Beer Is Less Harmful for the Liver than Plain Ethanol: Studies in Male Mice Using a Binge-Drinking Model.

AIMS: Mechanisms involved in the less damaging effects of beer in comparison to hard spirits have not yet been fully understood. The aim of the study was to determine if the effect of beer intake on the liver differs from that of plain ethanol and if so to determine mechanisms involved. METHODS: Male C57BL/6J mice received either ethanol, beer (ethanol content: 6 g/kg body weight) or iso-caloric maltodextrin solution. Markers of steatosis, lipogenesis, activation of the toll-like receptor-4 signaling cascade and lipid export in liver and tight junction proteins in duodenum were measured 6 and 12 h after acute ethanol or beer intake. RESULTS: Alcohol ingestion resulted in a significant increase of hepatic triglyceride accumulation 6 and 12 h after ingestion, respectively, being markedly lower in mice fed beer. Expression of sterol regulatory element-binding protein-1c mRNA was significantly lower 12 h after alcohol or beer exposure, while fatty acid synthase mRNA expression was induced in livers of ethanol-fed mice and to a lesser extent in mice fed beer 6 h after acute alcohol ingestion. Protein levels of tight junction proteins in the small intestine were similar between groups while expression of myeloid differentiation primary response gene 88 in livers was significantly induced in ethanol- but not in beer-fed mice. Concentrations of 4-hydroxynonenal protein adducts and inducible nitric oxide synthase protein were also only induced in livers of mice fed ethanol. Protein levels of apolipoprotein B were induced in livers of beer-fed mice only. CONCLUSION: Our data suggest that beer is less harmful on the development of acute alcohol-induced liver damage than plain ethanol in male mice.

Effect of acute beer ingestion on the liver: studies in female mice.

PURPOSE: The aim of the present study was to assess whether the effects of acute consumption of stout or pilsner beer on the liver differ from those of plain ethanol in a mouse model. METHODS: Seven-week-old female C57BL/6J mice received either ethanol, stout or pilsner beer (ethanol content: 6 g/kg body weight) or isocaloric maltodextrin solution. Plasma alanine transaminase, markers of steatosis, lipogenesis, activation of the toll-like receptor-4 signaling cascade as well as lipid peroxidation and fibrogenesis in the liver were measured 12 h after acute ethanol or beer intake. RESULTS: Acute alcohol ingestion caused a marked ~11-fold increase in hepatic triglyceride accumulation in comparison to controls, whereas in mice exposed to stout and pilsner beer, hepatic triglyceride levels were increased only by ~6.5- and ~4-fold, respectively. mRNA expression of sterol regulatory element-binding protein 1c and fatty acid synthase in the liver did not differ between alcohol and beer groups. In contrast, expression of myeloid differentiation primary response gene 88, inducible nitric oxide synthases, but also the concentrations of 4-hydroxynonenal protein adducts, nuclear factor κB and plasminogen activator inhibitor-1 were induced in livers of ethanol treated mice but not in those exposed to the two beers. CONCLUSION: Taken together, our results suggest that acute ingestion of beer and herein especially of pilsner beer is less harmful to the liver than the ingestion of plain ethanol.

Differences in the prevalence of metabolic disorders between prepubertal boys and girls from 5 to 8 years of age.

AIM: To determine the prevalence of metabolic abnormalities, and differences between the sexes, in prepubertal overweight and normal weight children aged from 5 to 8 years, without any signs of health impairments or metabolic disturbances at the time of recruitment. METHODS: General health status and inflammatory markers were assessed in 100 overweight and 51 normal weight children, who were living in Germany and had undergone mandatory medical examinations. The study comprised of 81 girls and 70 boys. RESULTS: Despite being recruited as healthy, 73% of the overweight children and 16% of the normal weight children were found to suffer from one or more metabolic abnormalities, such as hypertension or insulin resistance. Girls with a body mass index (BMI) percentile of ≥80th showed an increased susceptibility to metabolic disorders, and a similar effect was found for boys with a BMI percentile of ≥95th. Plasma levels of proinflammatory markers, such as plasminogen activator inhibitor-1 and leptin, were also significantly higher in overweight than normal weight children. CONCLUSION: Metabolic and cardiovascular abnormalities and pro-inflammatory markers were prevalent in overweight prepubertal children. The prevalence rates appeared to differ between the sexes.

Sex-specific differences in the development of acute alcohol-induced liver steatosis in mice.

AIMS: Results of several animal studies suggest that similar to humans, female rodents are more susceptible to chronic alcohol-induced liver disease (ALD). The aim of the present study was to determine whether female mice are more susceptible to acute alcohol-induced steatosis than male mice and to investigate possible mechanisms involved. METHODS: Male and female C57BL/6J mice received one single dose of ethanol (6 g/kg bodyweight) or isocaloric maltose-dextrin solution intragastrically. Plasma alcohol concentration, markers of hepatic steatosis, activation of the TLR-4 signaling cascade and triglyceride export as well as lipid peroxidation and of iron metabolism were measured 12 h after acute alcohol intake. RESULTS: In male and female ethanol-treated mice, plasma alcohol concentrations were still markedly increased 12 h after the alcohol challenge, which was associated with a significant accumulation of lipids in the liver and increase of transaminases in plasma; however, lipid accumulation was ∼3-fold higher in females in comparison with male animals. Expression of MyD88 was only found to be significantly induced in livers of female alcohol-exposed mice, whereas protein levels of ApoB were found to be significantly lower only in livers of female mice exposed to ethanol. Levels of 4-HNE protein adducts and ferritin were induced in livers of male and female ethanol-treated mice. CONCLUSION: Taken together, these data suggest that female mice are also more susceptible to acute alcohol-induced liver steatosis and that this involves an increased activation of TLR-4-dependent signaling pathways in the liver.

Dietary pattern and leisure time activity of overweight and normal weight children in Germany: sex-specific differences.

BACKGROUND: Several studies indicate that dietary pattern and leisure time activities of adults not only differ between sexes but also between overweight and normal weight individuals. The aim of the present study was to determine if sex-specific differences in dietary pattern and leisure time activity already exist and are associated with weight status in young childhood. METHODS: Nutritional intake, anthropometric parameters, leisure time activities and socio- demographical factors were assessed in 100 overweight and 51 normal weight children (81 girls and 70 boys), aged 5-8 years. RESULTS: In general, independent of body weight, boys ate more cheese while girls consumed more vegetables and spent more time with sedentary activities. Moreover, regardless of sex, total energy and macronutrient intake did not differ between normal weight and overweight children. Also, time spent with sportive activities did not differ between groups; however, overweight boys spent significantly more leisure time with sedentary activities than normal weight boys. Furthermore, BMI of mothers and time spent with sedentary activities were identified as independent risk factors for the development of overweight when performing multiple regression analyses. CONCLUSIONS: Taken together, results of our study suggest that already at young age sex influences dietary pattern independent of body weight. Furthermore, an increased time spent with sedentary activities and an elevated maternal BMI were found to be associated with an elevated body weight in children. ( TRIAL REGISTRATION: NCT01306396).

Lactobacillus casei Shirota protects from fructose-induced liver steatosis: a mouse model.

To test the hypothesis that Lactobacillus casei Shirota (Lcs) protects against the onset of non-alcoholic fatty liver disease (NAFLD) in a mouse model of fructose-induced steatosis, C57BL/6J mice were either fed tap water or 30% fructose solution +/- Lcs for 8 weeks. Chronic consumption of 30% fructose solution led to a significant increase in hepatic steatosis as well as plasma alanine-aminotransferase (ALT) levels, which was attenuated by treatment with Lcs. Protein levels of the tight junction protein occludin were found to be markedly lower in both fructose treated groups in the duodenum, whereas microbiota composition in this part of the intestine was not affected. Lcs treatment markedly attenuated the activation of the Toll-like receptor (TLR) 4 signalling cascade found in the livers of mice only treated with fructose. Moreover, in livers of fructose fed mice treated with Lcs peroxisome proliferator-activated receptor (PPAR)-γ activity was markedly higher than in mice only fed fructose. Taken together, the results of the present study suggest that the dietary intake of Lcs protects against the onset of fructose-induced NAFLD through mechanisms involving an attenuation of the TLR-4-signalling cascade in the liver.

Nutrition, intestinal permeability, and blood ethanol levels are altered in patients with nonalcoholic fatty liver disease (NAFLD).

BACKGROUND: A role of an altered dietary pattern (e.g., a diet rich in sugar) but also alterations at the level of the intestinal barrier have repeatedly been discussed to be involved in the development and progression of nonalcoholic fatty liver disease (NAFLD). AIMS: To determine if the nutritional intake, intestinal flora, and permeability and the development of NAFLD are related in humans. METHODS: Ten controls and 20 patients with NAFLD ranging from simple steatosis to steatohepatitis were included in the study. Bacterial overgrowth, orocecal transit time, and intestinal permeability were assessed. Alcohol, endotoxin, and plasminogen activator inhibitor (PAI-) 1 concentration were determined in plasma. Nutritional intake was assessed using a dietary history. RESULTS: Despite no differences in the prevalence of bacterial overgrowth and in the orocecal transit time, intestinal permeability, alcohol, and endotoxin levels in plasma were significantly higher in patients with NAFLD than in controls. Similar results were also found for PAI-1 plasma concentrations. Patients with NAFLD had a significantly higher intake of protein, total carbohydrates, and mono- as well as disaccharides than controls. PAI-1, endotoxin, and ALT plasma levels were positively related to total protein and carbohydrate intake. CONCLUSIONS: Taken together, our results indicate that intestinal permeability, endogenous alcohol synthesis, and nutritional intake are markedly altered in patients with NAFLD.

Toll-like receptors 1-9 are elevated in livers with fructose-induced hepatic steatosis.

Studies in animals and human subjects indicate that gut-derived bacterial endotoxins may play a critical role in the development of non-alcoholic fatty liver disease (NAFLD). In the present study, we investigated if the liver is also sensitised by other microbial components during the onset of fructose-induced steatosis in a mouse model. C57BL/6 mice were either fed with 30 % fructose solution or tap water (control) with or without antibiotics for 8 weeks. Expression of toll-like receptors (TLR)1-9, TNF-α, inducible NO synthase (iNOS), myeloid differentiation factor 88 (MyD88) and number of F4/80 positive cells in the liver were assessed. Occludin protein, DNA of microbiota in the small and large intestine and retinol binding protein 4 (RBP4) in plasma were analysed using Western blot, DNA fingerprinting and ELISA, respectively. F4/80 positive cells were determined by immunohistochemistry. The accumulation of TAG found in the livers of fructose-fed mice was associated with a significant induction of TLR 1-4 and 6-8. Plasma RBP4 concentration and hepatic mRNA expression levels of TNF-α, iNOS, MyD88 and number of F4/80 positive cells of fructose-fed animals were significantly higher than those of controls; however, these effects of fructose were attenuated in antibiotic-treated mice. Whereas protein concentration of occludin was lower in the duodenum of fructose-treated mice, no systematic alterations of microbiota were found in this part of the intestine. Taken together, these data support the hypothesis that (1) an increased intestinal translocation of microbial components and (2) an increased number of F4/80 positive cells and induction of several TLR and dependent pathways (e.g. MyD88 and iNOS) may be involved in the onset of fructose-induced NAFLD.

Fructose-induced steatosis in mice: role of plasminogen activator inhibitor-1, microsomal triglyceride transfer protein and NKT cells.

Plasminogen activator inhibitor-1 (PAI-1) is an acute-phase protein known to be involved in alcoholic liver disease and hepatic fibrosis. In the present study, the hypothesis that PAI-1 is causally involved in the onset of fructose-induced hepatic steatosis was tested in a mouse model. Wild-type C57BL/6J and PAI-1⁻/⁻ mice were fed with 30% fructose solution or water for 8 weeks. Markers of hepatic steatosis, expression of PAI-1, apolipoprotein B (ApoB), cluster of differentiation 1d (CD1d), markers of natural killer T (NKT) cells, protein levels of phospho-c-Met and tumor necrosis factor-α (TNF-α) were determined. Activity of the microsomal triglyceride transfer protein (MTTP) was measured in liver tissue. In comparison with water controls, chronic intake of 30% fructose solution caused a significant increase in hepatic triglycerides, PAI-1 expression and plasma alanine aminotransferase levels in wild-type mice. This effect of fructose feeding was markedly attenuated in PAI-1⁻/⁻ mice. Despite no differences in portal endotoxin levels and hepatic TNF-α protein levels between fructose-fed groups, the protective effect of the loss of PAI-1 against the onset of fructose-induced steatosis was associated with a significant increase in phospho-c-Met, phospho Akt, expression of ApoB and activity of MTTP in livers of PAI-1⁻/⁻ mice in comparison with fructose-fed wild types. Moreover, in PAI-1⁻/⁻ mice, expressions of CD1d and markers of CD1d-reactive NKT cells were markedly higher than in wild-type mice; however, expression of markers of activation of CD1d-reactive NKT cells (eg, interleukin-15 and interferon-γ) were only found to be increased in livers of fructose-fed PAI-1⁻/⁻ mice. Taken together, these data suggest that PAI-1 has a causal role in mediating the early phase of fructose-induced liver damage in mice through signaling cascades downstream of Kupffer cells and TNF-α.

Role of tumor necrosis factor α (TNFα) in the onset of fructose-induced nonalcoholic fatty liver disease in mice.

Tumor necrosis factor α (TNFα) is known to be involved in dysregulation of hepatic lipid metabolism and insulin signaling. However, whether TNFα also plays a casual role in the onset of fructose-induced nonalcoholic fatty liver disease (NAFLD) has not yet been determined. Therefore, wild-type and TNFα receptor 1 (TNFR1)-/- mice were fed with either 30% fructose solution or plain tap water. Hepatic triglycerides, markers of inflammation and ATP concentration as well as plasma ALT levels were determined. Hepatic PAI-1, SREBP-1, FAS mRNA expression was assessed by real-time RT-PCR. Furthermore, lipid peroxidation and indices of insulin resistance were determined in liver tissue and plasma. In comparison to water controls, chronic intake of 30% fructose solution caused a significant ∼5-fold increase in triglyceride accumulation and neutrophil infiltration in livers of wild-type mice and a ∼8-fold increase in plasma ALT levels. In TNFR1-/- mice, hepatic steatosis was attenuated and neutrophil infiltration in the liver as well as plasma ALT levels was similar to water controls. The protective effect of the TNFR1 deletion against the onset of fructose-induced steatosis was associated with increased phospho AMPK and Akt levels, decreased SREBP-1 and FAS expression in the liver and decreased RBP4 plasma levels, whereas hepatic lipid peroxidation, iNOS protein and ATP levels were similar between wild-type and TNFR1-/- mice fed fructose. Taken together, these data suggest that TNFα plays a casual role in the onset of fructose-induced liver damage as well as insulin resistance in mice through signaling cascades downstream of TNFR1.

A low fructose diet in the treatment of pediatric obesity: a pilot study.

BACKGROUND: Over the last three decades the prevalence of overweight and obesity has increased dramatically among children and adolescents worldwide. As the results of animal and human studies suggest that a diet rich in fructose may be a risk factor for the development of overweight, the aim of the pilot study was to evaluate if a dietary counseling aimed at a moderate reduction of dietary fructose intake (-50% in comparison to intake at baseline) has a positive effect on the body mass index (BMI) of overweight and obese children. METHODS: Fifteen overweight or obese children aged 5-8 years were included into the 3 month dietary intervention study. At baseline and after 4 and 8 weeks children and their parents were trained to reduce fructose in the children's diet. Anthropometric parameters for calculating BMI and BMI standard deviation scores (BMI-SDS) as well as nutritional intake were assessed at baseline, after the 12-week intervention and after 12 week of follow up. RESULTS: After the 12-week intervention children had significantly reduced their total energy, fructose, sucrose and glucose intake. BMI and BMI-SDS were significantly reduced by 0.68 kg/m(2) and 0.21, respectively, at the end of the intervention. At follow up, the BMI-SDS was significantly lower in comparison to baseline while the BMI was only decreased by trend (P= 0.08). CONCLUSIONS: The results of our pilot study indicate that counseling aimed towards a moderate reduction of dietary fructose and/or general sugar intake may have a positive effect on BMI in overweight and obese children.

Protective effect of bile acids on the onset of fructose-induced hepatic steatosis in mice.

Fructose intake is being discussed as a key dietary factor in the development of nonalcoholic fatty liver disease (NAFLD). Bile acids have been shown to modulate energy metabolism. We tested the effects of bile acids on fructose-induced hepatic steatosis. In C57BL/6J mice treated with a combination of chenodeoxycholic acid and cholic acid (100 mg/kg body weight each) while drinking water or a 30% fructose solution for eight weeks and appropriate controls, markers of hepatic steatosis, portal endotoxin levels, and markers of hepatic lipogenesis were determined. In mice concomitantly treated with bile acids, the onset of fructose-induced hepatic steatosis was markedly attenuated compared to mice only fed fructose. The protective effects of the bile acid treatment were associated with a downregulation of tumor necrosis factor (TNF)α, sterol regulatory element-binding protein (SREBP)1, FAS mRNA expression, and lipid peroxidation in the liver, whereas hepatic farnesoid X receptor (FXR) or short heterodimer partner (SHP) protein concentration did not differ between groups fed fructose. Rather, bile acid treatment normalized occludin protein concentration in the duodenum, portal endotoxin levels, and markers of Kupffer cell activation to the level of water controls. Taken together, these data suggest that bile acids prevent fructose-induced hepatic steatosis in mice through mechanisms involving protection against the fructose-induced translocation of intestinal bacterial endotoxin.

Toll-like receptor 4 is involved in the development of fructose-induced hepatic steatosis in mice.

UNLABELLED: A link between dietary fructose intake, gut-derived endotoxemia, and nonalcoholic fatty liver disease (NAFLD) has been suggested by the results of human and animal studies. To further investigate the role of gut-derived endotoxin in the onset of fructose-induced NAFLD, Toll-like receptor (TLR-) 4-mutant (C3H/HeJ) mice and wildtype (C3H/HouJ) mice were either fed plain water or water enriched with 30% fructose for 8 weeks. Hepatic steatosis, plasma alanine aminotransferase (ALT), and markers of insulin resistance as well as portal endotoxin levels were determined. Hepatic levels of myeloid differentiation factor 88 (MyD88), interferon regulatory factor (IRF) 3 and 7, and tumor necrosis factor alpha (TNFalpha) as well as markers of lipid peroxidation were assessed. Chronic intake of 30% fructose solution caused a significant increase in hepatic steatosis and plasma ALT levels in wildtype animals in comparison to water controls. In fructose-fed TLR-4 mutant mice, hepatic triglyceride accumulation was significantly reduced by approximately 40% in comparison to fructose-fed wildtype mice and plasma ALT levels were at the level of water-fed controls. No difference in portal endotoxin concentration between fructose-fed wildtype and TLR-4-mutant animals was detected. In contrast, hepatic lipid peroxidation, MyD88, and TNFalpha levels were significantly decreased in fructose-fed TLR-4-mutant mice in comparison to fructose-fed wildtype mice, whereas IRF3 and IRF7 expression remained unchanged. Markers of insulin resistance (e.g., plasma TNFalpha, retinol binding protein 4, and hepatic phospho-AKT) were only altered in fructose-fed wildtype animals. CONCLUSION: Taken together, these data further support the hypothesis that in mice the onset of fructose-induced NAFLD is associated with intestinal bacterial overgrowth and increased intestinal permeability, subsequently leading to an endotoxin-dependent activation of hepatic Kupffer cells.

Is nutrient intake a gender-specific cause for enhanced susceptibility to alcohol-induced liver disease in women?

AIM: Women have a higher susceptibility to alcohol-induced liver disease (ALD) than men. Gender-related differences in food preference were described in previous studies for several populations, but not in alcohol abusers. As certain micronutrients are reported to take influence on the development of ALD in animal experiments, the hypothesis of the present retrospective cross-sectional study was that gender-dependent (micro-) nutrient intake in patients with ALD may cause the higher susceptibility of women to this disease. METHODS: In 210 patients (male: 158, female: 52) with different stages of ALD (ALD1: mild stage of liver damage; ALD2: moderately severe changes of the liver with signs of hepatic inflammation; ALD3: severely impaired liver function) and in 336 controls (male: 208, female: 128), nutrient intake was determined by a computer-guided diet history, and related to the severity of ALD in dependence on the sex of the patients. RESULTS: No significant differences between males and females with ALD were calculated for the intake (per kg body weight/day) of protein, carbohydrates, fat, and the intake (per kg body weight/day) of most micronutrients. In females with ALD, higher intake was found for vitamin C (ALD3), calcium (ALD2), iron (ALD1 and ALD2), and zinc (ALD1), but the consumption of none of these micronutrients seems to contribute to a higher susceptibility to ALD in females. CONCLUSION: Though the present study confirms the higher susceptibility to ALD in women, the data of calculated daily macro- and micronutrient intake do not suggest any explicit influence of gender-specific nutrition in the development of ALD.

Saturation of retinol-binding protein correlates closely to the severity of alcohol-induced liver disease.

Impaired metabolism of retinol has been shown to occur in alcohol-induced liver disease (ALD). The purpose of the present study was to investigate the saturation of retinol-binding protein (RBP) in 6 patients with different stages of ALD. Hospitalized alcohol consumers (n=118) with different stages of ALD (ALD1: mild stage of liver damage; ALD2: moderately severe changes of the liver with signs of hepatic inflammation; ALD3: severely impaired liver function) and 45 healthy control subjects were nutritionally assessed, and retinol and RBP content was measured in plasma by high-performance liquid chromatography and enzyme-linked immunosorbent assay methods, respectively. No differences were noted in daily retinol intake, but subjects with ALD had significantly lower concentrations of retinol in plasma (ALD1: 1.81+/-0.17 micromol/l [mean+/-S.E.M.]; ALD2: 1.95+/-0.24 micromol/l; ALD3: 0.67+/-0.13 micromol/l) compared to controls (2.76+/-0.19 micromol/l). Subjects of group ALD2 had significantly higher plasma RBP levels than controls (P<.05) and patients with ALD1 (P<.05) and ALD3 (P<.001). The relative saturation of RBP with retinol decreased with severity of ALD (controls: 76.8+/-5.0%; ALD1: 55.8+/-6.5%; ALD2: 43.5+/-6.2%; ALD3: 29.0+/-5.1%). The present study indicates that plasma concentrations of retinol and RBP per se do not correlate to severity of ALD, but rather that the retinol/RBP ratio links to the severity of alcohol-induced liver damage. From these results, a reduced availability of retinol in the periphery due to an altered saturation of RBP can be concluded.