Silvia Marinho Ferolla

The role of intestinal bacteria overgrowth in obesity-related nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. It is a progressive disorder involving a spectrum of conditions that include pure steatosis without inflammation, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. The key factor in the pathophysiology of NAFLD is insulin resistance that determines lipid accumulation in the hepatocytes, which may be followed by lipid peroxidation, production of reactive oxygen species and consequent inflammation. Recent studies suggest that the characteristics of the gut microbiota are altered in NAFLD, and also, that small intestinal bacterial overgrowth (SIBO) contributes to the pathogenesis of this condition. This review presents the chief findings from all the controlled studies that evaluated SIBO, gut permeability and endotoxemia in human NAFLD. We also discuss the possible mechanisms involving SIBO, lipid accumulation and development of NASH. The understanding of these mechanisms may allow the development of new targets for NASH treatment in the future.

Probiotics as a complementary therapeutic approach in nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is currently recognized as one of the most common causes of chronic liver disease. It involves a spectrum of conditions that include pure steatosis without inflammation, steatohepatitis, fibrosis and cirrhosis. The key factor in the pathophysiology of NAFLD is insulin resistance that determines lipid accumulation in the hepatocytes and, thus, oxidative stress, which is followed by inflammatory response. However, NAFLD pathogenesis is still largely unknown and has been extensively investigated. Although life style modification with the aim of losing weight has been advocated to treat this disorder, its effectiveness is limited; additionally, there is no specific pharmacologic treatment until nowadays. Recent evidence suggests that the gut microbiota may play a role in the development of insulin resistance, hepatic steatosis, necroinflammation and fibrosis. Differences in gut microbiota between NAFLD patients and lean individuals as well as presence of small intestinal bacterial overgrowth in NAFLD subjects have been demonstrated. Furthermore, some data indicate that the immunoregulatory effects of probiotics may be beneficial in NAFLD treatment as they modulate the intestinal microbiota; improve epithelial barrier function and strengthen the intestinal wall decreasing its permeability; reduce bacterial translocation and endotoxemia; improve intestinal inflammation; and reduce oxidative and inflammatory liver damage. In this article, we review the clinical trials on the use of probiotics in the treatment of NAFLD and discuss the effects of these agents and their efficacy as an emerging therapeutic resource to treat NAFLD patients.

Dietary patterns in Brazilian patients with nonalcoholic fatty liver disease: a cross-sectional study.

OBJECTIVE: Recent evidence suggests that non-alcoholic fatty liver disease is associated with diet. Our aim was to investigate the dietary patterns of a Brazilian population with this condition and compare them with the recommended diet. METHODS: A cross-sectional study was conducted on 96 non-alcoholic fatty liver disease patients before any dietetic counseling. All patients underwent abdominal ultrasound, biochemical tests, dietary evaluations, and anthropometric evaluations. Their food intake was assessed by a semi-quantitative food-frequency questionnaire and 24-hour food recall. RESULTS: The median patient age was 53 years, and 77% of the individuals were women. Most (67.7%) participants were obese, and a large waist circumference was observed in 80.2% subjects. Almost 70% of the participants had metabolic syndrome, and 62.3% presented evidence of either insulin resistance or overt diabetes. Most patients (51.5, 58.5, and 61.7%, respectively) exceeded the recommendations for energy intake, as well as total and saturated fat. All patients consumed less than the amount of recommended monounsaturated fatty acids, and 52.1 and 76.6% of them consumed less polyunsaturated fatty acids and fiber, respectively, than recommended. In most patients, the calcium, sodium, potassium, pyridoxine, and vitamin C intake did not meet the recommendations, and in 10.5-15.5% of individuals, the tolerable upper limit intake for sodium was exceeded. The patients presented a significantly high intake of meats, fats, sugars, legumes (beans), and vegetables and a low consumption of cereals, fruits, and dairy products compared with the recommendations. CONCLUSIONS: Although patients with non-alcoholic fatty liver disease exhibited high energy and lipid consumption, most of them had inadequate intake of some micronutrients. The possible role of nutrient-deficient intake in the development of non-alcoholic fatty liver disease warrants investigation.

Dietary approach in the treatment of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has been identified as one of the most prevalent chronic liver disease in adults and children populations. NAFLD is usually associated with the metabolic syndrome (MS), which is chiefly related to insulin resistance and its consequences. Insulin resistance has a crucial role in the pathogenesis of hepatic steatosis and potentially nonalcoholic steatohepatitis (NASH). Because of the contemporary epidemics of MS and obesity, the burden of NAFLD is also expected to rise. Unhealthy diets, such as the so-called western diet, are enriched in fructose, trans-fatty acids and saturated fat and seem to be associated with the development of NAFLD. In human studies, certain dietary sugars, particularly fructose, are used as a substrate for lipogenesis leading to hepatic fatty infiltration, inflammation, and possibly fibrosis. Other investigations have shown that fat consumption especially cholesterol and trans/saturated fatty acids are also steatogenic and seem to increase visceral adiposity. The identification of specific dietary components that favor the development of NASH could be important for the management of this disorder. This review focuses on the effects of different dietary approaches to prevent and treat NAFLD emphasizing the macronutrients and energy composition.

Beneficial Effect of Synbiotic Supplementation on Hepatic Steatosis and Anthropometric Parameters, But Not on Gut Permeability in a Population with Nonalcoholic Steatohepatitis

Nonalcoholic fatty liver disease is the most prevalent chronic liver disease in Western countries; it can progress to nonalcoholic steatohepatitis (NASH), cirrhosis and hepatocarcinoma. The importance of gut-liver-adipose tissue axis has become evident and treatments targeting gut microbiota may improve inflammatory and metabolic parameters in NASH patients. In a randomized, controlled clinical trial, involving 50 biopsy-proven NASH patients, we investigated the effects of synbiotic supplementation on metabolic parameters, hepatic steatosis, intestinal permeability, small intestinal bacterial overgrowth (SIBO) and lipopolysaccharide (LPS) serum levels. Patients were separated into two groups receiving Lactobacillus reuteri with guar gum and inulin for three months and healthy balanced nutritional counseling versus nutritional counseling alone. Before and after the intervention we assessed steatosis by magnetic resonance imaging, intestinal permeability by lactulose/mannitol urinary excretion and SIBO by glucose breath testing. NASH patients presented high gut permeability, but low prevalence of SIBO. After the intervention, only the synbiotic group presented a reduction in steatosis, lost weight, diminished BMI and waist circumference measurement. Synbiotic did not improve intestinal permeability or LPS levels. We concluded that synbiotic supplementation associated with nutritional counseling seems superior to nutritional counseling alone for NASH treatment as it attenuates steatosis and may help to achieve weight loss.

Impact of body mass index on outcome in patients undergoing coronary artery bypass grafting and/or valve replacement surgery

Objective This study aimed to analyze the impact of body mass index on outcomes of 101 patients undergoing coronary artery bypass grafting, valve replacement, or combined valve/ coronary artery bypass grafting surgery in a private hospital in Belo Horizonte, Brazil. Methods This was a prospective cross-sectional study of patients undergoing cardiac surgery from May 2009 to December 2012. All patients were followed up from the first day of admission until discharge or death. Patients were divided into three groups according to BMI: normal weight, overweight, and obese. The main outcome measure was the association between BMI and postoperative morbidities and mortality. Results Multivariate analysis identified obesity as an independent predictor of increased risk of surgical reintervention (odds ratio [OR] 13.6; 95%CI 1.1 - 162.9; P=0.046) and reduced risk of bleeding (OR 0.05; 95% CI 0.09 - 0.69; P=0.025). Univariate analysis showed that obesity was associated with increased frequency of wound dehiscence (P=0.021). There was no association between BMI and other complications or mortality in univariate analysis. There was also no association between body mass index and duration of cardiopulmonary bypass, aortic clamping, mechanical ventilation, and intensive care unit or hospital stay. Conclusion Obese individuals undergoing coronary artery bypass grafting, valve replacement, or combined surgery have a higher postoperative risk of surgical reintervention and lower chances of bleeding.

High-fructose Intake in Obesity-related Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. NAFLD involves a spectrum of conditions that include pure steatosis without inflammation, nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Insulin resistance (IR) plays a main role in the pathophysiology of NAFLD by causing lipid accumulation in the hepatocytes, which may be followed by lipid peroxidation, production of reactive oxygen species and consequent inflammation. The consumption of carbohydrates, particularly sugars additives high in fructose increased dramatically in the past decades and appears to be at least one very important contributing factor in NAFDL pathogenesis. Recent studies suggest that the excessive consumption of fructose from sugar additives (mainly those found in sweetened beverages and processed foods) is linked to development and severity of NAFLD by induction of IR, postprandial hypertriglyceridemia and lipid accumulation in the liver, especially in individuals with overweight. We discuss the possible mechanisms involving fructose consumption, lipid accumulation and development of NASH. This review also presents the chief findings from all the studies that evaluated fructose consumption in human NAFLD.

Non-alcoholic Fatty Liver Disease in Obesity

Non-alcoholic fatty liver disease (NAFLD) is worldwide epidemic. This clinical entity is closely related to metabolic syndrome. Majority of the patients are obese. Metabolic factors and genetics play important roles in the pathogenesis of this disorder. NAFLD encompasses a spectrum of disorders including benign macrovesicular hepatic steatosis, non-alcoholic steatohepatitis, fibrosis, hepatic cirrhosis and hepatocellular carcinoma. Is expected that it is became the most common indication of liver transplantation in a few years. It is diagnosed by abnormal liver biochemistry, imaging methods and liver biopsy. Several therapeutic agents were investigated for optimal management of this disease, however, at the present, there are limited treatment options which include lifestyle modification to loss of body weight, vitamin E and thioglitazones.