Local inflammatory response to gastroesophageal reflux: Association of gene expression of inflammatory cytokines with esophageal multichannel intraluminal impedance-pH data

Causal association between gastroesophageal reflux disease and sepsis, and the mediating role of gut bacterial abundance, a Mendelian randomization study

Gastroesophageal reflux disease (GERD), akin to sepsis, is mediated by inflammatory reactions and exhibits a strong correlation with intestinal dysbiosis. We sought to examine whether these associations reflect causality using the Mendelian randomization (MR) mediation analysis. Genetic data were obtained from genome-wide association studies. Two-sample MR were performed to evaluate the causal association, accompanied by sensitivity analyses. Reverse direction MR was undertaken to assess the potential for reverse causation. Then, mediation analysis was performed to evaluate the mediating effect of gut bacterial pathway abundance in this relationship. Genetic predisposition to GERD was significantly associated with sepsis [inverse variance weighting: odds ratio = 1.366, P = 2.13E-09, 95% confidence interval [CI] 1.233-1.513] and sepsis-related 28-day mortality (inverse variance weighting: odds ratio = 1.412, P = 6.64E-03, 95% CI 1.101-1.812). There is no convincing evidence for reverse causation. Gut bacterial pathway abundance (ARO.PWY..chorismate.biosynthesis.I) mediates the effect of GERD on sepsis (β = 0.036, 95% CI 0.004-0.067, P = .025), accounting for 11.406% of the total effect; Gut bacterial pathway abundance (PWY.7219..adenosine.ribonucleotides.de.novo.biosynthesis) mediates the effect of GERD on sepsis (β = 0.026, 95% CI -0.003 to 0.056, P = .083), accounting for 8.486% of the total effect; gut bacterial pathway abundance (ARO.PWY..chorismate.biosynthesis.I) mediates the effect of GERD on sepsis (28-day death) (β = 0.079, 95% CI 0.005-0.153, P = .036), accounting for 22.890% of the total effect; gut bacterial pathway abundance (TRNA.CHARGING.PWY..tRNA.charging) mediates the effect of GERD on sepsis (28-day death) (β = -0.066, 95% CI -0.140 to 0.007, P = .078), accounting for -19.171% of the total effect. The present MR study supported GERD as a causal risk factor of sepsis and sepsis-related 28-day mortality. Three specific gut bacterial pathway abundances were identified that played a partial mediating role in the aforementioned causal relationship between GERD and sepsis.

Molecular mechanisms underlying oesophageal cancer development triggered by chronic alcohol consumption

This review explores the mechanisms underlying alcohol‐induced oesophageal carcinogenesis, including DNA damage, oxidative stress, and nutritional deficiencies. Alcohol metabolism primarily involves alcohol dehydrogenase (ADH) converting ethanol to acetaldehyde, which can cause DNA damage, inhibit repair mechanisms, and form DNA adducts thus inhibiting DNA replication. Plus, it delves into the epidemiological evidence, genetic susceptibility, epigenetic modifications, biomarkers, and preventive strategies associated with alcohol‐related oesophageal cancers. Consumption of alcohol increases the risk of gastroesophageal reflux disease thus compromising mucosal integrity of the oesophagus as dysregulation of cytokines such as IL‐18, TNFA, GATA3, TLR4, and CD68 expands the intercellular spaces of epithelial cells. Genetic variants, such as ADH1B rs1229984 and ALDH2 rs671, significantly influence susceptibility to alcohol‐related oesophageal cancers, with these variations affecting acetaldehyde metabolism and cancer risk. Understanding these factors is crucial for early detection, effective treatment, and the development of targeted prevention strategies. Biomarkers, such as miRNA and metabolite markers, offer non‐invasive methods for early detection, while advanced endoscopic techniques provide better diagnostic accuracy. Pharmacological interventions, such as statins and proton pump inhibitors, also show potential for reducing cancer progression in high‐risk individuals. Despite advances, late‐stage oesophageal cancer diagnoses are still common, highlighting the need for better screening and prevention. Further research, including this study, should aim to improve early detection, personalise prevention, and explore new treatments to reduce cases and enhance outcomes in alcohol‐related oesophageal cancers.

Causal relationship between air pollution, lung function, gastroesophageal reflux disease, and non-alcoholic fatty liver disease: univariate and multivariate Mendelian randomization study

Background

The association between air pollution, lung function, gastroesophageal reflux disease, and Non-alcoholic fatty liver disease (NAFLD) remains inconclusive. Previous studies were not convincing due to confounding factors and reverse causality. We aim to investigate the causal relationship between air pollution, lung function, gastroesophageal reflux disease, and NAFLD using Mendelian randomization analysis.

Methods

In this study, univariate Mendelian randomization analysis was conducted first. Subsequently, Steiger testing was performed to exclude the possibility of reverse association. Finally, significant risk factors identified from the univariate Mendelian analysis, as well as important factors affecting NAFLD from previous observational studies (type 2 diabetes and body mass index), were included in the multivariable Mendelian randomization analysis.

Results

The results of the univariable Mendelian randomization analysis showed a positive correlation between particulate matter 2.5, gastroesophageal reflux disease, and NAFLD. There was a negative correlation between forced expiratory volume in 1 s, forced vital capacity, and NAFLD. The multivariable Mendelian randomization analysis indicated a direct causal relationship between gastroesophageal reflux disease (OR = 1.537, p = 0.011), type 2 diabetes (OR = 1.261, p < 0.001), and NAFLD.

Conclusion

This Mendelian randomization study confirmed the causal relationships between air pollution, lung function, gastroesophageal reflux, and NAFLD. Furthermore, gastroesophageal reflux and type 2 diabetes were identified as independent risk factors for NAFLD, having a direct causal connection with the occurrence of NAFLD.

Effects of visceral obesity on cytokine and hormonal regulation in patients with gastroesophageal reflux disease

Background. In recent years, pathogenetic mechanisms underlying the association of gastroesophageal reflux disease (GERD) and metabolic syndrome have caused considerable interest among researchers. The purpose is to determine the features of cytokine balance, carbohydrate metabolism, leptin and ghrelin levels depending on the amount of visceral fat in patients with GERD. Materials and methods. Fifty-six patients with GERD were examined. According to the results of bioimpedance analysis, they were divided into the groups: 23 patients with a dangerous and 33 with a safe amount of visceral fat. The levels of tumor necrosis factor α, interleukin-6, interleukin-10, ghrelin and leptin were determined in the blood serum of all patients by the enzyme immunoassay method. Also, the levels of glucose, insulin were determined and the insulin resistance index (HOMA-IR) was calculated in patients with GERD. Results. In the group of GERD patients with a dangerous amount of visceral fat, an increase in the concentration of the pro-inflammatory cytokine interleukin-6 by 12 % was found with a simultaneous decrease in the level of the anti-inflammatory cytokine interleukin-10 by 22 % (p < 0.05), an increase in the HOMA-IR median by 1.3 times (p < 0.05) compared to the patients with a safe amount of visceral fat. The median level of ghrelin in patients with a dangerous visceral fat amount increased significantly, by 2.0 times (p < 0.05) compared to the control group. Correlation analysis showed an association between visceral fat and leptin (r = 0.37; p = 0.0008), interleukin-10 (r = –0.28; p = 0.0116), insulin (r = 0.41; p = 0.001), HOMA-IR (r = 0.48; p = 0.00001). Conclusions. In GERD patients, an increase in the amount of visceral fat was associated with a violation of the cytokine balance, carbohydrate metabolism, increased level of ghrelin. The determined statistically significant correlation between the amount of visceral fat and the level of leptin indicates a functional relationship between the body composition according to bioimpedance analysis and the hormonal activity of adipose tissue in patients with GERD.

Esophageal Mucosal Resistance in Reflux Esophagitis: What We Have Learned So Far and What Remains to Be Learned

Gastroesophageal reflux disease (GERD) has the highest prevalence among diseases of the digestive system and is characterized by a significant decrease in patients' quality of life, comparable to arterial hypertension and coronary heart disease. One in every ten cases of reflux esophagitis leads to the formation of Barrett's esophagus, which is associated with a high risk of esophagus adenocarcinoma. The key factors determining the progression of the disease are the frequency and duration of the reflux of the stomach's contents. As a result, refluxate, which includes hydrochloric acid, pepsin, and, in the case of concomitant duodeno-gastric reflux, bile acids and lysolecithin, is thrown into the overlying sections of the digestive tract. At the same time, in addition to aggression factors, it is necessary to take into account the state of resistance in the esophageal mucosa to the effects of aggressive refluxate molecules. This review was prepared using systematized data on the protective properties of the esophageal mucosa and modern methods to assess the mucosal barrier in reflux esophagitis. Lesions of the epithelial barrier structure in the esophagus are recognized as the main pathogenetic factor in the development of reflux esophagitis and are a potentially significant therapeutic target in the treatment of GERD and Barrett's esophagus. This article presents the characteristics of the esophageal mucosal barrier and the protective mechanisms of the esophagus's mucous membrane in conditions of gastroesophageal reflux. Diagnostic approaches for assessing the course of reflux esophagitis are described for both histological criteria and the possibility of a comprehensive assessment of the state of mucins, tight-junction proteins, and the proliferative activity of the mucosa, including under the conditions of ongoing therapy.