Nonalcoholic Fatty Liver Disease-A Novel Risk Factor for Recurrent Clostridioides difficile Infection

Effects of bacterial extracellular vesicles derived from oral and gastrointestinal pathogens on systemic diseases

Oral microbiota and gastrointestinal microbiota, the two largest microbiomes in the human body, are closely correlated and frequently interact through the oral-gut axis. Recent research has focused on the roles of these microbiomes in human health and diseases. Under normal conditions, probiotics and commensal bacteria can positively impact health. However, altered physiological states may induce dysbiosis, increasing the risk of pathogen colonization. Studies suggest that oral and gastrointestinal pathogens contribute not only to localized diseases at their respective colonized sites but also to the progression of systemic diseases. However, the mechanisms by which bacteria at these local sites are involved in systemic diseases remain elusive. In response to this gap, the focus has shifted to bacterial extracellular vesicles (BEVs), which act as mediators of communication between the microbiota and the host. Numerous studies have reported the targeted delivery of bacterial pathogenic substances from the oral cavity and the gastrointestinal tract to distant organs via BEVs. These pathogenic components subsequently elicit specific cellular responses in target organs, thereby mediating the progression of systemic diseases. This review aims to elucidate the extensive microbial communication via the oral-gut axis, summarize the types and biogenesis mechanisms of BEVs, and highlight the translocation pathways of oral and gastrointestinal BEVs in vivo, as well as the impacts of pathogens-derived BEVs on systemic diseases.

Steatotic Liver Disease and Sepsis Outcomes-A Prospective Cohort Study (SepsisFAT)

Background: While it has been shown that steatotic liver disease (SLD) is associated with systemic changes in immune response, the impact of SLD on sepsis outcomes has not yet been established. The aim of this study was to investigate the association between SLD and sepsis severity and outcomes. Methods: A prospective observational study included consecutively hospitalized adult patients with community-acquired sepsis during a 16-month period. Results: Of the 378 included patients (49.5% male, median age of 69, IQR 57-78 years), 174 (46%) were diagnosed with SLD. Patients with SLD were older and more frequently fulfilled the criteria for metabolic syndrome. There were no differences in the source and etiology of sepsis between the groups. Patients with SLD exhibited a higher incidence of acute kidney injury (29.3% vs. 17.6%), the need for renal replacement therapy (16.1% vs. 8.8%), and more frequent use of invasive mechanical ventilation (29.3% vs. 18.1%). In-hospital mortality was significantly higher in the SLD group (18.39% vs. 9.8%). The multivariable analysis indicated that SLD was associated with mortality (HR 2.82, 95% CI 1.40-5.71) irrespective of the other elements within metabolic syndrome. Conclusions: SLD might be associated with higher sepsis in-hospital mortality, and more frequent development of acute kidney and respiratory insufficiency requiring more critical care support.

Association of metabolic dysfunction-associated fatty liver disease with gastrointestinal infections: insights from National Inpatient Sample Database

OBJECTIVES

The study aimed to compare the risk of gastrointestinal infections among patients with and without metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

This was a population-based, retrospective, observational study using data from the National Inpatient Sample (NIS), the largest all-payer US inpatient care database.

SETTING

Hospitalisation of adults aged ≥18 years old admitted in 2020 was identified using the NIS. Patients were stratified by the presence and absence of MAFLD.

PARTICIPANTS

26.4 million adults aged ≥18 years old were included in the study. Patients younger than 18 and those with missing demographic or mortality data were excluded.

PRIMARY AND SECONDARY OUTCOMES

Primary outcome was to assess the overall risk of gastrointestinal infections in patients with and without MAFLD. Secondary outcomes were demographics and comorbidities stratified by the presence or absence of gastrointestinal infection, and the risk of specific gastrointestinal pathogens.

RESULTS

Of 26.4 million patients admitted in 2020, 755 910 (2.85%) had the presence of MAFLD. There was a higher prevalence of bacterial gastrointestinal infections in patients with MAFLD than those without (1.6% vs 0.9%, p<0.001). The incidence of Clostridioides difficile (1.3% vs 0.8%, p<0.001), Escherichia coli (0.3% vs 0.01%, p<0.001), and Salmonella (0.07% vs 0.03%, p<0.001) was higher in patients with MAFLD. The presence of MAFLD was associated with higher odds of developing gastrointestinal infections (adjusted OR (aOR) -1.75, 95% CI -1.68 to 1.83, p<0.001). After adjusting for confounders, results remained statistically significant (aOR -1.36, 95% CI - 1.30-1.42, p<0.001).

CONCLUSION

Even after adjusting for confounding factors, our study demonstrates an increased risk of gastrointestinal infections in patients with MAFLD, specifically of C. difficile, E. coli, and Salmonella. The immune and microbiota changes seen within MAFLD potentially contribute to the increased risk of gastrointestinal infections.

COVID-19 and Clostridioides difficile Coinfection Outcomes among Hospitalized Patients in the United States: An Insight from National Inpatient Database

The incidence of Clostridioides difficile infection (CDI) has been increasing compared to pre-COVID-19 pandemic levels. The COVID-19 infection and CDI relationship can be affected by gut dysbiosis and poor antibiotic stewardship. As the COVID-19 pandemic transitions into an endemic stage, it has become increasingly important to further characterize how concurrent infection with both conditions can impact patient outcomes. We performed a retrospective cohort study utilizing the 2020 NIS Healthcare Cost Utilization Project (HCUP) database with a total of 1,659,040 patients, with 10,710 (0.6%) of those patients with concurrent CDI. We found that patients with concurrent COVID-19 and CDI had worse outcomes compared to patients without CDI including higher in-hospital mortality (23% vs. 13.4%, aOR: 1.3, 95% CI: 1.12-1.5, p = 0.01), rates of in-hospital complications such as ileus (2.7% vs. 0.8%, p < 0.001), septic shock (21.0% vs. 7.2%, aOR: 2.3, 95% CI: 2.1-2.6, p < 0.001), length of stay (15.1 days vs. 8 days, p < 0.001) and overall cost of hospitalization (USD 196,012 vs. USD 91,162, p < 0.001). Patients with concurrent COVID-19 and CDI had increased morbidity and mortality, and added significant preventable burden on the healthcare system. Optimizing hand hygiene and antibiotic stewardship during in-hospital admissions can help to reduce worse outcomes in this population, and more efforts should be directly made to reduce CDI in hospitalized patients with COVID-19 infection.

Membrane Vesicles of Toxigenic Clostridioides difficile Affect the Metabolism of Liver HepG2 Cells

Clostridioides difficile infection (CDI) appears to be associated with different liver diseases. C. difficile secretes membrane vesicles (MVs), which may be involved in the development of nonalcoholic fatty liver disease (NALFD) and drug-induced liver injury (DILI). In this study, we investigated the presence of C. difficile-derived MVs in patients with and without CDI, and analyzed their effects on pathways related to NAFLD and DILI in HepG2 cells. Fecal extracellular vesicles from CDI patients showed an increase of Clostridioides MVs. C. difficile-derived MVs that were internalized by HepG2 cells. Toxigenic C. difficile-derived MVs decreased mitochondrial membrane potential and increased intracellular ROS compared to non-toxigenic C. difficile-derived MVs. In addition, toxigenic C. difficile-derived MVs upregulated the expression of genes related to mitochondrial fission (FIS1 and DRP1), antioxidant status (GPX1), apoptosis (CASP3), glycolysis (HK2, PDK1, LDHA and PKM2) and β-oxidation (CPT1A), as well as anti- and pro-inflammatory genes (IL-6 and IL-10). However, non-toxigenic C. difficile-derived MVs did not produce changes in the expression of these genes, except for CPT1A, which was also increased. In conclusion, the metabolic and mitochondrial changes produced by MVs obtained from toxigenic C. difficile present in CDI feces are common pathophysiological features observed in the NAFLD spectrum and DILI.

Clostridioides difficile infection in patients with nonalcoholic fatty liver disease-current status

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, leading to fibrosis, cirrhosis and hepatocellular carcinoma and also associated with increased cardiovascular disease mortality. The pathogenesis of NAFLD is not fully understood, although NAFLD is thought to be a hepatic form of metabolic syndrome. There is an increasing understanding of the role of microbiota disturbances in NAFLD pathogenesis, and as with many other conditions affecting the microbiota, NAFLD may be a novel risk factor for Clostridioides difficile (C. difficile) colonization (CDC) and C. difficile infection (CDI). CDI is an emerging nosocomial disease, and community-acquired cases of infection are growing, probably due to an increase in CDC rates. The association of NAFLD with CDI has been shown in only 4 studies to date, three of which included less than 1000 patients, although the frequency of NAFLD in these studies was observed in almost 20% of the total patient cohort. These data revealed that NAFLD is a risk factor for CDI development and, moreover, is a risk factor for intestinal complications of CDI. More studies are needed to investigate this association and move forward CDC and CDI screening efforts for this group of patients.

The Impact of Nonalcoholic Fatty Liver Disease on Severe Community-Acquired Pneumonia Outcomes

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality, while nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD is associated with systemic changes in immune response, possibly linked to CAP severity. However, the impact of NAFLD on CAP outcomes has not been determined. The aim of this study was to evaluate clinical course, complications and outcomes of severe CAP requiring ICU treatment in patients with NAFLD in the pre-COVID-19 era. A retrospective cohort study included 138 consecutively hospitalized adult patients with severe CAP admitted to the ICU during a 4-year period: 80 patients with NAFLD and 58 controls. Patients with NAFLD more frequently presented with ARDS (68.7% vs. 43.1%), and required invasive mechanical ventilation (86.2% vs. 63.8%), respiratory ECMO (50% vs. 24.1%), and continuous renal replacement therapy (62.5% vs. 29.3%). Mortality was significantly higher in the NAFLD group (50% vs. 20.7%), and the time from hospital admission to death was significantly shorter. In survival analysis, NAFLD (HR 2.21, 95%CI 1.03-5.06) was associated with mortality independently of other components of metabolic syndrome. In conclusion, our study identified NAFLD as an independent predictor of mortality in patients with severe CAP.

The Role of Non-Alcoholic Fatty Liver Disease in Infections

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, affecting one third of the Western population. The hallmark of the disease is excessive storage of fat in the liver. Most commonly, it is caused by metabolic syndrome (or one of its components). Even though the development of NAFLD has multiple effects on the human organism resulting in systemic chronic low-grade inflammation, this review is focused on NAFLD as a risk factor for the onset, progression, and outcomes of infectious diseases. The correlation between NAFLD and infections is still unclear. Multiple factors (obesity, chronic inflammation, altered immune system function, insulin resistance, altered intestinal microbiota, etc.) have been proposed to play a role in the development and progression of infections in people with NAFLD, although the exact mechanism and the interplay of mentioned factors is still mostly hypothesized. In this article we review only the selection of well-researched topics on NAFLD and infectious diseases (bacterial pneumonia, COVID, H. pylori, urinary tract infections, C. difficile, bacteremia, hepatitis B, hepatitis C, HIV, and periodontitis).

Oxidative Stress Linked Organ Lipid Hydroperoxidation and Dysregulation in Mouse Model of Nonalcoholic Steatohepatitis: Revealed by Lipidomic Profiling of Liver and Kidney

Nonalcoholic steatohepatitis (NASH) is a prevalent disease related to lipid metabolism disorder and oxidative stress. Lipid hydroperoxidation is known to be a critical driving force of various disorders and diseases. However, the combination of both intact and hydroperoxidized lipids in NASH has not yet been studied. In this work, the liver and kidney samples from NASH-model mice were comprehensively investigated by using the LC/MS-based lipidomic analysis. As a result, triglycerides showed the amount accumulation and the profile alteration for the intact lipids in the NASH group, while phosphatidylethanolamines, lysophosphatidylethanolamines, plasmalogens, and cardiolipins largely depleted, suggesting biomembrane damage and mitochondria dysfunction. Notably, the lipid hydroperoxide species of triglyceride and phosphatidylcholine exhibited a significant elevation in both the liver and the kidney of the NASH group and showed considerable diagnostic ability. Furthermore, the relationship was revealed between the lipid metabolism disturbance and the lipid hydroperoxide accumulation, which played a key role in the vicious circle of NASH. The present study suggested that the omics approach to the lipid hydroperoxide profile might be the potential diagnostic marker of NASH and other oxidative stress-related diseases, as well as the evaluative treatment index of antioxidants.