Choline intake in a large cohort of patients with nonalcoholic fatty liver disease

Association of diet quality scores with risk of metabolic-associated fatty liver disease in Iranian population: a nested case-control study

Background and aim

A healthy diet has been recommended for non-alcoholic fatty liver disease (NAFLD). We aim to investigate the associations of diet quality indices with the risk of developingmetabolic-associated fatty liver disease (MAFLD).

Methods

We conducted this nested case-control study by recruiting 968 cases with MAFLD and 964 controls from the participants of the baseline phase of the Sabzevar Persian Cohort Study (SPCS). MAFLD was defined as having a fatty liver index ≥ 60 plus at least one of the following: overweight or obese, Type II diabetes mellitus, or evidence of metabolic dysregulation. Healthy Eating Index-2015 (HEI-2015) and Alternative Healthy Eating Index-2010 (AHEI-2010) were calculated from a validated food frequency questionnaire. We estimated the associations of HEI-2015 and AHEI-2010 with MAFLD risk using multivariable logistic regression.

Results

Among those in the highest relative to the lowest quintile of HEI-2015 and AHEI-2010, the multivariable-adjusted odds ratios (OR) were 0.45 (95% CI [confidence interval] 0.29-0.69; P trend = 0.002) and 0.55 (95% CI 0.35-0.85; P trend = 0.04), respectively.

Conclusion

The results of our study suggest that there is a significant associationbetween adherence to a healthy diet, indicated by a higher score of HEI or AHEI, and a reduced likelihood of developingMAFLD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01544-x.

Total choline intake, liver fibrosis and the progression of metabolic dysfunction-associated steatotic liver disease: Results from 2017 to 2020 NHANES

OBJECTIVES

This study investigated the cross-sectional relationships of total choline intake with the prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and its progression to liver fibrosis.

STUDY DESIGN

The study used data on total choline intake, hepatic steatosis, and liver fibrosis from the cross-sectional 2017-2020 National Health and Nutrition Examination Survey, including 24-h dietary recalls and liver ultrasound elastography (FibroScan®).

MAIN OUTCOME MEASURES

Steatosis was defined as a controlled attenuation parameter score ≥ 285dB/m. Fibrosis was defined as median liver stiffness ≥8 kPa. Complex survey-adjusted regression models were used in all analyses. Effect modification by sex, race, and cardiometabolic risk factors was investigated.

RESULT

Total choline intake was not associated with MASLD status (n = 5687; odds ratio per 100 mg/d [95 % confidence interval]: 0.96 [0.85,1.09]; P = 0.55). However, among people with MASLD, a higher total choline intake was associated with higher odds of fibrosis (n = 2019; 1.15 [1.01,1.30]; P = 0.03). This association was observed in men (P-interaction = 0.1; 1.23 [1.02,1.48]; P = 0.03), but not in women (1.05 [0.88,1.24]; P = 1.0). Choline intake also tended to be positively associated with fibrosis in people with MASLD who were overweight or had central obesity (P-interaction = 0.02; 1.15 [1.00,1.34]; P = 0.06).

CONCLUSIONS

Overall, no significant association was observed between total choline intake and the prevalence of MASLD. However, in people with MASLD, a higher choline intake was associated with higher odds of developing liver fibrosis. This association appeared to differ by sex and cardiometabolic risk factors.

Assessing the Benefit of Dietary Choline Supplementation Throughout Adulthood in the Ts65Dn Mouse Model of Down Syndrome

BACKGROUND/OBJECTIVES

Down syndrome (DS) is the most common cause of early-onset Alzheimer's disease (AD). Dietary choline has been proposed as a modifiable factor to improve the cognitive and pathological outcomes of AD and DS, especially as many do not reach adequate daily intake levels of choline. While lower circulating choline levels correlate with worse pathological measures in AD patients, choline status and intake in DS is widely understudied. Perinatal choline supplementation (Ch+) in the Ts65Dn mouse model of DS protects offspring against AD-relevant pathology and improves cognition. Further, dietary Ch+ in adult AD models also ameliorates pathology and improves cognition. However, dietary Ch+ in adult Ts65Dn mice has not yet been explored; thus, this study aimed to supply Ch+ throughout adulthood to determine the effects on cognition and DS co-morbidities.

METHODS

We fed trisomic Ts65Dn mice and disomic littermate controls either a choline normal (ChN; 1.1 g/kg) or a Ch+ (5 g/kg) diet from 4.5 to 14 months of age.

RESULTS

We found that Ch+ in adulthood failed to improve genotype-specific deficits in spatial learning. However, in both genotypes of female mice, Ch+ significantly improved cognitive flexibility in a reverse place preference task in the IntelliCage behavioral phenotyping system. Further, Ch+ significantly reduced weight gain and peripheral inflammation in female mice of both genotypes, and significantly improved glucose metabolism in male mice of both genotypes.

CONCLUSIONS

Our findings suggest that adulthood choline supplementation benefits behavioral and biological factors important for general well-being in DS and related to AD risk.

Oral supplementation of choline attenuates the development of alcohol-related liver disease (ALD)

BACKGROUND

Chronic alcohol intake is associated with alterations of choline metabolism in various tissues. Here, we assessed if an oral choline supplementation attenuated the development of alcohol-related liver disease (ALD) in mice.

METHODS

Female C57BL/6 J mice (n = 8/group) were either pair-fed a liquid control diet, or a Lieber DeCarli liquid diet (5% ethanol) ± 2.7 g choline/kg diet for 29 days. Liver damage, markers of intestinal permeability and intestinal microbiota composition were determined. Moreover, the effects of choline on ethanol-induced intestinal permeability were assessed in an ex vivo model.

RESULTS

ALD development as determined by liver histology and assessing markers of inflammation (e.g., nitric oxide, interleukin 6 and 4-hydroxynonenal protein adducts) was attenuated by the supplementation of choline. Intestinal permeability in small intestine being significantly higher in ethanol-fed mice was at the level of controls in ethanol-fed mice receiving choline. In contrast, no effects of the choline supplementation were found on intestinal microbiota composition. Choline also significantly attenuated the ethanol-induced intestinal barrier dysfunction in small intestinal tissue ex vivo, an effect almost entirely abolished by the choline oxidase inhibitor dimbunol.

CONCLUSION

Our results suggest that an oral choline supplementation attenuates the development of ALD in mice and is related to a protection from intestinal barrier dysfunction.

Loss of flavin-containing monooxygenase 3 modulates dioxin-like polychlorinated biphenyl 126-induced oxidative stress and hepatotoxicity

Dioxin-like pollutants (DLPs), such as polychlorinated biphenyl 126 (PCB 126), are synthetic chemicals classified as persistent organic pollutants. They accumulate in adipose tissue and have been linked to cardiometabolic disorders, including fatty liver disease. The toxicity of these compounds is associated with activation of the aryl hydrocarbon receptor (Ahr), leading to the induction of phase I metabolizing enzyme cytochrome P4501a1 (Cyp1a1) and the subsequent production of reactive oxygen species (ROS). Recent research has shown that DLPs can also induce the xenobiotic detoxification enzyme flavin-containing monooxygenase 3 (FMO3), which plays a role in metabolic homeostasis. We hypothesized whether genetic deletion of Fmo3 could protect mice, particularly in the liver, where Fmo3 is most inducible, against PCB 126 toxicity. To test this hypothesis, male C57BL/6 wild-type (WT) mice and Fmo3 knockout (Fmo3 KO) mice were exposed to PCB 126 or vehicle (safflower oil) during a 12-week study, at weeks 2 and 4. Various analyses were performed, including hepatic histology, RNA-sequencing, and quantitation of PCB 126 and F2-isoprostane concentrations. The results showed that PCB 126 exposure caused macro and microvesicular fat deposition in WT mice, but this macrovesicular fatty change was absent in Fmo3 KO mice. Moreover, at the pathway level, the hepatic oxidative stress response was significantly different between the two genotypes, with the induction of specific genes observed only in WT mice. Notably, the most abundant F2-isoprostane, 8-iso-15-keto PGE2, increased in WT mice in response to PCB 126 exposure. The study's findings also demonstrated that hepatic tissue concentrations of PCB 126 were higher in WT mice compared to Fmo3 KO mice. In summary, the absence of FMO3 in mice led to a distinctive response to dioxin-like pollutant exposure in the liver, likely due to alterations in lipid metabolism and storage, underscoring the complex interplay of genetic factors in the response to environmental toxins.

NAFLD Fibrosis Progression and Type 2 Diabetes: The Hepatic-Metabolic Interplay

The bidirectional relationship between type 2 diabetes and (non-alcoholic fatty liver disease) NAFLD is indicated by the higher prevalence and worse disease course of one condition in the presence of the other, but also by apparent beneficial effects observed in one, when the other is improved. This is partly explained by their belonging to a multisystemic disease that includes components of the metabolic syndrome and shared pathogenetic mechanisms. Throughout the progression of NAFLD to more advanced stages, complex systemic and local metabolic derangements are involved. During fibrogenesis, a significant metabolic reprogramming occurs in the hepatic stellate cells, hepatocytes, and immune cells, engaging carbohydrate and lipid pathways to support the high-energy-requiring processes. The natural history of NAFLD evolves in a variable and dynamic manner, probably due to the interaction of a variable number of modifiable (diet, physical exercise, microbiota composition, etc.) and non-modifiable (genetics, age, ethnicity, etc.) risk factors that may intervene concomitantly, or subsequently/intermittently in time. This may influence the risk (and rate) of fibrosis progression/regression. The recognition and control of the factors that determine a rapid progression of fibrosis (or its regression) are critical, as the fibrosis stages are associated with the risk of liver-related and all-cause mortality.

Research Progress of Natural Products with the Activity of Anti-nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH), a multi-target disease, is becoming a global epidemic. Although several anti-NASH drug candidates are being evaluated in late-stage clinical trials, none have been approved by the FDA to date. Given the global prevalence of the disease, the lack of effective drugs, and the very limited therapeutic efficacy of most of the existing synthetic drugs focusing on a single target, there is an urgent need to continue to develop new therapeutic agents. In contrast, many natural products, including pure compounds and crude extracts, possess hepatoprotective activities. Usually, these natural components are characterized by multi-targeting and low side effects. Therefore, natural products are important resources for the development of new anti- NASH drugs. In this paper, we focus on reviewing the anti-NASH potential, structure, and some of the side effects of natural products based on structural classification. We hope this mini-review will help researchers design and develop new anti-NASH drugs, especially based on the structure of natural products.

Sex difference in liver diseases: How preclinical models help to dissect the sex-related mechanisms sustaining NAFLD and hepatocellular carcinoma

Only a few preclinical findings are confirmed in the clinic, posing a critical issue for clinical development. Therefore, identifying the best preclinical models can help to dissect molecular and mechanistic insights into liver disease pathogenesis while being clinically relevant. In this context, the sex relevance of most preclinical models has been only partially considered. This is particularly significant in NAFLD and HCC, which have a higher prevalence in men when compared to pre-menopause women but not to those in post-menopausal status, suggesting a role for sex hormones in the pathogenesis of the diseases. This review gathers the sex-relevant findings and the available preclinical models focusing on both in vitro and in vivo studies and discusses the potential implications and perspectives of introducing the sex effect in the selection of the best preclinical model. This is a critical aspect that would help to tailor personalized therapies based on sex.

Dietary choline intake and non-alcoholic fatty liver disease (NAFLD) in U.S. adults: National Health and Nutrition Examination Survey (NHANES) 2017-2018

BACKGROUND

Whether there is an association between dietary choline intake and non-alcoholic fatty liver disease (NAFLD) in American adults remains unclear.

METHODS

Data came from the National Health and Nutrition Examination Survey 2017-2018. Choline intake was defined by the mean amounts of two 24 h dietary recalls, and choline intake was categorized into three groups according to the quartiles: inadequate (P75). Hepatic steatosis was assessed with FibroScan®, in which VCTE was employed with controlled attenuation to derive the controlled attenuation parameter (CAP), and NAFLD was defined as a CAP score ≥285 dB/m. Multivariable linear regression was performed to assess the linear relationship between choline intake and CAP. Multivariable logistics regression models were conducted to assess the association between choline intake status and NAFLD in the final sample and subgroup analysis was then performed in men and women.

RESULTS

The amount of dietary choline was inversely associated with CAP score (β = -0.262, 95% CI: -0.280, -0.245). Compared to inadequate choline intake, optimal choline intake was related to a lower risk of NAFLD (OR: 0.705, 95% CI: 0.704-0.706) in the final sample. Subgroup analysis by gender revealed that the highest choline intake status was associated with a lower risk of NAFLD both in females (OR: 0.764, 95% CI: 0.762-0.766), and males (OR: 0.955, 95% CI: 0.953-0.958) when compared to the lowest choline intake.

CONCLUSIONS

With the latest NHANES data, we found that higher dietary choline was associated with a lower risk of NAFLD in American adults, and such a relationship exists in both females and males.

Association between dietary intakes of B vitamins and nonalcoholic fatty liver disease in postmenopausal women: a cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is increasingly common globally, particularly among postmenopausal women. Diet plays a fundamental role in the treatment of NAFLD. However, clinical research on the dietary intakes of B vitamins, specifically in postmenopausal women, is scant. Hence, it is imperative to study the impact of B vitamin dietary intake in postmenopausal women.

Methods

This study utilized National Health and Nutrition Examination Survey (NHANES) data for 668 postmenopausal women. Logistic regression analysis was conducted to investigate the association of the intakes of B vitamins with hepatic steatosis and liver fibrosis prevalence. The analysis accounted for various covariates and employed restricted cubic spline analysis to examine potential nonlinear relationships. Additionally, interactions among age, diabetes, and B-vitamin intakes, as well as the interaction between folate and vitamin B12 intake, were explored.

Results

Higher intakes of folate [0.30 (0.10-0.88)], choline [0.26 (0.07-0.95)], vitamin B1, and vitamin B2 were associated with a reduced risk of hepatic steatosis in postmenopausal women. The associations of niacin (P-nonlinear = 0.0003), vitamin B1 (P-nonlinear = 0.036), and vitamin B2 (P-nonlinear<0.0001) intakes with hepatic steatosis showed a nonlinear pattern. However, no significant associations were observed between the intakes of niacin, vitamin B6 and vitamin B12 and hepatic steatosis. Furthermore, there were no significant associations between B-vitamin intakes and liver fibrosis. No interaction effects were observed.

Conclusion

Dietary intakes of folate, choline, vitamin B1, and vitamin B2 may be associated with liver steatosis in postmenopausal women, these results suggest that optimizing the intake of these specific B vitamins may have a protective effect against liver steatosis in postmenopausal women, offering valuable insights into potential dietary strategies to promote their well-being.

The impact of nonalcoholic fatty liver disease on inflammatory bowel disease-related hospitalization outcomes: a systematic review

Evidence suggests that patients with inflammatory bowel disease are at higher risk of developing nonalcoholic fatty liver disease (NAFLD). However, there is limited information currently available on how NAFLD may affect the clinical course of IBD. Thus, we conducted a systematic review to evaluate the impact of NAFLD on IBD-related hospitalization outcomes. All observational studies assessing IBD-related hospitalization outcomes in patients with NAFLD were included. Exclusion criteria were studies published in languages other than English or French, or those involving pediatric population. Outcomes included IBD-related hospitalization and readmission rates, need for surgery, length of stay, inpatient mortality, and costs. Overall, 3252 citations were retrieved and seven studies met the inclusion criteria (1 574 937 patients); all were observational, of high quality, and originated in the United States. Measurable outcomes reported in these studies were few and with insufficient similarity across studies to complete a quantitative assessment. Only one study reports NAFLD severity. Two studies suggested a higher rate of hospitalization for patients with both NAFLD and IBD compared to IBD alone (incidence rate ratio of 1.54; 95% confidence interval: 1.33-1.79). This is the first systematic review to date that evaluates any possible association of NAFLD with IBD-related hospitalization outcomes. Despite the paucity and low quality of available data, our findings indicate that NAFLD may be associated with worse outcomes amongst IBD patients (especially Crohn's disease). Further and higher certainty of evidence is needed for better characterization of such clinical impact.

Nonalcoholic Fatty Liver Disease and Omega-3 Fatty Acids: Mechanisms and Clinical Use

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic fatty liver disease worldwide, particularly in obese and type 2 diabetic individuals. Currently, there are no therapies for NAFLD that have been approved by the US Food and Drug Administration. Herein, we examine the rationale for using ω3 polyunsaturated fatty acids (PUFAs) in NAFLD therapy. This focus is based on the finding that NAFLD severity is associated with a reduction of hepatic C20-22 ω3 PUFAs. Because C20-22 ω3 PUFAs are pleiotropic regulators of cell function, loss of C20-22 ω3 PUFAs has the potential to significantly impact hepatic function. We describe NAFLD prevalence and pathophysiology as well as current NAFLD therapies. We also present evidence from clinical and preclinical studies that evaluated the capacity of C20-22 ω3 PUFAs to treat NAFLD. Given the clinical and preclinical evidence, dietary C20-22 ω3 PUFA supplementation has the potential to decrease human NAFLD severity by reducing hepatosteatosis and liver injury.

PEMT rs7946 Polymorphism and Sex Modify the Effect of Adequate Dietary Choline Intake on the Risk of Hepatic Steatosis in Older Patients with Metabolic Disorders

In humans, PEMT rs7946 polymorphism exerts sex-specific effects on choline requirement and hepatic steatosis (HS) risk. Few studies have explored the interaction effect of the PEMT rs7946 polymorphism and sex on the effect of adequate choline intake on HS risk. In this cross-sectional study, we investigated the association between PEMT polymorphism and adequate choline intake on HS risk. We enrolled 250 older patients with metabolic disorders with (n = 152) or without (n = 98; control) ultrasonically diagnosed HS. An elevated PEMT rs7946 A allele level was associated with a lower HS risk and body mass index in both men and women. Dietary choline intake-assessed using a semiquantitative food frequency questionnaire-was associated with reduced obesity in men only (p for trend < 0.05). ROC curve analysis revealed that the cutoff value of energy-adjusted choline intake for HS diagnosis was 448 mg/day in women (AUC: 0.62; 95% CI: 0.57-0.77) and 424 mg/day in men (AUC: 0.63, 95% CI: 0.57-0.76). In women, GG genotype and high choline intake (>448 mg/day) were associated with a 79% reduction in HS risk (adjusted OR: 0.21; 95% CI: 0.05-0.82); notably, GA or AA genotype was associated with a reduced HS risk regardless of choline intake (p < 0.05). In men, GG genotype and high choline intake (>424 mg/day) were associated with a 3.7-fold increase in HS risk (OR: 3.7; 95% CI: 1.19-11.9). Further adjustments for a high-density lipoprotein level and body mass index mitigated the effect of choline intake on HS risk. Current dietary choline intake may be inadequate for minimizing HS risk in postmenopausal Taiwanese women carrying the PEMT rs7946 GG genotype. Older men consuming more than the recommended amount of choline may have an increased risk of nonalcoholic fatty liver disease; this risk is mediated by a high-density lipoprotein level and obesity.

The Role of Choline, Soy Isoflavones, and Probiotics as Adjuvant Treatments in the Prevention and Management of NAFLD in Postmenopausal Women

Nonalcoholic fatty liver disease (NAFLD) is a prevalent condition among postmenopausal women that can lead to severe liver dysfunction and increased mortality. In recent years, research has focused on identifying potential lifestyle dietary interventions that may prevent or treat NAFLD in this population. Due to the complex and multifactorial nature of NAFLD in postmenopausal women, the disease can present as different subtypes, with varying levels of clinical presentation and variable treatment responses. By recognizing the significant heterogeneity of NAFLD in postmenopausal women, it may be possible to identify specific subsets of individuals who may benefit from targeted nutritional interventions. The purpose of this review was to examine the current evidence supporting the role of three specific nutritional factors-choline, soy isoflavones, and probiotics-as potential nutritional adjuvants in the prevention and treatment of NAFLD in postmenopausal women. There is promising evidence supporting the potential benefits of these nutritional factors for NAFLD prevention and treatment, particularly in postmenopausal women, and further research is warranted to confirm their effectiveness in alleviating hepatic steatosis in this population.

In Vivo and In Vitro Models to Study Liver Fibrosis: Mechanisms and Limitations

Liver fibrosis is a common result of liver injury owing to various kinds of chronic liver diseases. A deeper understanding of the pathophysiology of liver fibrosis and identifying potential therapeutic targets of liver fibrosis is important because liver fibrosis may progress to advanced liver diseases, such as cirrhosis and hepatocellular carcinoma. Despite numerous studies, the underlying mechanisms of liver fibrosis remain unclear. Mechanisms of the development and progression of liver fibrosis differ according to etiologies. Therefore, appropriate liver fibrosis models should be selected according to the purpose of the study and the type of underlying disease. Many in vivo animal and in vitro models have been developed to study liver fibrosis. However, there are no perfect preclinical models for liver fibrosis. In this review, we summarize the current in vivo and in vitro models for studying liver fibrosis and highlight emerging in vitro models, including organoids and liver-on-a-chip models. In addition, we discuss the mechanisms and limitations of each model.

Different choline supplement metabolism in adults using deuterium labelling

BACKGROUND

Choline deficiency leads to pathologies particularly of the liver, brain and lung. Adequate supply is important for preterm infants and patients with cystic fibrosis. We analysed the assimilation of four different enterally administered deuterium-labelled (D9-) choline supplements in adults.

METHODS

Prospective randomised cross-over study (11/2020-1/2022) in six healthy men, receiving four single doses of 2.7 mg/kg D9-choline equivalent each in the form of D9-choline chloride, D9-phosphorylcholine, D9-alpha-glycerophosphocholine (D9-GPC) or D9-1-palmitoyl-2-oleoyl-glycero-3-phosphoryl-choline (D9-POPC), in randomised order 6 weeks apart. Plasma was obtained at baseline (t = - 0.1 h) and at 0.5 h to 7d after intake. Concentrations of D9-choline and its D9-labelled metabolites were analysed by tandem mass spectrometry. Results are shown as median and interquartile range.

RESULTS

Maximum D9-choline and D9-betaine concentrations were reached latest after D9-POPC administration versus other components. D9-POPC and D9-phosphorylcholine resulted in lower D9-trimethylamine (D9-TMAO) formation. The AUCs (0-7d) of plasma D9-PC concentration showed highest values after administration of D9-POPC. D9-POPC appeared in plasma after fatty acid remodelling, predominantly as D9-1-palmitoyl-2-linoleyl-PC (D9-PLPC), confirming cleavage to 1-palmitoyl-lyso-D9-PC and re-acylation with linoleic acid as the most prominent alimentary unsaturated fatty acid.

CONCLUSION

There was a delayed increase in plasma D9-choline and D9-betaine after D9-POPC administration, with no differences in AUC over time. D9-POPC resulted in a higher AUC of D9-PC and virtually absent D9-TMAO levels. D9-POPC is remodelled according to enterocytic fatty acid availability. D9-POPC seems best suited as choline supplement to increase plasma PC concentrations, with PC as a carrier of choline and targeted fatty acid supply as required by organs. This study was registered at Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020498, 22.01.2020.

STUDY REGISTRATION

This study was registered at Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020498.

Physiologic and epigenetic effects of nutrients on disease pathways

BACKGROUND/OBJECTIVES

Epigenetic regulation by nutrients can influence the development of specific diseases. This study sought to examine the effect of individual nutrients and nutrient families in the context of preventing chronic metabolic diseases via epigenetic regulation. The inhibition of lipid accumulation and inflammation by nutrients including proteins, lipids, vitamins, and minerals were observed, and histone acetylation by histone acetyltransferase (HAT) was measured. Correlative analyses were also performed.

MATERIALS/METHODS

Nutrients were selected according to information from the Korean Ministry of Food and Drug Safety. Selected nutrient functionalities, including the attenuation of fatty acid-induced lipid accumulation and lipopolysaccharide-mediated acute inflammation were evaluated in mouse macrophage Raw264.7 and mouse hepatocyte AML-12 cells. Effects of the selected nutrients on in vitro HAT inhibition were also evaluated.

RESULTS

Nitric oxide (NO) production correlated with HAT activity, which was regulated by the amino acids group, suggesting that amino acids potentially contribute to the attenuation of NO production via the inhibition of HAT activity. Unsaturated fatty acids tended to attenuate inflammation by inhibiting NO production, which may be attributable to the inhibition of in vitro HAT activity. In contrast to water-soluble vitamins, the lipid-soluble vitamins significantly decreased NO production. Water- and lipid-soluble vitamins both exhibited significant inhibitory activities against HAT. In addition, calcium and manganese significantly inhibited lipid accumulation, NO production, and HAT activity.

CONCLUSIONS

Several candidate nutrients and their family members may have roles in the prevention of diseases, including hepatic steatosis and inflammation-related diseases (i.e., nonalcoholic steatohepatitis) via epigenetic regulation. Further studies are warranted to determine which specific amino acids, unsaturated fatty acids and lipid-soluble vitamins or specific minerals influence the development of steatosis and inflammatory-related diseases.

Histone Methylation Regulation as a Potential Target for Non-alcoholic Fatty Liver Disease

Epigenetic modulations are currently emerging as promising targets in metabolic diseases, including non-alcoholic fatty liver disease (NAFLD), for their roles in pathogenesis and therapeutic potential. The molecular mechanisms and modulation potential of histone methylation as a histone post-transcriptional modification in NAFLD have been recently addressed. However, a detailed overview of the histone methylation regulation in NAFLD is lacking. In this review, we comprehensively summarize the mechanisms of histone methylation regulation in NAFLD. We conducted a comprehensive database search in the PubMed database with the keywords 'histone', 'histone methylation', 'NAFLD', and 'metabolism' without time restriction. Reference lists of key documents were also reviewed to include potentially omitted articles. It has been reported that these enzymes can interact with other transcription factors or receptors under pro-NAFLD conditions, such as nutritional stress, which lead to recruitment to the promoters or transcriptional regions of key genes involved in glycolipid metabolism, ultimately regulating gene transcriptional activity to influence the expression. Histone methylation regulation has been implicated in mediating metabolic crosstalk between tissues or organs in NAFLD and serves a critical role in NAFLD development and progression. Some dietary interventions or agents targeting histone methylation have been suggested to improve NAFLD; however, there is still a lack of additional research and clinical translational relevance. In conclusion, histone methylation/demethylation has demonstrated an important regulatory role in NAFLD by mediating the expression of key glycolipid metabolism-related genes, and more research is needed in the future to explore its potential as a therapeutic target.

Usual intake of one-carbon metabolism nutrients in a young adult population aged 19-30 years: a cross-sectional study

One-carbon nutrients play an important role in epigenetic mechanisms and cellular methylation reactions. Inadequate intake of these nutrients is linked to metabolic perturbations, yet the current intake levels of these nutrients have rarely been studied in Asia. This cross-sectional study surveyed the usual dietary intake of one-carbon nutrients (folate, choline and vitamins B2, B6 and B12) among Thai university students aged 19-30 years (n 246). Socioeconomic background, health information, anthropometric data and 24-h dietary recall data were collected. The long-term usual intake was estimated using the multiple-source method. The average usual intake levels for men and women were (mean ± sd) 1⋅85 ± 0⋅95 and 2⋅42 ± 8⋅7 mg/d of vitamin B2, 1⋅96 ± 1⋅0 and 2⋅49 ± 8⋅7 mg/d of vitamin B6, 6⋅20 ± 9⋅5 and 6⋅28 ± 12 μg/d of vitamin B12, 195 ± 154 and 155 ± 101 μg dietary folate equivalent/d of folate, 418 ± 191 and 337 ± 164 mg/d of choline, respectively. Effect modification by sex was observed for vitamin B2 (P-interaction = 0⋅002) and choline (P-interaction = 0⋅02), where every 1 mg increase in vitamin B2 and 100 mg increase in choline intake were associated with a 2⋅07 (P = 0⋅01) and 0⋅81 kg/m² (P = 0⋅04) lower BMI, respectively, in men. The study results suggest that Thai young adults meet the recommended levels for vitamins B2, B6 and B12. The majority of participants had inadequate folate intake and did not achieve recommended intake levels for choline. The study was approved by the Ethics Committee at the Faculty of Medicine, Chiang Mai University. This trial was registered at www.thaiclinicaltrials.gov (TCTR20210420007).

Gut dysbiosis in nonalcoholic fatty liver disease: pathogenesis, diagnosis, and therapeutic implications

The incidence of nonalcoholic fatty liver disease (NAFLD) is increasing recently and has become one of the most common clinical liver diseases. Since the pathogenesis of NAFLD has not been completely elucidated, few effective therapeutic drugs are available. As the "second genome" of human body, gut microbiota plays an important role in the digestion, absorption and metabolism of food and drugs. Gut microbiota can act as an important driver to advance the occurrence and development of NAFLD, and to accelerate its progression to cirrhosis and hepatocellular carcinoma. Growing evidence has demonstrated that gut microbiota and its metabolites directly affect intestinal morphology and immune response, resulting in the abnormal activation of inflammation and intestinal endotoxemia; gut dysbiosis also causes dysfunction of gut-liver axis via alteration of bile acid metabolism pathway. Because of its composition diversity and disease-specific expression characteristics, gut microbiota holds strong promise as novel biomarkers and therapeutic targets for NAFLD. Intervening intestinal microbiota, such as antibiotic/probiotic treatment and fecal transplantation, has been a novel strategy for preventing and treating NAFLD. In this article, we have reviewed the emerging functions and association of gut bacterial components in different stages of NAFLD progression and discussed its potential implications in NAFLD diagnosis and therapy.

Gut-Liver Axis and Non-Alcoholic Fatty Liver Disease: A Vicious Circle of Dysfunctions Orchestrated by the Gut Microbiome

Non-alcoholic fatty liver disease (NAFLD) is a prevalent, multifactorial, and poorly understood liver disease with an increasing incidence worldwide. NAFLD is typically asymptomatic and coupled with other symptoms of metabolic syndrome. The prevalence of NAFLD is rising in tandem with the prevalence of obesity. In the Western hemisphere, NAFLD is one of the most prevalent causes of liver disease and liver transplantation. Recent research suggests that gut microbiome dysbiosis may play a significant role in the pathogenesis of NAFLD by dysregulating the gut-liver axis. The so-called "gut-liver axis" refers to the communication and feedback loop between the digestive system and the liver. Several pathological mechanisms characterized the alteration of the gut-liver axis, such as the impairment of the gut barrier and the increase of the intestinal permeability which result in endotoxemia and inflammation, and changes in bile acid profiles and metabolite levels produced by the gut microbiome. This review will explore the role of gut-liver axis disruption, mediated by gut microbiome dysbiosis, on NAFLD development.

Food and Gut Microbiota-Derived Metabolites in Nonalcoholic Fatty Liver Disease

Diet and lifestyle are crucial factors that influence the susceptibility of humans to nonalcoholic fatty liver disease (NAFLD). Personalized diet patterns chronically affect the composition and activity of microbiota in the human gut; consequently, nutrition-related dysbiosis exacerbates NAFLD via the gut-liver axis. Recent advances in diagnostic technology for gut microbes and microbiota-derived metabolites have led to advances in the diagnosis, treatment, and prognosis of NAFLD. Microbiota-derived metabolites, including tryptophan, short-chain fatty acid, fat, fructose, or bile acid, regulate the pathophysiology of NAFLD. The microbiota metabolize nutrients, and metabolites are closely related to the development of NAFLD. In this review, we discuss the influence of nutrients, gut microbes, their corresponding metabolites, and metabolism in the pathogenesis of NAFLD.

Inhibition of microbial deconjugation of micellar bile acids protects against intestinal permeability and liver injury

Altered host-microbe interactions and increased intestinal permeability have been implicated in disease pathogenesis. However, the mechanisms by which intestinal microbes affect epithelial barrier integrity remain unclear. Here, we investigate the impact of bacterial metabolism of host-produced bile acid (BA) metabolites on epithelial barrier integrity. We observe that rats fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) exhibit reduced intestinal abundance of host-produced conjugated BAs at early time points, coinciding with increased gut permeability. We show that in vitro, conjugated BAs protect gut epithelial monolayers from damage caused by bacterially produced unconjugated BAs through micelle formation. We then demonstrate that inhibition of bacterial BA deconjugation with a small-molecule inhibitor prevents the development of pathologic intestinal permeability and hepatic inflammation in CDAHFD-fed rats. Our study identifies a signaling-independent, physicochemical mechanism for conjugated BA-mediated protection of epithelial barrier function and suggests that rational manipulation of microbial BA metabolism could be leveraged to regulate gut barrier integrity.

Hepatic PEMT Expression Decreases with Increasing NAFLD Severity

Choline deficiency causes hepatic fat accumulation, and is associated with a higher risk of nonalcoholic fatty liver disease (NAFLD) and more advanced NAFLD-related hepatic fibrosis. Reduced expression of hepatic phosphatidylethanolamine N-methyltransferase (PEMT), which catalyzes the production of phosphatidylcholine, causes steatosis, inflammation, and fibrosis in mice. In humans, common PEMT variants impair phosphatidylcholine synthesis, and are associated with NAFLD risk. We investigated hepatic PEMT expression in a large cohort of patients representing the spectrum of NAFLD, and examined the relationship between PEMT genetic variants and gene expression. Hepatic PEMT expression was reduced in NAFLD patients with inflammation and fibrosis (i.e., nonalcoholic steatohepatitis or NASH) compared to participants with normal liver histology (β = −1.497; p = 0.005). PEMT levels also declined with increasing severity of fibrosis with cirrhosis < incomplete cirrhosis < bridging fibrosis (β = −1.185; p = 0.011). Hepatic PEMT expression was reduced in postmenopausal women with NASH compared to those with normal liver histology (β = −3.698; p = 0.030). We detected a suggestive association between rs7946 and hepatic fibrosis (p = 0.083). Although none of the tested variants were associated with hepatic PEMT expression, computational fine mapping analysis indicated that rs4646385 may impact PEMT levels in the liver. Hepatic PEMT expression decreases with increasing severity of NAFLD in obese individuals and postmenopausal women, and may contribute to disease pathogenesis in a subset of NASH patients.

Dietary Supplements for Weight Management: A Narrative Review of Safety and Metabolic Health Benefits

Dietary supplements for weight management include myriad ingredients with thermogenic, lipotropic, satiety, and other metabolic effects. Recently, the safety of this product category has been questioned. In this review, we summarize the safety evidence as well as relevant clinical findings on weight management and metabolic effects of six representative dietary supplement ingredients: caffeine, green tea extract (GTE), green coffee bean extract (GCBE), choline, glucomannan, and capsaicinoids and capsinoids. Of these, caffeine, GTE (specifically epigallocatechin gallate [EGCG]), and choline have recommended intake limits, which appear not to be exceeded when used according to manufacturers’ instructions. Serious adverse events from supplements with these ingredients are rare and typically involve unusually high intakes. As with any dietary component, the potential for gastrointestinal intolerance, as well as possible interactions with concomitant medications/supplements exist, and the health status of the consumer should be considered when consuming these components. Most of the ingredients reviewed also improved markers of metabolic health, such as glucose, lipids, and blood pressure, although the data are limited for some. In summary, weight management supplements containing caffeine, GTE, GCBE, choline, glucomannan, and capsaicinoids and capsinoids are generally safe when taken as directed and demonstrate metabolic health benefits for overweight and obese people.

NAFLD in normal weight individuals

Nonalcoholic fatty liver disease (NAFLD) can develop in lean individuals. Despite a better metabolic profile, the risk of disease progression to hepatic inflammation, fibrosis, and decompensated cirrhosis in the lean is similar to that in obesity-related NAFLD and lean individuals may experience more severe hepatic consequences and higher mortality relative to those with a higher body mass index (BMI). In the absence of early symptoms and abnormal laboratory findings, lean individuals are not likely to be screened for NAFLD or related comorbidities; however, given the progressive nature of the disease and the increased risk of morbidity and mortality, a clearer understanding of the natural history of NAFLD in lean individuals, as well as efforts to raise awareness of the potential health risks of NAFLD in lean individuals, are warranted. In this review, we summarize available data on NAFLD prevalence, clinical characteristics, outcomes, and mortality in lean individuals and discuss factors that may contribute to the development of NAFLD in this population, including links between dietary and genetic factors, menopausal status, and ethnicity. We also highlight the need for greater representation of lean individuals in NAFLD-related clinical trials, as well as more studies to better characterize lean NAFLD, develop improved screening algorithms, and determine specific treatment strategies based on underlying etiology.

Optimal Dietary Intake Composition of Choline and Betaine Is Associated with Minimized Visceral Obesity-Related Hepatic Steatosis in a Case-Control Study

Few studies on humans have comprehensively evaluated the intake composition of methyl-donor nutrients (MDNs: choline, betaine, and folate) in relation to visceral obesity (VOB)-related hepatic steatosis (HS), the hallmark of non-alcoholic fatty liver diseases. In this case-control study, we recruited 105 patients with HS and 104 without HS (controls). HS was diagnosed through ultrasound examination. VOB was measured using a whole-body analyzer. MDN intake was assessed using a validated quantitative food frequency questionnaire. After adjustment for multiple HS risk factors, total choline intake was the most significant dietary determinant of HS in patients with VOB (Beta: -0.41, p = 0.01). Low intake of choline (<6.9 mg/kg body weight), betaine (<3.1 mg/kg body weight), and folate (<8.8 μg/kg body weight) predicted increased odds ratios (ORs) of VOB-related HS (choline: OR: 22, 95% confidence interval [CI]: 6.5-80; betaine: OR: 14, 95% CI: 4.4-50; and folate: OR: 19, 95% CI: 5.2-74). Combined high intake of choline and betaine, but not folate, was associated with an 81% reduction in VOB-related HS (OR: 0.19, 95% CI: 0.05-0.69). Our data suggest that the optimal intake of choline and betaine can minimize the risk of VOB-related HS in a threshold-dependent manner.

Impact of Genetic Polymorphism on Response to Therapy in Non-Alcoholic Fatty Liver Disease

In the last decades, the global prevalence of non-alcoholic fatty liver disease (NAFLD) has reached pandemic proportions with derived major health and socioeconomic consequences; this tendency is expected to be further aggravated in the coming years. Obesity, insulin resistance/type 2 diabetes mellitus, sedentary lifestyle, increased caloric intake and genetic predisposition constitute the main risk factors associated with the development and progression of the disease. Importantly, the interaction between the inherited genetic background and some unhealthy dietary patterns has been postulated to have an essential role in the pathogenesis of NAFLD. Weight loss through lifestyle modifications is considered the cornerstone of the treatment for NAFLD and the inter-individual variability in the response to some dietary approaches may be conditioned by the presence of different single nucleotide polymorphisms. In this review, we summarize the current evidence on the influence of the association between genetic susceptibility and dietary habits in NAFLD pathophysiology, as well as the role of gene polymorphism in the response to lifestyle interventions and the potential interaction between nutritional genomics and other emerging therapies for NAFLD, such as bariatric surgery and several pharmacologic agents.

Gut Microbiota-Related Cellular and Molecular Mechanisms in the Progression of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common and increasing liver diseases worldwide. NAFLD is a term that involves a variety of conditions such as fatty liver, steatohepatitis, or fibrosis. Gut microbiota and its products have been extensively studied because of a close relation between NAFLD and microbiota in pathogenesis. In the progression of NAFLD, various microbiota-related molecular and cellular mechanisms, including dysbiosis, leaky bowel, endotoxin, bile acids enterohepatic circulation, metabolites, or alcohol-producing microbiota, are involved. Currently, diagnosis and treatment techniques using these mechanisms are being developed. In this review, we will introduce the microbiota-related mechanisms in the progression of NAFLD and future directions will be discussed.

Dietary patterns and risk of non-alcoholic fatty liver disease in adults: A prospective cohort study

BACKGROUND AND AIMS

Prospective cohort studies linking dietary patterns and non-alcoholic fatty liver disease (NAFLD) are limited, especially in Asian populations. This study aimed to prospectively investigate the association between dietary patterns and risk of NAFLD in a general Chinese adult population.

METHODS

This study included a total of 17,360 participants free from NAFLD at baseline. Dietary patterns at baseline were identified with factor analysis based on responses to a validated 100-item food frequency questionnaire. NAFLD was diagnosed by abdominal ultrasound after excluding other causes related to chronic liver disease. Cox proportional regression models were used to assess the association between dietary patterns and risk of NAFLD.

RESULTS

During a median follow-up of 4.2 years, 4034 NAFLD cases were documented. Three main dietary patterns were extracted: sugar rich dietary pattern, vegetable rich dietary pattern, and animal food dietary pattern. After adjusting for age, sex, body mass index, smoking, alcohol, education, occupation, income, physical activity, total energy intake, personal and family history of disease, depressive symptoms, dietary supplement use, inflammation markers, and each other dietary pattern score, comparing the highest with the lowest quartiles of dietary pattern scores, the multivariable hazard ratios (95% confidence interval) of NAFLD were 1.11 (1.01, 1.23) for sugar rich dietary pattern, 0.96 (0.86, 1.07) for vegetable rich dietary pattern, and 1.22 (1.10, 1.36) for animal food dietary pattern. Further adjustment for waist circumference instead of body mass index provided similar results.

CONCLUSION

Dietary patterns rich in animal foods or sugar were associated with a higher risk of NAFLD among Chinese adults, whereas a vegetable rich dietary pattern was not associated.

Understanding Choline Bioavailability and Utilization: First Step Toward Personalizing Choline Nutrition

Choline is an essential macronutrient involved in neurotransmitter synthesis, cell-membrane signaling, lipid transport, and methyl-group metabolism. Nevertheless, the vast majority are not meeting the recommended intake requirement. Choline deficiency is linked to nonalcoholic fatty liver disease, skeletal muscle atrophy, and neurodegenerative diseases. The conversion of dietary choline to trimethylamine by gut microbiota is known for its association with atherosclerosis and may contribute to choline deficiency. Choline-utilizing bacteria constitutes less than 1% of the gut community and is modulated by lifestyle interventions such as dietary patterns, antibiotics, and probiotics. In addition, choline utilization is also affected by genetic factors, further complicating the impact of choline on health. This review overviews the complex interplay between dietary intakes of choline, gut microbiota and genetic factors, and the subsequent impact on health. Understanding of gut microbiota metabolism of choline substrates and interindividual variability is warranted in the development of personalized choline nutrition.

Clinical impact of sexual dimorphism in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH)

NAFLD/NASH is a sex-dimorphic disease, with a general higher prevalence in men. Women are at reduced risk of NAFLD compared to men in fertile age, whereas after menopause women have a comparable prevalence of NAFLD as men. Indeed, sexual category, sex hormones and gender habits interact with numerous NAFLD factors including cytokines, stress and environmental factors and alter the risk profiles and phenotypes of NAFLD. In the present review, we summarized the last findings about the influence of sex on epidemiology, pathogenesis, progression in cirrhosis, indication for liver transplantation and alternative therapies, including lifestyle modification and pharmacological strategies. We are confident that an appropriate consideration of sex, age, hormonal status and sociocultural gender differences will lead to a better understanding of sex differences in NAFLD risk, therapeutic targets and treatment responses and will aid in achieving sex-specific personalized therapies.

New Developments in Microbiome in Alcohol-Associated and Nonalcoholic Fatty Liver Disease

Alcohol-associated liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) are important causes of morbidity and mortality worldwide. The intestinal microbiota is involved in the development and progression of both ALD and NAFLD. Here we describe associated changes in the intestinal microbiota, and we detail randomized clinical trials in ALD and NAFLD which evaluate treatments modulating the intestinal microbiome including fecal microbiota transplantation, probiotics, prebiotics, synbiotics, and antibiotics. Finally, we discuss precision medicine approaches targeting the intestinal microbiome to ameliorate ALD and NAFLD.

ESPEN practical guideline: Clinical nutrition in liver disease

BACKGROUND

The Practical guideline is based on the current scientific ESPEN guideline on Clinical Nutrition in Liver Disease.

METHODS

It has been shortened and transformed into flow charts for easier use in clinical practice. The guideline is dedicated to all professionals including physicians, dieticians, nutritionists and nurses working with patients with chronic liver disease.

RESULTS

A total of 103 statements and recommendations are presented with short commentaries for the nutritional and metabolic management of patients with (i) acute liver failure, (ii) alcoholic steatohepatitis, (iii) non-alcoholic fatty liver disease, (iv) liver cirrhosis, and (v) liver surgery/transplantation. The disease-related recommendations are preceded by general recommendations on the diagnostics of nutritional status in liver patients and on liver complications associated with medical nutrition.

CONCLUSION

This practical guideline gives guidance to health care providers involved in the management of liver disease to offer optimal nutritional care.

NAFLD and NASH in Postmenopausal Women: Implications for Diagnosis and Treatment

Nonalcoholic fatty liver disease (NAFLD) prevalence in women is increasing worldwide. Women of reproductive age have lower rates of NAFLD compared with men; however, this protection is lost following the menopausal transition when NAFLD prevalence in postmenopausal women becomes similar to or surpasses that in age-matched male counterparts. Ongoing epidemiological, clinical, and experimental studies indicate greater NAFLD risk and higher rates of severe hepatic fibrosis in postmenopausal women relative to premenopausal women, and that older women with NAFLD experience greater mortality than men. Investigations involving ovariectomized animal models demonstrate a causal relationship between estrogen deficiency and heightened susceptibility to the development of fatty liver and steatohepatitis, although dietary factors may exacerbate this complex relationship. The accumulated findings suggest that a better understanding of the interplay among menopausal status, metabolic comorbidities, and sex steroids in NAFLD pathogenesis is needed. Further, the mechanisms underlying the difference in NAFLD risk between postmenopausal and premenopausal women remain incompletely understood. The goals of this review are to summarize studies of NAFLD risk in postmenopausal women, discuss results from animal models of estrogen deficiency, and explore the development of NAFD within the context of altered sex hormone profiles resulting from the menopausal transition. Potential implications for the prevention, diagnosis, and treatment of NAFLD in this relatively understudied cohort are also addressed.

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

Trimethylamine N-oxide levels are associated with NASH in obese subjects with type 2 diabetes

AIMS

Trimethylamine N-oxide (TMAO), choline and betaine serum levels have been associated with metabolic diseases including type 2 diabetes (T2D) and non-alcoholic fatty liver disease (NAFLD). These associations could be mediated by insulin resistance. However, the relationships among these metabolites, insulin resistance and NAFLD have not been thoroughly investigated. Moreover, it has recently been suggested that TMAO could play a role in NAFLD by altering bile acid metabolism. We examined the association between circulating TMAO, choline and betaine levels and NAFLD in obese subjects.

METHODS

Serum TMAO, choline, betaine and bile acid levels were measured in 357 Mexican obese patients with different grades of NAFLD as determined by liver histology. Associations of NAFLD with TMAO, choline and betaine levels were tested. Moreover, association of TMAO levels with non-alcoholic steatohepatitis (NASH) was tested separately in patients with and without T2D.

RESULTS

TMAO and choline levels were significantly associated with NAFLD histologic features and NASH risk. While increased serum TMAO levels were significantly associated with NASH in patients with T2D, in non-T2D subjects this association lost significance after adjusting for sex, BMI and HOMA2-IR. Moreover, circulating secondary bile acids were associated both with increased TMAO levels and NASH.

CONCLUSIONS

In obese patients, circulating TMAO levels were associated with NASH mainly in the presence of T2D. Functional studies are required to evaluate the role of insulin resistance and T2D in this association, both highly prevalent in NASH patients.

The Relationship between Choline Bioavailability from Diet, Intestinal Microbiota Composition, and Its Modulation of Human Diseases

Choline is a water-soluble nutrient essential for human life. Gut microbial metabolism of choline results in the production of trimethylamine (TMA), which, upon absorption by the host is converted into trimethylamine-N-oxide (TMAO) in the liver. A high accumulation of both components is related to cardiovascular disease, inflammatory bowel disease, non-alcoholic fatty liver disease, and chronic kidney disease. However, the relationship between the microbiota production of these components and its impact on these diseases still remains unknown. In this review, we will address which microbes contribute to TMA production in the human gut, the extent to which host factors (e.g., the genotype) and diet affect TMA production, and the colonization of these microbes and the reversal of dysbiosis as a therapy for these diseases.

Bile Acid Sequestrant, Sevelamer Ameliorates Hepatic Fibrosis with Reduced Overload of Endogenous Lipopolysaccharide in Experimental Nonalcoholic Steatohepatitis

Despite the use of various pharmacotherapeutic strategies, fibrosis due to nonalcoholic steatohepatitis (NASH) remains an unsatisfied clinical issue. We investigated the effect of sevelamer, a hydrophilic bile acid sequestrant, on hepatic fibrosis in a murine NASH model. Male C57BL/6J mice were fed a choline-deficient, L-amino acid-defined, high-fat (CDHF) diet for 12 weeks with or without orally administered sevelamer hydrochloride (2% per diet weight). Histological and biochemical analyses revealed that sevelamer prevented hepatic steatosis, macrophage infiltration, and pericellular fibrosis in CDHF-fed mice. Sevelamer reduced the portal levels of total bile acid and inhibited both hepatic and intestinal farnesoid X receptor activation. Gut microbiome analysis demonstrated that sevelamer improved a lower α-diversity and prevented decreases in Lactobacillaceae and Clostridiaceae as well as increases in Desulfovibrionaceae and Enterobacteriaceae in the CDHF-fed mice. Additionally, sevelamer bound to lipopolysaccharide (LPS) in the intestinal lumen and promoted its fecal excretion. Consequently, the sevelamer treatment restored the tight intestinal junction proteins and reduced the portal LPS levels, leading to the suppression of hepatic toll-like receptor 4 signaling pathway. Furthermore, sevelamer inhibited the LPS-mediated induction of fibrogenic activity in human hepatic stellate cells in vitro. Collectively, sevelamer inhibited the development of murine steatohepatitis by reducing hepatic LPS overload.

Nutrition and Nonalcoholic Fatty Liver Disease: Current Perspectives

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis are diseases in their own right as well as modifiable risk factors for cardiovascular disease and type 2 diabetes. With expanding knowledge on NAFLD pathogenesis, insights have been gleaned into molecular targets for pharmacologic and nonpharmacologic approaches. Lifestyle modifications constitute a cornerstone of NAFLD management. This article reviews roles of key dietary macronutrients and micronutrients in NAFLD pathogenesis and their effects on molecular targets shared with established or emerging pharmacotherapies. Based on current evidence, a recommendation for a dietary framework as part of the comprehensive management strategy for NAFLD is provided.

Attenuation of the Hepatoprotective Effects of Ileal Apical Sodium Dependent Bile Acid Transporter (ASBT) Inhibition in Choline-Deficient L-Amino Acid-Defined (CDAA) Diet-Fed Mice

Non-alcoholic fatty liver disease (NAFLD) is a major growing worldwide health problem. We previously reported that interruption of the enterohepatic circulation of bile acids using a non-absorbable apical sodium-dependent bile acid transporter inhibitor (ASBTi; SC-435) reduced the development of NAFLD in high fat diet fed mice. However, the ability of ASBTi treatment to impact the progression of NAFLD to non-alcoholic steatohepatitis (NASH) and fibrosis in a diet-induced mouse model remains untested. In the current study, we assessed whether ASBTi treatment is hepatoprotective in the choline-deficient, L-amino acid-defined (CDAA) diet model of NASH-induced fibrosis.

Methods: Male C57Bl/6 mice were fed with: (A) choline-sufficient L-amino acid-defined diet (CSAA) (31 kcal% fat), (B) CSAA diet plus ASBTi (SC-435; 60 ppm), (C) CDAA diet, or (D) CDAA diet plus ASBTi. Body weight and food intake were monitored. After 22 weeks on diet, liver histology, cholesterol and triglyceride levels, and gene expression were measured. Fecal bile acid and fat excretion were measured, and intestinal fat absorption was determined using the sucrose polybehenate method.

Results: ASBTi treatment reduced bodyweight gain in mice fed either the CSAA or CDAA diet, and prevented the increase in liver to body weight ratio observed in CDAA-fed mice. ASBTi significantly reduced hepatic total cholesterol levels in both CSAA and CDAA-fed mice. ASBTi-associated significant reductions in hepatic triglyceride levels and histological scoring for NAFLD activity were observed in CSAA but not CDAA-fed mice. These changes correlated with measurements of intestinal fat absorption, which was significantly reduced in ASBTi-treated mice fed the CSAA (85 vs. 94%, P < 0.001) but not CDAA diet (93 vs. 93%). As scored by Ishak staging of Sirius red stained liver sections, no hepatic fibrosis was evident in the CSAA diet mice. The CDAA diet-fed mice developed hepatic fibrosis, which was increased by the ASBTi.

Conclusions: ASBT inhibition reduced intestinal fat absorption, bodyweight gain and hepatic steatosis in CSAA diet-fed mice. The effects of the ASBTi on steatosis and fat absorption were attenuated in the context of dietary choline-deficiency. Inhibition of intestinal absorption of fatty acids may be involved in the therapeutic effects of ASBTi treatment.

Leveraging Human Genetics to Identify Potential New Treatments for Fatty Liver Disease

Fatty liver disease (FLD), including its more severe pathologies, namely steatohepatitis, hepatocarcinoma, and cirrhosis, is the most common cause of chronic liver disease worldwide and is projected to become the leading cause of hepatocellular carcinoma and end-stage liver disease. FLD is heterogeneous with multiple etiologies and diverse histological phenotypes, so therapies will ultimately need to be individualized for relevant targets. Inherited factors contribute to FLD, and most of the genetic variation influencing liver disease development and progression is derived from genes involved in lipid biology, including PNPLA3, TM6SF2, GCKR, MBOAT7, and HSD17B13. From this point of view, we focus in this perspective on how human molecular genetics of FLD have highlighted defects in hepatic lipid handling as a major common mechanism of its pathology and how this insight could be leveraged to treat and prevent its more serious complications.

Pathology of liver disease: advances in the last 50 years

Liver disease has been recognized in various forms for centuries. Incredible advances, however, have been made especially in the last 50 years, driven by improvements in histology, the development of immunostains, the development of high resolution imaging methods, improved biopsy and resection methods, and the emergence of the molecular era. With these tools, pathologists and their clinical and basic science colleagues moved from classifying liver disease using an observational, pattern-based approach to a refined classification of disease, one based on etiology for medical disease and tumor classification for neoplastic disease. Examples of liver specific diseases are used to illustrate these exciting advances. These impressive advances of the past provide the foundation for hope in the future, as liver pathology continues to play an important role in improving patient care through disease identification and classification and emerging roles in guiding therapy for cures.

Adiposity May Moderate the Link Between Choline Intake and Non-alcoholic Fatty Liver Disease

Background: In animal models, histological and biochemical changes are observed in response to choline deficiency. It is unclear whether dietary choline is linked to non-alcoholic fatty liver disease (NAFLD). Objective: We examined the link among liver tests, fatty liver index (FLI), and choline consumption. Furthermore, we evaluated the impact of adiposity on this association. Method: The National Health and Nutrition Examination Survey (NHANES) was used to obtain data on choline intake and liver function biomarkers. Masked variance and weighting methodology were performed to account for the complex NHANES data. Results: Of the 20,643 participants, 46.8% were men and 45.6% had NAFLD (defined as United States FLI ≥30). In a fully adjusted model (for demographic, dietary, and clinical factors), a significant negative association was found between FLI and choline consumption (β = -0.206, p < 0.001). Participants in the highest quartile (Q4) of choline intake had a 14% lower risk of NAFLD compared with those in the first quartile (Q1). This link was stronger for postmenopausal women; women in Q4 had a 26% lower risk of NAFLD compared with those in Q1. Body mass index (BMI) strongly moderated the link between FLI and choline intake. For example, when choline consumption increased from low (272 mg/d) to high (356 mg/d), FLI decreased from 79.3 to 74.1 in the low BMI category (mean BMI = 22.1 kg/m²) and from 32.1 to 20.6 in the high BMI category (mean BMI =35.9 kg/m²). Conclusions: Our results suggest the presence of a reverse significant association between choline intake and risk of NAFLD. Furthermore, BMI was shown to mediate this relationship since changes in FLI, in relation to choline consumption, were more pronounced in participants with a higher BMI.

Exogenous Administration of Low-Dose Lipopolysaccharide Potentiates Liver Fibrosis in a Choline-Deficient l-Amino-Acid-Defined Diet-Induced Murine Steatohepatitis Model

Various rodent models have been proposed for basic research; however, the pathogenesis of human nonalcoholic steatohepatitis (NASH) is difficult to closely mimic. Lipopolysaccharide (LPS) has been reported to play a pivotal role in fibrosis development during NASH progression via activation of toll-like receptor 4 (TLR4) signaling. This study aimed to clarify the impact of low-dose LPS challenge on NASH pathological progression and to establish a novel murine NASH model. C57BL/6J mice were fed a choline-deficient l-amino-acid-defined (CDAA) diet to induce NASH, and low-dose LPS (0.5 mg/kg) was intraperitoneally injected thrice a week. CDAA-fed mice showed hepatic CD14 overexpression, and low-dose LPS challenge enhanced TLR4/NF-κB signaling activation in the liver of CDAA-fed mice. LPS challenge potentiated CDAA-diet-mediated insulin resistance, hepatic steatosis with upregulated lipogenic genes, and F4/80-positive macrophage infiltration with increased proinflammatory cytokines. It is noteworthy that LPS administration extensively boosted pericellular fibrosis with the activation of hepatic stellate cells in CDAA-fed mice. Exogenous LPS administration exacerbated pericellular fibrosis in CDAA-mediated steatohepatitis in mice. These findings suggest a key role for LPS/TLR4 signaling in NASH progression, and the authors therefore propose this as a suitable model to mimic human NASH.

Pancreatic and mucosal enzymes in choline phospholipid digestion

The digestion of choline phospholipids is important for choline homeostasis, lipid signaling, postprandial lipid and energy metabolism, and interaction with intestinal bacteria. The digestion is mediated by the combined action of pancreatic and mucosal enzymes. In the proximal small intestine, hydrolysis of phosphatidylcholine (PC) to 1-lyso-PC and free fatty acid (FFA) by the pancreatic phospholipase A₂ IB coincides with the digestion of the dietary triacylglycerols by lipases, but part of the PC digestion is extended and must be mediated by other enzymes as the jejunoileal brush-border phospholipase B/lipase and mucosal secreted phospholipase A₂ X. Absorbed 1-lyso-PC is partitioned in the mucosal cells between degradation and reacylation into chyle PC. Reutilization of choline for hepatic bile PC synthesis, and the reacylation of 1-lyso-PC into chylomicron PC by the lyso-PC-acyl-CoA-acyltransferase 3 are important features of choline recycling and postprandial lipid metabolism. The role of mucosal enzymes is emphasized by sphingomyelin (SM) being sequentially hydrolyzed by brush-border alkaline sphingomyelinase (alk-SMase) and neutral ceramidase to sphingosine and FFA, which are well absorbed. Ceramide and sphingosine-1-phosphate are generated and are both metabolic intermediates and important lipid messengers. Alk-SMase has anti-inflammatory effects that counteract gut inflammation and tumorigenesis. These may be mediated by multiple mechanisms including generation of sphingolipid metabolites and suppression of autotaxin induction and lyso-phosphatidic acid formation. Here we summarize current knowledge on the roles of pancreatic and mucosal enzymes in PC and SM digestion, and its implications in intestinal and liver diseases, bacterial choline metabolism in the gut, and cholesterol absorption.

ESPEN guideline on clinical nutrition in liver disease

This update of evidence-based guidelines (GL) aims to translate current evidence and expert opinion into recommendations for multidisciplinary teams responsible for the optimal nutritional and metabolic management of adult patients with liver disease. The GL was commissioned and financially supported by ESPEN. Members of the guideline group were selected by ESPEN. We searched for meta-analyses, systematic reviews and single clinical trials based on clinical questions according to the PICO format. The evidence was evaluated and used to develop clinical recommendations implementing the SIGN method. A total of 85 recommendations were made for the nutritional and metabolic management of patients with acute liver failure, severe alcoholic steatohepatitis, non-alcoholic fatty liver disease, liver cirrhosis, liver surgery and transplantation as well as nutrition associated liver injury distinct from fatty liver disease. The recommendations are preceded by statements covering current knowledge of the underlying pathophysiology and pathobiochemistry as well as pertinent methods for the assessment of nutritional status and body composition.

Gut Microbiota-Derived Mediators as Potential Markers in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common, multifactorial, and poorly understood liver disease whose incidence is globally rising. During the past decade, several lines of evidence suggest that dysbiosis of intestinal microbiome represents an important factor contributing to NAFLD occurrence and its progression into NASH. The mechanisms that associate dysbiosis with NAFLD include changes in microbiota-derived mediators, deregulation of the gut endothelial barrier, translocation of mediators of dysbiosis, and hepatic inflammation. Changes in short chain fatty acids, bile acids, bacterial components, choline, and ethanol are the result of altered intestinal microbiota. We perform a narrative review of the previously published evidence and discuss the use of gut microbiota-derived mediators as potential markers in NAFLD.