Helicobacter pylori infection and nonalcoholic fatty liver disease: Are the four meta-analyses favoring an intriguing association pointing to the right direction?

Portal hypertension aggravates Helicobacter pylori induced liver injury in mice via activating pyroptosis pathway

In recent years, it has been discovered that the pathogenic effect of Helicobacter pylori (H. pylori) is not only limited to the gastroduodenal region, but also plays a certain role in the occurrence and development of liver diseases. The aim of this study is to ascertain the existence of Helicobacter pylori translocation, investigate whether it leads to liver injury and its potential mechanism and examine whether portal hypertension exacerbates liver damage caused by H. pylori translocation. Twenty four male SPF C57BL/6J mice were divided into four groups (6 in each group): (1) control group (Normal); (2) portal hypertension group (PHT); (3) H. pylori infected group (Hp); (4) H. pylori and Portal hypertension group (Hp and PHT). The histopathological changes of the liver and gastric tissues were measured by HE staining and immunohistochemistry (IHC); ALT, AST, IL-6 and INF-γ was measured by ELISA; Western blot detected the expression of pyroptotic proteins in the liver. The pro-inflammatory mediators and liver function indexes of mice in Hp group, Hp and PHT group were higher than those in the normal and PHT group. In addition, the liver inflammatory cell infiltration and ballooning of the two groups of mice were more severe than those in the normal group and PHT group, Hp and PHT group were more severe; Hp group, Hp and PHT group mice liver tissues activated the pyroptotic process through NLRP3 inflammasome, which eventually led to cell damage. Post mice infection by H. pylori, H. pylori will translocate to the liver, and induce liver injury by aggravating inflammation and promoting pyroptosis. Moreover, when portal hypertension occurs, it promotes the displacement of H. pylori, thereby aggravating liver injury.

Impact of Mast Cell Activation on Neurodegeneration: A Potential Role for Gut-Brain Axis and Helicobacter pylori Infection

BACKGROUND

The innate immune response aims to prevent pathogens from entering the organism and/or to facilitate pathogen clearance. Innate immune cells, such as macrophages, mast cells (MCs), natural killer cells and neutrophils, bear pattern recognition receptors and are thus able to recognize common molecular patterns, such as pathogen-associated molecular patterns (PAMPs), and damage-associated molecular patterns (DAMPs), the later occurring in the context of neuroinflammation. An inflammatory component in the pathology of otherwise "primary cerebrovascular and neurodegenerative" disease has recently been recognized and targeted as a means of therapeutic intervention. Activated MCs are multifunctional effector cells generated from hematopoietic stem cells that, together with dendritic cells, represent first-line immune defense mechanisms against pathogens and/or tissue destruction.

METHODS

This review aims to summarize evidence of MC implication in the pathogenesis of neurodegenerative diseases, namely, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis.

RESULTS

In view of recent evidence that the gut-brain axis may be implicated in the pathogenesis of neurodegenerative diseases and the characterization of the neuroinflammatory component in the pathology of these diseases, this review also focuses on MCs as potential mediators in the gut-brain axis bi-directional communication and the possible role of Helicobacter pylori, a gastric pathogen known to alter the gut-brain axis homeostasis towards local and systemic pro-inflammatory responses.

CONCLUSION

As MCs and Helicobacter pylori infection may offer targets of intervention with potential therapeutic implications for neurodegenerative disease, more clinical and translational evidence is needed to elucidate this field.

Impact of Helicobacter pylori and metabolic syndrome on mast cell activation-related pathophysiology and neurodegeneration

Both Helicobacter pylori (H. pylori) infection and metabolic syndrome (MetS) are highly prevalent worldwide. The emergence of relevant research suggesting a pathogenic linkage between H. pylori infection and MetS-related cardio-cerebrovascular diseases and neurodegenerative disorders, particularly through mechanisms involving brain pericyte deficiency, hyperhomocysteinemia, hyperfibrinogenemia, elevated lipoprotein-a, galectin-3 overexpression, atrial fibrillation, and gut dysbiosis, has raised stimulating questions regarding their pathophysiology and its translational implications for clinicians. An additional stimulating aspect refers to H. pylori and MetS-related activation of innate immune cells, mast cells (MC), which is an important, often early, event in systemic inflammatory pathologies and related brain disorders. Synoptically, MC degranulation may play a role in the pathogenesis of H. pylori and MetS-related obesity, adipokine effects, dyslipidemia, diabetes mellitus, insulin resistance, arterial hypertension, vascular dysfunction and arterial stiffness, an early indicator of atherosclerosis associated with cardio-cerebrovascular and neurodegenerative disorders. Meningeal MC can be activated by triggers including stress and toxins resulting in vascular changes and neurodegeneration. Likewise, H.pylori and MetS-related MC activation is linked with: (a) vasculitis and thromboembolic events that increase the risk of cardio-cerebrovascular and neurodegenerative disorders, and (b) gut dysbiosis-associated neurodegeneration, whereas modulation of gut microbiota and MC activation may promote neuroprotection. This narrative review investigates the intricate relationship between H. pylori infection, MetS, MC activation, and their collective impact on pathophysiological processes linked to neurodegeneration. Through a comprehensive search of current literature, we elucidate the mechanisms through which H. pylori and MetS contribute to MC activation, subsequently triggering cascades of inflammatory responses. This highlights the role of MC as key mediators in the pathogenesis of cardio-cerebrovascular and neurodegenerative disorders, emphasizing their involvement in neuroinflammation, vascular dysfunction and, ultimately, neuronal damage. Although further research is warranted, we provide a novel perspective on the pathophysiology and management of brain disorders by exploring potential therapeutic strategies targeting H. pylori eradication, MetS management, and modulation of MC to mitigate neurodegeneration risk while promoting neuroprotection.

Impact of Helicobacter pylori and metabolic syndrome-related mast cell activation on cardiovascular diseases

Helicobacter pylori, a widely renowned bacterium, has recently gained attention owing to its potential impact on extragastric health. The emergence of research linking H. pylori infection with metabolic syndrome (MetS)-related cardiovascular diseases (CVDs) has raised intriguing questions about the pathogenic linkage and its translational implications for clinicians. MetS encompasses a collection of metabolic abnormalities that considerably elevate the risk of CVDs and cerebrovascular diseases. Emerging evidence supports a potential pathogenetic role of H. pylori for MetS-related disorders through mechanisms implicating chronic smoldering inflammation, insulin resistance (IR), and modulation of immune responses. One intriguing aspect of this possible connection is the role of mast cells (MCs), a subset of immune cells representing innate immune system effector cells. They play a fundamental role in innate immune responses and the modulation of adaptive immunity. Activated MCs are commonly found in patients with MetS-related CVD. Recent studies have also suggested that H. pylori infection may activate MCs, triggering the release of pro-inflammatory mediators that contribute to IR and atherosclerosis. Understanding these intricate interactions at the cellular level provides new insights into the development of therapeutic strategies targeting both H. pylori infection and MetS-related MCs activation. This review investigates the current state of research regarding the potential impact of H. pylori infection and MetS-related MCs activation on the pathophysiology of CVD, thereby opening up new avenues for related research and paving the way for innovative approaches to prevention and treatment in clinical practice

Prospective cohort study of Helicobacter pylori infection on the risk of nonalcoholic fatty liver disease

To investigate the epidemiological connection between nonalcoholic fatty liver disease (NAFLD) and Helicobacter pylori ( H. pylori). 6,478 retired and active workers, aged 22-69 years, were included in the study. Their baseline measures of height, weight, waist measurement, body mass index, blood pressure, fasting blood sugar, plasma lipid, liver function index, glycosylated hemoglobin, abdominal ultrasonography, and findings from the line “13 C urea breath test” H. pylori test were analyzed, and follow-up with consistent baseline methods and criteria was performed annually. Over a 4-year period, the prevalence of NAFLD increased by 16.9%, with 612 (18.7%) of those who tested positive for H. pylori developing NAFLD, whereas 484 (15.1%) of those who did not test positive for H. pylori were later diagnosed with new NAFLD ( χ2 = 14.862, P < 0.05). One of the risk factors identified in the univariable Cox regression model for NAFLD was H. pylori (Hazard Ratio = 1.297; 95.0% confidence interval (CI) 1.150,1.485, P < 0.000); however, H. pylori continued to be an independent factor affecting the risk of NAFLD even after accounting for gender, age, and aspects of the metabolic syndrome (Hazard Ratio = 1.240; 95.0% CI 1.077,1.429, P = 0.003). The growth of NAFLD may be correlated with H. pylori infection.

The possible role of Helicobacter pylori in liver diseases

According to previous studies, Helicobacter pylori infection is associated with liver disease. In order to better understand the risk of acquiring various liver diseases, we reviewed current knowledge on the impact of H. pylori on the onset, intensification, and progression of various liver diseases caused by the infection of H. pylori. It has been estimated that between 50 and 90% of people worldwide have been infected with H. pylori. The bacterium is mostly responsible for inflamed gastric mucosa, ulcers, and cancers associated with the gastric mucosa. Through the active antioxidant system in H. pylori, the bacteria can neutralize free radicals by synthesizing VacA, a toxin that causes cell damage and apoptosis. Furthermore, there is a possibility that CagA genes may play a role in cancer development. People who have been infected with H. pylori are likely to develop lesions in the skin, the circulation system, and the pancreas. Moreover, transferring blood from the stomach may allow H. pylori to colonize the liver. The bacterium worsened liver function during autoimmune inflammation, toxic injury, chronic HCV infection, chronic HBV infection, and liver cirrhosis. Increasing portal pressure, hyperammonemia, and esophageal varices may be associated with H pylori infection. As a result, it is crucial to diagnose and treat this infection in patients with H. pylori.

Association between Helicobacter pylori infection and non-alcoholic fatty liver disease for Asian and non-Asian population: A systematic review and meta-analysis

Background

Several studies have revealed a positive correlation between a Helicobacter pylori (HP) infection and the risk of non-alcoholic fatty liver disease (NAFLD). This meta-analysis was conducted to explore further the relationship between HP infection and NAFLD in the Asian and non-Asian populations.

Methods

Relevant studies published from inception to July 22, 2021, in the following databases: PubMed, EMBASE, the Cochrane library, and Web of Science were comprehensively searched. The odds ratio (OR) and hazard ratio (HR) with a 95% confidence interval (95%CI) were pooled by the random-effects model or fixed-effects model. Additionally, subgroup and sensitivity analyses were performed. The funnel plot and the Egger test were used to estimate publication bias.

Results

This meta-analysis included 25 studies involving 107,306 participants. Positive associations between HP infection and NAFLD were found both for the Asian (OR = 1.30, 95% CI: 1.13-1.49, P < 0.01; I 2 = 94.30%, P < 0.01) and non-Asian populations (OR = 1.42, 95% CI: 1.04-1.94, P = 0.03; I 2 = 44.90%, P = 0.09). Moreover, similar results were observed in the Asian female group (OR = 1.31, 95% CI: 1.17-1.46, P < 0.01; I 2 = 46.30%, P = 0.07) but not for the Asian male group. Subgroup analyses for the Asian population showed that there were differences in the association among NAFLD diagnosis methods (P < 0.01) and the study design (P < 0.01). However, subgroup and sensitivity analyses results showed that the association for the non-Asian population was not stable enough.

Conclusions

The data obtained in this systematic review and meta-analysis suggested that an HP infection was associated with an increased risk of NAFLD for Asian and non-Asian populations. However, the association was not found for Asian males. Further studies are required to establish the causal association, especially for the non-Asian population.

Systematic review registration

Identifier: CRD42021266871.

Diagnostic gene biomarkers for predicting immune infiltration in endometriosis

OBJECTIVE

To determine the potential diagnostic markers and extent of immune cell infiltration in endometriosis (EMS).

METHODS

Two published profiles (GSE7305 and GSE25628 datasets) were downloaded, and the candidate biomarkers were identified by support vector machine recursive feature elimination analysis and a Lasso regression model. The diagnostic value and expression levels of biomarkers in EMS were verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting, then further validated in the GSE5108 dataset. CIBERSORT was used to estimate the composition pattern of immune cell components in EMS.

RESULTS

One hundred and fifty-three differential expression genes (DEGs) were identified between EMS and endometrial with 83 upregulated and 51 downregulated genes. Gene sets related to arachidonic acid metabolism, cytokine-cytokine receptor interactions, complement and coagulation cascades, chemokine signaling pathways, and systemic lupus erythematosus were differentially activated in EMS compared with endometrial samples. Aquaporin 1 (AQP1) and ZW10 binding protein (ZWINT) were identified as diagnostic markers of EMS, which were verified using qRT-PCR and western blotting and validated in the GSE5108 dataset. Immune cell infiltrate analysis showed that AQP1 and ZWINT were correlated with M2 macrophages, NK cells, activated dendritic cells, T follicular helper cells, regulatory T cells, memory B cells, activated mast cells, and plasma cells.

CONCLUSION

AQP1 and ZWINT could be regarded as diagnostic markers of EMS and may provide a new direction for the study of EMS pathogenesis in the future.

Towards harnessing the value of organokine crosstalk to predict the risk for cardiovascular disease in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Importantly, NAFLD increases the risk for cardiovascular disease (CVD). A causal relationship has been substantiated. Given the pandemic proportions of NAFLD, a reliable scoring system for predicting the risk of NAFLD-associated CVD is an urgent medical need. We here review cumulative evidence suggesting that systemically released organokines - especially certain adipokines, hepatokines, and cardiokines - may serve this purpose. The underlying rationale is that these signalers directly communicate between white adipose tissue, liver, and heart as key players in the pathogenesis of NAFLD and resultant CVD events. Moreover, evidence suggests that these organ-specific cytokines are secreted in a biologically predetermined, cascade-like pattern. Consequently, upon pinpointing organokines of relevance, we sketch requirements to establish an algorithm predictive of the CVD risk in patients with NAFLD. Such an algorithm, as to be consolidated in the form of an applicable equation, may be improved continuously by machine learning. To the best of our knowledge, such an option has not yet been considered. Establishing and implementing a reliable algorithm for determining the NAFLD-associated CVD risk has the potential to save many NAFLD patients from life-threatening CVD events.

Is the Occurrence or Reversal of Nonalcoholic Fatty Liver Disease Associated with Long-Term Helicobacter pylori Infection among Chinese Adults? A Cohort Study

Background

Previous studies have suggested a link between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD), yet long-term follow-up studies to elucidate this association are lacking. We aimed to identify the relationship between NAFLD and H. pylori in these people.

Methods

A total of 2,934 adults between June 2013 and October 2017 were collected; among them, 675 people met the requirements. People were assessed for H. pylori infection diagnosis as detected by the carbon-13 urea breath test; they were also assessed for NAFLD diagnosis by ultrasound.

Results

H. pylori infection was present in 206 patients (30.5%), and 469 (69.5%) participants were classified as controls. Participants with H. pylori infection had a higher rate of incident NAFLD than those who were uninfected (37/206; 18% versus 73/469; 15.6%) (p < 0.001). Compared with the control group, the recovery rate of NAFLD in the H. pylori+ve group was low (6/206, 2.9% versus 33/469, 7.0%) (p < 0.001). Besides, the incidence of uric acid, postprandial blood glucose, TG, LDL-C, HDL-C, and fasting plasma glucose was significantly different between the two groups (p < 0.001), but no difference was found in alanine aminotransferase (ALT), liver-total protein, urea nitrogen, and cholesterol (p > 0.05).

Conclusion

H. pylori infection was a risk factor for NAFLD and affected the occurrence or reversal of NAFLD, indicating that H. pylori infection eradication might play a role in reducing the risk of NAFLD.

Impact of Helicobacter pylori-Related Metabolic Syndrome Parameters on Arterial Hypertension

Arterial hypertension is a risk factor for several pathologies, mainly including cardio-cerebrovascular diseases, which rank as leading causes of morbidity and mortality worldwide. Arterial hypertension also constitutes a fundamental component of the metabolic syndrome. Helicobacter pylori infection is one of the most common types of chronic infection globally and displays a plethora of both gastric and extragastric effects. Among other entities, Helicobacter pylori has been implicated in the pathogenesis of the metabolic syndrome. Within this review, we illustrate the current state-of-the-art evidence, which may link several components of the Helicobacter pylori-related metabolic syndrome, including non-alcoholic fatty liver disease and arterial hypertension. In particular, current knowledge of how Helicobacter pylori exerts its virulence through dietary, inflammatory and metabolic pathways will be discussed. Although there is still no causative link between these entities, the emerging evidence from both basic and clinical research supports the proposal that several components of the Helicobacter pylori infection-related metabolic syndrome present an important risk factor in the development of arterial hypertension. The triad of Helicobacter pylori infection, the metabolic syndrome, and hypertension represents a crucial worldwide health problem on a pandemic scale with high morbidity and mortality, like COVID-19, thereby requiring awareness and appropriate management on a global scale.

Seroprevalence of Helicobacter pylori and its association with metabolic syndrome in a rural community of Bangladesh

BACKGROUND AND AIM

As the interrelationship between Helicobacter pylori, metabolic syndrome (MetS), and non-alcoholic fatty liver disease (NAFLD) is controversial, we undertook a community-based study with the aim to find the seroprevalence of H. pylori and its relationship with MetS and NAFLD.

METHODS

This door-to-door survey was conducted among the adult subjects (≥18 years) of two villages (Charcharia of Dhaka district and Kharrah of Munshiganj district) of Bangladesh. Interviews using a structured questionnaire, clinical examination, anthropometric measurements, ultrasonogram of the liver, and biochemical tests were performed.

RESULTS

Of 1021 subjects, 781 responded (76.49%), and 767 were included in the final analysis (mean age 40.35 ± 15.56 years; female 63.5%). Anti-H. pylori antibodies were found in 418 of 767 (54.5%). There were no H. pylori serostatus association with MetS and diabetes mellitus (DM) in univariate or multivariate analysis (all P > 0.05). However, H. pylori seropositive subjects had lower systolic blood pressure (odds ratio [OR] = -2.95 [-5.58, -0.32]) and low density lipoprotein -cholesterol (OR -7.79 [-15, -0.57]) compared to seronegative subjects in the linear regression model. Seronegativity of H. pylori was associated with NALFD in univariate (P = 0.007) but not multivariate analysis (P = 0.086). There were no differences in the frequency of H. pylori seropositivity among the participants with nonobese compared to obese NAFLD (19/42 [45%] vs 43/99 [43.4%], P = 0.844).

CONCLUSION

In a rural community of Bangladesh, about 55% of the population were H. pylori seropositive, which was more common among the underweight than normal or obese subjects. However, there was no relationship observed between H. pylori seroprevalence and MetS, DM, or NAFLD.

Reconsidering the "protective" hypothesis of Helicobacter pylori infection in eosinophilic esophagitis

Since its discovery, Helicobacter pylori (H. pylori) has attracted attention in the biomedical world with its numerous pathophysiologic implications, both gastrointestinal and systemic. Beyond its well-established carcinogenic properties, emerging evidence also supports "harmful" proinflammatory and neurodegenerative roles of H. pylori. On the other hand, H. pylori infection has been proposed to be "protective" against several diseases, such as asthma and gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) is a relatively new, allergen/immune-mediated disease, which has also been linked to these considerations. Main arguments are a postulated shift of immune responses by H. pylori from T helper 2 (T_H 2) to T_H 1 polarization, as well as a potential decline of the H. pylori burden with the dramatic parallel rise of ΕοΕ: a series of observational studies reported an inverse association. In this review, we counter these arguments by providing further epidemiological data, which point out that this generalization might be rather incomplete. We also discuss the limitations of the existing studies evaluating a possible association. Furthermore, we provide current evidence on common pathogenetic components, which share both entities. In summary, the claim that H. pylori is protective against EoE is rather incomplete, and further mechanistic studies are necessary to elucidate a possible association.

Active Helicobacter pylori Infection is Independently Associated with Nonalcoholic Steatohepatitis in Morbidly Obese Patients

Nonalcoholic fatty liver disease (NAFLD) emerges as an important global burden and Helicobacter pylori infection (Hp-I) has been suggested as a risk factor of NAFLD, although controversy exists. This retrospective study aimed to investigate a potential impact of active Hp-I on NAFLD severity in morbidly obese patients, subjected to bariatric surgery and gastric biopsy for documentation of Hp-I. Of 64 eligible participants, 15 (23.4%) were diagnosed with active Hp-I, showing higher rates of nonalcoholic steatohepatitis (NASH) than those without Hp-I (86.7% vs. 26.5%, respectively; p < 0.001). Concerning histological lesions, steatosis grade (p = 0.027), ballooning (p < 0.001), lobular inflammation (p = 0.003), and fibrosis stage (p < 0.001) were also more severe in Hp-I positive patients. Likewise, liver function tests, insulin resistance, dyslipidemia, and arterial hypertension were significantly higher in Hp-I positive patients. Hp-I was independently positively associated with NASH (beta = 3.27; p = 0.002), severe NASH (beta = 2.37; p = 0.018), and the presence of fibrosis (beta = 3.86; p = 0.001) in a binary regression model, after adjustment for potential confounders. In conclusion, active Hp-Ι was independently associated with NASH and fibrosis, findings offering potential clinical implication.