicating that extrapineal sources such as GIT rather than pineal gland are the major producers of this indole. In the upper portion of GIT, melatonin exhibits a wide spectrum of activities such as circadian entrainment, free radicals scavenging activity, protection of mucosa against various irritants and healing of various GIT lesions such as stomatitis, esophagitis, gastritis and peptic ulcer. This review concentrates on the generation and pathophysiological implication of melatonin in upper GIT.

Localization and biological activities of melatonin in intact and diseased gastrointestinal tract (GIT).

Melatonin (MT), an indole formed enzymatically from L-trytophan (Trp), was first discovered in the bovine pineal gland in 1958 by Lerner et al. Melatonin is the most versatile and ubiquitous hormonal molecule produced not only in the pineal gland but also in various other tissues of invertebrates and vertebrates, particularly in the gastrointestinal tract (GIT). This review focuses on the localization, production, metabolism and the functions of MT in GIT and the duodenal unit (liver, biliary routes and pancreas), where multi-step biosynthetic pathways of this indole, similar to those in pinealocytes, have been identified. These biosynthetic steps of MT, including two major rate limiting enzymes; arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), transforming L-tryptophan (Trp), originally identified in pinealocytes, have been also detected in entero-endocrine (EE) cells of GIT, where this indole appears to act in endocrine, paracrine and/or luminal pathway directly or through G-protein coupled MT receptors. Studies of the distribution of MT in GIT mucosa showed that this indole is generated in GIT in much larger amounts than it is produced in the pineal gland. Melatonin acts in GIT, partly locally in paracrine fashion and is partly released into portal circulation, to be taken up by the liver. It is then metabolized and excreted with the bile to small bowel and finally returns to liver through entero-hepatic circulation. The production of MT by the pineal gland shows circadian rhythm with high night-time surge, especially at younger age, followed by the fall during the day-light time. As a highly lipophylic substance, MT reaches all body cells within minutes, thus, serving as a convenient circadian timing signal. Following pinealectomy, the light/dark cycle of plasma MT levels disappears, while its day-time blood concentration is maintained mainly due to its release from the GIT. According to our experience, after oral application of Trp, the plasma MT increases in dose-dependent manner both in intact and pinealectomized animals and humans, indicating that GIT but not the pineal gland is a source of this indole. In GIT MT exhibits a wide spectrum of activities such as circadian entrainment, antioxidant and free radicals scavenging activity, Melatonin (MT), an indole formed enzymatically from L-trytophan (Trp), was first discovered in the bovine pineal gland in 1958 by Lerner et al. Melatonin is the most versatile and ubiquitous hormonal molecule produced not only in the pineal gland but also in various other tissues of invertebrates and vertebrates, particularly in the gastrointestinal tract (GIT). This review focuses on the localization, production, metabolism and the functions of MT in GIT and the duodenal unit (liver, biliary routes and pancreas), where multi-step biosynthetic pathways of this indole, similar to those in pinealocytes, have been identified. These biosynthetic steps of MT, including two major rate limiting enzymes; arylalkylamine-N-acetyltransferase (AA-NAT) and hydroxyindole-O-methyltransferase (HIOMT), transforming L-tryptophan (Trp), originally identified in pinealocytes, have been also detected in entero-endocrine (EE) cells of GIT, where this indole appears to act in endocrine, paracrine and/or luminal pathway directly or through G-protein coupled MT receptors. Studies of the distribution of MT in GIT mucosa showed that this indole is generated in GIT in much larger amounts than it is produced in the pineal gland. Melatonin acts in GIT, partly locally in paracrine fashion and is partly released into portal circulation, to be taken up by the liver. It is then metabolized and excreted with the bile to small bowel and finally returns to liver through entero-hepatic circulation. The production of MT by the pineal gland shows circadian rhythm with high night-time surge, especially at younger age, followed by the fall during the day-light time. As a highly lipophylic substance, MT reaches all body cells within minutes, thus, serving as a convenient circadian timing signal. Following pinealectomy, the light/dark cycle of plasma MT levels disappears, while its day-time blood concentration is maintained mainly due to its release from the GIT. According to our experience, after oral application of Trp, the plasma MT increases in dose-dependent manner both in intact and pinealectomized animals and humans, indicating that GIT but not the pineal gland is a source of this indole. In GIT MT exhibits a wide spectrum of activities such as circadian entrainment, antioxidant and free radicals scavenging activity, cytoprotective, anti-inflammatory and healing efficacy of various GIT lesions such as esophagitis, gastritis, peptic ulcer, pancreatitis and colitis. This review concentrates on the generation and pathophysiological implication of MT in GIT and related organs.

Protective influence of melatonin against acute esophageal lesions involves prostaglandins, nitric oxide and sensory nerves.

Melatonin (MT) is known to protect gastrointestinal mucosa against various types of injury but its effects on esophageal damage have not been studied. We examined the effects of MT on acute esophageal injury and the mechanism involved in the action of this indole. Acute esophageal lesions were induced by perfusion with acid-pepsin solution using tube inserted through the oral cavity into the mid of esophagus of anaesthetized rats with or without inhibition of prostaglandin (PG) generation by indomethacin (5 mg/kg/day), nitric oxide (NO) formation by N(G)-nitro-L-arginine (L-NNA, 20 mg/kg/day) or sensory nerves deactivation by capsaicin (125 mg/kg, sc). The esophageal injury was assessed by macroscopic score and histologic activity index. The esophageal mucosal blood flow (EBF) was determinated by H(2)-gas clearance method. The plasma TNF-alpha and nitrate/nitrite (NOx) levels and mucosal PGE(2) contents were assessed by immunoassays. Esophageal acid-pepsin perfusion induced noticeable esophageal mucosal injury as compared to perfusion with vehicle saline. The pretreatment with MT prevented significantly esophageal injury, raised EBF and mucosal content of PGE(2), while decreasing the levels of TNF-alpha. Inhibition of COX/PG and NOS/NO systems by indomethacin and L-NNA, respectively, or inactivation of sensory nerves by capsaicin, that manifested in further increase of esophageal injury, reduced the levels of EBF, markedly raised the levels TNF-alpha and reduced mucosal PGE(2), but the pretreatment with MT prevented significantly esophageal injury, improved EBF and raised mucosal PGE(2) contents. These studies suggest that MT can be considered as a novel esophagoprotector, acting, at least in part, through the COX/PG and NOS/NO systems and activation of sensory nerves.

Role of circadian rhythm and endogenous melatonin in pathogenesis of acute gastric bleeding erosions induced by stress.

Stress that appears as a consequence of burns, surgical trauma and life threatening conditions is a serious clinical entity, can result in acute gastric mucosal lesions. Such stress lesions can develop in response to the imbalance between the aggressive factors promoting mucosal damage and the gastric mucosal defense mechanisms including predominantly gastric blood flow (GBF), biosynthesis of gastroprotective prostaglandins (PG) and enhanced mucus/bicarbonate secretion. Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Melatonin is released during the night but little is known about the effect of circadian rhythm and day/night alterations in melatonin secretion on the formation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. It was found that the gastric mucosa exposed to WRS of various time duration's lasting 1.5, 3 and 6 h, time-dependently increased the number of gastric lesions and this effect was accompanied by the time-dependent fall in the GBF and an increase in the plasma and luminal melatonin levels. Pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS lesions were significantly reduced at night hours and showed circadian variations in plasma levels melatonin with significantly higher plasma melatonin levels at night than in the day and with a greater magnitude of damage induced in the daily hours than at night hours. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels Stress that appears as a consequence of burns, surgical trauma and life threatening conditions is a serious clinical entity, can result in acute gastric mucosal lesions. Such stress lesions can develop in response to the imbalance between the aggressive factors promoting mucosal damage and the gastric mucosal defense mechanisms including predominantly gastric blood flow (GBF), biosynthesis of gastroprotective prostaglandins (PG) and enhanced mucus/bicarbonate secretion. Melatonin, a major hormone of pineal gland, whose activity is also abundant in the gastrointestinal tract, was shown to inhibit gastric acid secretion, augment GBF and scavenge free radicals, resulting in the attenuation of stress-induced gastric lesions. Melatonin is released during the night but little is known about the effect of circadian rhythm and day/night alterations in melatonin secretion on the formation of stress-induced gastric lesions. Using rats with intact pineal glands and those with removed pineal glands (pinealectomy) exposed to water immersion and restraint stress (WRS) at both, day and night hours, we studied the effect of light and nocturnal melatonin on the formation of these lesions, and accompanying changes in GBF and plasma melatonin levels. It was found that the gastric mucosa exposed to WRS of various time duration's lasting 1.5, 3 and 6 h, time-dependently increased the number of gastric lesions and this effect was accompanied by the time-dependent fall in the GBF and an increase in the plasma and luminal melatonin levels. Pinealectomy augmented WRS-induced lesions at each time intervals of WRS and produced a marked fall in the GBF and plasma and luminal melatonin levels at each time interval of WRS tested. WRS lesions were significantly reduced at night hours and showed circadian variations in plasma levels melatonin with significantly higher plasma melatonin levels at night than in the day and with a greater magnitude of damage induced in the daily hours than at night hours. WRS-induced gastric mucosal lesions were markedly enhanced in pinealectomized rats, both at day and night, and this was accompanied by a significant fall in plasma melatonin levels with a pronounced reduction in mucosal generation of PGE(2) and GBF and by a small increase in plasma melatonin levels during the dark phase. We conclude that 1) stress-induced gastric bleeding erosions exhibit circadian rhythm with an increase in the day and attenuation at night and that these fluctuations in the formation of stress-induced gastric damage may depend upon the melatonin synthesis 2) the progressive increase in plasma melatonin in pinealectomized animals exposed to various time intervals of WRS suggests that extra-pineal melatonin possibly that derived from gastrointestinal tract, play an important role in the gastric mucosal defense against stress-induced gastric damage.

[Therapeutic modulation of intestinal microbiota in irritable bowel syndrome. From probiotics to fecal microbiota therapy]. / Therapeutische Modulation der Darmmikrobiota beim Reizdarmsyndrom : Von Probiotika bis zur fäkalen Mikrobiota-Therapie.

BACKGROUND: An abnormal intestinal microbiota (dysbiosis) plays a central role in the pathogenesis of the irritable bowel syndrome. METHOD: An overview of four current options for the treatment of irritable bowel syndrome, which are characterized by modulation of intestinal microbiota, is given. RESULTS AND CONCLUSIONS: Probiotics have very different effects on the individual symptoms of the irritable bowel. The choice of the appropriate preparation should therefore be based on the clinical symptomatology. The antibiotic rifaximin is effective in selected patients. Some patients also benefit from the repetition of this therapy. A FODMAP-reduced diet has shown significant alleviation of irritable bowel symptoms in studies. The fecal microbiota therapy (FMT) is a promising treatment option. At present, however, there are no such placebo-controlled studies to assess the effectiveness of this method.