The Role of Morbid Obesity in the Promotion of Metabolic Disruptions and Non-Alcoholic Steatohepatitis by Helicobacter Pylori

Persistently Active Helicobacter pylori Infection Is Associated with the Development of Metabolic Dysfunction-Associated Steatotic Liver Disease

Background/Objectives: Previous studies suggested a link between Helicobacter pylori (H. pylori) infection and steatotic liver disease, now termed metabolic dysfunction-associated steatotic liver disease (MASLD). This study aimed to identify the association of active H. pylori infection and the new concept of MASLD in a longitudinal cohort. Methods: We reviewed 1497 health examinees who had two endoscopic biopsies for H. pylori activity without hepatic steatosis at the baseline abdominal ultrasonography. Subjects were classified into four groups based on H. pylori activity. Multivariable Cox models assessed the link between active H. pylori infection status and incident MASLD. Results: Over a median follow-up of 31.1 months, 247 subjects (16.5%) developed MASLD. The groups were: H. pylori naïve (n = 57, 15.6%), de novo (n = 31, 15.3%), eradicated (n = 32, 16.1%), and persistent (n = 127, 17.4%). The H. pylori persistent group had a higher risk of MASLD compared to naïve group (hazard ratio: 1.41; 95% confidence interval: 1.01-1.96; p-value = 0.045). The association between H. pylori infection and incident MASLD was significant only with ongoing infection. Conclusions: Persistent H. pylori infection increases the risk of MASLD, indicating that active infection may contribute to MASLD development. Eradicating active H. pylori infection might help lower the incidence of MASLD.

Association between Helicobacter pylori infection, MASLD, and liver fibrosis in patients with severe obesity: a single-center experience

BACKGROUND AND METHODS

Our study sought to evaluate if an association exists between Helicobacter pylori (H. pylori), metabolic dysfunction- associated steatotic liver disease (MASLD), and liver fibrosis in patients with severe obesity (BMI > 35). Our retrospective study included 584 patients over the age of 18 years with severe obesity, who underwent preoperative liver transient elastography (VCTE), upper endoscopy, blood work, and intra-operative liver biopsy concurrent with bariatric surgery at a single institution from July 2020 to September 2021. Liver fibrosis scores including FIB-4, APRI, NAFLD fibrosis score, BARD score, AST: ALT ratio, and NAFLD activity score (NAS) were calculated from the laboratory results and liver biopsy findings. The presence or absence of H. pylori was determined based on gastric biopsies obtained during upper endoscopy. Other variables collected included age, gender, mean preoperative weight, BMI, and the presence or absence of comorbidities. Student's t-test and non-parametric testing were used for the analysis of continuous variables and Chi-square analysis was used for categorical data.

RESULTS

Of the 584 patients, 14.7% were H. pylori positive and 85.3% were negative. Liver fibrosis scores including FIB-4, APRI, and NAFLD fibrosis scores were significantly higher in the positive group (p < 0.05), but there was no difference in AST: ALT ratio and BARD score. A significantly higher VCTE steatosis and fibrosis scores were noted in the H. pylori-positive group (p < 0.05). Similarly, a significantly higher NAS (NAFLD activity score) on liver biopsies was noted in the positive group, with all the individual components of NAS (steatosis, lobular inflammation, and hepatocyte ballooning) being significantly higher in the positive group (p < 0.05). A significantly higher incidence of fibrosis on liver biopsies was noted in the positive group overall and across all stages of fibrosis (p < 0.05). There were no significant differences between the groups in relation to gender, mean weight, BMI, presence of comorbidities including Diabetes Mellitus, and laboratory values.

CONCLUSION

Our study demonstrates that H. pylori colonization or infection is associated with a higher risk of development of MASLD and progression to fibrosis. Further, population-based studies are needed to corroborate our findings.

Both extracellular vesicles from helicobacter pylori-infected cells and helicobacter pylori outer membrane vesicles are involved in gastric/extragastric diseases

Bacterial-derived extracellular vesicles (EVs) have emerged as crucial mediators in the cross-talk between hosts and pathogens, playing a significant role in infectious diseases and cancers. Among these pathogens, Helicobacter pylori (H. pylori) is a particularly important bacterium implicated in various gastrointestinal disorders, gastric cancers, and systemic illnesses. H. pylori achieves these effects by stimulating host cells to secrete EVs and generating internal outer membrane vesicles (OMVs). The EVs derived from H. pylori-infected host cells modulate inflammatory signaling pathways, thereby affecting cell proliferation, apoptosis, cytokine release, immune cell modification, and endothelial dysfunction, as well as disrupting cellular junctional structures and inducing cytoskeletal reorganization. In addition, OMVs isolated from H. pylori play a pivotal role in shaping subsequent immunopathological responses. These vesicles incite both inflammatory and immunosuppressive reactions within the host environment, facilitating pathogen evasion of host defenses and invasion of host cells. Despite this growing understanding, research involving H. pylori-derived EVs remains in its early stages across different domains. In this comprehensive review, we present recent advancements elucidating the contributions of EV components, such as non-coding RNAs (ncRNAs) and proteins, to the pathogenesis of gastric and extragastric diseases. Furthermore, we highlight their potential utility as biomarkers, therapeutic targets, and vehicles for targeted delivery.

Helicobacter pylori infection increases the risk of nonalcoholic fatty liver disease: Possible relationship from an updated meta-analysis

BACKGROUND

The relationship between Helicobacter pylori (H pylori) infection and nonalcoholic fatty liver disease (NAFLD) has long been debated. Although it has been investigated in many observational studies, the results remain controversial. Therefore, we performed an updated meta-analysis to assess the association between H pylori infection and risk of NAFLD by collecting relevant articles.

METHODS

Literature collections were conducted by searching PubMed, EMBASE, Web of Science and Cochrane Library databases. Pooled odds ratios with corresponding 95% confidence intervals were calculated to estimate the strength of the link between H pylori infection and NAFLD using Stata 12.0 software.

RESULTS

28 studies with 68,047 cases of NAFLD patients and 134,866 controls were finally included in the meta-analysis. Overall, The results suggested a 27.5% increased risk of developing NAFLD in patients with H pylori infection (odds ratios 1.275 95% confidence intervals 1.179-1.379), although significant heterogeneity was observed. There is no significant publication bias observed based on the funnel plot and Begg test. Subgroup analysis revealed that variables of the study design, study region, publication year, and the method of diagnosing H pylori and NAFLD all contribute to the high heterogeneity, while the positive correlation was seen in all subgroup analysis.

CONCLUSION

This meta-analysis disclosed 1.275-fold increased risk of the occurrence and development of NAFLD in H pylori (+) group compared with the H pylori (-) group, indicating that H pylori is a serious risk factor in patients susceptible to NAFLD.

HELICOBACTER AND HEPATOBILIARY DISEASES: UPDATE 2023

•Clinical studies have shown that hepatobiliary diseases of inflammatory and neoplastic origin are associated with Helicobacter infection. •Translocation and the ascending pathway are putative mechanisms for Helicobacter spp to enter the hepatobiliary system. •H. pylori infection has a systemic effect through the activity of pro-inflammatory cytokines, TNF-α, leukotrienes, interferon-β, interferon-γ, and acute phase proteins. •Histopathological confirmation is needed to present that H. pylori eradication prevents or improves hepatobiliary disease progression. Helicobacter Pylori (H. pylori) is one of the main infectious causes of gastroduodenal diseases, however, its role in developing different extragastric diseases has been proven. The possible involvement of H. pylori in the pathogenesis of cardiovascular, metabolic, neurodegenerative, skin, and hepatobiliary diseases is suggested. The bacterium has been found in tissue samples from the liver, biliary tract, and gallstones of animals and humans. However, the role of H. pylori infection in the pathogenesis of liver and biliary diseases has not been finally established. The histopathological confirmation of the positive effect of H. pylori eradication is needed. In addition, there are discussions on the clinical significance of other Helicobacter species. The review presents the data available for and against the involvement of H. pylori in hepatobi-liary disease development and progression.

Relationship of Helicobacter pylori Infection with Nonalcoholic Fatty Liver Disease: A Meta-Analysis

BACKGROUND AND AIMS

Helicobacter pylori (H. pylori) and nonalcoholic fatty liver disease (NAFLD) have become increasingly recognized, both of which affect human health globally. The association of H. pylori infection with NAFLD remains unclear.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched. Only a random-effects model was used. Odds ratios (ORs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for the combined estimates of raw data. Adjusted ORs (aORs) and hazard ratios (aHRs) with 95% CIs were calculated for the combined estimates of data adjusted for confounders.

RESULTS

Thirty-four studies with 218573 participants were included. Based on unadjusted data from 26 cross-sectional studies and 3 case-control studies, H. pylori infection was significantly associated with the presence of NAFLD (OR = 1.26, 95% CI = 1.17-1.36, P < 0.001). Based on adjusted data from 15 cross-sectional studies and 1 case-control study, H. pylori infection was significantly associated with the presence of NAFLD (aOR = 1.25, 95% CI = 1.08-1.44, P < 0.001). Compared with control subjects without NAFLD, patients with moderate (OR = 1.67, 95% CI = 1.17-2.39, P = 0.005) and severe (OR = 1.71, 95% CI = 1.30-2.24, P < 0.001) NAFLD, but not those with mild NAFLD (OR = 1.14, 95% CI = 0.9-1.45, P = 0.286), had significantly higher proportions of H. pylori infection. The association of H. pylori infection with the occurrence of NAFLD was statistically significant based on adjusted data from 3 cohort studies (aHR = 1.18, 95% CI = 1.05-1.34, P = 0.007), but not based on unadjusted data from 3 cohort studies (RR = 1.41, 95% CI = 0.80-2.48, P = 0.237).

CONCLUSION

H. pylori infection is associated with NAFLD, especially moderate and severe NAFLD. The impact of H. pylori eradication on the prevention of NAFLD should be further explored.

Is Helicobacter pylori infection associated with non-alcoholic fatty liver disease in individuals undergoing bariatric surgery? Cross-sectional study

BACKGROUND

A possible direct link between nonalcoholic fatty liver disease (NAFLD) and Helicobacter pylori (H. pylori) infection has recently emerged.

OBJECTIVE

This study aimed to analyze associations between the presence of histologically demonstrated NAFLD aspects with H. pylori infection in individuals with obesity undergoing bariatric surgery.

DESIGN AND SETTING

An observational analytical cross-sectional study was conducted based on data collected from the medical records of individuals undergoing bariatric surgery at a tertiary university hospital in 2019.

METHODS

NAFLD was assessed through histological examination of wedge liver biopsies collected during the proceedings. H. pylori infection was analyzed through the association of the urease test and histological examination performed in biopsies routinely collected during preoperative esophagogastroduodenoscopy.

RESULTS

Of the 88 participants, 85% were female, and the average age was 39.1 ± 8.4 years. H. pylori infection was present in 61.4% of the patients. The mean body mass index was 36.6 ± 3.4 kg/m2. The most prevalent histopathological aspects of NAFLD were macrovesicular steatosis (92%), hepatocellular ballooning (92%), lobular inflammation (93.2%), portal inflammation (96.6%), and fibrosis (93.2%). No histopathological aspect of NAFLD was found to be significantly associated with H. pylori infection.

CONCLUSION

In this study population, H. pylori infection was not significantly associated with the histopathological aspects of NAFLD in individuals with obesity undergoing bariatric surgery.

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.

Non-alcoholic fatty liver disease is not independently associated with Helicobacter pylori in a central European screening cohort

BACKGROUND

The association between Helicobacter pylori (Hp) infection and non-alcoholic fatty liver disease (NAFLD) is subject of a contentious debate. Data mainly stem from Asian cohorts whereas European data are scarce. We, therefore, investigated an Austrian colorectal cancer screening cohort for an association between Hp and NAFLD.

METHODS

In total, 5338 consecutive participants undergoing screening colonoscopy at a single center in Austria were evaluated in this cross-sectional study. The primary risk factor was being Hp negative or positive. The primary endpoint was the presence of NAFLD defined by ultrasound (NAFLD; primary endpoint). Uni- and multivariable logistic regression models were fitted to obtain odds ratios (OR) and 95% confidence intervals (95%CI). Finally, this association was analyzed in a subgroup of 1128 patients in whom NAFLD was diagnosed by transient elastography (TE, secondary endpoint).

RESULTS

NAFLD prevalence defined by ultrasound did not differ between Hp positive (48%) and negative patients (45%, P=0.097). Accordingly, in uni- (OR 1.12 95% CI 0.98-1.29; P=0.098) and multivariable analysis adjusting for different risk factors (aOR 0.96 95%CI 0.82-1.13; P=0.601) no independent association was found. On subgroup analysis, NAFLD diagnosed by TE was more prevalent in the Hp positive compared to the Hp negative group (49% vs. 38%, P=0.004) and these patients also had higher steatosis grades. However, after adjustment for risk factors, no independent association between Hp positivity and NAFLD diagnosed by TE (aOR 1.26 95%CI 0.89-1.78; P=0.194) was confirmed.

CONCLUSIONS

In this Central European cohort, Hp-positivity was not associated with the diagnosis of NAFLD. Although Hp positive patients seem to be more likely to have a concomitant NAFLD diagnosis, this association might rather relate to a cardiometabolic risk phenotype than causality.

No evidence for a causal link between Helicobacter pylori infection and nonalcoholic fatty liver disease: A bidirectional Mendelian randomization study

Although clinical studies have shown the possible relationship between Helicobacter pylori (H. pylori) infection and the development of nonalcoholic fatty liver disease (NAFLD), their causal relationship is still unknown. This bidirectional Mendelian randomization (MR) study aimed to investigate the causal link between H. pylori infection and NAFLD. Two previously reported genetic variants SNPs rs10004195 and rs368433 were used as the instrumental variables (IVs) of H. pylori infection. The genetic variants of NAFLD were extracted from the largest genome-wide association study (GWAS) summary data with 1,483 cases and 17,781 controls. The exposure and outcome data were obtained from the publicly available GWAS dataset. Then, a bidirectional MR was carried out to evaluate the causal relationship between H. pylori infection and NAFLD. In addition, the GWAS data were also collected to explore the causal relationship between H. pylori infection and relevant clinical traits of NAFLD, including triglycerides, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting blood glucose (FBG), and body mass index (BMI). Genetically predicted H. pylori infection showed no association with NAFLD both in FinnGen GWAS (OR, 1.048; 95% CI, 0.778-1.411; value of p = 0.759) and the GWAS conducted by Anstee (OR, 0.775; 95% CI, 0.475-1.265; value of p = 0.308). An inverse MR showed no causal effect of NAFLD on H. pylori infection (OR,0.978;95% CI, 0.909-1.052; value of p = 0.543). No significant associations were observed between H. pylori infection and the levels of triglycerides, LDL-C, HDL-C, or FBG, while H. pylori infection was associated with an increase in BMI. These results indicated that there was no genetic evidence for a causal link between H. pylori and NAFLD, suggesting that the eradication or prevention of H. pylori infection might not benefit NAFLD and vice versa.

Involvement of Helicobacter pylori in Preoperative Gastric Findings on a Bariatric Population

The prevalence of Helicobacter pylori (Hp) in bariatric patients is common and related to gastric pathology. With preoperative upper gastrointestinal endoscopy (UGE), these pathologies and the presence of Hp are diagnosed. The histopathological study of the UGE biopsies is classified based on the Sydney System, a scoring system that stages chronic gastritis (CG) and precancerous gastric lesions. The objective is to assess the histological findings of gastric biopsies during routine UGE and to determine the involvement of Hp in gastric disorders in patients undergoing bariatric surgery. A multicenter retrospective review of prospectively collected databases was performed. The presence of CG, gastric atrophy (GA), and gastric intestinal metaplasia (GIM) in the study of the biopsies was assessed and correlated with Hp infection. The incidence of Hp among our bariatric population was 36.1%, and it increases with age. The percentage of patients with severe Hp infection is higher in patients with GA or GIM. The Hp eradication rate is also reduced when GA and GIM are present. A histological examination of all the biopsies did not show features of malignancy in any of the cases. Hp is not the only factor involved in the development of gastric pathology in bariatric patients.

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.

Association between Helicobacter pylori infection and risk of nonalcoholic fatty liver disease: An updated meta-analysis

BACKGROUND

Recent studies that have examined the association between Helicobacter pylori infection and risk of nonalcoholic fatty liver disease (NAFLD) have produced conflicting data. We have performed a systematic review and meta-analysis to assess the association between H. pylori infection and risk of NAFLD.

METHODS

We searched PubMed, Web of Science and Scopus databases using predefined keywords to identify observational studies (published up to November 2018), in which NAFLD was diagnosed by histology, imaging or biochemistry. Data from selected studies were extracted and meta-analysis was performed using random-effects modeling. The statistical heterogeneity among studies (I2-index), subgroup analyses and the possibility of publication bias were assessed.

RESULTS

Thirteen observational (11 cross-sectional/case-control and 2 longitudinal) studies involving a total of 81,162 middle-aged individuals of predominantly Asian ethnicity (47.5% of whom had H. pylori infection diagnosed by urea breath test, faecal or serological tests) were included in the final analysis. Meta-analysis of data from cross-sectional and case-control studies showed that H. pylori infection was associated with increased risk of prevalent NAFLD (n = 11 studies; random-effects odds ratio [OR] 1.20, 95% CI 1.07-1.35; I2 = 59.6%); this risk remained significant in those studies where analysis was fully adjusted for age, sex, smoking, adiposity measures, diabetes or dyslipidemia (random-effects OR 1.19, 95% CI 1.07-1.32, I2 = 0%). Meta-analysis of data from longitudinal studies showed that H. pylori infection was also associated with increased NAFLD incidence (n = 2 studies; random-effects hazard ratio 1.14, 95% CI 1.05-1.23; I2 = 0%). Sensitivity analyses did not alter these findings. Funnel plot did not reveal significant publication bias.

CONCLUSIONS

H. pylori infection is associated with mildly increased risk of both prevalent and incident NAFLD in middle-aged individuals. More prospective studies, particularly in non-Asian populations, and mechanistic studies are required to better elucidate the link between chronic H. pylori infection and NAFLD.

A Helicobacter pylori-associated insulin resistance in asymptomatic sedentary young men does not correlate with inflammatory markers and urine levels of 8-iso-PGF2-α or 1,4-dihydroxynonane mercapturic acid

A potential contribution of H. pylori contamination to low-grade inflammation, oxidative stress (OS) and insulin resistance as well as correlations between these parameters in asymptomatic sedentary males was analysed. We enrolled 30 apparently healthy asymptomatic young subjects (18 H. pylori negative and 12 positive) and measured whole blood glucose, glycated haemoglobin, insulin, C-peptide, cortisol, aldosterone, testosterone, thyroid stimulating hormone, C-reactive protein, interleukins 6 and 10, TNF-alpha and comet assay. As markers of OS, we used urine levels of iso-PGF₂-α and 1,4-dihydroxynonane mercapturic acid (DHN-MA). Twofold elevation of fasting insulin level and HOMA index in H. pylori-positive subjects (p < .05) was shown. Inflammatory parameters and monocyte DNA damage, urine levels of DHN-MA and iso-PGF2-α did not show significant differences between the groups. The early stage of H. pylori-triggered metabolic derangements in sedentary subjects include development of insulin resistance in H. pylori-positive subjects; however, there is no evidence of systemic inflammatory and OS-related changes.

NAFLD, Helicobacter species and the intestinal microbiome

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. It is well-accepted that gut dysbiosis is associated with NAFLD, however, there is some conflicting evidence regarding the nature of these alterations. Infection with Helicobacter species, mainly H. pylori, has also been associated with increased NAFLD risk, however, some studies have failed to reproduce this finding. Further studies including large study samples and standardised procedures for microbiota analyses, H. pylori detection and NAFLD diagnostic criteria, are required. The mechanisms involving Helicobacter species and the intestinal microbiome in NAFLD pathogenesis appear to be part of the multiple-hit theory, in which increased intestinal permeability, inflammatory responses, altered choline, bile acids and carbohydrate metabolism, production of short-chain fatty acids, urea cycle and urea transport systems, altered maintenance of hepatic γδT-17 cells, insulin resistance, hormones secreted by the adipose tissue, metabolic hormones, bacterial metabolites and Helicobacter toxins, are all implicated.