Non-alcoholic fatty liver disease phenotypes in patients with inflammatory bowel disease

NAFLD Is Associated With Quiescent Rather Than Active Crohn's Disease

BACKGROUND AND AIMS

Crohn's disease (CD) confers an increased risk of nonalcoholic fatty liver disease (NAFLD), but the pathogenesis remains poorly understood. We determined if active intestinal inflammation increases the risk of NAFLD in patients with CD.

METHODS

Two cohorts (2017/2018 and 2020) with CD and no known liver disease were enrolled consecutively during staging magnetic resonance enterography. We quantified proton density fat fraction, MaRIA (Magnetic Resonance Index of Activity), and visceral adipose tissue. NAFLD was diagnosed when proton density fat fraction ≥5.5%. Synchronous endoscopy was graded by the Simple Endoscopic Score for CD and Rutgeerts score, while clinical activity was graded by the Harvey-Bradshaw index. Cytokine profiling was performed for the 2020 cohort. Transient elastography and liver biopsy were requested by standard of care.

RESULTS

NAFLD was diagnosed in 40% (n = 144 of 363), with higher prevalence during radiographically quiescent disease (odds ratio, 1.7; P = .01), independent of body mass index/visceral adipose tissue (adjusted odds ratio, 7.8; P = .03). These findings were corroborated by endoscopic disease activity, but not by aggregate clinical symptoms. Circulating interleukin-8 was independent of body mass index to predict NAFLD, but traditional proinflammatory cytokines were not. NAFLD subjects had similar liver stiffness estimates regardless of CD activity. Definitive or borderline steatohepatitis was present in most patients that underwent liver biopsy.

CONCLUSIONS

Quiescent CD is associated with risk of NAFLD. These findings suggest potentially distinct pathogenic mechanisms of NAFLD in patients with CD compared with the prevailing leaky gut hypothesis proposed for individuals without inflammatory bowel disease. Future validation and mechanistic studies are needed to dissect these distinct disease modifying factors.

Prevalence of metabolic syndrome in patients with inflammatory bowel disease: a systematic review and meta-analysis

OBJECTIVES

Patients with inflammatory bowel disease (IBD) may experience comorbidities involving metabolic syndrome (MetS). However, this association remains controversial. Our objective was to estimate the prevalence of MetS in patients with IBD and assess whether MetS is more strongly associated with ulcerative colitis (UC) or Crohn's disease (CD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Cochrane Library, Web of Science, EMBASE and MEDLINE were searched from their inception to July 2022.

ELIGIBILITY CRITERIA

Observational studies reporting data regarding the rate of comorbid MetS among patients with IBD and published in English.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Meta-analysis of Observational Studies in Epidemiology reporting guidelines were followed. Pooled prevalence, ORs and 95% CIs were calculated using random-effects models. The Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality checklist were used. Heterogeneity, sensitivity and stratified analyses were performed using R (V.4.2.1).

RESULTS

11 eligible studies involving 2501 patients were included. Of these studies, four reported MetS prevalence separately by IBD phenotype, and only one contained a non-IBD comparison group. Overall, the methodological quality of the included studies was moderate. The pooled prevalence of MetS in IBD was 19.4% (95% CI 15.1% to 23.8%), with a moderate heterogeneity (I2=51.8%, Cochrane Q statistic=12.4, p=0.053). Stratified analyses demonstrated that the aggregate estimate of comorbid MetS was significantly higher in UC than in CD (38.2% vs 13.6%, χ2=4.88, p=0.03). We found a positive association between MetS and UC compared with CD (OR=2.11, 95% CI 1.19 to 3.74, p=0.01). Additionally, four studies identified that higher age was a risk factor associated with the development of MetS.

CONCLUSIONS

MetS is not rare in IBD, especially in UC. However, longitudinal studies are needed to further clarify the relationship between IBD and MetS.

PROSPERO REGISTRATION NUMBER

CRD42022346340.

Magnesium isoglycyrrhizinate attenuates nonalcoholic fatty liver disease by strengthening intestinal mucosal barrier

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH) has recently risen to the top spot among chronic liver diseases in the world. However, there are no recognized treatments for it. Magnesium isoglycyrrhizate (MgIG) has potential as a NAFLD/NASH therapy.

AIMS

To investigate the efficacy of MgIG in improving NAFLD/NASH and the possible pathways and mechanisms.

METHODS

C57bl/6 mice were fed a high-fat diet (HFD) and 1 % dextran sulfate sodium (DSS) for 12 weeks to establish the NAFLD/NASH model. MgIG was administered by gavage during the last 7 weeks. First, the therapeutic effects of MgIG on hepatic steatosis and fibrosis, liver injury, and inflammation in the NAFLD/NASH mice were evaluated. Second, liver oxidative stress and hepatocyte apoptosis were detected. Finally, the effect of MgIG on intestinal permeability and short-chain fatty acid (SCFA) levels in mice's intestinal contents were examined.

RESULTS

MgIG administration attenuated HFD-induced hepatic steatosis and fibrosis, improved serum biochemical and NAFLD/NASH mice, reduced liver oxidative stress and hepatocyte apoptosis, improved intestinal permeability, and increased fecal SCFA levels in NAFLD/NASH mice.

CONCLUSION

MgIG protects against HFD-induced NAFLD/NASH through multiple pathways as well as mechanisms and holds promise as a potentially effective treatment for NAFLD/NASH.

Crohn´s disease is an independent risk factor for liver fibrosis in patients with inflammatory bowel disease and non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Controversial data have been reported regarding the prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD) in Inflammatory Bowel Disease (IBD) population and IBD-related risk factors. The aim of the study was to assess the prevalence and risk factors associated with NAFLD and liver fibrosis in IBD participants compared with non-IBD controls.

METHODS

Cross-sectional, case-control study including 741 IBD cases and 170 non-IBD controls, matched by sex and age. All participants underwent liver ultrasound, transient elastography and laboratory tests. A logistic regression multivariable analysis was performed adjusting for classic metabolic risk factors and history of systemic steroid use.

RESULTS

The prevalence of NAFLD and significant liver fibrosis was 45 % and 10 % in IBD group, and 40 % and 2.9 % in non-IBD group (p = 0.255 and 0.062, respectively). Longer IBD duration (aOR 1.02 95% CI (1.001-1.04)) and older age at IBD diagnosis (aOR 1.02 95 % CI (1.001-1.04)) were independent risk factors for NAFLD in IBD group. Crohn´s Disease was an independent risk factor for significant liver fibrosis in participants with IBD and NAFLD (aOR 3.97 95 % CI (1.78-8.96)). NAFLD occurred at lower BMI levels in IBD group with NAFLD compared to non-IBD group with NAFLD (aOR 0.92 95 % CI (0.87-0.98)).

CONCLUSIONS

Although we found no differences in the prevalence of NAFLD and liver fibrosis between IBD group and non-IBD group, our findings suggest that liver fibrosis progression should be closely monitored in patients with concomitant CD and NAFLD, more in particular in those with long standing active disease.

Causal effects from inflammatory bowel disease on liver function and disease: a two-sample Mendelian randomization study

Background

Accumulating evidence has shown that patients with inflammatory bowel disease (IBD) have liver function abnormalities and are susceptible to liver diseases. However, the existence of a causal relationship between IBD and liver function or disease remains unclear.

Methods

A two-sample Mendelian randomization (MR) analysis was performed using genetic associations from publicly available genome-wide association studies (GWAS). These associations encompass ulcerative colitis (UC), Crohn's disease (CD), liver function traits, and liver disease phenotypes. The liver function traits comprised hepatic biochemistries, percent liver fat, and liver iron content from the UK Biobank. Furthermore, the liver disease phenotypes included cholelithiasis, non-alcoholic fatty liver disease (NAFLD), primary sclerosing cholangitis (PSC), and primary biliary cholangitis (PBC) in cohorts of European ancestry. The primary estimation used the inverse-variance weighted method, with GWAS of C-reactive protein (CRP) in the UK Biobank serving as a positive control outcome.

Results

Genetically predicted UC is causally associated with decreased levels of albumin (ALB) and liver iron content, while genetically predicted CD is causally associated with increased levels of alkaline phosphatase (ALP). Moreover, genetically predicted UC or CD increases the risk of PSC, and CD increases the risk of PBC. Neither UC nor CD causally increases the risk of cholelithiasis and NAFLD.

Conclusion

UC affects the levels of ALB and liver iron content, while CD affects the levels of ALP. Both UC and CD increase the risk of PSC, and CD increases the risk of PBC.

Disruption of gut barrier integrity and host-microbiome interactions underlie MASLD severity in patients with type-2 diabetes mellitus

Aberration of the "gut-liver axis" contributes to the development and progression of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we use multi-omics to analyze the gut microbiota composition and metabolic profile of patients with type-2 diabetes mellitus (T2DM). T2DM patients were screened for liver disease by blood tests, ultrasound, and liver stiffness measurements. Stool microbiota was analyzed by 16S rRNA gene sequencing; metabolomic profiling by Nuclear Magnetic Resonance spectroscopy and Ultra-High Performance-Mass Spectrometry. Microbiome and metabolic signatures were analyzed in the whole cohort and in matched subsets to identify signatures specific for steatosis (MASLD±) or fibrosis (Fibrosis±). Gut permeability was assessed in-vitro using monolayers of MDCK cells and trans-epithelial electric resistance (TEER). Cytokine profile was assessed in serum and stools.Overall, 285 patients were enrolled: 255 serum, 252 urine and 97 stool samples were analyzed. Anaeroplasma and Escherichia/Shigella ASVs were higher, while Butyricicoccus ASVs were lower in those with normal liver. In MASLD±, Butyricicoccus ASV was significantly higher in those with steatosis. In the Fibrosis±, Butyricicoccus ASV was significantly lower in those with fibrosis. Glycochenodeoxycholic acid-3-sulfate (G-UDCA-3S) appeared to be higher in MASLD with fibrosis. Fecal water from patients with MASLD and fibrosis caused the greatest drop in the TEER vs those with normal liver; this was reversed with protease inhibitors. Finally, fecal IL-13 was lower in MASLD with fibrosis. We identified microbiome signatures which were specific for steatosis and fibrosis and independent of other metabolic risk factors. Moreover, we conclude that protease-related gut permeability plays a role in those MASLD patients with fibrosis, and that disease progression is linked to a gut-liver axis which is at least partially independent of T2DM.

Ultrasound Prevalence and Clinical Features of Nonalcoholic Fatty Liver Disease in Patients with Inflammatory Bowel Diseases: A Real-Life Cross-Sectional Study

Background and Objectives: Inflammatory bowel disease (IBD) is a condition characterized by chronic intestinal inflammation. We can identify two major forms: Crohn's disease (CD) and ulcerative colitis (UC). One of the extraintestinal manifestations of IBD is nonalcoholic fatty liver disease (NAFLD). IBD and NAFLD share common pathogenetic mechanisms. Ultrasound (US) examination is the most commonly used imaging method for the diagnosis of NAFLD. This cross-sectional observational retrospective study aimed to evaluate the US prevalence of NAFLD in IBD patients and their clinical features. Materials and Methods: A total of 143 patients with IBD underwent hepatic US and were divided into two different groups according to the presence or absence of NAFLD. Subsequently, new exclusion criteria for dysmetabolic comorbidities (defined as plus) were applied. Results: The US prevalence of NAFLD was 23% (21% in CD and 24% in UC, respectively). Most IBD-NAFLD patients were male and older and showed significantly higher values for body mass index, waist circumference, disease duration, and age at onset than those without NAFLD. IBD-NAFLD patients showed a significantly higher percentage of stenosing phenotype and left-side colitis. Regarding metabolic features, IBD-NAFLD patients showed a significantly higher percentage of hypertension and IBD plus dysmetabolic criteria. Also, higher values of alanine aminotransferase and triglycerides and lower levels of high-density lipoproteins are reported in these patients. Conclusions: We suggest performing liver US screening in subjects affected by IBD to detect NAFLD earlier. Also, patients with NAFLD present several metabolic comorbidities that would fall within the new definition of metabolic-associated fatty liver disease. Finally, we encourage larger longitudinal studies, including healthy controls, to provide further confirmation of our preliminary data.

Crohn's Disease is a Greater Risk Factor for Nonalcoholic Fatty Liver Disease Compared to Ulcerative Colitis: A Systematic Review

Crohn's disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases that have been associated with nonalcoholic fatty liver disease (NAFLD). This systematic review aimed to examine whether Crohn's disease confers a greater risk for nonalcoholic fatty liver disease compared to ulcerative colitis. A comprehensive search of electronic databases from January 2000 to May 2023 was conducted to identify observational studies investigating the association between Crohn's disease or ulcerative colitis and nonalcoholic fatty liver disease. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 checklist ensured transparent reporting, and the Newcastle-Ottawa Scale was used to assess study quality. Data synthesis revealed higher nonalcoholic fatty liver disease prevalence among Crohn's disease patients compared to ulcerative colitis patients across regions. Ten studies published between 2016 and 2022, encompassing a total of 4164 participants from three continents, were included in the review. The median proportion of Crohn's disease patients with nonalcoholic fatty liver disease was 37.22% (range: 10.95-53.80%), while it was 27.55% (range: 8.60-46.20%) for ulcerative colitis patients. Subgroup analysis by region confirmed CD's higher NAFLD risk. Median proportions for CD patients who developed NAFLD from North America, Europe, and Asia were 25.97% (range: 14.6-37.33%), 47.01% (range: 14.2-53.8%), and 20.78% (range: 10.95-30.6%), respectively, and the median proportion of persons with UC who developed NAFLD in studies from North America, Europe, and Asia were 17.28% (range: 8.6-25.96%), 37.70% (range: 25.64-46.20%), and 19.52% (range: 10.14-28.90%), respectively. Variations suggest differing mechanisms, disease features, and therapeutics. Transmural inflammation in Crohn's disease may increase metabolic abnormalities, including nonalcoholic fatty liver disease. Geographic differences in lifestyle, genetics, and environmental variables may also contribute. This review demonstrates that Crohn's disease patients face a higher nonalcoholic fatty liver disease risk than ulcerative colitis patients, emphasizing the need for early monitoring and prevention. Further studies are warranted to understand mechanisms and develop tailored management approaches.

Liver Fibrosis in Non-Alcoholic Fatty Liver Disease and Progression to Hepatocellular Carcinoma in Patients with Inflammatory Bowel Disease: A Systematic Review

The aim of the systematic review is to assess the prevalence and risk factors of liver fibrosis in patients with Inflammatory Bowel Disease (IBD) and Non-Alcoholic Fatty Liver Disease (NAFLD) and to discuss the role of liver fibrosis in the progression to hepatocellular carcinoma (HCC). We performed a structured search in PubMed, Web of Science, Embase, and Scopus up to 3 March 2023 to identify observational studies reporting liver fibrosis in patients with NAFLD and IBD. Quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) score. A total of 23 studies met our inclusion criteria, including 629,781 patients. A total of 10 cross-sectional, 3 case-control, and 10 cohort studies were included. Fourteen studies had a NOS score ≥ 7 points. NAFLD was diagnosed in 2162/6332 (34.1%) IBD participants. However, NAFLD diagnosis was established in 924/2962 (31.2%) healthy individuals without IBD. Advanced liver fibrosis was found in 116 (11.6%) of 992 IBD patients with NAFLD. Most studies found an association between NAFLD and classic cardiovascular risk factors such as older age, male sex, higher BMI, diabetes, hypertension and dyslipidemia. In addition, metabolic syndrome features were also associated with an increased risk of significant and advanced liver fibrosis. Although no strong association between NAFLD and IBD therapy was reported, some studies associated NAFLD with IBD diagnosis, Crohn's Disease, a complicated course of IBD, disease activity, and IBD duration. Advanced liver fibrosis was also associated with Crohn's disease in several studies. In conclusion, NAFLD and advanced liver fibrosis are prevalent and clinically relevant extraintestinal manifestations, so its diagnosis and potential progression to HCC should be carefully considered in daily clinical practice.

FGF21 Depletion Attenuates Colitis through Intestinal Epithelial IL-22-STAT3 Activation in Mice

Fibroblast growth factor 21 (FGF21) is a glucose and lipid metabolic regulator. Recent research revealed that FGF21 was also induced by inflammatory stimuli. Its role in inflammatory bowel disease (IBD) has not been investigated. In this study, an experimental IBD model was established in FGF21 knockout (KO) and wild-type (WT) mice by adding 2.5% (wt/vol) dextran sodium sulfate (DSS) to their drinking water for 7 days. The severity of the colitis and the inflammation of the mouse colon tissues were analyzed. In WT mice, acute DSS treatment induced an elevation in plasma FGF21 and a significant loss of body weight in a time-dependent manner. Surprisingly, the loss of body weight and the severity of the colitis induced by DSS treatment in WT mice were significantly attenuated in FGF21 KO mice. Colon and circulating pro-inflammatory factors were significantly lower in the FGF21 KO mice compared to the WT mice. As shown by BrdU staining, the FGF21 KO mice demonstrated increased colonic epithelial cell proliferation. DSS treatment reduced intestinal Paneth cell and goblet cell numbers in the WT mice, and this effect was attenuated in the FGF21 KO mice. Mechanistically, FGF21 deficiency significantly increased the signal transducer and activator of transcription (STAT)-3 activation in intestinal epithelial cells and increased the expression of IL-22. Further study showed that the expression of suppressor of cytokine signaling-2/3 (SOCS 2/3), a known feedback inhibitor of STAT3, was significantly inhibited in the DSS-treated FGF2 KO mice compared to the WT mice. We conclude that FGF21 deficiency attenuated the severity of DSS-induced acute colitis, which is likely mediated by enhancing the activation of the IL-22-STAT3 signaling pathway in intestinal epithelial cells.

Disturbance of lipid metabolism in germ-free mice transplanted with gut microbiota of DSS-induced colitis mice

Hepatobiliary abnormality and metabolic disorders are frequently observed complications in patients with inflammatory bowel diseases (IBD). Given that microbiota dysbiosis is a common pathophysiological feature of both IBD and metabolic diseases, we examined how the IBD-induced dysbiosis affects the host metabolism and contributes to the development of associated metabolic diseases using germ-free (GF) mice transplanted with fecal microbiota of DSS-induced colitis mice. There was no significant change in inflammation or barrier integrity in the gut of GF mice that received microbiota from colitis mice compared to their counterparts that were transplanted with microbiota from non-colitis healthy mice. Interestingly, it was observed that the GF recipients of colitis-induced altered microbiota showed a significant decrease in the weight of adipose tissues including mesenteric, epididymal, subcutaneous, and brown fat without any change in body weight, which was accompanied by abnormalities in adipose tissue functions such as fat storage and adiponectin production. Transplantation of colitis-induced altered microbiota also disrupted hepatic lipid metabolism in the GF recipient mice, which was observed by increases in synthesis and accumulation of cholesterol and bile acids in hepatocytes and a decrease in plasma HDL-cholesterol. Additional observations including elevated plasma levels of insulin, decreased hepatic production of FGF21, and decreased levels of fecal short chain fatty acids (SCFAs) and hepatic expression of SCFA receptors led to a conclusion that the transplantation of the colitis-associated dysbiotic microbiota was causally associated with impairments of insulin action and FGF21-adiponectin axis, possibly due to the low SCFA-producing capacity of the colonized microbiota, leading to metabolic abnormalities including adipose tissue dysfunction and dysregulated hepatic lipid metabolism. Our findings suggest potential mechanisms that explain how colitis-associated gut dysbiosis may contribute to the development of metabolic dysfunctions, which could be applied to clinical practice to improve the efficacy of treatment of IBD patients with comorbid metabolic disorders or vice versa.

Tetrastigma hemsleyanum leaf extracts ameliorate NAFLD in mice with low-grade colitis via the gut-liver axis

Nonalcoholic fatty liver disease (NAFLD) is a complex metabolic disorder, manifested as oxidative stress, lipid accumulation, and inflammation of the liver. Tetrastigma hemsleyanum leaves (THL), which are rich in flavonoids and phenolic acids, have good anti-inflammatory, antioxidant, and hepatoprotective effects. However, it is unknown whether THL extracts can improve NAFLD and the underlying mechanisms are unknown. Hence, this study was designed to investigate the effects of THL extracts on NAFLD and perform a preliminary inquiry into the underlying mechanism based on the gut-liver axis. The results showed that THL extracts could reverse NAFLD-related oxidative stress, lipid accumulation, and inflammation. Additionally, the protective effect of THL extracts on the gut includes the maintenance of the intestinal barrier and the regulation of gut microbiota, which may be one of the mechanisms by which THL improves NAFLD. To be specific, in our study, THL extracts alleviated hepatic lipid accumulation and oxidative stress by regulating the expression of lipid synthesis/catabolism and the oxidative stress genes (SREBP-1c/ACC-1/PPAR-α/PPAR-γ/Keap1/Nrf2). In addition, THL extracts reduced damage to the intestinal barrier (ZO-1/Mucin2/occludin) and increased the relative abundance of Lactobacillales, Ruminococcaceae, and Bifidobacteriales in NAFLD mice. In short, THL extracts alleviated NAFLD-related oxidative stress, lipid accumulation, and inflammation in NAFLD mice which may be via the gut-liver axis (gut barrier integrity and gut microbiota).

Screening for Liver Steatosis and Fibrosis in Patients with Inflammatory Bowel Disease Using Vibration Controlled Transient Elastography with Controlled Attenuation Parameter

BACKGROUND AND AIMS

Inflammatory bowel diseases (IBD) are frequently associated with extraintestinal manifestations, hepatic injury being of concern in these patients. Current literature reports an increased prevalence of liver steatosis and fibrosis in subjects with IBD and the pathophysiology is yet to be completely understood. The aim of this study was to assess the prevalence of non-alcoholic fatty liver disease (NAFLD) in patients with IBD, as well as to determine the factors that connect these two disorders.

METHODS

From September 2021 to June 2022, 82 consecutive IBD patients were enrolled from a tertiary care center hospital in Iasi. Vibration-Controlled Transient Elastography with Controlled Attenuation Parameter (CAP) was used to assess the presence of NAFLD, with a cut-off score for CAP of 248 dB/m. Significant liver fibrosis was considered at a cut-off for liver stiffness measurements (LSM) of 7.2 kPa.

RESULTS

In total, 82 IBD patients (54.8% men, mean age of 49 ± 13 years) were included, 38 (46.3%) of them being diagnosed with NAFLD, with a mean CAP score of 286 ± 35.4 vs. 203 ± 29.7 in patients with IBD only. Age (β = 0.357, p = 0.021), body mass index (BMI) (β = 0.185, p = 0.048), disease duration (β = 0.297, p = 0.041), C-reactive protein (β = 0.321, p = 0.013), fasting plasma glucose (β = 0.269, p = 0.038), and triglycerides (β = 0.273, p = 0.023) were strongly associated with the presence of liver steatosis. The multivariate analysis showed that older age, BMI, and disease duration were strongly associated with significant liver fibrosis in our group.

CONCLUSIONS

NAFLD is a multifaced pathology with growing prevalence among IBD patients. Additional studies are needed to completely understand this problem and to create a solid evidence-based framework for more effective preventative and intervention strategies.

Gingerenone A Alleviates Ferroptosis in Secondary Liver Injury in Colitis Mice via Activating Nrf2-Gpx4 Signaling Pathway

Patients with ulcerative colitis (UC) have been found to be frequently associated with secondary liver injury (SLI). In this study, we investigated the protective effect of GA on dextran sodium sulfate (DSS)-induced SLI in mice and its mechanism. The SLI was established by adding 4% DSS in the drinking water of mice, and the effects of GA (5, 20 mg/kg, p.o., once a day for 7 days) in hepatic tissues were analyzed. HepG2 cells were induced by lipopolysaccharide (LPS) to detect the effect of GA on ferroptosis and the underlying mechanism. Pathological damage was determined by H&E. Liver parameters (AST and ALT), antioxidant enzyme activities (MDA and SOD), and the level of Fe²⁺ in the liver were detected by kits. Cytokine levels (TNF-α, IL-1β, and IL-6) and Gpx4 activity in the liver were detected by ELISA. Finally, the activation of nuclear factor erythroid 2-like 2 (Nrf2) was detected to explore the mechanism. The results indicated that GA significantly attenuated DSS-induced hepatic pathological damage, liver parameters, and cytokine levels and increased the antioxidant enzyme activities. Moreover, GA attenuated ferroptosis in DSS-induced liver injury and upregulated Gpx4 expression in DSS-induced mice. Mechanistic experiments revealed that GA activated Nrf2 in mice. Taken together, this study demonstrates that GA can alleviate ferroptosis in SLI in DSS-induced colitis mice, and its protective effects are associated with activating the Nrf2-Gpx4 signaling pathway.

Enhancement of liver mitochondrial complex I and energy metabolism induced by enteritis: The key role of gut microbiota derived endotoxins

Inflammation is an energy-intensive process and the liver is a key organ in energy regulation. Since the intestine and liver exchange nutrients and metabolites, enteritis can affect the liver. To investigate the correlation between enteritis and liver metabolism, we developed an intestinal inflammation model with concentration-dependent 2,4,6-trinitrobenzene sulfonic acid (TNBS) in gibel carp (Carassius gibelio). The results showed the dysregulation of intestinal tight junction, increased permeability of the gut barrier, and apoptosis of epithelial cells during the development of enteritis. The liver metabolome was analyzed by LC-MS and the live respiration was determined using Oxygraph-2k. The results showed that glycolysis, the TCA cycle and pyrimidine metabolism were affected by intestinal inflammation. In particular, the activity of hepatic mitochondrial respiratory chain complex I was significantly increased. Structure and abundance changes of gut microbiota were analyzed by 16S rRNA sequencing analysis. Pathogenic bacteria in the intestine, as well as plasma LPS, increased significantly. Using a liver cell line, we verified that the dysfunctional metabolism of the liver is related to the dislocation of LPS. All results imply the existence of a connection between enteritis and liver metabolism in gibel carp, and the gut microbiome plays a critical role in this process.

Andrographolide sodium bisulfite ameliorates dextran sulfate sodium-induced colitis and liver injury in mice via inhibiting macrophage proinflammatory polarization from the gut-liver axis

Ulcerative colitis (UC), an inflammatory disease, is widely thought to be associated with colonic barrier damage and inflammatory response. With the destruction of the colonic barrier, lipopolysaccharide (LPS) enters the liver through the portal vein and causes liver injury. Liver injury in turn exacerbates UC to form a vicious cycle, so the treatment of liver injury cannot be ignored. Andrographolide (Andro) has a protective effect against colitis and liver injury, but with low bioavailability. Andrographolide sodium bisulfite (ASB), a water-soluble sulfonate of Andro, has better bioavailability, whether it has a better curative effect against UC and liver injury is rarely reported. Hence, we investigated the protective effect and potential mechanism of ASB against dextran sulfate sodium (DSS)-induced UC and liver injury in mice. The results showed that treatment with ASB significantly relieved the clinical symptoms of UC and liver injury by reducing disease activity index, inhibiting gut-derived LPS leakage, and improving colonic and hepatic injury, and its curative effect was better than Andro. Moreover, ASB effectively decreased the YAP-mediated colonic inflammation and TLR4/MyD88/NF-κB-mediated pro-inflammatory factor release in the liver. Both colonic and hepatic inflammation were associated with macrophage proinflammatory polarization, but they were significantly inhibited by ASB. ASB showed good safety in the treatment of UC and liver injury and has no nephrotoxicity as previously described. In conclusion, ASB has an effective protective effect on DSS-induced UC and liver injury, mainly by suppressing macrophage proinflammatory polarization from the gut-liver axis.

Inflammatory Bowel Disease-associated Fatty Liver Disease: the Potential Effect of Biologic Agents

Inflammatory bowel diseases [IBD] exhibit intestinal and systemic manifestations. Nonalcoholic fatty liver disease [NAFLD] is a common co-existing condition, possibly contributing to the cardio-metabolic burden and overall morbidity. Εmerging therapeutic choices of biologic agents have modified the clinical course of IBD; however, their impact on IBD-associated NAFLD has not been extensively evaluated. The prevalence of NAFLD varies among IBD patients, but it appears higher than in the general population in the majority of quality studies. In terms of pathogenetic and risk factors of NAFLD, they may vary with IBD activity. Dysbiosis, mucosal damage, and cytokine release have been implicated in the pathogenesis during the relapses, whereas metabolic risk factors seem to play a dominant role during the remissions of IBD. Considering biologics, although quality data are scarce, agents suppressing tumour necrosis factor may offer potential benefits in IBD-associated NAFLD, whereas anti-integrins do not appear to confer any therapeutic advantage. In conclusion, IBD-associated NAFLD possibly follows two different patterns, one manifested during the relapses and one during the remissions of IBD. Some, but not all, biologics may benefit NAFLD in patients with IBD. Further mechanistic and prospective cohort studies are warranted to illuminate the effects of various biologics on NAFLD.

The Impact of NAFLD on Hospitalization Outcomes in Patients With Inflammatory Bowel Diseases: Nationwide Analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with inflammatory bowel diseases (IBD). Yet, the impact of NAFLD on outcomes, along with the contribution of nonmetabolic factors to NAFLD development, is unclear. To investigate these topics, we conducted a nationwide study examining the impact of NAFLD on hospitalization outcomes in IBD patients after adjusting for metabolic factors.

METHODS

Patients with IBD-related hospitalizations were identified using the Nationwide Readmissions Database from 2016 to 2018. Inflammatory bowel disease patients with and without NAFLD were matched based on IBD type, age, sex, metabolic syndrome, and diabetes mellitus. Primary outcomes were IBD-related readmission, IBD-related surgery, and death. Secondary outcomes were length of stay (LOS) and cost of care (COC). The primary multivariable model adjusted for obesity, dyslipidemia, Charlson-Deyo comorbidity index, hospital characteristics, payer, patient income, and elective status of admissions.

RESULTS

Nonalcoholic fatty liver disease was associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.90; P < .01) and death (adjusted hazard ratio, 2.73; P < .01), 0.71-day longer LOS (P < .01), and $7312 higher COC (P < .01) in those with Crohn's disease. Nonalcoholic fatty liver disease was also associated with a higher risk of IBD-related readmission (adjusted hazard ratio, 1.65; P < .01), 0.64-day longer LOS (P < .01), and $9392 (P < .01) higher COC, but there was no difference in death in those with UC. No differences in risk of IBD-related surgery were observed.

CONCLUSIONS

Nonalcoholic fatty liver disease is associated with worse hospitalization outcomes in IBD patients after adjusting for metabolic factors. These data suggest nonmetabolic factors may be implicated in the pathogenesis of NAFLD in IBD patients and may contribute to worsened clinical outcomes.

Amelioratory Effect of Resistant Starch on Non-alcoholic Fatty Liver Disease via the Gut-Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome with a global prevalence. Impaired gut barrier function caused by an unhealthy diet plays a key role in disrupting the immune-metabolic homeostasis of the gut-liver axis (GLA), leading to NAFLD. Therefore, dietary interventions have been studied as feasible alternative therapeutic approaches to ameliorate NAFLD. Resistant starches (RSs) are prebiotics that reduce systemic inflammation in patients with metabolic syndrome. The present review aimed to elucidate the mechanisms of the GLA in alleviating NAFLD and provide insights into how dietary RSs counteract diet-induced inflammation in the GLA. Emerging evidence suggests that RS intake alters gut microbiota structure, enhances mucosal immune tolerance, and promotes the production of microbial metabolites such as short-chain fatty acids (SCFAs) and secondary bile acids. These metabolites directly stimulate the growth of intestinal epithelial cells and elicit GPR41/GPR43, FXR, and TGR5 signaling cascades to sustain immune-metabolic homeostasis in the GLA. The literature also revealed the dietary-immune-metabolic interplay by which RSs exert their regulatory effect on the immune-metabolic crosstalk of the GLA and the related molecular basis, suggesting that dietary intervention with RSs may be a promising alternative therapeutic strategy against diet-induced dysfunction of the GLA and, ultimately, the risk of developing NAFLD.

Z-DNA binding protein 1 mediates necroptotic and apoptotic cell death pathways in murine astrocytes following herpes simplex virus-1 infection

Background

The mechanisms by which glia respond to viral central nervous system (CNS) pathogens are now becoming apparent with the demonstration that microglia and astrocytes express an array of pattern recognition receptors that include intracellular RNA and DNA sensors. We have previously demonstrated that glia express Z-DNA binding protein 1 (ZBP1) and showed that this cytosolic nucleic acid sensor contributes to the inflammatory/neurotoxic responses of these cells to herpes simplex virus-1 (HSV-1). However, the relative contribution made by ZBP1- to HSV-1-mediated cell death in glia has not been determined.

Methods

We have investigated the relative contribution made by ZBP1- to HSV-1-mediated cell death in primary astrocytes derived from mice genetically deficient in this sensor. We have used capture ELISAs and immunoblot analysis to assess inflammatory cytokine production and ZBP1 and phosphorylated mixed lineage kinase domain-like protein (MLKL) expression levels, respectively, following HSV-1 challenge. Furthermore, we have used a commercially available cell viability assay to determine the proportion and rate of cell death in cells following infection with laboratory and neuroinvasive clinical strains of HSV-1, and pharmacological inhibitors of necroptotic and apoptotic pathway components to assess the relative role of each.

Results

We show that the loss of ZBP1 in astrocytes results in an increase in the number of viral particles released following HSV-1 infection. Importantly, we have confirmed that HSV-1 induces necroptosis in astrocytes and have established the ability of ZBP1 to mediate this cell death pathway. Interestingly, while ZBP1 is best known for its role in necroptotic signaling, our findings indicate that this sensor can also contribute to virally induced apoptosis in these glia.

Conclusions

Our findings indicate that ZBP1 serves as a restriction factor for HSV-1 infection and is associated with the induction of both necroptotic and apoptotic cell death pathways in primary murine astrocytes. While it remains to be seen whether ZBP1-mediated activation of cell death in astrocytes contributes significantly to host protection or, rather, exacerbates HSV-1 encephalitis pathology, the identification of such a role in resident CNS cells may represent a novel target for therapeutic intervention to reduce HSV encephalitis-associated morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02469-z.

Glucocorticosteroids and the Risk of NAFLD in Inflammatory Bowel Disease

Each year, the incidence of nonalcoholic fatty liver (NAFLD) disease increases. NAFLD is a chronic disease. One of the most common causes of NAFLD is an inadequate lifestyle, which is characterized by a lack or low physical activity and eating highly processed foods rich in saturated fat and salt and containing low amount of fiber. Moreover, disturbances in intestinal microbiome and the use of certain drugs may predispose to NAFLD. NAFLD is an increasingly described disease in patients with inflammatory bowel disease (IBD). Recent data also indicate a frequent coexistence of metabolic syndrome in this group of patients. Certain groups of drugs also increase the risk of developing inflammation, liver fibrosis, and cirrhosis. Particularly important in the development of NAFLD are steroids, which are used in the treatment of many diseases, for example, IBD. NAFLD is one of the most frequent parenteral manifestations of the disease in IBD patients. However, there is still insufficient information on what dose and exposure time of selected types of steroids may lead to the development of NAFLD. It is necessary to conduct further research in this direction. Therefore, patients with IBD should be constantly monitored for risk factors for the development of NAFLD.

Hepatoprotective mechanism of Silybum marianum on nonalcoholic fatty liver disease based on network pharmacology and experimental verification

The study aimed to identify the key active components in Silybum marianum (S. marianum) and determine how they protect against nonalcoholic fatty liver disease (NAFLD). TCMSP, DisGeNET, UniProt databases, and Venny 2.1 software were used to identify 11 primary active components, 92 candidate gene targets, and 30 core hepatoprotective gene targets in this investigation, respectively. The PPI network was built using a string database and Cytoscape 3.7.2. The KEGG pathway and GO biological process enrichment, biological annotation, as well as the identified hepatoprotective core gene targets were analyzed using the Metascape database. The effect of silymarin on NAFLD was determined using H&E on pathological alterations in liver tissues. The levels of liver function were assessed using biochemical tests. Western blot experiments were used to observe the proteins that were expressed in the associated signaling pathways on the hepatoprotective effect, which the previous network pharmacology predicted. According to the KEGG enrichment study, there are 35 hepatoprotective signaling pathways. GO enrichment analysis revealed that 61 biological processes related to the hepatoprotective effect of S. marianum were identified, which mainly involved in response to regulation of biological process and immune system process. Silymarin was the major ingredient derived from S. marianum, which exhibited the hepatoprotective effect by reducing the levels of ALT, AST, TC, TG, HDL-C, LDL-C, decreasing protein expressions of IL-6, MAPK1, Caspase 3, p53, VEGFA, increasing protein expression of AKT1. The present study provided new sights and a possible explanation for the molecular mechanisms of S. marianum against NAFLD.

Hepatobiliary manifestations in inflammatory bowel disease: A practical approach

Inflammatory bowel diseases (IBD) are associated with various hepatobiliary disorders. They can occur at any moment in the course of the disease or associated with the treatment. The prevalence of liver dysfunction can reach up to 50% in different studies. Nonalcoholic fatty liver disease is considered the most common hepatobiliary complication in IBD, while primary sclerosing cholangitis is the most specific. Management of hepatic manifestations in IBD involves a multidisciplinary approach that includes a high index of suspicion and joint management with hepatologists. The medical confrontation with abnormal liver tests must include an exhaustive study to determine if these patterns can be related to IBD, associated diseases or to the therapies used.

Liver-side of inflammatory bowel diseases: Hepatobiliary and drug-induced disorders

Hepatobiliary disorders are among the most common extraintestinal manifestations in inflammatory bowel diseases (IBD), both in Crohn’s disease and ulcerative colitis (UC), and therefore represent a diagnostic challenge. Immune-mediated conditions include primary sclerosing cholangitis (PSC) as the main form, variant forms of PSC (namely small-duct PSC, PSC-autoimmune hepatitis overlap syndrome and IgG4-related sclerosing cholangitis) and granulomatous hepatitis. PSC is by far the most common, presenting in up to 8% of IBD patients, more frequently in UC. Several genetic foci have been identified, but environmental factors are preponderant on disease pathogenesis. The course of the two diseases is typically independent. PSC diagnosis is based mostly on typical radiological findings and exclusion of secondary cholangiopathies. Risk of cholangiocarcinoma is significantly increased in PSC, as well as the risk of colorectal cancer in patients with PSC and IBD-related colitis. No disease-modifying drugs are approved to date. Thus, PSC management is directed against symptoms and complications and includes medical therapies for pruritus, endoscopic treatment of biliary stenosis and liver transplant for end-stage liver disease. Other non-immune-mediated hepatobiliary disorders are gallstone disease, whose incidence is higher in IBD and reported in up to one third of IBD patients, non-alcoholic fatty liver disease, pyogenic liver abscess and portal vein thrombosis. Drug-induced liver injury (DILI) is an important issue in IBD, since most IBD therapies may cause liver toxicity; however, the incidence of serious adverse events is low. Thiopurines and methotrexate are the most associated with DILI, while the risk related to anti-tumor necrosis factor-α and anti-integrins is low. Data on hepatotoxicity of newer drugs approved for IBD, like anti-interleukin 12/23 and tofacitinib, are still scarce, but the evidence from other rheumatic diseases is reassuring. Hepatitis B reactivation during immunosuppressive therapy is a major concern in IBD, and adequate screening and vaccination is warranted. On the other hand, hepatitis C reactivation does not seem to be a real risk, and hepatitis C antiviral treatment does not influence IBD natural history. The approach to an IBD patient with abnormal liver function tests is complex due to the wide range of differential diagnosis, but it is of paramount importance to make a quick and accurate diagnosis, as it may influence the therapeutic management.

Djulis Hull Improves Insulin Resistance and Modulates the Gut Microbiota in High-Fat Diet (HFD)-Induced Hyperglycaemia

In this study, we annotated the major flavonoid glycoside, rutin, of djulis hull crude extract using a Global Natural Products Social Molecular Networking (GNPS) library and its MS/MS spectra. To evaluate the protective effect of djulis hull crude extract and rutin on glucose tolerance, we fed mice a high-fat diet (HFD) for 16 weeks to induce hyperglycaemia. These results showed that crude extract significantly decreased HFD-induced elevation in the area under the curve (AUC) of weekly random blood glucose and oral glucose tolerance tests (OGTT), homeostasis model assessment (HOMA-IR), and advanced glycation end product (AGE) levels, and significantly increased pIRS1 and Glut4 protein expression in epididymal white adipose tissue (eWAT) and liver. Furthermore, the HFD-induced reduction in the activity of glutathione peroxidase (GPx) and catalase (CAT) was reversed by crude extract. In addition, ZO-1 and occludin protein expression in the colon was markedly downregulated in HFD-fed mice, resulting in decreased intestinal permeability and lipopolysaccharide (LPS) translocation, but were restored following crude extract. Moreover, the crude extract intervention had a profound effect on the alpha diversity and microbial community in the gut microbiota. Therefore, djulis hull crude extract could improve blood glucose and increase insulin receptor sensitivity in HFD-induced hyperglycaemia, which is likely due to its modulation of the gut microbiota, preservation of the integrity of the intestinal barrier to reduce body inflammation, increased antioxidant activity, and modulation of insulin signalling.

Analysis of Common Pathways and Markers From Non-Alcoholic Fatty Liver Disease to Immune-Mediated Diseases

Metabolic associated fatty liver disease (MAFLD) is the most prevalent form of liver disease worldwide, accounting for a high liver-related mortality and morbidity with extensive multi-organ involvement. This entity has displaced viral hepatitis as the main cause of severe forms of hepatic diseases, although the onset and transition of MAFLD stages still remains unclear. Nevertheless, innate and adaptive immune responses seem to play an essential role in the establishment and further progression of this disease. The immune system is responsible of safeguard and preserves organs and systems function, and might be altered under different stimuli. Thus, the liver suffers from metabolic and immune changes leading to different injuries and loss of function. It has been stablished that cell-cell crosstalk is a key process in the hepatic homeostasis maintenance. There is mounting evidence suggesting that MAFLD pathogenesis is determined by a complex interaction of environmental, genetic and host factors that leads to a full plethora of outcomes. Therefore, herein we will revisit and discuss the interplay between immune mechanisms and MAFLD, highlighting the potential role of immunological markers in an attempt to clarify its relationship.

Dextran Sulfate Sodium Salt-Induced Colitis Aggravates Gut Microbiota Dysbiosis and Liver Injury in Mice With Non-alcoholic Steatohepatitis

Objective: Inflammatory bowel disease (IBD) is characterized by gut microbiota dysbiosis, which is also frequently observed in patients with non-alcoholic fatty liver disease. Whether gut microbiota dysbiosis in IBD patients promotes the development of non-alcoholic steatohepatitis (NASH) remains unclear. We aimed to explore the role of gut microbiota dysbiosis in the development of NASH in mice with dextran sulfate sodium salt (DSS) induced colitis. Design: Dextran sulfate sodium salt was used to induce colitis, and high fat (HF), in combination with a high-fructose diet, was used to induce NASH in C57BL/6J male mice. Mice were treated with (1%) DSS to induce colitis in cycles, and each cycle consisted of 7 days of DSS administration followed by a 10-day interval. The cycles were repeated throughout the experimental period of 19 weeks. Pathological alterations in colitis and NASH were validated by hematoxylin and eosin (H&E), oil red O, Sirius red staining, and immunofluorescence. Gut microbiota was examined by 16S rRNA sequencing, and gene expression profiles of hepatic non-parenchymal cells (NPCs) were detected by RNA sequencing. Results: Dextran sulfate sodium salt administration enhanced the disruption of the gut-vascular barrier and aggravated hepatic inflammation and fibrosis in mice with NASH. DSS-induced colitis was accompanied by gut microbiota dysbiosis, characterized by alteration in the core microbiota composition. Compared with the HF group, the abundance of p_Proteobacteria and g_Bacteroides increased, while that of f_S24-7 decreased in the DSS + HF mice. Specifically, gut microbiota dysbiosis was characterized by enrichment of lipopolysaccharide producing bacteria and decreased abundance of short-chain fatty acid-producing bacteria. Gene expression analysis of liver NPCs indicated that compared with the HF group, genes related to both inflammatory response and angiocrine signaling were altered in the DSS + HF group. The expression levels of inflammation-related and vascular development genes correlated significantly with the abundance of p_Proteobacteria, g_Bacteroides, or f_S24-7 in the gut microbiota, implying that gut microbiota dysbiosis induced by DSS might aggravate hepatic inflammation and fibrosis by altering the gene expression in NPCs. Conclusion: Dextran sulfate sodium salt-induced colitis may promote the progression of liver inflammation and fibrosis by inducing microbiota dysbiosis, which triggers an inflammatory response and disrupts angiocrine signaling in liver NPCs. The abundance of gut microbiota was associated with expression levels of inflammation-related genes in liver NPCs and may serve as a potential marker for the progression of NASH.

Non-alcoholic fatty liver disease in patients with intestinal, pulmonary or skin diseases: Inflammatory cross-talk that needs a multidisciplinary approach

Non-alcoholic fatty liver disease (NAFLD) is currently considered the most common cause of liver disease. Its prevalence is increasing in parallel with the obesity and type 2 diabetes mellitus (DM2) epidemics in developed countries. Several recent studies have suggested that NAFLD may be the hepatic manifestation of a systemic inflammatory metabolic disease that also affects other organs, such as intestine, lungs, skin and vascular endothelium. It appears that local and systemic proinflammatory/anti-inflammatory cytokine imbalance, together with insulin resistance and changes in the intestinal microbiota, are pathogenic mechanisms shared by NAFLD and other comorbidities. NAFLD is more common in patients with extrahepatic diseases such as inflammatory bowel disease (IBD), obstructive syndrome apnea (OSA) and psoriasis than in the general population. Furthermore, there is evidence that this association has a negative impact on the severity of liver lesions. Specific risk characteristics for NAFLD have been identified in populations with IBD (i.e. age, obesity, DM2, previous bowel surgery, IBD evolution time, methotrexate treatment), OSA (i.e. obesity, DM2, OSA severity, increased transaminases) and psoriasis (i.e. age, metabolic factors, severe psoriasis, arthropathy, elevated transaminases, methotrexate treatment). These specific phenotypes might be used by gastroenterologists, pneumologists and dermatologists to create screening algorithms for NAFLD. Such algorithms should include non-invasive markers of fibrosis used in NAFLD to select subjects for referral to the hepatologist. Prospective, controlled studies in NAFLD patients with extrahepatic comorbidities are required to demonstrate a causal relationship and also that appropriate multidisciplinary management improves these patients’ prognosis and survival.

Molecular and Pathophysiological Links between Metabolic Disorders and Inflammatory Bowel Diseases

Despite considerable epidemiological evidence indicating comorbidity between metabolic disorders, such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, as well as common pathophysiological features shared by these two categories of diseases, the relationship between their pathogenesis at molecular levels are not well described. Intestinal barrier dysfunction is a characteristic pathological feature of IBD, which also plays causal roles in the pathogenesis of chronic inflammatory metabolic disorders. Increased intestinal permeability is associated with a pro-inflammatory response of the intestinal immune system, possibly leading to the development of both diseases. In addition, dysregulated interactions between the gut microbiota and the host immunity have been found to contribute to immune-mediated disorders including the two diseases. In connection with disrupted gut microbial composition, alterations in gut microbiota-derived metabolites have also been shown to be closely related to the pathogeneses of both diseases. Focusing on these prominent pathophysiological features observed in both metabolic disorders and IBD, this review highlights and summarizes the molecular risk factors that may link between the pathogeneses of the two diseases, which is aimed at providing a comprehensive understanding of molecular mechanisms underlying their comorbidity.

Severe steatosis and mild colitis are important for the early occurrence of hepatocellular carcinoma

The number of patients with non-alcoholic steatohepatitis (NASH) and inflammatory bowel disease (IBD) is increasing. This study elucidates the effect of both NASH and IBD on hepatocellular carcinoma (HCC) using a mouse model combining NASH and IBD. The melanocortin 4 receptor-deficient (Mc4r-KO) mice were divided into four groups with or without a high-fat diet (HFD) and with or without dextran sulfate sodium (DSS) to induce colitis, and the differences in liver damage and occurrence of HCC were analyzed. In the HFD + DSS group, the body weight, liver weight/body weight ratio, and serum levels of albumin and alanine aminotransferase were significantly lower than those in the HFD group. We further found that steatosis was significantly lower and lobular inflammation was significantly higher in the HFD + DSS group than those in the HFD group, and that individual steatosis and lobular inflammation state in the HFD + DSS mice varied. We detected HCC only in the HFD + DSS group, and mice with severe steatosis and mild colitis were found to be at high risk of HCC. Presently, the prediction of HCC is very difficult. In some cases, severe colitis reverses the fat accumulation due to appetite loss. Our findings clearly showed that severe steatohepatitis and mild colitis are simultaneously essential for the occurrence of HCC in patients with NASH and IBD.

Gut inflammation exacerbates high-fat diet induced steatosis by suppressing VLDL-TG secretion through HNF4α pathway

Nonalcoholic fatty liver disease (NAFLD) is increasingly identified in inflammatory bowel disease (IBD) patients with unclear etiology. In the current study we assessed the contribution of colonic inflammation to NAFLD development and the underlying mechanism in a mouse model for IBD. Our results showed that dextran sulfate sodium (DSS)-induced gut colitis directly led to hepatic inflammation, injury and further exacerbated hepatic steatosis caused by high fat diet (HF) feeding. The essential genes assessment, hepatic metabolic analysis and triglyceride-rich very low-density lipoprotein (VLDL-TG) secretion assays revealed a higher β-oxidation of fatty acids (FAs) but impaired VLDL-TG secretion in liver of DSS-treated mice. Disruption of the intestinal barrier by DSS promoted liver inflammation, which strongly suppressed hepatic VLDL-TG secretion and further aggravated HF-induced VLDL-TG secretion impairment through down-regulation of apolipoprotein B (APOB), hence promoting the storage of triglycerides (TG) in the liver. Inflammation induced by mixed proinflammatory cytokines or LPS obviously inhibited the expression of microsomal triglyceride transfer protein (MTP) and APOB expression and subsequently increased TG content via the suppression of HNF4α in mouse primary hepatocytes. In addition, the downregulation of MTP and APOB by proinflammatory cytokines was also rescued through activating Hnf4α by cortisol. Altogether, our results demonstrated that chronic inflammation exacerbated hepatic steatosis by inhibiting the secreting of hepatic VLDL-TG through HNF4α pathway, suggesting that restoring hepatic VLDL-TG secretion may be a novel strategy for treatment of NAFLD in IBD.

The Other Side of Malnutrition in Inflammatory Bowel Disease (IBD): Non-Alcoholic Fatty Liver Disease

Steatohepatitis and hepatobiliary manifestations constitute some of the most common extra-intestinal manifestations of Inflammatory Bowel Disease (IBD). On the other hand, non-alcoholic fatty liver disease (NAFLD) affects around 25% of the world’s population and is attracting ever more attention in liver transplant programs. To outline the specific pathways linking these two conditions is a pressing task for 21st-century researchers. We are accustomed to expecting the occurrence of fatty liver disease in obese people, but current evidence suggests that there are several different pathways also occurring in underweight patients. Genetic factors, inflammatory signals and microbiota are key players that could help in understanding the entire pathogenesis of NAFLD, with the aim of defining the multiple expressions of malnutrition. In the current review, we summarize the most recent literature regarding the epidemiology, pathogenesis and future directions for the management of NAFLD in patients affected by IBD.

Mastiha has efficacy in immune-mediated inflammatory diseases through a microRNA-155 Th17 dependent action

Mastiha is a natural nutritional supplement with known anti-inflammatory properties. Non-alcoholic fatty liver disease (NAFLD) and Inflammatory bowel disease (IBD) are immune mediated inflammatory diseases that share common pathophysiological features. Mastiha has shown beneficial effects in both diseases. MicroRNAs have emerged as key regulators of inflammation and their modulation by phytochemicals have been extensively studied over the last years. Therefore, the aim of this study was to investigate whether a common route exists in the anti-inflammatory activity of Mastiha, specifically through the regulation of miRNA levels. Plasma miR-16, miR-21 and miR-155 were measured by Real-Time PCR before and after two double blinded and placebo-controlled randomized clinical trials with Mastiha. In IBD and particularly in ulcerative colitis patients in relapse, miR-155 increased in the placebo group (p = 0.054) whereas this increase was prevented by Mastiha. The mean changes were different in the two groups even after adjusting for age, sex and BMI (p = 0.024 for IBD and p = 0.042). Although the results were not so prominent in NAFLD, miR-155 displayed a downward trend in the placebo group (p = 0.054) whereas the levels did not changed significantly in the Mastiha group in patients with less advanced fibrosis. Our results propose a regulatory role for Mastiha in circulating levels of miR-155, a critical player in T helper-17 (Th17) differentiation and function.

Characterization of terminal-ileal and colonic Crohn's disease in treatment-naïve paediatric patients based on transcriptomic profile using logistic regression

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic and idiopathic inflammatory disorder of the gastrointestinal tract and comprises ulcerative colitis (UC) and Crohn's disease (CD). Crohn's disease can affect any part of the gastrointestinal tract, but mainly the terminal ileum and colon. In the present study, we aimed to characterize terminal-ileal CD (ICD) and colonic CD (CCD) at the molecular level, which might enable a more optimized approach for the clinical care and scientific research of CD.

METHODS

We analyzed differentially expressed genes in samples from 23 treatment-naïve paediatric patients with CD and 25 non-IBD controls, and compared the data with previously published RNA-Seq data using multi-statistical tests and confidence intervals. We implemented functional profiling and proposed statistical methods for feature selection using a logistic regression model to identify genes that are highly associated in ICD or CCD. We also validated our final candidate genes in independent paediatric and adult cohorts.

RESULTS

We identified 550 genes specifically expressed in patients with CD compared with those in healthy controls (p < 0.05). Among these DEGs, 240 from patients with CCD were mainly involved in mitochondrial dysfunction, whereas 310 from patients with ICD were enriched in the ileum functions such as digestion, absorption, and metabolism. To choose the most effective gene set, we selected the most powerful genes (p-value ≤ 0.05, accuracy ≥ 0.8, and AUC ≥ 0.8) using logistic regression. Consequently, 33 genes were identified as useful for discriminating CD location; the accuracy and AUC were 0.86 and 0.83, respectively. We then validated the 33 genes with data from another independent paediatric cohort (accuracy = 0.93, AUC = 0.92) and adult cohort (accuracy = 0.88, AUC = 0.72).

CONCLUSIONS

In summary, we identified DEGs that are specifically expressed in CCD and ICD compared with those in healthy controls and patients with UC. Based on the feature selection analysis, 33 genes were identified as useful for discriminating CCD and ICD with high accuracy and AUC, for not only paediatric patients but also independent cohorts. We propose that our approach and the final gene set are useful for the molecular classification of patients with CD, and it could be beneficial in treatments based on disease location.

DSS-induced colitis is associated with adipose tissue dysfunction and disrupted hepatic lipid metabolism leading to hepatosteatosis and dyslipidemia in mice

Considering high prevalence of non-alcoholic fatty liver diseases (NAFLD) in patients with inflammatory bowel disease (IBD), this study aimed to elucidate molecular mechanisms for how intestinal inflammatory conditions are causally linked to hepatic steatosis and dyslipidemia. Both younger and older mice treated with acute or chronic dextran sodium sulfate (DSS) developed colitis, which was evidenced by weight loss, colon length shortening, and elevated disease activity index and inflammation score. They also showed decreased expression of intestinal barrier function-related proteins and elevated plasma lipopolysaccharide level, indicating DSS-induced barrier dysfunction and thereby increased permeability. Interestingly, they displayed phenotypes of hepatic fat accumulation and abnormal blood lipid profiles. This DSS-induced colitis-associated lipid metabolic dysfunction was due to overall disruption of metabolic processes including fatty acid oxidation, lipogenesis, lipolysis, reverse cholesterol transport, bile acid synthesis, and white adipose tissue browning and brown adipose tissue thermogenesis, most of which are mediated by key regulators of energy homeostasis such as FGF21, adiponectin, and irisin, via SIRT1/PGC-1α- and LXRα-dependent pathways. Our study suggests a potential molecular mechanism underlying the comorbidity of NAFLD and IBD, which could provide a key to understanding how the two diseases are pathogenically linked and discovering critical therapeutic targets for their treatment.

Chronic systemic exposure to IL6 leads to deregulation of glycolysis and fat accumulation in the zebrafish liver

Inflammation is a constant in Non-Alcoholic Fatty Liver Disease (NAFLD), although their relationship is unclear. In a transgenic zebrafish system with chronic systemic overexpression of human IL6 (IL6-OE) we show that inflammation can cause intra-hepatic accumulation of triglycerides. Transcriptomics and proteomics analysis of the IL6-OE liver revealed a deregulation of glycolysis/gluconeogenesis pathway, especially a striking down regulation of the glycolytic enzyme aldolase b. Metabolomics analysis by mass spectrometry showed accumulation of hexose monophosphates and their derivatives, which can act as precursors for triglyceride synthesis. Our results suggest that IL6-driven repression of glycolysis/gluconeogenesis, specifically aldolase b, may be a novel mechanism for fatty liver. This mechanism may be relevant for NAFLD in lean individuals, an emerging class of NAFLD prevalent more in Asian Indian populations.

β-patchoulene simultaneously ameliorated dextran sulfate sodium-induced colitis and secondary liver injury in mice via suppressing colonic leakage and flora imbalance

Ulcerative colitis (UC) often occurs accompanied by colonic leakage and flora imbalance, resulting in secondary liver injury (SLI). SLI, in turn, aggravates UC, so the treatment of UC should not ignore it. β-patchoulene (β-PAE), a tricyclic sesquiterpene isolated from Pogostemon cablin, has been reported to exert a protective effect in gastrointestinal disease in our previous studies. However, its protection against UC and SLI remains unknown. Here we explored the protective effect and underlying mechanism of β-PAE against dextran sulfate sodium-induced UC and SLI in mice. The results indicated that β-PAE significantly reduced disease activity index, splenic index and attenuated the shortening of colonic length in UC mice. It alleviated colonic pathological changes and apoptosis through protecting tight junctions, reducing neutrophil aggregation, and inhibiting the release of pro-inflammatory cytokines and adhesion molecules. These effects of β-PAE were associated with the inhibition of TLR4/MyD88/NF-κB and ROCK1/MLC2 signalling pathway. UC-induced colonic leakage caused abnormally high LPS levels to result in SLI, and β-PAE markedly inhibited it. β-PAE simultaneously ameliorated SLI with reduced biomarker levels of endotoxin exposure and hepatic inflammation. High levels of LPS were also associated with flora imbalance in UC mice. However, β-PAE restored the diversity of gut microbiota and altered the relative abundance of characteristic flora of UC mice. Escherichia-dominated gut microbiota of UC mice was changed to Oscillospira-dominated after β-PAE treatment. In conclusion, pharmacological effects of β-PAE on UC and SLI were mainly contributed by suppressing colonic leakage and flora imbalance. The findings may have implications for UC treatment that not neglect the treatment of SLI.

Prevalence of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a significant public health burden, with up to 30% of the US population affected. The prevalence of NAFLD among inflammatory bowel disease (IBD) patients is unknown. Understanding risk factors for NAFLD in IBD patients has implications in the treatment of these patients. The purpose of this study was to determine the prevalence of NAFLD among IBD patients and to identify risk factors associated with NAFLD development.

METHODS

Embase and MEDLINE databases were searched using Medical Subject Headlines to find studies that assessed the prevalence of NAFLD among IBD patients. Twenty-seven English-language research abstracts/articles were identified between January 2005 and April 2018. Meta-analyses were performed using random-effects models. Prevalence of NAFLD among IBD patients was compared with prevalence of NAFLD in the general population.

RESULTS

Based on data pooled from all 27 studies, the prevalence of NAFLD among IBD patients was 32% (95% CI, 24%-40%) with substantial heterogeneity (I2 = 98%). The prevalence of NAFLD among IBD patients (32%) is statistically significantly higher than the prevalence of NAFLD in the general population (25.2%; P < 0.001). Factors associated with the development of NAFLD among IBD patients included age, BMI, diabetes, IBD duration, and prior history of bowel resection.

CONCLUSIONS

There is a higher prevalence of NAFLD among IBD patients compared with the general population. Previous treatment regimens may be a risk factor for the development of NAFLD. Future studies are needed to further clarify these risk factors and determine screening recommendations.

Non-alcoholic fatty liver disease in inflammatory bowel disease patients

Non-alcoholic fatty liver disease is a highly prevalent medical condition, characterized by intrahepatic fat accumulation which may eventually lead to hepatic inflammation, cell death and reactive fibrosis. Obesity and metabolic disturbances constitute significant contributors to liver steatosis pathogenesis, however, there is a growing awareness that fatty liver may emerge even in normal weight or metabolically healthy individuals. In recent years, advanced imaging techniques have revealed that liver steatosis is quite common in inflammatory bowel disease patients, suggesting that intestinal inflammation and disturbances of the liver-gut axis may also play a key role in non-alcoholic fatty liver disease pathophysiology. The current review focuses on the co-occurrence of the two disorders, integrating research findings on epidemiology, clinical characteristics and common pathophysiological processes. The study of liver steatosis in inflammatory bowel disease patients may provide useful insights on the complex links between dietary fat intake, metabolic dysregulation, gut physiology and intrahepatic cellular mechanisms underlying liver inflammation and damage.

Non-alcoholic fatty liver disease: A review with clinical and pathological correlation

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in North America and Europe, with increasing prevalence in other regions of the world. Its spectrum encompass steatosis, non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. It is considered as the manifestation of metabolic syndrome in liver, and its development and progression is influenced by complex interaction of environmental and genetic factors. In this review we discuss the histopathological features, differential diagnoses, and the commonly used grading and staging systems of NAFLD. NAFLD associated with other diseases, histological changes after therapeutic intervention and recurrence or occurrence of NAFLD after liver transplantation are also addressed.

The Molecular and Mechanistic Insights Based on Gut-Liver Axis: Nutritional Target for Non-Alcoholic Fatty Liver Disease (NAFLD) Improvement

Non-alcoholic fatty liver disease (NAFLD) is recognized as the most frequent classification of liver disease around the globe. Along with the sequencing technologies, gut microbiota has been regarded as a vital factor for the maintenance of human and animal health and the mediation of multiple diseases. The modulation of gut microbiota as a mechanism affecting the pathogenesis of NAFLD is becoming a growing area of concern. Recent advances in the communication between gut and hepatic tissue pave novel ways to better explain the molecular mechanisms regarding the pathological physiology of NAFLD. In this review, we recapitulate the current knowledge of the mechanisms correlated with the development and progression of NAFLD regulated by the gut microbiome and gut-liver axis, which may provide crucial therapeutic strategies for NAFLD. These mechanisms predominantly involve: (1) the alteration in gut microbiome profile; (2) the effects of components and metabolites from gut bacteria (e.g., lipopolysaccharides (LPS), trimethylamine-N-oxide (TMAO), and N,N,N-trimethyl-5-aminovaleric acid (TMAVA)); and (3) the impairment of intestinal barrier function and bile acid homeostasis. In particular, the prevention and therapy of NAFLD assisted by nutritional strategies are highlighted, including probiotics, functional oligosaccharides, dietary fibers, ω-3 polyunsaturated fatty acids, functional amino acids (L-tryptophan and L-glutamine), carotenoids, and polyphenols, based on the targets excavated from the gut-liver axis.

Metabolomic Analysis of the Liver of a Dextran Sodium Sulfate-Induced Acute Colitis Mouse Model: Implications of the Gut-Liver Connection

The incidence of ulcerative colitis (UC) is increasing worldwide, and it has become a growing problem in Asia. Previous research on UC has focused on serum, plasma, urine, gut tissues, and fecal metabolic profiling, but a comprehensive investigation into the correlation between the severity of colitis and changes in liver metabolism is still lacking. Since the liver and gut exchange nutrients and metabolites through a complex network, intestinal diseases can affect both the liver and other organs. In the present study, concentration-dependent dextran sodium sulfate (DSS)-induced ulcerative colitis was employed to examine changes in liver metabolism using a proton nuclear magnetic resonance spectroscopy (¹H-NMR)-and ultra-performance liquid chromatography time of flight mass spectroscopy (UPLC-TOF MS)-based metabolomics study. Using the multivariate statistical analysis method orthogonal projections to latent structures discriminant analysis (OPLS-DA), changes in metabolites depending on the DSS dose could be clearly distinguished. Specifically, hepatic metabolites involved in one-carbon metabolism, carnitine-related metabolism, and nucleotide synthesis were found to be affected by intestinal inflammation, implying the existence of a metabolic connection between the gut and liver. We are currently investigating the significance of this metabolic condition in UC.

Switching to a Healthy Diet Prevents the Detrimental Effects of Western Diet in a Colitis-Associated Colorectal Cancer Model

Inflammatory bowel disease increases the odds of developing colitis-associated cancer. We hypothesized that Western-style diet (WD) aggravates azoxymethane (AOM)/dextran sulfate sodium salt (DSS)-induced colitis-associated tumorigenesis and that switching to the standard AIN93G diet will ameliorate disease symptoms even after cancer initiation. Female BALB/c mice received either WD (WD group) or standard AIN93G diet (AIN group) for the whole experimental period. After five weeks, the mice received 12.5 mg/kg AOM intraperitoneally, followed by three DSS cycles. In one group of mice, the WD was switched to AIN93G the day before starting the first DSS cycle (WD/AIN group). Feeding the WD during the whole experimental period aggravated colitis symptoms, shortened the colon (p < 0.05), changed microbiota composition and increased tumor promotion. On molecular level, the WD reduced proliferation (p < 0.05) and increased expression of the vitamin D catabolizing enzyme Cyp24a1 (p < 0.001). The switch to the AIN93G diet ameliorated this effect, reflected by longer colons, fewer (p < 0.05) and smaller (p < 0.01) aberrant colonic crypt foci, comparable with the AIN group. Our results show that switching to a healthy diet, even after cancer initiation is able to revert the deleterious effect of the WD and could be an effective preventive strategy to reduce colitis symptoms and prevent tumorigenesis.

Loganin alleviates LPS-activated intestinal epithelial inflammation by regulating TLR4/NF-κB and JAK/STAT3 signaling pathways

Inflammatory bowel disease (IBD) is a chronic, recurrent gastrointestinal inflammation that affects millions of people around the world. Loganin, an iridoid glycoside, has shown the anti-inflammatory effects. However, the effect of loganin on IBD and its underlying molecular mechanism are not clear. The present study aimed to investigate whether loganin could alleviate IBD and its mechanisms. The intestinal epithelial Caco-2 cell line was treated with lipopolysaccharide (LPS) to establish an in vitro IBD model. MTT assay was used to detect cell viability. The expression and release level of inflammatory factors were determined by both real-time-PCR and ELISA. Western blotting was used to assess the NF-κB and JAK/STAT3 pathway-related protein levels. The results showed that loganin repressed the expression and release of IL-6, TNF-α, and IL-1β, and inhibited TLR4/NF-κB and JAK/STAT3 signaling pathways in a concentration-dependent manner. Overexpression of TLR4 could reverse the effect of loganin, leading to activation of NF-κB signaling and production of inflammatory factors. Meanwhile, IGF-1, a JAK/STAT3 signaling activator, could also reverse the anti-inflammation effect of loganin. In conclusion, loganin inhibited LPS-activated intestinal epithelial inflammation by repressing TLR4/NF-κB and JAK/STAT3 signaling pathway.

Systematic Review With Meta-analysis: Epidemiology of Nonalcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasingly identified in patients with inflammatory bowel disease (IBD), but there are few systematic reviews and meta-analyses of the studies of NAFLD in IBD patients.

METHODS

MEDLINE, Web of Science, Cochrane Library, and Scopus were searched (until August 2018) to identify observational studies that reported the prevalence and risk factors for NAFLD in IBD patients. Pooled prevalence, odds ratios (OR), mean difference (MD), and 95% confidence intervals (95% CI) were calculated. Study quality was assessed using the modified Newcastle-Ottawa scale.

RESULTS

Of the 662 citations evaluated, 19 studies (including 5620 subjects) reported the prevalence of NAFLD in IBD population and were included for the analysis. The overall pooled prevalence was 27.5% (95% CI, 20.7%-34.2%). The prevalence was higher in older patients (MD = 8.22; 95% CI, 6.22-10.22), type 2 diabetes (OR = 3.85; 95% CI, 2.49-5.95), hypertension (OR = 3.18; 95% CI, 2.36-4.28), obesity (OR = 2.79; 95% CI, 1.73-4.50), insulin resistance (OR = 6.66; 95% CI, 1.28-34.77), metabolic syndrome (OR = 4.96; 95% CI, 3.05-8.05), chronic kidney disease (OR = 4.83; 95% CI, 1.79-13.04), methotrexate use (OR = 1.76; 95% CI, 1.02-3.06), surgery for IBD (OR = 1.28; 95% CI, 1.02-1.62), and longer duration of IBD (MD = 5.60; 95% CI, 2.24-8.97).

CONCLUSIONS

We found that NAFLD was not uncommon in the IBD population. Older age, metabolic risk factors, methotrexate use, prior surgery, and longer duration of IBD are predictors for the presence of NAFLD in IBD. Screening of NAFLD might be recommended among IBD patients with the aforementioned factors.

Nonalcoholic fatty liver disease in patients with inflammatory bowel disease: Beyond the natural history

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a frequently reported condition in patients with inflammatory bowel disease (IBD). Both intestinal inflammation and metabolic factors are believed to contribute to the pathogenesis of IBD-associated NAFLD.

AIM

To evaluate the prevalence of steatosis and liver fibrosis (LF) in a cohort of IBD patients and the identification of metabolic- and IBD-related risk factors for NAFLD and LF.

METHODS

IBD patients were consecutively enrolled from December 2016 to January 2018. Demographic, anthropometric and biochemical data were collected so as eating habits. Abdominal ultrasound and transient elastography were performed to evaluate the presence of NAFLD and LF respectively.

RESULTS

A total of 178 consecutive patients were enrolled and included in the analysis (95 Ulcerative colitis, 83 Crohn’s disease). NAFLD was detected by imaging in 72 (40.4%) patients. Comparison between patients with and without NAFLD showed no significant differences in terms of IBD severity, disease duration, location/extension, use of IBD-related medications (i.e., steroids, anti-TNFs, and immunomodulators) and surgery. NAFLD was significantly associated with the presence of metabolic syndrome [MetS; odds ratio (OR): 4.13, P = 0.001] and obesity defined by body mass index (OR: 9.21, P = 0.0002). IBD patients with NAFLD showed higher caloric intake and lipid consumption than those without NAFLD, regardless disease activity. At the multivariate analysis, male sex, advanced age and high lipid consumption were independent risk factors for the development of NAFLD. An increased liver stiffness was detected in 21 patients (16%) and the presence of MetS was the only relevant factor associated to LF (OR: 3.40, P = 0.01).

CONCLUSION

In this study, we demonstrate that risk factors for NAFLD and LF in the IBD population do not differ from those in the general population.