Dietary fructose in nonalcoholic fatty liver disease

Effects of dietary sugar restriction on hepatic fat in youth with obesity

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in children. Like adults, children can develop the progressive form of NAFLD, nonalcoholic steatohepatitis (NASH), which is characterized by hepatic inflammation, often in the presence of fibrosis. Children with NAFLD are at higher risk of liver-related complications, metabolic dysfunction, and cardiovascular disease in adulthood. Many factors contribute to the escalating prevalence of NAFLD in the pediatric population, among which are an array of dietary patterns such as overnutrition, poor diet quality, and heavy consumption of fat and sugar, including fructose. Findings from an increasing number of epidemiological studies support a connection between high habitual sugar consumption and NAFLD, especially within the context of obesity, but these studies are not able to demonstrate whether sugar is a contributing factor or instead an indicator of an overall poor diet (or lifestyle) quality. To date, only four randomized controlled dietary interventions assessing the effects of sucrose/fructose restriction on hepatic fat fraction in youth with obesity have been published. The objectives of this review are to summarize the key findings from these dietary interventions to achieve a better understanding of the strength of the relationship between dietary sugar restriction and liver fat reduction, despite their inherent limitations, and to discuss the potential impact of weight loss and fat mass reduction on improvement in hepatic steatosis.

A short-term rodent model for non-alcoholic steatohepatitis induced by a high-fat diet and carbon tetrachloride

Several models of mice-fed high-fat diets have been used to trigger non-alcoholic steatohepatitis and some chemical substances, such as carbon tetrachloride. The present study aimed to evaluate the joint action of a high-fat diet and CCl4 in developing a short-term non-alcoholic steatohepatitis model. C57BL6/J mice were divided into two groups: standard diet-fed (SD), the high-fat diet-fed (HFD) and HFD + fructose-fed and carbon tetrachloride (HFD+CCl4). The animals fed with HFD+CCl4 presented increased lipid deposition compared with both SD and HFD mice. Plasma cholesterol was increased in animals from the HFD+CCl4 group compared with the SD and HFD groups, without significant differences between the SD and HFD groups. Plasma triglycerides showed no significant difference between the groups. The HFD+CCl4 animals had increased collagen deposition in the liver compared with both SD and HFD groups. Hydroxyproline was also increased in the HFD+CCl4 group. Liver enzymes, alanine aminotransferase and aspartate aminotransferase, were increased in the HFD+CCl4 group, compared with SD and HFD groups. Also, CCl4 was able to trigger an inflammatory process in the liver of HFD-fed animals by promoting an increase of ∼2 times in macrophage activity, ∼6 times in F4/80 gene expression, and pro-inflammatory cytokines (IL-1b and TNFa), in addition to an increase in inflammatory pathway protein phosphorylation (IKKbp). HFD e HFD+CCl4 animals increased glucose intolerance compared with SD mice, associated with reduced insulin-stimulated AKT activity in the liver. Therefore, our study has shown that short-term HFD feeding associated with fructose and CCl4 can trigger non-alcoholic steatohepatitis and cause damage to glucose metabolism.

Fructose-induced metabolic reprogramming of cancer cells

Excess dietary fructose consumption has been long proposed as a culprit for the world-wide increase of incidence in metabolic disorders and cancer within the past decades. Understanding that cancer cells can gradually accumulate metabolic mutations in the tumor microenvironment, where glucose is often depleted, this raises the possibility that fructose can be utilized by cancer cells as an alternative source of carbon. Indeed, recent research has increasingly identified various mechanisms that show how cancer cells can metabolize fructose to support their proliferating and migrating needs. In light of this growing interest, this review will summarize the recent advances in understanding how fructose can metabolically reprogram different types of cancer cells, as well as how these metabolic adaptations can positively support cancer cells development and malignancy.

Relevant Aspects of Combined Protocols for Prevention of N(M)AFLD and Other Non-Communicable Diseases

Obesity is a global health issue characterized by the excessive fat accumulation, leading to an increased risk of chronic noncommunicable diseases (NCDs), including metabolic dysfunction-associated fatty liver disease (MAFLD), which can progress from simple steatosis to steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. Currently, there are no approved pharmacological protocols for prevention/treatment of MAFLD, and due the complexity lying beneath these mechanisms, monotherapies are unlikely to be efficacious. This review article analyzes the possibility that NCDs can be prevented or attenuated by the combination of bioactive substances, as they could promote higher response rates, maximum reaction results, additive or synergistic effects due to compounds having similar or different mechanisms of action and/or refraining possible side effects, related to the use of lower doses and exposures times than monotherapies. Accordingly, prevention of mouse MAFLD is observed with the combination of the omega-3 docosahexaenoic acid with the antioxidant hydroxytyrosol, whereas attenuation of mild cognitive impairment is attained by folic acid plus cobalamin in elderly patients. The existence of several drawbacks underlying published monotherapies or combined trials, opens space for adequate and stricter experimental and clinical tryouts to achieve meaningful outcomes with human applicability.

Hyperacetylated histone H4 is a source of carbon contributing to lipid synthesis

Histone modifications commonly integrate environmental cues with cellular metabolic outputs by affecting gene expression. However, chromatin modifications such as acetylation do not always correlate with transcription, pointing towards an alternative role of histone modifications in cellular metabolism. Using an approach that integrates mass spectrometry-based histone modification mapping and metabolomics with stable isotope tracers, we demonstrate that elevated lipids in acetyltransferase-depleted hepatocytes result from carbon atoms derived from deacetylation of hyperacetylated histone H4 flowing towards fatty acids. Consistently, enhanced lipid synthesis in acetyltransferase-depleted hepatocytes is dependent on histone deacetylases and acetyl-CoA synthetase ACSS2, but not on the substrate specificity of the acetyltransferases. Furthermore, we show that during diet-induced lipid synthesis the levels of hyperacetylated histone H4 decrease in hepatocytes and in mouse liver. In addition, overexpression of acetyltransferases can reverse diet-induced lipogenesis by blocking lipid droplet accumulation and maintaining the levels of hyperacetylated histone H4. Overall, these findings highlight hyperacetylated histones as a metabolite reservoir that can directly contribute carbon to lipid synthesis, constituting a novel function of chromatin in cellular metabolism.

The pathophysiology of MASLD: an immunometabolic perspective

INTRODUCTION

Metabolic-associated liver diseases have emerged pandemically across the globe and are clinically related to metabolic disorders such as obesity and type 2 diabetes. The new nomenclature and definition (i.e. metabolic dysfunction-associated steatotic liver disease - MASLD; metabolic dysfunction-associated steatohepatitis - MASH) reflect the nature of these complex systemic disorders, which are characterized by inflammation, gut dysbiosis and metabolic dysregulation. In this review, we summarize recent advantages in understanding the pathophysiology of MASLD, which we parallel to emerging therapeutic concepts.

AREAS COVERED

We summarize the pathophysiologic concepts of MASLD and its transition to MASH and subsequent advanced sequelae of diseases. Furthermore, we highlight how dietary constituents, microbes and associated metabolites, metabolic perturbations, and immune dysregulation fuel lipotoxicity, hepatic inflammation, liver injury, insulin resistance, and systemic inflammation. Deciphering the intricate pathophysiologic processes that contribute to the development and progression of MASLD is essential to develop targeted therapeutic approaches to combat this escalating burden for health-care systems.

EXPERT OPINION

The rapidly increasing prevalence of metabolic dysfunction-associated steatotic liver disease challenges health-care systems worldwide. Understanding pathophysiologic traits is crucial to improve the prevention and treatment of this disorder and to slow progression into advanced sequelae such as cirrhosis and hepatocellular carcinoma.

Bile acids mediate fructose-associated liver tumour growth in mice

High fructose diets are associated with an increased risk of liver cancer. Previous studies in mice suggest increased lipogenesis is a key mechanism linking high fructose diets to liver tumour growth. However, these studies administered fructose to mice at supraphysiological levels. The aim of this study was to determine whether liver tumour growth and lipogenesis were altered in mice fed fructose at physiological levels. To test this, we injected male C57BL/6 mice with the liver carcinogen diethylnitrosamine and then fed them diets without fructose or fructose ranging from 10 to 20 % total calories. Results showed mice fed diets with ≥15 % fructose had significantly increased liver tumour numbers (2-4-fold) and total tumour burden (∼7-fold) vs mice fed no-fructose diets. However, fructose-associated tumour burden was not associated with lipogenesis. Conversely, unbiased metabolomic analyses revealed bile acids were elevated in the sera of mice fed a 15 % fructose diet vs mice fed a no-fructose diet. Using a syngeneic ectopic liver tumour model, we show that ursodeoxycholic acid, which decreases systemic bile acids, significantly reduced liver tumour growth in mice fed the 15 % fructose diet but not mice fed a no-fructose diet. These results point to a novel role for systemic bile acids in mediating liver tumour growth associated with a high fructose diet. Overall, our study shows fructose intake at or above normal human consumption (≥15 %) is associated with increased liver tumour numbers and growth and that modulating systemic bile acids inhibits fructose-associated liver tumour growth in mice.

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) and Thyroid Function in Childhood Obesity: A Vicious Circle?

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a multisystem disorder characterized by the presence of fatty liver degeneration associated with excess adiposity or prediabetes/type 2 diabetes or metabolic dysregulation. An intricate relationship between the liver and thyroid has been reported in both health and disease. Simultaneously, there is a strong correlation between obesity and both MAFLD and thyroid dysfunction. In this narrative review, we highlighted the relationship between MAFLD and thyroid function in children and adolescents with obesity in order to explore how thyroid hormones (THs) act as predisposing factors in the onset, progression, and sustainability of MAFLD. THs are integral to the intricate balance of metabolic activities, ensuring energy homeostasis, and are indispensable for growth and development. Regarding liver homeostasis, THs have been suggested to interact with liver lipid homeostasis through a series of processes, including stimulating the entry of free fatty acids into the liver for esterification into triglycerides and increasing mitochondrial β-oxidation of fatty acids to impact hepatic lipid accumulation. The literature supports a correlation between MAFLD and obesity, THs and obesity, and MAFLD and THs; however, results in the pediatric population are very limited. Even though the underlying pathogenic mechanism involved in the relationship between MAFLD and thyroid function remains not fully elucidated, the role of THs as predisposing factors of MAFLD could be postulated. A potential vicious circle among these three conditions cannot be excluded. Identifying novel elements that may contribute to MAFLD could offer a practical approach to assessing children at risk of developing the condition.

Mannose Supplementation Curbs Liver Steatosis and Fibrosis in Murine MASH by Inhibiting Fructose Metabolism

Metabolic dysfunction-associated steatohepatitis (MASH) can progress to cirrhosis and liver cancer. There are no approved medical therapies to prevent or reverse disease progression. Fructose and its metabolism in the liver play integral roles in MASH pathogenesis and progression. Here we focus on mannose, a simple sugar, which dampens hepatic stellate cell activation and mitigates alcoholic liver disease in vitro and in vivo . In the well-validated FAT-MASH murine model, oral mannose supplementation improved both liver steatosis and fibrosis at low and high doses, whether administered either at the onset of the model ("Prevention") or at week 6 of the 12-week MASH regimen ("Reversal"). The in vivo anti-fibrotic effects of mannose supplementation were validated in a second model of carbon tetrachloride-induced liver fibrosis. In vitro human and mouse primary hepatocytes revealed that the anti-steatotic effects of mannose are dependent on the presence of fructose, which attenuates expression of ketohexokinase (KHK), the main enzyme in fructolysis. KHK is decreased with mannose supplementation in vivo and in vitro, and overexpression of KHK abrogated the anti-steatotic effects of mannose. Our study identifies mannose as a simple, novel therapeutic candidate for MASH that mitigates metabolic dysregulation and exerts anti-fibrotic effects.

Dietary Galactose Increases the Expression of Mitochondrial OXPHOS Genes and Modulates the Carbohydrate Oxidation Pathways in Mouse Intestinal Mucosa

BACKGROUND

Prolonged lactation provides substantial health benefits, possibly because of galactose as part of milk sugar lactose. Isocaloric replacement of dietary glucose [16 energy%(en%)] with galactose within a normal diet (64en% carbohydrates) during a 3-wk postweaning period provided substantial benefits on short- and long-term physiologic and metabolic parameters at the whole-body level and liver in female mice, which might be attributable to intestinal function.

OBJECTIVES

This study aimed to investigate if partial dietary replacement of glucose with galactose alters intestinal metabolism underlying hepatic health effects.

METHODS

Proximal intestinal mucosa gene profiles in female mice were analyzed using RNAseq technology, validated, and correlated with hepatic health parameters.

RESULTS

Transcriptome analysis revealed that the presence of galactose primarily affected the pathways involved in energy metabolism. A consistently higher expression was observed in the subset of mitochondrial transcripts (78 of 80, all P.adj < 0.1). Oxidative phosphorylation (OXPHOS) represented the most upregulated process (all top 10 pathways) independent of the total mitochondrial mass (P = 0.75). Moreover, galactose consistently upregulated carbohydrate metabolism pathways, specifically glycolysis till acetyl-CoA production and fructose metabolism. Also, the expression of transcripts involved in these pathways was negatively correlated with circulating serum amyloid A3 protein, a marker of hepatic inflammation [R (-0.61, -0.5), P (0.002, 0.01)]. Accordingly, CD163+ cells were decreased in the liver. Additionally, the expression of key fructolytic enzymes in the small intestinal mucosa was negatively correlated with triglyceride accumulation in the liver [R (-0.45, -0.4), P (0.03, 0.05)].

CONCLUSIONS

To our knowledge, our results show for the first time the role of galactose as an OXPHOS activator in vivo. Moreover, the concept of intestinal cells acting as the body's metabolic gatekeeper is strongly supported, as they alter substrate availability and thereby contribute to the maintenance of metabolic homeostasis, protecting other organs, as evidenced by their potential ability to shield the liver from the potentially detrimental effects of fructose.

Dietary inflammatory potential is associated with higher odds of hepatic steatosis in US adults: a cross-sectional study

OBJECTIVE

Inflammation plays a critical role in the progression of chronic liver diseases, and diet can modulate inflammation. Whether an inflammatory dietary pattern is associated with higher risk of hepatic steatosis or fibrosis remains unclear. We aimed to investigate the associations between inflammatory dietary pattern and the odds of hepatic steatosis and fibrosis.

DESIGN

In this nationwide cross-sectional study, diet was measured using two 24-h dietary recalls. Empirical dietary inflammatory pattern (EDIP) score was derived to assess the inflammatory potential of usual diet, which has been validated to highly predict inflammation markers in the study population. Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were derived from FibroScan to define steatosis and fibrosis, respectively.

SETTING

US National Health and Nutrition Examination Survey.

PARTICIPANTS

4171 participants aged ≥18 years.

RESULTS

A total of 1436 participants were diagnosed with S1 steatosis (CAP ≥ 274 dB/m), 255 with advanced fibrosis (LSM ≥ 9·7 kPa). Compared with those in the lowest tertile of EDIP-adherence scores, participants in the highest tertile had 74 % higher odds of steatosis (OR: 1·74, 95 % CI (1·26, 2·41)). Such positive association persisted among never drinkers, or participants who were free of hepatitis B and/or C. Similarly, EDIP was positively associated with CAP in multivariate linear model (P < 0·001). We found a non-significant association of EDIP score with advanced fibrosis or LSM (P = 0·837).

CONCLUSIONS

Our findings suggest that a diet score that is associated with inflammatory markers is associated with hepatic steatosis. Reducing or avoiding pro-inflammatory diets intake might be an attractive strategy for fatty liver disease prevention.

Association between diet soft drink consumption and metabolic dysfunction-associated steatotic liver disease: findings from the NHANES

BACKGROUND

Lifestyle change plays a crucial role in the prevention and treatment of metabolic dysfunction-associated steatotic liver disease (MASLD). In recent years, diet soft drinks that emphasize "zero sugar and zero calories" have become all the rage, but whether diet soft drink consumption is associated with MASLD is not clear.

METHODS

This study included data from the National Health and Nutrition Examination Surveys (NHANES) in 2003-2006. The assessment of MASLD status primarily relied on the Fatty Liver Index (FLI). Weighted multiple Logistic regression models were constructed to evaluate the association between diet soft drink consumption and MASLD. Additionally, mediation analysis was performed to examine the mediating effect of body mass index (BMI).

RESULTS

A total of 2,378 participants were included in the study, among which 1,089 individuals had MASLD, and the weighted prevalence rate was 43.64%. After adjusting for variables related to demographic, lifestyle, and metabolic syndrome, excessive diet soft drink consumption (the "always" frequency) remained significantly associated with the occurrence of MASLD (OR = 1.98, 95%CI = 1.36-2.89, P = 0.003). It was estimated that 84.7% of the total association between diet soft drink consumption and MASLD was mediated by BMI (P < 0.001).

CONCLUSIONS

Excessive diet soft drink consumption was associated with the occurrence of MASLD. BMI may play a mediating role in the association between diet soft drink consumption and MASLD.

Association between soft drink consumption and carotid atherosclerosis in a large-scale adult population: The TCLSIH cohort study

BACKGROUND AND AIMS

Carotid atherosclerosis indicates an increased risk for cardiac-cerebral vascular disease. Given the pattern of consumption in China, sugar-sweetened beverage is the main type of soft drink consumed. As soft drinks contain a high amount of fructose, they may be a risk factor of carotid atherosclerosis. A prospective cohort study was conducted to investigate the association between soft drink consumption and the incidence of carotid atherosclerosis in a Chinese adult population.

METHODS AND RESULTS

A total of 3828 participants (men: 2007 and women: 1821) were included. Carotid atherosclerosis was measured by using ultrasonography and was defined by increased carotid intima-media thickness and/or carotid plaques. Soft drink consumption was assessed using a validated food frequency questionnaire. Cox proportional hazards regression analysis was used to assess the association of soft drink consumption categories with the incidence of carotid atherosclerosis. During a mean follow-up of 3.20 years, 1009 individuals of the 3828 eligible participants developed carotid atherosclerosis. After adjusting for potential confounding factors, we compared the higher levels to the lowest level of soft drink consumption in women, and we estimated the multivariable hazard ratios and 95% confidence intervals of incident carotid atherosclerosis to be 1.09 (0.80, 1.50), and 1.56 (1.14, 2.13) (P for trend <0.05). However, there was no significant association between soft drink consumption and the incidence of carotid atherosclerosis in men or total population.

CONCLUSION

The result indicated that soft drink consumption was associated with a higher incidence of carotid atherosclerosis in women.

TRIAL REGISTERED

UMIN Clinical Trials Registry.

TRIAL REGISTRATION NUMBER

UMIN000027174. TRIAL REGISTRATION WEBSITE: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000031137.

Gut commensal Kineothrix alysoides mitigates liver dysfunction by restoring lipid metabolism and gut microbial balance

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease, is a widespread liver condition characterized by excessive fat buildup in hepatocytes without significant alcohol consumption. Manipulation of the gut microbiome has been considered to prevent and improve the occurrence and progression of MASLD, particularly through the gut-liver axis. This study aimed to investigate the correlation between the gut microbiome and liver function and determine whether the gut microbiome can ameliorate MASLD. We comparatively analyzed the gut microbiome composition between mice fed normal chow and those fed a high-fat diet and observed that the abundance of Kineothrix alysoides decreased in the high-fat group. Further analysis showed that treatment with K. alysoides in the high-fat diet group led to decreased weight loss, and MASLD attenuation. Importantly, K. alysoides treatment attenuated MASLD in mice fed a high-fat, high-fructose diet (HFHF), which can cause advanced liver damage. Furthermore, administration of K. alysoides altered the gut microbial composition in the HFHF diet group and improved MASLD. Overall, these findings demonstrate the potential of K. alysoides in restoring gut health and facilitating lipid metabolism to prevent and treat MASLD.

Antioxidant action of xanthine oxidase inhibitor febuxostat protects the liver and blood vasculature in SHRSP5/Dmcr rats

BACKGROUND

Xanthine oxidase (XO) generates reactive oxygen species during uric acid production. Therefore, XO inhibitors, which suppress oxidative stress, may effectively treat non-alcoholic steatohepatitis (NASH) and atherosclerosis via uric acid reduction. In this study, we examined the antioxidant effect of the XO inhibitor febuxostat on NASH and atherosclerosis in stroke-prone spontaneously hypertensive 5 (SHRSP5/Dmcr) rats.

METHODS

SHRSP5/Dmcr rats were divided into three groups: SHRSP5/Dmcr + high-fat and high-cholesterol (HFC) diet [control group, n = 5], SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) [fructose group, n = 5], and SHRSP5/Dmcr + HFC diet + 10% fructose (40 ml/day) + febuxostat (1.0 mg/kg/day) [febuxostat group, n = 5]. Glucose and insulin resistance, blood biochemistry, histopathological staining, endothelial function, and oxidative stress markers were evaluated.

RESULTS

Febuxostat reduced the plasma uric acid levels. Oxidative stress-related genes were downregulated, whereas antioxidant factor-related genes were upregulated in the febuxostat group compared with those in the fructose group. Febuxostat also ameliorated inflammation, fibrosis, and lipid accumulation in the liver. Mesenteric lipid deposition decreased in the arteries, and aortic endothelial function improved in the febuxostat group.

CONCLUSIONS

Overall, the XO inhibitor febuxostat exerted protective effects against NASH and atherosclerosis in SHRSP5/Dmcr rats.

Ellagitannins-Derived Intestinal Microbial Metabolite Urolithin A Ameliorates Fructose-Driven Hepatosteatosis by Suppressing Hepatic Lipid Metabolic Reprogramming and Inducing Lipophagy

Excessive fructose consumption exacerbates the progression of nonalcoholic fatty liver disease (NAFLD) by disrupting hepatic lipid homeostasis. This study sought to evaluate the efficacy of urolithin A (UroA) in a fructose-induced NAFLD mouse model. UroA was administered in the high-fructose-fed mice to investigate the antisteatotic effects in vivo. Fructose-stimulated HepG2 cells and primary hepatocytes were established for in vitro mechanistic assessment. The results suggested that UroA ameliorated fructose-induced hepatic steatosis in mice. Mechanistically, UroA impaired lipogenesis and enhanced β-oxidation in the livers of fructose-fed mice. Notably, UroA facilitated hepatic lipophagy through the AMPK/ULK1 pathway both in vivo and in vitro, degrading lipid droplets for fueling β-oxidation. This study indicates that UroA alleviates excessive lipid accumulation and restores lipid homeostasis in the livers of fructose-fed mice by suppressing lipid metabolic reprogramming and triggering lipophagy. Therefore, dietary supplementation of UroA or ellagitannins-rich foods may be beneficial for NAFLD individuals with high fructose intake.

Identification of Gut Microbial Lysine and Histidine Degradation and CYP-Dependent Metabolites as Biomarkers of Fatty Liver Disease

Numerous studies have described specific metabolites as biomarkers of severe liver diseases, but very few have measured gut microbiota (GM)-produced metabolites in fatty liver disease. We aimed at finding GM signatures and metabolite markers in plasma and feces related to high liver fat content. Based on imaging, we divided study participants into low (<5%, LF, n = 25) and high (>5%, HF, n = 39) liver fat groups. Fecal (LF n = 14, HF n = 25) and plasma (LF n = 11, HF n = 7) metabolomes of subsets of participants were studied using liquid chromatography/high resolution mass spectrometry. The GM were analyzed using 16S rRNA gene sequencing. Additionally, blood clinical variables and diet were studied. Dyslipidemia, higher liver enzymes and insulin resistance characterized the HF group. No major differences in diet were found between the groups. In the GM, the HF group had lower abundance of Bacteroides and Prevotellaceae NK3B31 group than the LF group after adjusting for metformin use or obesity. In feces, the HF group had higher levels of lysine and histidine degradation products, while 6-hydroxybetatestosterone (metabolized by CYP3A4) was low. Higher plasma levels of caffeine and its metabolites in the HF group indicate that the activity of hepatic CYP1A2 was lower than in the LF group. Our results suggest, that low fecal Prevotellaceae NK3B31 and Bacteroides abundance, and increased lysine and histidine degradation may serve as GM biomarkers of high liver fat. Altered plasma caffeine metabolites and lowered testosterone metabolism may specify decreased CYP activities, and their potential utility, as biomarkers of fatty liver disease. IMPORTANCE Because the high prevalence of nonalcoholic fatty liver disease sets diagnostic challenges to health care, identification of new biomarkers of the disease that in the future could have potential utility as diagnostic biomarkers of high liver fat content is important. Our results show that increased amino acid degradation products in the feces may be such biomarkers. In the blood, molecules that indicate defective hepatic metabolic enzyme activities were identified in individuals with high liver fat content.

Role of liquid fructose/sucrose in regulating the hepatic transcriptome in a high-fat Western diet model of NAFLD

Nonalcoholic fatty liver disease (NAFLD), which ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), is the most common chronic liver disease. Yet, the molecular mechanisms for the progression of steatosis to NASH remain largely undiscovered. Thus, there is a need for identifying specific gene and pathway changes that drive the progression of NAFLD. This study uses high-fat Western diet (HFWD) together with liquid sugar [fructose and sucrose (F/S)] feeding for 12 weeks in mice to induce obesity and examine hepatic transcriptomic changes that occur in NAFLD progression. The combination of a HFWD+F/S in the drinking water exacerbated HFWD-induced obesity, hyperinsulinemia, hyperglycemia, hepatic steatosis, inflammation, and human and murine fibrosis gene set enrichment that is consistent with progression to NASH. RNAseq analysis revealed differentially expressed genes (DEGs) associated with HFWD and HFWD+F/S dietary treatments compared to Chow-fed mice. However, liquid sugar consumption resulted in a unique set of hepatic DEGs in HFWD+F/S-fed mice, which were enriched in the complement and coagulation cascades using network and biological analysis. Cluster analysis identified Orosomucoid (ORM) as a HFWD+F/S upregulated complement and coagulation cascades gene that was also upregulated in hepatocytes treated with TNFα or free fatty acids in combination with hypoxia. ORM expression was found to correlate with NAFLD parameters in obese mice. Taken together, this study examined key genes, biological processes, and pathway changes in the liver of HFWD+F/S mice in an effort to provide insight into the molecular basis for which the addition of liquid sugar promotes the progression of NAFLD.

Dietary and nutrition considerations in caring for patients with nonalcoholic fatty liver disease: Updates for the practicing clinician

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide, affecting up to one-third of the global population. The disease is defined by excess fat deposition in the liver and has a strong correlation with metabolic syndrome, which, in turn, is also a risk factor for disease progression, including the development of steatohepatitis, advanced fibrosis, cirrhosis, and hepatocellular carcinoma. Although a number of medications are being explored for disease mitigation, nothing is currently approved, and the mainstay of therapy remains dietary and lifestyle intervention that promotes weight loss as well as management of comorbid conditions. The landscape that guides care for patients with NAFLD continues to evolve. Clinicians caring for these patients need to consider underlying disease state and nutrition risk in addition to concurrent related diagnoses, such as insulin resistance and hyperlipidemia, when formulating treatment plans. The following is a comprehensive review of the current dietary and nutrition considerations in the management of patients with NAFLD, with a special emphasis on implications for the practicing clinician.

Disruption of the Intestinal Mucosal Barrier Induced by High Fructose and Restraint Stress Is Regulated by the Intestinal Microbiota and Microbiota Metabolites

Environmental (restraint stress) and dietary (high fructose) factors are key triggers for flares of inflammatory bowel disease; however, the mechanisms involved in this phenomenon are not fully elucidated. This study aimed to investigate the mechanisms by which restraint stress and high fructose damage the intestinal mucosal immune barrier. The feces of C57BL/6J mice were subjected to 16S rRNA and untargeted metabolome sequencing, and the intestinal histological structure was analyzed by immunohistochemistry and immunofluorescence staining. The mRNA and protein levels of the intestinal protein were analyzed by reverse transcription-PCR (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). The metabolites of the microbiota were tested in vitro, and Akkermansia muciniphila was used for colonization in vivo. Dietary fructose exacerbated the development of restraint stress, with an extensive change in the composition of the gut microbiota and microbial metabolites. The disturbance of the microbiota composition led to an increase in the abundance of histamine and a decrease in the abundance of taurine, which inhibited the expression of tight junction and MUC2 proteins, destroyed the function of NLRP6, and reduced intestinal autophagy level; this in turn disrupted the function of colonic goblet cells to secrete mucus, leading to defects in the intestinal mucosal barrier, which ultimately codrives colon autoinflammation. However, A. muciniphila supplementation counteracted damage to the intestinal mucosal barrier by high fructose and restraint stress. Therefore, the gut microbiota and microbiota metabolites play an important role in maintaining microenvironment homeostasis of the intestinal mucosal barrier. IMPORTANCE A high-fructose diet aggravated restraint stress-induced changes in the composition of the intestinal microbiome, in which the abundance of A. muciniphila was significantly increased. The high-fructose diet exacerbated restraint stress-induced the changes in the composition of the microbial metabolites, with taurine abundance being downregulated and histamine abundance upregulated. High fructose and restraint stress induced colonic mucosal immune barrier damage, possibly due to changes in the abundance of the microbial metabolites taurine and histamine. Colonization with A. muciniphila stimulated the expression of the NLRP6 inflammasome and activated autophagy in goblet cells, thereby producing more new mucins, which could protect the intestinal mucosal barrier.

The Caffeine Content of Energy Drinks in accordance with the Information on the Package Label

Six different brands of energy drinks (EDs) were analyzed to determine the concentration of caffeine in accordance with the information on the package label. Approximately 28.1 milligrams per 100 milliliters (mg/100 ml) of caffeine was present in the Mo energy drink brand, which was nearly 1.5 times the caffeine concentration listed on the product label. The energy drink with the highest caffeine content was Dragon, which contained 30.1 mg/100 ml, or a total of 150.5 mg per 500 ml bottle. Manufacturers of energy drinks (EDs) should accurately list the amount of caffeine and other ingredients on the product label so that consumers know how much of each ingredient they are taking. Taking too much caffeine can be bad for your health.

Effects of Different Vegetable Oils on the Nonalcoholic Fatty Liver Disease in C57/BL Mice

Background

Nonalcoholic fatty liver disease (NAFLD) is the most common hepatic disorder, affecting 22-28% of the adult population and more than 50% of obese people all over the world. Modulation of the fatty acids in diet as a means of prevention against nonalcoholic fatty liver disease in animal models (NAFLD) remains unclear. The treatment of NAFLD has not been described in specific guidelines so far. Thus, the justification for the study is to check modifications in macronutrients composition, fatty acids, in particular, play a significant role in the treatment of NAFLD regardless of weight loss.

Aim

To investigate different vegetable oils in prevention and progression of NAFLD in animal models.

Methods

For the experiment were used fifty C57BL/6J mice male fed with high fat and fructose diet (HFD) to induce the NAFLD status and they received different commercial vegetable oils for 16 weeks to prevent steatosis. Liver steatosis and oxidative stress parameters were analyzed using biochemical and histological methods. Fatty acids profile in the oils and in the liver samples was obtained.

Results

The high fat and fructose diet led to obesity and the vegetable oils offered were effective in maintaining body weight similar to the control group. At the end of the experiment (16 weeks), the HFHFr group had a greater body weight compared to control and treated groups (HFHFr: 44.20 ± 2.34 g/animal vs. control: 34.80 ± 3.45 g/animal; p < 0.001; HFHFr/OL: 35.40 ± 4.19 g/animal; HFHFr/C: 36.10 ± 3.92 g/animal; HFHFr/S: 36.25 ± 5.70 g/animal; p < 0.01). Furthermore, the HFD diet has caused an increase in total liver fat compared to control (p < 0.01). Among the treated groups, the animals receiving canola oil showed a reduction of hepatic and retroperitoneal fat (p < 0.05). These biochemical levels were positively correlated with the hepatic histology findings. Hepatic levels of omega-3 decreased in the olive oil and high fat diet groups compared to the control group, whereas these levels increased in the groups receiving canola and soybean oil compared to control and the high fat groups.

Conclusion

In conclusion, the commercial vegetable oils either contributed to the prevention or reduction of induced nonalcoholic fatty liver with high fat and fructose diet, especially canola oil.

Clinical features and metabolic complications for non-alcoholic fatty liver disease (NAFLD) in youth with obesity

Pediatric obesity has become in the last forty years the most common metabolic disease in children and adolescents affecting about 25% of the pediatric population in the western world. As obesity worsens, a whole-body insulin resistance (IR) occurs. This phenomenon is more pronounced during adolescence, when youth experience a high degree of insulin resistance due the production of growth hormone. As IR progresses, the blunted control of insulin on adipose tissue lipolysis causes an increased flux of fatty acids with FFA deposition in ectopic tissues and organs such as the liver, leading to the development of NAFLD. In this brief review, we will discuss the clinical implications of IR and NAFLD in the context of pediatric obesity. We will review the pathogenesis and the link between these two entities, the major pathophysiologic underpinnings, including the role of genetics and metagenomics, how these two entities lead to the development of type 2 diabetes, and which are the therapeutic options for NAFLD in youth.

Effects of time-restricted feeding (16/8) combined with a low-sugar diet on the management of non-alcoholic fatty liver disease: A randomized controlled trial

OBJECTIVES

Emerging studies have employed time-restricted feeding (TRF) and a low-sugar diet alone in the management of non-alcoholic fatty liver disease (NAFLD), but their combination has not been tested. The aim of this study was to investigate the effects of TRF combined with a low-sugar diet on NAFLD parameters, cardiometabolic and inflammatory biomarkers, and body composition in patients with NAFLD.

METHODS

A 12-wk randomized controlled trial was performed to compare the effects of TRF (16 h fasting/8 h feeding daily [16/8]) plus a low-sugar diet versus a control diet based on traditional meal distribution in patients with NAFLD. Changes in body composition, anthropometric indices, and liver and cardiometabolic markers were investigated.

RESULTS

TRF 16/8 with a low-sugar diet reduced body fat (26.7 ± 5.4 to 24.2 ± 4.9 kg), body weight (83.8 ± 12.7 to 80.5 ± 12.1 kg), waist circumference (104.59 ± 10.47 to 101.91 ± 7.42 cm), and body mass index (29.1 ± 2.6 to 28 ± 2.7 kg/m²), as well as circulating levels of fasting blood glucose and liver (alanine aminotransferase, 34 ± 13.9 to 21.2 ± 5.4 U/L; aspartate aminotransferase, 26.3 ± 6.2 to 20.50 ± 4 U/L; γ-glutamyl transpeptidase, 33 ± 15 to 23.2 ± 11.1 U/L; fibrosis score, 6.3 ± 1 to 5.2 ± 1.2 kPa; and controlled attenuation parameter, 322.9 ± 34.9 to 270.9 ± 36.2 dB/m), lipids (triacylglycerols, 201.5 ± 35.3 to 133.3 ± 48.7 mg/dL; total cholesterol, 190 ± 36.6 to 157.8 ± 33.6 mg/dL; and low-density lipoprotein cholesterol, 104.6 ± 27.3 to 84 ± 26.3 mg/dL), and inflammatory markers (high-sensitivity C-reactive protein, 3.1 ± 1.1 to 2 ± 0.9 mg/L; and cytokeratin-18, 1.35 ± 0.03 to 1.16 ± 0.03 ng/mL). These results were statistically significant (P < 0.05) compared with the control group.

CONCLUSIONS

TRF plus a low-sugar diet can reduce adiposity and improve liver, lipid, and inflammatory markers in patients with NAFLD.

Non-Alcoholic Fatty Liver Disease (NAFLD) Pathogenesis and Natural Products for Prevention and Treatment

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, affecting approximately one-quarter of the global population, and has become a world public health issue. NAFLD is a clinicopathological syndrome characterized by hepatic steatosis, excluding ethanol and other definite liver damage factors. Recent studies have shown that the development of NAFLD is associated with lipid accumulation, oxidative stress, endoplasmic reticulum stress, and lipotoxicity. A range of natural products have been reported as regulators of NAFLD in vivo and in vitro. This paper reviews the pathogenesis of NAFLD and some natural products that have been shown to have therapeutic effects on NAFLD. Our work shows that natural products can be a potential therapeutic option for NAFLD.

Camel milk protein hydrosylate alleviates hepatic steatosis and hypertension in high fructose-fed rats

CONTEXT

Camel milk is used in traditional medicine to treat diabetes mellitus hypertension and other metabolic disorders.

OBJECTIVE

This study evaluated the antisteatotic and antihypertensive effects of camel milk protein hydrolysate (CMH) in high fructose (HF)-fed rats and compared it with the effects afforded by the intact camel milk protein extract (ICM).

MATERIALS AND METHODS

Adult male Wistar rats were divided into 6 groups (n = 8 each) as 1) control, 2) ICM (1000 mg/kg), 3) CMH (1000 mg/kg), 4) HF (15% in drinking water), 5) HF (15%) + ICM (1000 mg/kg), and 6) HF (15%) + CMH (1000 mg/kg). All treatments were given orally for 21 weeks, daily.

RESULTS

Both ICM and CMH reduced fasting glucose and insulin levels, serum and hepatic levels of cholesterol and triglycerides, and serum levels of ALT and AST, angiotensin II, ACE, endothelin-1, and uric acid in HF-fed rats. In addition, both ICM and CMH reduced hepatic fat deposition in the hepatocytes and reduced hepatocyte damage. This was associated with an increase in the hepatic activity of AMPK, higher PPARα mRNA, reduced expression of fructokinase C, SREBP1, SREBP2, fatty acid synthase, and HMG-CoA-reductase. Both treatments lowered systolic and diastolic blood pressure. However, the effects of CMH on all these parameters were greater as compared to ICM.

DISCUSSION AND CONCLUSIONS

The findings of this study encourage the use of CMH in a large-scale population and clinical studies to treat metabolic steatosis and hypertension.

Adherence to low carbohydrate diets and non-alcoholic fatty liver disease: a case control study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is defined as the excessive accumulation of fat in the liver cells of people who do not drink alcohol. The aim of study is investigated the association between low carbohydrate diets (LCDs) and NAFLD.

METHODS

This age and gender-matched case-control study was conducted on 120 patients newly diagnosed with NAFLD and 120 adults without NAFLD. Diagnosis of NAFLD based on laboratory tests and abdominal ultrasound. Low carbohydrate diets score calculated on the percentage of energy as carbohydrate, fat, and protein. Participants in the highest rank intake of fat and protein and lowest intake of carbohydrate received 10 points. Multivariable logistic odds ratio was used for examine the relation between LCDs and NAFLD.

RESULTS

This study showed subjects in the highest tertile of LCD has more intake of zinc and vitamin B12 compare to lowest. Also, intake of protein (p = 0.02) carbohydrate (p < 0.02) and cholesterol (p = 0.02) were significantly higher in patient with NAFLD compare to control subjects. There was no significant association between LCD and risk of NAFLD (OR: 1.36; 95% CI: 0.97-1.92; P-trend = 0.13) in crude and adjusted (OR: 1.31; 95% CI: 0.84-2.04; P-trend = 0.23) model.

CONCLUSION

However, we showed that intake of protein, carbohydrate and cholesterol are higher in NAFLD, but our results of study showed that LCDs with higher proportion intakes of protein and fat was not associated with NAFLD. Further prospective studies are required for confirm these associations.

The protective roles of augmenter of liver regeneration in hepatocytes in the non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) occurs in 25% of the global population and manifests as lipid deposition, hepatocyte injury, activation of Kupffer and stellate cells, and steatohepatitis. Predominantly expressed in hepatocytes, the augmenter of liver regeneration (ALR) is a key factor in liver regulation that can alleviate fatty liver disease and protect the liver from abnormal liver lipid metabolism. ALR has three isoforms (15-, 21-, and 23-kDa), amongst which 23-kDa ALR is the most extensively studied. The 23-kDa ALR isoform is a sulfhydryl oxidase that resides primarily in the mitochondrial intermembrane space (IMS), whereby it protects the liver against various types of injury. In this review, we describe the role of ALR in regulating hepatocytes in the context of NAFLD. We also discuss questions about ALR that remain to be explored in the future. In conclusion, ALR appears to be a promising therapeutic target for treating NAFLD.

Dissecting ultra-processed foods and drinks: Do they have a potential to impact the brain?

Ultra-processed foods and drinks (UPF) are formulation of ingredients, mostly of exclusive industrial use, that result from a series of industrial processes. They usually have a low nutrient but high energy density, with a high content of saturated and trans fats, and added sugars. In addition, they have characteristic organoleptic properties, and usually contain sophisticated additives, including artificial sweeteners, to intensify their sensory qualities and imitate the appearance of minimally processed foods. In addition, recent research has warned about the presence of chemicals (e.g., bisphenol) and neo-formed contaminants in these products. UPF production and consumption growth have been spectacular in the last decades, being specially consumed in children and adolescents. UPF features have been associated with a range of adverse health effects such as overeating, the promotion of inflammatory and oxidative stress processes, gut dysbiosis, and metabolic dysfunction including problems in glucose regulation. The evidence that these UPF-related adverse health effects may have on the neural network implicated in eating behavior are discussed, including the potential impact on serotonergic and dopaminergic neurotransmission, brain integrity and function. We end this review by placing UPF in the context of current food environments, by suggesting that an increased exposure to these products through different channels, such as marketing, may contribute to the automatic recruitment of the brain regions associated with food consumption and choice, with a detrimental effect on inhibitory-related prefrontal cortices. While further research is essential, preliminary evidence point to UPF consumption as a potential detrimental factor for brain health and eating behavior.

Effects of oily fish and its fatty acid intake on non-alcoholic fatty liver disease development among South Korean adults

Background

The benefits of fish fatty acid intake for non-alcoholic fatty liver disease (NAFLD) are rarely reported, although a previous study assessed the relationship between oily fish consumption and the prevalence of NAFLD.

Aims

We investigated whether oily fish and fish-based monounsaturated fatty acids, polyunsaturated fatty acids, and omega-3 fatty acids affect the development of NAFLD in South Korean adults.

Methods

In this large-scale cohort study, 44,139 participants of the Health Examinees study were selected for analysis after 5 years of follow-up. NAFLD is diagnosed with a non-invasive index, the fatty liver index. Using multivariable Cox proportional hazards models, adjusted for age, body mass index, total energy intake, education, physical activity, smoking status, and drinking (alcohol) status, we calculated the hazard ratios and 95% confidence intervals.

Results

For men, NAFLD had no statistically significant associations with quartiles of total oily fish or its fatty acid intake. However, among women, an inverse association was observed (all p for trend <0.05). Regarding the standard deviation (SD) increment of total oily fish or its fatty acid intake by one, all fatty acids from oily fish showed inverse associations for NAFLD in both men and women. After stratified analyses, we found that drinking status and menopause status were independent risk factors for NAFLD. Oily fish or its fatty acid intake has the same benefit pattern on metabolic dysfunction-associated fatty liver disease as NAFLD.

Conclusion

Oily fish and its fatty acid intake showed a preventative benefit for NAFLD and metabolic dysfunction-associated fatty liver disease, especially in South Korean women.

Nonalcoholic Fatty Liver Disease in Children with Obesity: Narrative Review and Research Gaps

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the leading hepatic disease in children, ranging from steatosis to steatohepatitis and fibrosis. Age, sex, hormonal levels, pubertal stages, genetic risk- and epigenetic factors are among the many influencing factors. Appearing predominantly in children with obesity, but not exclusively, it is the liver's manifestation of the metabolic syndrome but can also exist as an isolated entity.

SUMMARY

Pediatric NAFLD differs from the adult phenotype. This narrative review on NAFLD in children with obesity provides an overview of the current knowledge on risk factors, screening, and diagnostic methods, as well state-of-the-art treatment. The recent discussion on the proposition of a new nomenclature - Metabolic [Dysfunction-] Associated Liver Disease - is featured, and current gaps of knowledge are discussed.

KEY MESSAGES

Currently, there is no international consensus on screening and monitoring of pediatric NAFLD. With lifestyle interventions being the cornerstone of treatment, no registered pharmacological treatment for pediatric NAFLD is available. Development and validation of additional noninvasive biomarkers, scores and imaging tools suitable to subcategorize, screen and monitor pediatric patients are necessary. With a variety of upcoming and promising agents, clear recommendations for pediatric nonalcoholic steatohepatitis trials are urgently needed.

Liver Steatosis: A Marker of Metabolic Risk in Children

Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as 'Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)', supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD's therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis.

Perceptions of weight status and energy balance behaviors among patients with non-alcoholic fatty liver disease

Weight loss through behavioral modification is central to treating non-alcoholic fatty liver disease (NAFLD). To achieve this, patients need to accurately self-perceive their health behaviors. We aimed to identify predictors of concordance between self-perception and objective measures of body weight, physical activity (PA) and dietary behaviors. We used data from the Harris County NAFLD Cohort, an ongoing prospective study in a regional safety-net healthcare system. Patients completed self-administered baseline questionnaires on demographics, diet, PA, and self-perceptions. We assessed concordance between actual and self-perceived body weight and energy-balance behaviors. Multivariable logistic regression identified predictors of concordance. Patients (n = 458; average age 46.5 years) were 90% Hispanic and 76% female. PA and fruit/vegetable intake guidelines were met among 37% and 9%, respectively. Most (89%) overweight/obese patients accurately perceived themselves as such. However, 41% of insufficiently-active and 34% of patients not meeting fruit/vegetable intake guidelines inaccurately self-perceived their behaviors as "just right". Women were 3 times more likely to accurately self-perceive weight status (adjusted odds ratio [AOR] 3.24; 95% CI 1.68-6.25) but 51% less likely to accurately self-perceive PA levels than men (AOR 0.49; 95% CI 0.29-0.81). Lower acculturation was associated with higher odds of accurate PA self-perception. Patients with prediabetes or diabetes vs normoglycemia were more likely to accurately self-perceive their fruit/vegetable intake. Most NAFLD patients accurately self-perceived their body weight. A third or more of those not meeting fruit/vegetable intake or PA guidelines had inaccurate perceptions about their behaviors. Our findings highlight key areas to target in NAFLD-specific behavioral modification programs.

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.

Molecular Probes, Chemosensors, and Nanosensors for Optical Detection of Biorelevant Molecules and Ions in Aqueous Media and Biofluids

Synthetic molecular probes, chemosensors, and nanosensors used in combination with innovative assay protocols hold great potential for the development of robust, low-cost, and fast-responding sensors that are applicable in biofluids (urine, blood, and saliva). Particularly, the development of sensors for metabolites, neurotransmitters, drugs, and inorganic ions is highly desirable due to a lack of suitable biosensors. In addition, the monitoring and analysis of metabolic and signaling networks in cells and organisms by optical probes and chemosensors is becoming increasingly important in molecular biology and medicine. Thus, new perspectives for personalized diagnostics, theranostics, and biochemical/medical research will be unlocked when standing limitations of artificial binders and receptors are overcome. In this review, we survey synthetic sensing systems that have promising (future) application potential for the detection of small molecules, cations, and anions in aqueous media and biofluids. Special attention was given to sensing systems that provide a readily measurable optical signal through dynamic covalent chemistry, supramolecular host-guest interactions, or nanoparticles featuring plasmonic effects. This review shall also enable the reader to evaluate the current performance of molecular probes, chemosensors, and nanosensors in terms of sensitivity and selectivity with respect to practical requirement, and thereby inspiring new ideas for the development of further advanced systems.

Current considerations for clinical management and care of non-alcoholic fatty liver disease: Insights from the 1st International Workshop of the Canadian NASH Network (CanNASH)

Non-alcoholic fatty liver disease (NAFLD) affects approximately 8 million Canadians. NAFLD refers to a disease spectrum ranging from bland steatosis to non-alcoholic steatohepatitis (NASH). Nearly 25% of patients with NAFLD develop NASH, which can progress to liver cirrhosis and related end-stage complications. Type 2 diabetes and obesity represent the main risk factors for the disease. The Canadian NASH Network is a national collaborative organization of health care professionals and researchers with a primary interest in enhancing understanding, care, education, and research around NAFLD, with a vision of best practices for this disease state. At the 1st International Workshop of the CanNASH network in April 2021, a joint event with the single topic conference of the Canadian Association for the Study of the Liver (CASL), clinicians, epidemiologists, basic scientists, and community members came together to share their work under the theme of NASH. This symposium also marked the initiation of collaborations between Canadian and other key opinion leaders in the field representative of international liver associations. The main objective is to develop a policy framework that outlines specific targets, suggested activities, and evidence-based best practices to guide provincial, territorial, and federal organizations in developing multidisciplinary models of care and strategies to address this epidemic.

Mineralocorticoid receptor modulation by dietary sodium influences NAFLD development in mice

INTRODUCTION AND OBJECTIVES

Nonalcoholic-fatty-liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome (MetS). Mineralocorticoid receptor (MR) activation is associated with increased risk of MetS but few studies have assessed the role of liver MR on NAFLD. We aimed to evaluate the effect of MR modulation by sodium intake in liver injury in experimental models of NAFLD.

MATERIALS AND METHODS

C57BL/6J mice were fed either a high-fat-diet (HFD) or a choline/methionine deficient (MCD) diet with different sodium concentrations. Hepatic concentration of lipid species, serum aldosterone levels, expression of MR, proinflammatory and profibrotic markers and liver histology were assessed.

RESULTS

Mice fed with High-Na⁺/HFD showed a lower MR expression in liver (p = 0.01) and less steatosis on histology (p = 0.04). Consistently, animals from this group exhibited lower levels of serum aldosterone (p = 0.028) and lower hepatic triglyceride content (p = 0.008). This associated to a reduced expression of lipogenic genes, significant changes in lipid subspecies, lower HOMA-IR (p < 0.05), and lower expression of pro-inflammatory and profibrotic markers compared to those mice fed a Low-Na⁺/HFD. Additionally, mice fed a High-Na⁺/HFD showed higher expression of salt-inducible kinase (SIK)-1 and lower expression of serum-and-glucocorticoid-inducible kinase (SGK)-1. Similar results were observed with the MCD diet model.

CONCLUSION

We identified in two experimental models of NAFLD that High-Na⁺ diet content is associated to lower serum aldosterone levels and hepatic MR downregulation, associated to decreased steatosis and reduced de novo hepatic lipogenesis, proinflammatory and profibrotic markers. Decreased activation of hepatic MR seems to generate beneficial downstream inhibition of lipogenesis in experimental NAFLD.

The crucial role of oxidative stress in non-alcoholic fatty liver disease-induced male reproductive toxicity: the ameliorative effects of Iranian indigenous probiotics

Several studies have focused on the high potential effects of probiotics on the reproductive system. However, there is a paucity of information regarding the ameliorative intracellular roles of indigenous Iranian yogurt-extracted/cultured probiotics on animals' reproductive health suffering from obesity and/or fatty liver disease, such as non-alcoholic fatty liver disease (NAFLD). For this purpose, simultaneously with the consumption of D-fructose (200 g/1000 mL water, induction of NAFLD model), all pubertal animals were also gavaged every day for 63 consecutive days with extracted probiotics, including 1 × 109 CFU/mL of Lactobacillus acidophilus (LA), Bifidobacterium spp. (BIF), Bacillus coagulans (BC), Lactobacillus rhamnosus (LR), and a mixture form (LA + BIF + BC + LR). At the end of the ninth week, the indices of epididymal sperm, and oxidative stress, as well as histopathological changes, were assessed. The results show that NAFLD could induce robust oxidative stress, highlighted as considerable increments in ROS level, TBARS content, total oxidized protein levels, along with severe decrements in reduced glutathione reservoirs, total antioxidant capacity in the hepatic and testicular tissues, as well as testicular and hepatic histopathological alterations. Moreover, a significant decrease in the percentage of sperm progressive motility, sperm count, and membrane integrity along with an increment in the percentage of sperm abnormality was detected in NAFLD animals. The observed adverse effects were significantly reversed upon probiotics treatment, especially in the group challenged with a mixture of all probiotics. Taken together, these findings indicate that the indigenous yogurt-isolated/cultured probiotics had a high potential antioxidant activity and the ameliorative effect against reprotoxicity and blood biochemical alterations induced by the NAFLD model. Highlights: 1. Reproductive indices could be reversely affected by xenobiotics and diseases. 2. NAFLD and cholestasis considerably affect the reproductive system in both genders. 3. NAFLD induced hepatic and testicular oxidative stress (OS). 4. NAFLD induced histopathological alterations and spermatotoxicity through OS. 5. The adverse effects were significantly reversed upon exposure to probiotics.

Metabolism and Health Effects of Rare Sugars in a CACO-2/HepG2 Coculture Model

Non-alcoholic fatty liver disease (NAFLD) has become the most prevalent liver disease worldwide and is impacted by an unhealthy diet with excessive calories, although the role of sugars in NAFLD etiology remains largely unexplored. Rare sugars are natural sugars with alternative monomers and glycosidic bonds, which have attracted attention as sugar replacers due to developments in enzyme engineering and hence an increased availability. We studied the impact of (rare) sugars on energy production, liver cell physiology and gene expression in human intestinal colorectal adenocarcinoma (Caco-2) cells, hepatoma G2 (HepG2) liver cells and a coculture model with these cells. Fat accumulation was investigated in the presence of an oleic/palmitic acid mixture. Glucose, fructose and galactose, but not mannose, l-arabinose, xylose and ribose enhanced hepatic fat accumulation in a HepG2 monoculture. In the coculture model, there was a non-significant trend (p = 0.08) towards higher (20–55% increased) median fat accumulation with maltose, kojibiose and nigerose. In this coculture model, cellular energy production was increased by glucose, maltose, kojibiose and nigerose, but not by trehalose. Furthermore, glucose, fructose and l-arabinose affected gene expression in a sugar-specific way in coculture HepG2 cells. These findings indicate that sugars provide structure-specific effects on cellular energy production, hepatic fat accumulation and gene expression, suggesting a health potential for trehalose and l-arabinose, as well as a differential impact of sugars beyond the distinction of conventional and rare sugars.

The Contribution of Dietary Fructose to Non-alcoholic Fatty Liver Disease

Fructose, especially industrial fructose (sucrose and high fructose corn syrup) is commonly used in all kinds of beverages and processed foods. Liver is the primary organ for fructose metabolism, recent studies suggest that excessive fructose intake is a driving force in non-alcoholic fatty liver disease (NAFLD). Dietary fructose metabolism begins at the intestine, along with its metabolites, may influence gut barrier and microbiota community, and contribute to increased nutrient absorption and lipogenic substrates overflow to the liver. Overwhelming fructose and the gut microbiota-derived fructose metabolites (e.g., acetate, butyric acid, butyrate and propionate) trigger the de novo lipogenesis in the liver, and result in lipid accumulation and hepatic steatosis. Fructose also reprograms the metabolic phenotype of liver cells (hepatocytes, macrophages, NK cells, etc.), and induces the occurrence of inflammation in the liver. Besides, there is endogenous fructose production that expands the fructose pool. Considering the close association of fructose metabolism and NAFLD, the drug development that focuses on blocking the absorption and metabolism of fructose might be promising strategies for NAFLD. Here we provide a systematic discussion of the underlying mechanisms of dietary fructose in contributing to the development and progression of NAFLD, and suggest the possible targets to prevent the pathogenetic process.

"Sweet death": Fructose as a metabolic toxin that targets the gut-liver axis

Glucose and fructose are closely related simple sugars, but fructose has been associated more closely with metabolic disease. Until the 1960s, the major dietary source of fructose was fruit, but subsequently, high-fructose corn syrup (HFCS) became a dominant component of the Western diet. The exponential increase in HFCS consumption correlates with the increased incidence of obesity and type 2 diabetes mellitus, but the mechanistic link between these metabolic diseases and fructose remains tenuous. Although dietary fructose was thought to be metabolized exclusively in the liver, evidence has emerged that it is also metabolized in the small intestine and leads to intestinal epithelial barrier deterioration. Along with the clinical manifestations of hereditary fructose intolerance, these findings suggest that, along with the direct effect of fructose on liver metabolism, the gut-liver axis plays a key role in fructose metabolism and pathology. Here, we summarize recent studies on fructose biology and pathology and discuss new opportunities for prevention and treatment of diseases associated with high-fructose consumption.

The Effects of Butyrate on Induced Metabolic-Associated Fatty Liver Disease in Precision-Cut Liver Slices

Metabolic-associated fatty liver disease (MAFLD) starts with hepatic triglyceride accumulation (steatosis) and can progress to more severe stages such as non-alcoholic steatohepatitis (NASH) and even cirrhosis. Butyrate, and butyrate-producing bacteria, have been suggested to reduce liver steatosis directly and systemically by increasing liver β-oxidation. This study aimed to examine the influence of butyrate directly on the liver in an ex vivo induced MAFLD model. To maintain essential intercellular interactions, precision-cut liver slices (PCLSs) were used. These PCLSs were prepared from male C57BL/6J mice and cultured in varying concentrations of fructose, insulin, palmitic acid and oleic acid, to mimic metabolic syndrome. Dose-dependent triglyceride accumulation was measured after 24 and 48 h of incubation with the different medium compositions. PCLSs viability, as indicated by ATP content, was not affected by medium composition or the butyrate concentration used. Under induced steatotic conditions, butyrate did not prevent triglyceride accumulation. Moreover, it lowered the expression of genes encoding for fatty acid oxidation and only increased C4 related carnitines, which indicate butyrate oxidation. Nevertheless, butyrate lowered the fibrotic response of PCLSs, as shown by reduced gene expression of fibronectin, alpha-smooth muscle actin and osteopontin, and protein levels of type I collagen. These results suggest that in the liver, butyrate alone does not increase lipid β-oxidation directly but might aid in the prevention of MAFLD progression to NASH and cirrhosis.

An Efficient Model of Non-alcoholic Fatty Liver Disease (NAFLD) Versus Current Experimental Models: Effects of Fructose, Fat, and Carbon Tetrachloride on NAFLD

Background: Accumulation of fat in the liver is one of the causes of non-alcoholic fatty liver disease (NAFLD), which affects about 30% of the world's population. Animal models have been useful tools for investigating the mechanisms involved in the etiology of NAFLD and developing new drugs. Objectives: This study aimed to present a new model for the detection of NAFLD in rats. Methods: Forty-eight rats were randomly divided into six experimental groups: (1) control; (2) 45% fructose + 35% olive oil + carbon tetrachloride (FFC1); (3) carbon tetrachloride (1: 4 in olive oil) (C1); (4) carbon tetrachloride (1: 6 in olive oil) (C2); (5) 12.5% fructose + 12.5% olive oil (FF); and (6) 20% fructose + carbon tetrachloride (1: 4 in olive oil) (FC1). Blood samples were taken in three steps, and liver tissue was dissected at the end of the sixth week for histopathological assessments. Results: After six weeks, the alanine transaminase (131.63 ± 1.51), aspartate transaminase (275 ± 1.0), and gamma-glutamyl transferase (4.30 ± 0.1) levels increased significantly in the C1 group (P < 0.05). The serum lipid profile showed significant changes in all groups compared to the controls (P < 0.01). According to the histological results, all experimental groups, except the C2 group, showed symptoms of NAFLD; nevertheless, a higher NAFLD Activity Score (NAS) was found in the C1 group, followed by the FC1 group, compared to the other groups. Conclusions: The present results revealed that injection of 0.1 mL/kg of carbon tetrachloride (C1 group), alone or along with a diet containing 20% fructose (FC1 group), provided useful animal models of NAFLD, although carbon tetrachloride injection alone is the most effective model in inducing NAFLD model that can be used as a new strategy in nutritional and pharmacological studies.

Nectar-feeding bats and birds show parallel molecular adaptations in sugar metabolism enzymes

In most vertebrates, the demand for glucose as the primary substrate for cellular respiration is met by the breakdown of complex carbohydrates, or energy is obtained by protein and lipid catabolism. In contrast, a few bat and bird species have convergently evolved to subsist on nectar, a sugar-rich mixture of glucose, fructose, and sucrose.^1-4 How these nectar-feeders have adapted to cope with life-long high sugar intake while avoiding the onset of metabolic syndrome and diabetes^5-7 is not understood. We analyzed gene sequences obtained from 127 taxa, including 22 nectar-feeding bat and bird genera that collectively encompass four independent origins of nectarivory. We show these divergent taxa have undergone pervasive molecular adaptation in sugar catabolism pathways, including parallel selection in key glycolytic and fructolytic enzymes. We also uncover convergent amino acid substitutions in the otherwise evolutionarily conserved aldolase B (ALDOB), which catalyzes rate-limiting steps in fructolysis and glycolysis, and the mitochondrial gatekeeper pyruvate dehydrogenase (PDH), which links glycolysis and the tricarboxylic acid cycle. Metabolomic profile and enzyme functional assays are consistent with increased respiratory flux in nectar-feeding bats and help explain how these taxa can both sustain hovering flight and efficiently clear simple sugars. Taken together, our results indicate that nectar-feeding bats and birds have undergone metabolic adaptations that have enabled them to exploit a unique energy-rich dietary niche among vertebrates.