Randomised clinical trial: The beneficial effects of VSL#3 in obese children with non-alcoholic steatohepatitis

Bile salt hydrolase-overexpressing Lactobacillus strains can improve hepatic lipid accumulation in vitro in an NAFLD cell model

Background

Non-alcoholic fatty liver disease (NAFLD) includes a range of liver diseases that occur in the absence of significant alcohol consumption. The probiotic bacterial strains Lactobacillus casei LC2W, which overexpresses the bile salt hydrolase (BSH) gene (referred to as pWQH01), and Lactobacillus plantarum AR113, which exhibits high BSH activity, have been shown to improve hepatic lipid accumulation and may lower cholesterol levels in vivo. These effects may be BSH-dependent, as L. casei LC2W without BSH activity did not exert these beneficial effects.

Objective

This study aimed to investigate the effects of Lactobacillus with high BSH activity on cholesterol accumulation and lipid metabolism abnormalities in oleic acid (OA)- and cholesterol-induced HepG2 cell models, and to determine the mechanism underlying the effects.

Design

A HepG2 cell model of OA-induced steatosis and cholesterol-induced cholesterol accumulation was developed. OA- and cholesterol-treated HepG2 cells were incubated with L. plantarum AR113, L. casei LC2W or L. casei pWQH01 for 6 h at 37°C with 5% CO₂. Subsequently, a series of indicators and gene expressions were analysed.

Results

Both L. plantarum AR113 and L. casei pWQH01 significantly reduced lipid accumulation, total cholesterol (TC) levels and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) mRNA expression relative to the control group, whereas L. casei LC2W had no similar effect. Additionally, exposure to L. plantarum AR113 or L. casei pWQH01 significantly reduced the expression of sterol regulatory element-binding protein 1c (SREBP-1c), Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and tumour necrosis factor-α (TNF-α) andsignificantly increased the expression of 5' adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor alpha (PPARα).

Conclusion

Both L. plantarum AR113 and L. casei pWQH01 appear to improve steatosis in vitro in a BSH-dependent manner.

Role of gut microbiota via the gut-liver-brain axis in digestive diseases

The gut-brain axis is a bidirectional information interaction system between the central nervous system (CNS) and the gastrointestinal tract, in which gut microbiota plays a key role. The gut microbiota forms a complex network with the enteric nervous system, the autonomic nervous system, and the neuroendocrine and neuroimmunity of the CNS, which is called the microbiota-gut-brain axis. Due to the close anatomical and functional interaction of the gut-liver axis, the microbiota-gut-liver-brain axis has attracted increased attention in recent years. The microbiota-gut-liver-brain axis mediates the occurrence and development of many diseases, and it offers a direction for the research of disease treatment. In this review, we mainly discuss the role of the gut microbiota in the irritable bowel syndrome, inflammatory bowel disease, functional dyspepsia, non-alcoholic fatty liver disease, alcoholic liver disease, cirrhosis and hepatic encephalopathy via the gut-liver-brain axis, and the focus is to clarify the potential mechanisms and treatment of digestive diseases based on the further understanding of the microbiota-gut- liver-brain axis.

The pharmacological treatment of nonalcoholic fatty liver disease in children

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in childhood/adolescence. It comprises a broad spectrum of liver disease severity ranging from simple steatosis to steatohepatitis and fibrosis. To date lifestyle modifications, diet and physical activity represent the main option for the management of pediatric NAFLD, but numerous treatments classified depending on the mechanism of action, have been introduced. In keeping with, bariatric surgery, insulin sensitizers, antioxidants, probiotic and dietary supplementations have been evaluated in pediatric clinical trials.

AREAS COVERED

This review describes, after a search in PubMed/MEDLINE database, the current pediatric NAFLD non-pharmacological and pharmacological treatments and their effects on biochemical and histological features. We report not only the efficacy of the diet coupled with regular exercise but also advantages of the pharmacological treatments used in combination with lifestyle interventions in pediatric NAFLD.

EXPERT OPINION

Since pharmacological and non-pharmacological interventions have demonstrated variable effects in pediatric NAFLD, it is clear that safe and specific and efficient therapeutic strategies have not yet been identified. Therefore, large and long-term clinical trials in children are needed to find a way to reverse the liver tissue damage and the NAFLD-related long-term morbidity and mortality.

Microbial Metabolites: Critical Regulators in NAFLD

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease throughout the world. The relationship between gut microbiota and NAFLD has been extensively investigated. The gut microbiota is involved in the regulation of NAFLD by participating in the fermentation of indigestible food, interacting with the intestinal mucosal immune system, and influencing the intestinal barrier function, leading to signaling alteration. Meanwhile, the microbial metabolites not only affect the signal transduction pathway in the gut but also reach the liver far away from gut. In this review, we focus on the effects of certain key microbial metabolites such as short-chain fatty acids, trimethylamine-N-oxide, bile acids, and endogenous ethanol and indole in NAFLD, and also summarize several potential therapies targeting the gut-liver axis and modulation of gut microbiota metabolites including antibiotics, prebiotics, probiotics, bile acid regulation, and fecal microbiota transplantation. Understanding the complex interactions between microbial metabolites and NAFLD may provide crucial insight into the pathogenesis and treatment of NAFLD.

Pathogenesis and pathways: nonalcoholic fatty liver disease & alcoholic liver disease

Alcoholic liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD) account for the majority of hepatic morbidity and deaths due to cirrhosis in the United States. ALD is an umbrella term for a number of conditions linked to excessive alcohol consumption including simple steatosis, cirrhosis, acute alcoholic hepatitis (AH) with or without cirrhosis, and hepatocellular carcinoma (HCC) as a complication of cirrhosis. Although it presents with histological features resembling alcohol-induced liver injury, NAFLD occurs in patients with little or no history of alcohol consumption. NAFLD is a broad-spectrum term used to describe anything from fat accumulation in hepatocytes without inflammation or fibrosis (simple hepatic steatosis) to hepatic steatosis with a necroinflammatory component (steatohepatitis) with or without associated fibrosis. The pathogenesis is not fully understood for either disease. Development of severe liver disease is highly variable amongst chronic abusers of alcohol. Sex, age, genetics, host microbiome, and behavior are all factors linked to the development of ALD. These factors also contribute to NAFLD, but by contrast, insulin resistance is widely believed to be the main driver of nonalcoholic hepatic steatosis. The mechanism behind the transition from nonalcoholic steatosis to steatohepatitis remains a matter of debate with insulin resistance, oxidative injury, hepatic iron, gut hormones, antioxidant deficiency, and host microbiome all suspected to play part of the role.

Nonalcoholic fatty liver disease and colorectal cancer: Correlation and missing links

Nonalcoholic fatty liver disease (NAFLD) is one of the major metabolic diseases that occur in almost one in every four global population, while colorectal cancer (CRC) is one of the leading causes of cancer related deaths in the world. Individuals with pre-existing NAFLD show a higher rate of developing CRC and liver metastasis, suggesting a causal relationship. Interestingly, both of these diseases are strongly associated with obesity, which is also a growing global health concern. In this current review, we will explore scientific findings that demonstrate the relationship between NAFLD, CRC and obesity, as well as the underlying mechanisms. We will also indicate the missing links and knowledge gaps that require more in-depth investigation.

The role of gut microbiota in cancer treatment: friend or foe?

The gut microbiota has been implicated in cancer and shown to modulate anticancer drug efficacy. Altered gut microbiota is associated with resistance to chemo drugs or immune checkpoint inhibitors (ICIs), whereas supplementation of distinct bacterial species restores responses to the anticancer drugs. Accumulating evidence has revealed the potential of modulating the gut microbiota to enhance the efficacy of anticancer drugs. Regardless of the valuable findings by preclinical models and clinical data of patients with cancer, a more thorough understanding of the interactions of the microbiota with cancer therapy helps researchers identify novel strategy for cancer prevention, stratify patients for more effective treatment and reduce treatment complication. In this review, we discuss the scientific evidence on the role of gut microbiota in cancer treatment, and highlight the latest knowledge and technologies leveraged to target specific bacteria that contribute to tumourigenesis. First, we provide an overview of the role of the gut microbiota in cancer, establishing the links between bacteria, inflammation and cancer treatment. Second, we highlight the mechanisms used by distinct bacterial species to modulate cancer growth, immune responses, as well as the efficacy of chemotherapeutic drugs and ICIs. Third, we demonstrate various approaches to modulate the gut microbiota and their potential in translational research. Finally, we discuss the limitations of current microbiome research in the context of cancer treatment, ongoing efforts to overcome these challenges and future perspectives.

Effects of probiotic and prebiotic supplementation on metabolic parameters, liver aminotransferases, and systemic inflammation in nonalcoholic fatty liver disease: A randomized clinical trial

This study aimed to evaluate the clinical efficacy of probiotic and prebiotic supplementation on the metabolic parameters, liver enzymes, and inflammation in patients with nonalcoholic fatty liver disease (NAFLD). In this study, patients with NAFLD were assigned to receive either probiotic capsule + placebo of prebiotic (probiotic group), oligofructose + placebo of probiotic (prebiotic group), or placebo of probiotic + placebo of prebiotic (control group) for 12 weeks. All participants followed a weight loss diet and physical activity recommendation during intervention. Anthropometric measurements decreased in all three groups, but there was no significant difference among groups. Probiotic supplementation was able to decrease triglyceride, alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and alkaline phosphatase compared to control group. The serum levels of triglyceride, total and low-density lipoprotein cholesterol, ALT, AST, and GGT differed significantly in prebiotic group in comparison to the placebo. High-sensitive C-reactive protein significantly decreased within all groups; however, there was no significant difference among groups after intervention. Probiotic and prebiotic may be beneficial in improving liver enzymes and lipid profile in patients with NAFLD.

THE THERAPEUTIC IMPACT OF PROBIOTICS ON NONALCOHOLIC FATTY LIVER DISEASE IN PEDIATRICS: A SYSTEMATIC REVIEW

Objective:

Evaluate the effects of probiotics use, compared with placebo, in pediatric patients with non-alcoholic fatty liver disease (NAFLD), using laboratorial and ultrasonographic parameters as outcomes.

Methods:

A systematic review of the literature was performed through MEDLINE and Lilacs databases. The articles selected were randomized controlled clinical trials published until November 2018, without any language restriction, dealing with pediatric patients with NAFLD. Patients were divided into 2 groups. One group received probiotic therapy and the other group, only received placebo. The primary outcome evaluated was the difference between the serum levels of alanine aminotransferase (ALT) before and after receiving probiotics or placebo. The secondary outcomes evaluated were the serum aspartate aminotransferase levels, body mass index, serum triglycerides, waist circumference and level of liver steatosis on the ultrasonography.

Results:

A total of 46 articles were recovered, and 3 articles were included in the qualitative analysis, totaling 128 patients. Two trials revealed a significant decrease of alanine aminotransferase levels after treatment with probiotics (Lactobacillus rhamnosus for 8 weeks; Bifidobacterium+Lactobacillus for 12 weeks), when compared to the placebo. The other variables did not show a statistically significant difference between both groups.

Conclusions:

Probiotic therapy has contributed to the reduction of ALT serum levels in pediatric patients with nonalcoholic fatty liver disease, which is in line with results found by other authors in scientific literature. Regarding the secondary outcomes, the use of probiotics did not show benefits or damages compared to placebo.

Liver Steatosis, Gut-Liver Axis, Microbiome and Environmental Factors. A Never-Ending Bidirectional Cross-Talk

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and parallels comorbidities such as obesity, metabolic syndrome, dyslipidemia, and diabetes. Recent studies describe the presence of NAFLD in non-obese individuals, with mechanisms partially independent from excessive caloric intake. Increasing evidences, in particular, point towards a close interaction between dietary and environmental factors (including food contaminants), gut, blood flow, and liver metabolism, with pathways involving intestinal permeability, the composition of gut microbiota, bacterial products, immunity, local, and systemic inflammation. These factors play a critical role in the maintenance of intestinal, liver, and metabolic homeostasis. An anomalous or imbalanced gut microbial composition may favor an increased intestinal permeability, predisposing to portal translocation of microorganisms, microbial products, and cell wall components. These components form microbial-associated molecular patterns (MAMPs) or pathogen-associated molecular patterns (PAMPs), with potentials to interact in the intestine lamina propria enriched in immune cells, and in the liver at the level of the immune cells, i.e., Kupffer cells and stellate cells. The resulting inflammatory environment ultimately leads to liver fibrosis with potentials to progression towards necrotic and fibrotic changes, cirrhosis. and hepatocellular carcinoma. By contrast, measures able to modulate the composition of gut microbiota and to preserve gut vascular barrier might prevent or reverse NAFLD.

The Gut Microbiota and Its Metabolites, Novel Targets for Treating and Preventing Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent metabolic disorders worldwide, along with obesity and type 2 diabetes. NAFLD involves a series of liver abnormalities from simple hepatic steatosis to non-alcoholic steatohepatitis, which can ultimately lead to liver cirrhosis and cancer. The gut-liver axis plays an important role in the development of NAFLD, which depends mainly on regulation of the gut microbiota and its bacterial products. These intestinal bacterial species and their metabolites, including bile acids, tryptophan catabolites, and branched-chain amino acids, regulate adipose tissue and intestinal homeostasis and contribute to the pathogenesis of NAFLD/non-alcoholic steatohepatitis. In this review, the current evidence regarding the key role of the gut microbiota and its metabolites in the pathogenesis and development of NAFLD is highlighted, and the advances in the progression and applied prospects of gut microbiota-targeted dietary and exercise therapies is also discussed.

Effects of gut microbiome-targeted therapies on cardiometabolic outcomes in children and adolescents: A protocol for systematic review and meta-analysis

BACKGROUND

Emerging evidence indicates the role of gut microbiota in the development of cardiovascular diseases. Thus, gut microbiota is increasingly recognized as a potential therapeutic target of cardiovascular disease. However, the effects of gut microbiome-targeted therapies on cardiometabolic outcomes in children and adolescents remain unclear.

METHODS

We plan to perform a systematic search from PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science. Two authors will independently select the relevant studies and extract data according to a previously defined data extraction sheet. We will use the Stata 14.0 statistical software and RevMan V.5.3 software to conduct data analyses.

RESULTS AND CONCLUSION

The results of this study will be published in a peer-reviewed journal and provide more evidence for the application of gut microbiome-targeted therapies in children and adolescents for the intervention of cardiovascular risk factors in clinical practice.

PROTOCOL REGISTRATION NUMBER

INPLASY202060050.

Probiotics for the Treatment of Overweight and Obesity in Humans-A Review of Clinical Trials

The World Health Organization (WHO) reports that 400 million people are obese, and over 1.6 billion adults are overweight worldwide. Annually, over 2.8 million people die from obesity-related diseases. The incidence of overweight and obesity is steadily increasing, and this phenomenon is referred to as a 21st-century pandemic. The main reason for this phenomenon is an easy access to high-energy, processed foods, and a low-activity lifestyle. These changes lead to an energy imbalance and, as a consequence, to the development of body fat. Weight gain contributes to the development of heart diseases, skeletal system disorders, metabolic disorders such as diabetes, and certain types of cancer. In recent years, there have been many works linking obesity with intestinal microbiota. Experiments on germ-free animals (GFs) have provided much evidence for the contribution of bacteria to obesity. The composition of the gut microbiota (GM) changes in obese people. These changes affect the degree of energy obtained from food, the composition and secretory functions of adipose tissue, carbohydrate, and lipid metabolism in the liver, and the activity of centers in the brain. The study aimed to present the current state of knowledge about the role of intestinal microbiota in the development of obesity and the impact of supplementation with probiotic bacteria on the health of overweight and obese patients.

Health Impact and Therapeutic Manipulation of the Gut Microbiome

Recent advances in microbiome studies have revealed much information about how the gut virome, mycobiome, and gut bacteria influence health and disease. Over the years, many studies have reported associations between the gut microflora under different pathological conditions. However, information about the role of gut metabolites and the mechanisms by which the gut microbiota affect health and disease does not provide enough evidence. Recent advances in next-generation sequencing and metabolomics coupled with large, randomized clinical trials are helping scientists to understand whether gut dysbiosis precedes pathology or gut dysbiosis is secondary to pathology. In this review, we discuss our current knowledge on the impact of gut bacteria, virome, and mycobiome interactions with the host and how they could be manipulated to promote health.

Advances in the Involvement of Gut Microbiota in Pathophysiology of NAFLD

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis and progresses to non-steatohepatitis (NASH) when the liver displays overt inflammatory damage. Increasing evidence has implicated critical roles for dysbiosis and microbiota-host interactions in NAFLD pathophysiology. In particular, microbiota alter intestine absorption of nutrients and intestine permeability, whose dysregulation enhances the delivery of nutrients, endotoxin, and microbiota metabolites to the liver and exacerbates hepatic fat deposition and inflammation. While how altered composition of gut microbiota attributes to NAFLD remains to be elucidated, microbiota metabolites are shown to be involved in the regulation of hepatocyte fat metabolism and liver inflammatory responses. In addition, intestinal microbes and circadian coordinately adjust metabolic regulation in different stages of life. During aging, altered composition of gut microbiota, along with circadian clock dysregulation, appears to contribute to increased incidence and/or severity of NAFLD.

Gut Microbiota Metabolites in NAFLD Pathogenesis and Therapeutic Implications

Gut microbiota dysregulation plays a key role in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) through its metabolites. Therefore, the restoration of the gut microbiota and supplementation with commensal bacterial metabolites can be of therapeutic benefit against the disease. In this review, we summarize the roles of various bacterial metabolites in the pathogenesis of NAFLD and their therapeutic implications. The gut microbiota dysregulation is a feature of NAFLD, and the signatures of gut microbiota are associated with the severity of the disease through altered bacterial metabolites. Disturbance of bile acid metabolism leads to underactivation of bile acid receptors FXR and TGR5, causal for decreased energy expenditure, increased lipogenesis, increased bile acid synthesis and increased macrophage activity. Decreased production of butyrate results in increased intestinal inflammation, increased gut permeability, endotoxemia and systemic inflammation. Dysregulation of amino acids and choline also contributes to lipid accumulation and to a chronic inflammatory status. In some NAFLD patients, overproduction of ethanol produced by bacteria is responsible for hepatic inflammation. Many approaches including probiotics, prebiotics, synbiotics, faecal microbiome transplantation and a fasting-mimicking diet have been applied to restore the gut microbiota for the improvement of NAFLD.

The food-gut axis: lactic acid bacteria and their link to food, the gut microbiome and human health

Lactic acid bacteria (LAB) are present in foods, the environment and the animal gut, although fermented foods (FFs) are recognized as the primary niche of LAB activity. Several LAB strains have been studied for their health-promoting properties and are employed as probiotics. FFs are recognized for their potential beneficial effects, which we review in this article. They are also an important source of LAB, which are ingested daily upon FF consumption. In this review, we describe the diversity of LAB and their occurrence in food as well as the gut microbiome. We discuss the opportunities to study LAB diversity and functional properties by considering the availability of both genomic and metagenomic data in public repositories, as well as the different latest computational tools for data analysis. In addition, we discuss the role of LAB as potential probiotics by reporting the prevalence of key genomic features in public genomes and by surveying the outcomes of LAB use in clinical trials involving human subjects. Finally, we highlight the need for further studies aimed at improving our knowledge of the link between LAB-fermented foods and the human gut from the perspective of health promotion.

Multistrain Probiotic Increases the Gut Microbiota Diversity in Obese Pregnant Women: Results from a Randomized, Double-Blind Placebo-Controlled Study

BACKGROUND

Maternal obesity is associated with adverse pregnancy outcomes. Probiotic supplementation during pregnancy may have positive effects on blood glucose, gestational weight gain (GWG), and the risk of gestational diabetes mellitus [GDM and glycated hemoglobin (HbA1c)].

OBJECTIVES

This feasibility study involved a daily probiotic intervention in obese pregnant women from the early second trimester until delivery. The primary aim was to investigate the effect on GWG and maternal glucose homeostasis (GDM and HbA1c). Secondary aims were the effect on infant birth weight, maternal gut microbiota, and other pregnancy outcomes.

METHODS

We carried out a randomized double-blinded placebo-controlled study in 50 obese pregnant women. Participants were randomly allocated (1:1) to multistrain probiotic (4 capsules of Vivomixx®; total of 450 billion CFU/d) or placebo at 14-20 weeks of gestation until delivery. Participants were followed with 2 predelivery visits at gestational week 27-30 and 36-37 and with 1 postdelivery visit. All visits included blood and fecal sampling. An oral-glucose-tolerance test was performed at inclusion and gestational week 27-30.

RESULTS

Forty-nine participants completed the study. Thirty-eight participants took >80% of the capsules (n = 21), placebo (n = 17). There was no significant difference in GWG, GDM, HbA1c concentrations, and infant birth weight between groups. Fecal microbiota analyses showed an overall increase in α-diversity over time in the probiotic group only (P = 0.016).

CONCLUSIONS

Administration of probiotics during pregnancy is feasible in obese women and the women were willing to participate in additional study visits and collection of fecal samples during pregnancy. Multistrain probiotic can modulate the gut microbiota in obese women during pregnancy. A larger study population is needed to uncover pregnancy effects after probiotic supplementation. This trial was registered at clincaltrials.gov as NCT02508844.

Probiotic Strains and Intervention Total Doses for Modulating Obesity-Related Microbiota Dysbiosis: A Systematic Review and Meta-analysis

Obesity is a growing health threat worldwide. Administration of probiotics in obesity has also parallelly increased but without any protocolization. We conducted a systematic review exploring the administration pattern of probiotic strains and effective doses for obesity-related disorders according to their capacity of positively modulating key biomarkers and microbiota dysbiosis. Manuscripts targeting probiotic strains and doses administered for obesity-related disorders in clinical studies were sought. MEDLINE, Scopus, Web of Science, and Cochrane Library databases were searched using keywords during the last fifteen years up to April 2020. Two independent reviewers screened titles, abstracts, and then full-text papers against inclusion criteria according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. From 549 interventional reports identified, we filtered 171 eligible studies, from which 24 full-text assays were used for calculating intervention total doses (ITD) of specific species and strains administered. Nine of these reports were excluded in the second-step because no specific data on gut microbiota modulation was found. Six clinical trials (CT) and 9 animal clinical studies were retained for analysis of complete outcome prioritized (body mass index (BMI), adiposity parameters, glucose, and plasma lipid biomarkers, and gut hormones). Lactobacillus spp. administered were double compared to Bifidobacterium spp.; Lactobacillus as single or multispecies formulations whereas most Bifidobacteria only through multispecies supplementations. Differential factors were estimated from obese populations' vs. obesity-induced animals: ITD ratio of 2 × 106 CFU and patterns of administrations of 11.3 weeks to 5.5 weeks, respectively. Estimation of overall probiotics impact from selected CT was performed through a random-effects model to pool effect sizes. Comparisons showed a positive association between the probiotics group vs. placebo on the reduction of BMI, total cholesterol, leptin, and adiponectin. Moreover, negative estimation appeared for glucose (FPG) and CRP. While clinical trials including data for positive modulatory microbiota capacities suggested that high doses of common single and multispecies of Lactobacillus and Bifidobacterium ameliorated key obesity-related parameters, the major limitation was the high variability between studies and lack of standardized protocols. Efforts in solving this problem and searching for next-generation probiotics for obesity-related diseases would highly improve the rational use of probiotics.

Current and Future Treatments in the Fight Against Non-Alcoholic Fatty Liver Disease

Obesity is recognised as a risk factor for many types of cancers, in particular hepatocellular carcinoma (HCC). A critical factor in the development of HCC from non-alcoholic fatty liver disease (NAFLD) is the presence of non-alcoholic steatohepatitis (NASH). Therapies aimed at NASH to reduce the risk of HCC are sparse and largely unsuccessful. Lifestyle modifications such as diet and regular exercise have poor adherence. Moreover, current pharmacological treatments such as pioglitazone and vitamin E have limited effects on fibrosis, a key risk factor in HCC progression. As NAFLD is becoming more prevalent in developed countries due to rising rates of obesity, a need for directed treatment is imperative. Numerous novel therapies including PPAR agonists, anti-fibrotic therapies and agents targeting inflammation, oxidative stress and the gut-liver axis are currently in development, with the aim of targeting key processes in the progression of NASH and HCC. Here, we critically evaluate literature on the aetiology of NAFLD-related HCC, and explore the potential treatment options for NASH and HCC.

A Role for Gut Microbiome Fermentative Pathways in Fatty Liver Disease Progression

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial disease in which environmental and genetic factors are involved. Although the molecular mechanisms involved in NAFLD onset and progression are not completely understood, the gut microbiome (GM) is thought to play a key role in the process, influencing multiple physiological functions. GM alterations in diversity and composition directly impact disease states with an inflammatory course, such as non-alcoholic steatohepatitis (NASH). However, how the GM influences liver disease susceptibility is largely unknown. Similarly, the impact of strategies targeting the GM for the treatment of NASH remains to be evaluated. This review provides a broad insight into the role of gut microbiota in NASH pathogenesis, as a diagnostic tool, and as a therapeutic target in this liver disease. We highlight the idea that the balance in metabolic fermentations can be key in maintaining liver homeostasis. We propose that an overabundance of alcohol-fermentation pathways in the GM may outcompete healthier, acid-producing members of the microbiota. In this way, GM ecology may precipitate a self-sustaining vicious cycle, boosting liver disease progression.

Nonalcoholic Fatty Liver Disease in Children: Unique Considerations and Challenges

Nonalcoholic fatty liver disease (NAFLD) is increasing in prevalence in concert with the global epidemic of obesity and is being diagnosed at increasingly younger ages. The unique histologic features and early presentation of disease in pediatrics suggest that children and adults may differ with regard to etiopathogenesis, with children displaying a greater vulnerability to genetic and environmental factors. Of significant relevance to pediatrics, in utero and perinatal stressors may alter the lifelong health trajectory of a child, increasing the risk of NAFLD and other cardiometabolic diseases. The development and progression of disease in childhood is likely to carry increased risk of long-term morbidity. Novel biomarkers and therapeutic agents are needed to avoid the otherwise inevitable health and societal consequences of this rapidly expanding pediatric population.

Nonalcoholic Fatty Liver Disease: Modulating Gut Microbiota to Improve Severity?

Gut microbiota plays a role in the pathophysiology of metabolic diseases, which include nonalcoholic fatty liver diseases, through the gut-liver axis. To date, clinical guidelines recommend a weight loss goal of 7%-10% to improve features of nonalcoholic fatty liver diseases. Because this target is not easily achieved by all patients, alternative therapeutic options are currently being evaluated. This review focuses on therapeutics that aim to modulate the gut microbiota and the gut-liver axis. We discuss how probiotics, prebiotics, synbiotic, fecal microbiota transfer, polyphenols, specific diets, and exercise interventions have been found to modify gut microbiota signatures; improve nonalcoholic fatty liver disease outcomes; and detail, when available, the different mechanisms by which these beneficial outcomes might occur. Apart from probiotics that have already been tested in human randomized controlled trials, most of these potential therapeutics have been studied in animals. Their efficacy still warrants confirmation in humans using appropriate design.

Therapeutic advances in non-alcoholic fatty liver disease: A microbiota-centered view

Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent metabolic disorder with steadily increasing incidence rates worldwide, especially in the West. There are no drugs available at present to treat NAFLD, and the primary therapeutic options include weight loss and the combination of healthy diet and exercise. Therefore, novel interventions are required that can target the underlying risk factors. Gut microbiota is an "invisible organ" of the human body and vital for normal metabolism and immuno-modulation. The number and diversity of microbes differ across the gastrointestinal tract from the mouth to the anus, and is most abundant in the intestine. Since dysregulated gut microbiota is an underlying pathological factor of NAFLD, it is a viable therapeutic target that can be modulated by antibiotics, probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and microbial metabolites. In this review, we summarize the most recent advances in gut microbiota-targeted therapies against NAFLD in clinical and experimental studies, and critically evaluate novel targets and strategies for treating NAFLD.

Probiotic mixture VSL#3: An overview of basic and clinical studies in chronic diseases

Probiotics are known as “live microorganisms” and have been proven to have a health effect on hosts at the proper dose. Recently, a kind of probiotic mixture including eight live bacterial strains, VSL#3, has attracted considerable attention for its combined effect. VSL#3 is the only probiotic considered as a kind of medical food; it mainly participates in the regulation of the intestinal barrier function, including improving tight junction protein function, balancing intestinal microbial composition, regulating immune-related cytokine expression and so on. The objective of this review is to discuss the treatment action and mechanism for the administration of VSL#3 in chronic diseases of animals and humans (including children). We found that VSL#3 has a therapeutic or preventive effect in various systemic diseases per a large number of studies, including digestive systemic diseases (gastrointestinal diseases and hepatic diseases), obesity and diabetes, allergic diseases, nervous systemic diseases, atherosclerosis, bone diseases, and female reproductive systemic diseases.

Microbial Medicine: Prebiotic and Probiotic Functional Foods to Target Obesity and Metabolic Syndrome

Obesity has become a global epidemic and a public health crisis in the Western World, experiencing a threefold increase in prevalence since 1975. High-caloric diets and sedentary lifestyles have been identified as significant contributors to this widespread issue, although the role of genetic, social, and environmental factors in obesity's pathogenesis remain incompletely understood. In recent years, much attention has been drawn to the contribution of the gut microbiota in the development of obesity. Indeed, research has shown that in contrast to their healthier counterparts the microbiomes of obese individuals are structurally and functionally distinct, strongly suggesting microbiome as a potential target for obesity therapeutics. In particular, pre and probiotics have emerged as effective and integrative means of modulating the microbiome, in order to reverse the microbial dysbiosis associated with an obese phenotype. The following review brings forth animal and human research supporting the myriad of mechanisms by which the microbiome affects obesity, as well as the strengths and limitations of probiotic or prebiotic supplementation for the prevention and treatment of obesity. Finally, we set forth a roadmap for the comprehensive development of functional food solutions in combatting obesity, to capitalize on the potential of pre/probiotic therapies in optimizing host health.

Metabolic syndrome in children

Despite plenty of currently available information on metabolic syndrome (MetS) in children and adolescents, there are still uncertainties regarding definition, prevention, management and treatment of MetS in children. The first approach to MetS in children consists of lifestyle interventions (nutritional education, physical activity). These recommendations are often difficult to achieve, especially for adolescents, therefore, there is usually a lack of successful outcomes. A pharmacological intervention in obese children may be needed in some cases, with the aim to improve the effects of these primary prevention interventions. Metformin seems to be safe and presents evident positive effects on insulin sensitivity, but long-term and consistent data are still missing to establish its role in the pediatric population and the possible effectiveness of other emergent treatments such as glucagon-like peptide-1 analogues, dipeptidylpeptidase-4 inhibitors, dual inhibitors of SGLT1 and SGLT2 and weight loss drugs. Bariatric surgery might be helpful in selected cases. The aim of this review is to present the most recent available treatments for the main components of metabolic syndrome, with a focus on insulin resistance. A short mention of management of congenital forms of insulin resistance will be included too.

Probiotics VSL#3 are effective in reversing non-alcoholic steatohepatitis in a mouse model

Background

Probiotic VSL#3 is used to treat ulcerative colitis. This study examines the effect of VSL#3 in non-alcoholic steatohepatitis (NASH) that has liver carcinogenic potential.

Methods

Western diet (WD)-fed wild-type (WT) mice that do not have hepatic inflammation with lymphocyte infiltration and carcinogenic potential were used for baseline comparison. Age-, sex-, and diet-matched bile acid (BA) receptor farnesoid X receptor (FXR) knockout (KO) mice, which developed severe NASH and had the potential for liver cancer development, were supplemented with and without VSL#3 for 7 months. All the mice were euthanized when they were 10 months old.

Results

Supplementation with VSL#3 completely abolished hepatic lymphocyte infiltration, reduced hepatic fat content, and improved insulin sensitivity in WD-fed FXR KO mice. In addition, VSL#3 normalized dysregulated BA homoeostasis by inhibiting the classical BA synthesis pathway, inducing the alternative BA pathway, and activating ileal G-protein coupled BA receptor 1 (GPBAR1)-regulated signaling. Moreover, VSL#3 reconstructed the gut microbiota by reducing Bacteroidaceae, Porphyromonadaceae, and Helicobacteraceae as well as increasing Lachnospiraceae. Further, VSL#3 enriched the abundance of Ruminococcus and Faecalibacterium, which generate butyrate, at the genus level. It also increased the copy number of the butyrate-producing genes bcoA and buk, suggesting their anti-inflammatory and metabolic effects.

Conclusions

VSL#3 is useful in reversing NASH that occurred due to dysregulated BA synthesis and dysbiosis, suggesting its potential in liver cancer prevention.

Dysregulated FXR-FGF19 signaling and choline metabolism are associated with gut dysbiosis and hyperplasia in a novel pig model of pediatric NASH

To investigate the role of bile acids (BAs) in the pathogenesis of diet-induced nonalcoholic steatohepatitis (NASH), we fed a "Western-style diet" [high fructose, high fat (HFF)] enriched with fructose, cholesterol, and saturated fat for 10 wk to juvenile Iberian pigs. We also supplemented probiotics with in vitro BA deconjugating activity to evaluate their potential therapeutic effect in NASH. Liver lipid and function, cytokines, and hormones were analyzed using commercially available kits. Metabolites, BAs, and fatty acids were measured by liquid chromatography-mass spectrometry. Histology and gene and protein expression analyses were performed using standard protocols. HFF-fed pigs developed NASH, cholestasis, and impaired enterohepatic Farnesoid-X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling in the absence of obesity and insulin resistance. Choline depletion in HFF livers was associated with decreased lipoprotein and cholesterol in serum and an increase of choline-containing phospholipids in colon contents and trimethylamine-N-oxide in the liver. Additionally, gut dysbiosis and hyperplasia increased with the severity of NASH, and were correlated with increased colonic levels of choline metabolites and secondary BAs. Supplementation of probiotics in the HFF diet enhanced NASH, inhibited hepatic autophagy, increased excretion of taurine and choline, and decreased gut microbial diversity. In conclusion, dysregulation of BA homeostasis was associated with injury and choline depletion in the liver, as well as increased biliary secretion, gut metabolism and excretion of choline-based phospholipids. Choline depletion limited lipoprotein synthesis, resulting in hepatic steatosis, whereas secondary BAs and choline-containing phospholipids in colon may have promoted dysbiosis, hyperplasia, and trimethylamine synthesis, causing further damage to the liver.NEW & NOTEWORTHY Impaired Farnesoid-X receptor (FXR)-fibroblast growth factor 19 (FGF19) signaling and cholestasis has been described in nonalcoholic fatty liver disease (NAFLD) patients. However, therapeutic interventions with FXR agonists have produced contradictory results. In a swine model of pediatric nonalcoholic steatohepatitis (NASH), we show that the uncoupling of intestinal FXR-FGF19 signaling and a decrease in FGF19 levels are associated with a choline-deficient phenotype of NASH and increased choline excretion in the gut, with the subsequent dysbiosis, colonic hyperplasia, and accumulation of trimethylamine-N-oxide in the liver.

Low serum amylase, lipase, and trypsin as biomarkers of metabolic disorders: A systematic review and meta-analysis

AIMS

While there is plentiful evidence on elevated serum levels of amylase, lipase, and trypsin in acute illness, low serum levels of these digestive enzymes have been studied infrequently. The aim was to systematically review published studies on the relationship between low serum levels of amylase, lipase, or trypsin and metabolic disorders.

METHODS

The search was conducted in MEDLINE and Scopus databases. Studies in humans were included if they reported on the association between serum levels of amylase, lipase, or trypsin within normal range and metabolic disorders. Random-effects meta-analysis was conducted.

RESULTS

A total of 20 studies encompassing 20,916 participants were included. Compared with healthy individuals, individuals with type 2 diabetes mellitus (mean difference = -5.3; p < 0.001), metabolic syndrome (mean difference = -5.1; p < 0.001), and overweight/obesity (mean difference = -0.8; p = 0.02) had significantly lower serum levels of amylase. Both individuals with type 1 diabetes mellitus (mean difference = -1.8; p < 0.001) and type 2 diabetes mellitus (mean difference = -0.8; p < 0.001) had significantly lower serum levels of lipase compared with healthy individuals. Data on serum trypsin were not suitable for meta-analysis. In the pooled analysis, individuals with type 2 diabetes mellitus had 3.1-times lower serum levels of amylase, 2.9-times lower serum levels of lipase, and 2.5-times lower serum levels of trypsin levels than the upper limits of normal for the three digestive enzymes.

CONCLUSION

Low serum levels of amylase and lipase are significantly associated with type 2 diabetes mellitus, type 1 diabetes mellitus, excess adiposity, and metabolic syndrome. The role of digestive enzymes in the pathogenesis of metabolic disorders warrants further investigations.

Intestinal microbiome and NAFLD: molecular insights and therapeutic perspectives

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of dysregulated lipid and glucose metabolism, which is often associated with obesity, dyslipidemia and insulin resistance. In view of the high morbidity and health risks of NAFLD, the lack of effective cure has drawn great attention. In recent years, a line of evidence has suggested a close linkage between the intestine and liver diseases such as NAFLD. We summarized the composition and characteristics of intestinal microbes and reviewed molecular insights into the intestinal microbiome in development and progression of NAFLD. Intestinal microbes mainly include bacteria, archaea, viruses and fungi, and the crosstalk between non-bacterial intestinal microbes and human liver diseases should be paid more attention. Intestinal microbiota imbalance may not only increase the intestinal permeability to gut microbes but also lead to liver exposure to harmful substances that promote hepatic lipogenesis and fibrosis. Furthermore, we focused on reviewing the latest "gut-liver axis"-targeting treatment, including the application of antibiotics, probiotics, prebiotics, synbiotics, farnesoid X receptor agonists, bile acid sequestrants, gut-derived hormones, adsorbents and fecal microbiota transplantation for NAFLD. In this review, we also discussed the potential mechanisms of "gut-liver axis" manipulation and efficacy of these therapeutic strategies for NAFLD treatment.

Hepatic dysfunction after spinal cord injury: A vicious cycle of central and peripheral pathology?

The liver is essential for numerous physiological processes, including filtering blood from the intestines, metabolizing fats, proteins, carbohydrates and drugs, and regulating iron storage and release. The liver is also an important immune organ and plays a critical role in response to infection and injury throughout the body. Liver functions are regulated by autonomic parasympathetic innervation from the brainstem and sympathetic innervation from the thoracic spinal cord. Thus, spinal cord injury (SCI) at or above thoracic levels disrupts major regulatory mechanisms for hepatic functions. Work in rodents and humans shows that SCI induces liver pathology, including hepatic inflammation and fat accumulation characteristic of a serious form of non-alcoholic fatty liver disease (NAFLD) called non-alcoholic steatohepatitis (NASH). This hepatic pathology is associated with and likely contributes to indices of metabolic dysfunction often noted in SCI individuals, such as insulin resistance and hyperlipidemia. These occur at greater rates in the SCI population and can negatively impact health and quality of life. In this review, we will: 1) Discuss acute and chronic changes in human and rodent liver pathology and function after SCI; 2) Describe how these hepatic changes affect systemic inflammation, iron regulation and metabolic dysfunction after SCI; 3) Describe how disruption of the hepatic autonomic nervous system may be a key culprit in post-injury chronic liver pathology; and 4) Preview ongoing and future research that aims to elucidate mechanisms driving liver and metabolic dysfunction after SCI.

Non-alcoholic fatty liver diseases: from role of gut microbiota to microbial-based therapies

Non-alcoholic fatty liver disease (NAFLD) is the well-known disease of the liver in adults and children throughout the world. The main manifestations related to NAFLD are an unusual storage of lipid in hepatocytes (hepatic steatosis) and progression of inflammation for non-alcoholic steatohepatitis (NASH). NAFLD is described as a multifactorial complication due to the genetic predisposition, metabolic functions, inflammatory, gut microbiota (GM), and environmental factors. The GM dysregulation among these factors is correlated to NAFLD development. In recent decades, advanced microbial profiling methods are continuing to shed light on the nature of the changes in the GM caused by NASH and NAFLD. In the current review, we aim to perform a literature review in different library databases and electronic searches (Science Direct, PubMed, and Google Scholar) which were randomly obtained. This will be done in order to provide an overview of the relation between GM and NAFLD, and the role of prebiotics, probiotics, and fecal microbiota transplantation (FMT), as potential therapeutic challenges for NAFLD.

Systematic Review with Meta-Analysis: The Effects of Probiotics in Nonalcoholic Fatty Liver Disease

Background and Aims

Probiotics was considered as a potential therapy for nonalcoholic fatty liver disease (NAFLD) without approval and comprehensive assessment in recent years, which call for a meta-analysis.

Methods

We performed electronic and manual searches including English and Chinese databases published before April 2019, with the use of mesh term and free text of "nonalcoholic fatty liver disease" and "probiotics." Clinical trials evaluating the efficacy of probiotic therapy in NAFLD patients were included according to the eligibility criteria. With the use of random effects models, clinical outcomes were presented as weighted mean difference (WMD) with 95% confidence interval (CI), while heterogeneity and meta-regression were also assessed.

Results

28 clinical trials enrolling 1555 criterion proven NAFLD patients with the use of probiotics from 4 to 28 weeks were included. Overall, probiotic therapy had beneficial effects on body mass index (WMD: -1.46, 95% CI: [-2.44, -0.48]), alanine aminotransferase (WMD: -13.40, 95% CI: [-17.03, -9.77]), aspartate transaminase (WMD: -13.54, 95% CI: [-17.86, -9.22]), gamma-glutamyl transpeptidase (WMD: -9.88, 95% CI: [-17.77, -1.99]), insulin (WMD: -1.32, 95% CI: [-2.43, -0.21]), homeostasis model assessment-insulin resistance (WMD: -0.42, 95% CI: [-0.73, -0.12]), and total cholesterol (WMD: -15.38, 95% CI: [-26.50, -4.25]), but not in fasting blood sugar, lipid profiles, or tumor necrosis factor-alpha.

Conclusion

The systematic review and meta-analysis support that probiotics are superior to placebo in NAFLD patients and could be utilized as a common complementary therapeutic approach.

Efficacy of Probiotics and Synbiotics in Patients with Nonalcoholic Fatty Liver Disease: A Meta-Analysis

BACKGROUND AND AIM

Extensive epidemiological evidence suggests that nonalcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide. However, some studies have showed conflicting results on the effects of probiotics and synbiotics supplementation. Therefore, we conducted a systematic review and meta-analysis to investigate the effectiveness of the supplementation in subjects with NAFLD.

METHODS

We searched systematically PubMed, Cochrane, and Embase databases up to April 2018 and checked manually the bibliography of the original articles. The quality of the studies was evaluated using the Cochrane Risk of Bias Tool.

RESULTS

This study analyzed 15 randomized, controlled trials involving 782 patients with NAFLD. Probiotics and synbiotics supplementation could significantly improve liver steatosis, alanine aminotransferase, aspartate aminotransferase, triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, homeostasis model assessment-insulin resistance, liver stiffness and tumor necrosis factor-alpha (all P < 0.05). But the supplementation could not ameliorate body mass index (mean difference [MD] = -0.00; 95% confidence interval [CI]: -0.22 to 0.22, P = 0.99), waist circumference (MD = -0.01; 95% CI -0.03 to 0.02, P = 0.57) and fasting blood sugar (standard mean difference [SMD] = -0.10; 95% CI -0.32 to 0.12, P = 0.39).

CONCLUSION

We present clear evidence for the benefit of probiotics and synbiotics supplementation for liver steatosis, liver enzymes, lipid profiles and liver stiffness in patients with NAFLD.

Role of Probiotics in Non-alcoholic Fatty Liver Disease: Does Gut Microbiota Matter?

Non-alcoholic fatty liver disease (NAFLD) is the hepatic consequence of metabolic syndrome, which often also includes obesity, diabetes, and dyslipidemia. The connection between gut microbiota (GM) and NAFLD has attracted significant attention in recent years. Data has shown that GM affects hepatic lipid metabolism and influences the balance between pro/anti-inflammatory effectors in the liver. Although studies reveal the association between GM dysbiosis and NAFLD, decoding the mechanisms of gut dysbiosis resulting in NAFLD remains challenging. The potential pathophysiology that links GM dysbiosis to NAFLD can be summarized as: (1) disrupting the balance between energy harvest and expenditure, (2) promoting hepatic inflammation (impairing intestinal integrity, facilitating endotoxemia, and initiating inflammatory cascades with cytokines releasing), and (3) altered biochemistry metabolism and GM-related metabolites (i.e., bile acid, short-chain fatty acids, aromatic amino acid derivatives, branched-chain amino acids, choline, ethanol). Due to the hypothesis that probiotics/synbiotics could normalize GM and reverse dysbiosis, there have been efforts to investigate the therapeutic effect of probiotics/synbiotics in patients with NAFLD. Recent randomized clinical trials suggest that probiotics/synbiotics could improve transaminases, hepatic steatosis, and reduce hepatic inflammation. Despite these promising results, future studies are necessary to understand the full role GM plays in NAFLD development and progression. Additionally, further data is needed to unravel probiotics/synbiotics efficacy, safety, and sustainability as a novel pharmacologic approaches to NAFLD.

Gut Microbiota and Obesity: A Role for Probiotics

Nowadays, obesity is one of the most prevalent human health problems. Research from the last 30 years has clarified the role of the imbalance between energy intake and expenditure, unhealthy lifestyle, and genetic variability in the development of obesity. More recently, the composition and metabolic functions of gut microbiota have been proposed as being able to affect obesity development. Here, we will report the current knowledge on the definition, composition, and functions of intestinal microbiota. We have performed an extensive review of the literature, searching for the following keywords: metabolism, gut microbiota, dysbiosis, obesity. There is evidence for the association between gut bacteria and obesity both in infancy and in adults. There are several genetic, metabolic, and inflammatory pathophysiological mechanisms involved in the interplay between gut microbes and obesity. Microbial changes in the human gut can be considered a factor involved in obesity development in humans. The modulation of the bacterial strains in the digestive tract can help to reshape the metabolic profile in the human obese host as suggested by several data from animal and human studies. Thus, a deep revision of the evidence pertaining to the use probiotics, prebiotics, and antibiotics in obese patients is conceivable

The Role of Probiotics in Nonalcoholic Fatty Liver Disease: A New Insight into Therapeutic Strategies

Nonalcoholic fatty liver disease (NAFLD) encompasses a broad spectrum of pathological hepatic conditions ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), which may predispose to liver cirrhosis and hepatocellular carcinoma (HCC). Due to the epidemic obesity, NAFLD is representing a global health issue and the leading cause of liver damage worldwide. The pathogenesis of NAFLD is closely related to insulin resistance (IR), adiposity and physical inactivity as well as genetic and epigenetic factors corroborate to the development and progression of hepatic steatosis and liver injury. Emerging evidence has outlined the implication of gut microbiota and gut-derived endotoxins as actively contributors to NAFLD pathophysiology probably due to the tight anatomo-functional crosstalk between the gut and the liver. Obesity, nutrition and environmental factors might alter intestinal permeability producing a favorable micro-environment for bacterial overgrowth, mucosal inflammation and translocation of both invasive pathogens and harmful byproducts, which, in turn, influence hepatic fat composition and exacerbated pro-inflammatory and fibrotic processes. To date, no therapeutic interventions are available for NAFLD prevention and management, except for modifications in lifestyle, diet and physical exercise even though they show discouraging results due to the poor compliance of patients. The premise of this review is to discuss the role of gut–liver axis in NAFLD and emphasize the beneficial effects of probiotics on gut microbiota composition as a novel attractive therapeutic strategy to introduce in clinical practice.

The good bugs: the use of probiotics in pediatrics

PURPOSE OF REVIEW

There is growing evidence encouraging the use of probiotics in many conditions in children. However, given the wide number of probiotics available and contradictory data in the literature, the health-care provider is often faced with uncertainness about whether or not to use probiotics and which one(s) to choose. We here review current hypotheses regarding the efficacy and safety of probiotics and evaluate the available data on the use of probiotics in most common diseases in children. Considering that probiotics have strain-specific effects, we will focus on individual probiotic strains rather than on probiotics in general.

RECENT FINDINGS

Strain-specific efficacy was clearly demonstrated with Lactobacillus rhamnosus GG and Saccharomyces boulardii I-745 in the treatment of acute infectious diarrhea, Lactobacillus reuteri DSM 17938 in infantile colics, Lactobacillus rhamnosus GG, and VSL#3 in irritable bowel syndrome. In addition, encouraging results are seen for use of probiotics in necrotizing enterocolitis, food allergy, and nonalcoholic fatty liver disease. However, the data available for constipation are to be considered somewhat equivocal.

SUMMARY

The clinical relevance of these findings indicates that healthcare providers need to take strain-specificity and disease specificity of probiotics into consideration when recommending probiotic for their patients.

Effects of probiotics on nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) has become prevalent in recent decades, especially in developed countries, and approaches for the prevention and treatment of NAFLD are not clear. The aim of this research was to analyze and summarize randomized controlled trials that investigated the effects of probiotics on NAFLD.

METHODS

Seven databases (PubMed, Embase, the Web of Science, the Cochrane Library, China National Knowledge Infrastructure, Wan Fang Data, and VIP Database) were searched. Then, eligible studies were identified. Finally, proper data extraction, synthesis and analysis were performed by trained researchers.

RESULTS

Anthropometric parameters: with use of probiotics weight was reduced by 2.31 kg, and body mass index (BMI) was reduced by 1.08 kg/m². Liver function: probiotic treatment reduced the alanine aminotransferase level by 7.22 U/l, the aspartate aminotransferase level by 7.22 U/l, the alkaline phosphatase level by 25.87 U/l, and the glutamyl transpeptidase level by -5.76 U/l. Lipid profiles: total cholesterol, low-density lipoprotein cholesterol, and triglycerides were significantly decreased after probiotic treatment. Their overall effects (shown as standard mean difference) were -0.73, -0.54, and -0.36, respectively. Plasma glucose: probiotics reduced the plasma glucose level by 4.45 mg/dl and the insulin level by 0.63. Cytokines: probiotic treatment decreased tumor necrosis factor alpha by 0.62 and leptin by 1.14. Degree of liver fat infiltration (DFI): the related risk of probiotics for restoring DFI was 2.47 (95% confidence interval, 1.61-3.81, p < 0.001).

CONCLUSION

Probiotic treatment or supplementation is a promising therapeutic method for NAFLD.

Prebiotic and probiotic treatment of nonalcoholic fatty liver disease: a systematic review and meta-analysis

Context

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent and underdiagnosed comorbidity of many chronic diseases that is associated with altered intestinal bacterial communities. This association has prompted research into alternative treatments aimed at modulating intestinal microbiota. Given the novelty of these treatments, scarce evidence regarding their effectiveness in clinical populations exists.

Objective

This meta-analysis sought to systemically review and quantitatively synthesize evidence on prebiotic, probiotic, and synbiotic therapies for patients with NAFLD in randomized controlled trials.

Data sources

PRISMA guidelines ensured transparent reporting of evidence. PICOS criteria defined the research question for the systematic review. A systematic keyword search in PubMed and EMBASE identified 25 studies: 9 assessed prebiotic, 11 assessed probiotic, and 7 assessed symbiotic therapies for a total of 1309 patients.

Data extraction

Basic population characteristics, the primary variables of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) (utilized for NAFLD diagnosis), and the secondary variables of body mass index (BMI), gamma-glutamyl transferase (γ-GT), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), and triglyceridges (TAG) were extracted. Pooled effect sizes of these variables were calculated by meta-analysis. No publication bias was identified using Begg's and Egger's tests or Cochrane bias assessment tool.

Results

Meta-analysis indicated that microbial therapies significantly reduced BMI (-0.37 kg/m2; 95% confidence interval [CI], -0.46 to -0.28; P < 0.001), hepatic enzymes (ALT, -6.9 U/L [95%CI, -9.4 to -4.3]; AST, -4.6 U/L [95%CI, -6.6 to -2.7]; γ-GT, -7.9 U/L [95%CI, -11.4 to -4.4]; P < 0.001), serum cholesterol (-10.1 mg/dL 95%CI, -13.6 to -6.6; P < 0.001), LDL-c (-4.5 mg/dL; 95%CI, -8.9 to -0.17; P < 0.001), and TAG (-10.1 mg/dL; 95%CI, -18.0 to -2.3; P < 0.001), but not inflammation (TNF-α, -2.0 ng/mL; [95%CI, -4.7 to 0.61]; CRP, -0.74 mg/L [95%CI, -1.9 to 0.37]). Subgroup analysis by treatment category indicated similar effects of prebiotics and probiotics on BMI and liver enzymes but not total cholesterol, HDL-c, and LDL-c.

Conclusion

This meta-analysis supports the potential use of microbial therapies in the treatment of NAFLD and sheds light on their potential mode of action. Further research into these treatments should consider the limitations of biomarkers currently used for the diagnosis and progression of NAFLD, in addition to the inherent challenges of personalized microbial-based therapies.

Review article: can bugs be drugs? The potential of probiotics and prebiotics as treatment for non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver condition. A major current research effort is ongoing to find potential strategies to treat NAFLD-non-alcoholic steatohepatitis (NASH), with special attention to the gut microbiota. Multiple animal studies and pilot clinical trials are assessing different gut microbiota modulating strategies such as faecal microbiota transplantation, antibiotics, probiotics, prebiotics and synbiotics.

AIM

To review the role of microbiota in NAFLD-NASH and determine whether pro- and prebiotics have potential as treatment METHODS: Information was obtained from critically reviewing literature on PubMed on targeting the gut microbiota in NAFLD. Search terms included NAFLD, NASH, non-alcoholic fatty liver disease, steatohepatitis; combined with microbiome, microbiota, gut bacteria, probiotics and prebiotics.

RESULTS

Animal studies and the first emerging studies in humans show promising results for both the common probiotics Lactobacillus, Bifidobacterium and Streptococci as for short chain fatty acid (SCFA) butyrate-producing bacteria. Also, prebiotics have positive effects on different mechanisms underlying NAFLD-NASH.

CONCLUSIONS

The most promising strategies thus far developed to alter the microbiome in NAFLD-NASH are probiotics and prebiotics. However, pre- and probiotic treatment of NAFLD-NASH is relatively new and still under development. Actual understanding of the involved mechanisms is lacking and changes in the intestinal microbiota composition after treatment are rarely measured. Furthermore, large clinical trials with comparative endpoints are unavailable. Personalised treatment based on metagenomics gut microbiota analysis will probably be part of the future diagnosis and treatment of NAFLD-NASH.

NAFLD in children: new genes, new diagnostic modalities and new drugs

Nonalcoholic fatty liver disease (NAFLD) has rapidly become the most common form of chronic liver disease in children and adolescents. Over the past 5 years, developments have revolutionized our understanding of the genetic factors, natural history, diagnostic modalities and therapeutic targets for this disease. New polymorphisms, such as those in PNPLA3, TM6SF2, MBOAT7 and GCKR, have been identified and used to predict the development and severity of NAFLD in both adults and children, and their interaction with environmental factors has been elucidated. Studies have demonstrated the true burden of paediatric NAFLD and its progression to end-stage liver disease in adulthood. In particular, nonalcoholic steatohepatitis can progress to advanced fibrosis and cirrhosis, emphasizing the importance of early diagnosis. Non-invasive imaging tests, such as transient elastography, will probably replace liver biopsy for the diagnosis of nonalcoholic steatohepatitis and the assessment of fibrosis severity in the near future. The therapeutic landscape is also expanding rapidly with the development of drugs that can modify liver steatosis, inflammation and fibrosis, indicating that pharmacotherapy for NAFLD will become available in the future. In this Review, we summarize current knowledge and new advances related to the pathogenesis and management of paediatric NAFLD.

Pediatric non-alcoholic fatty liver disease: current perspectives on diagnosis and management

Non-alcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in childhood. To date, the "multiple-hit" hypothesis is largely recognized as an explanation of NAFLD pathogenesis and progression. Obesity and features of the metabolic syndrome have been closely linked to NAFLD development. Due to the increased prevalence of obesity worldwide, NAFLD has reached epidemic proportions over time. Given its unfavorable cardiometabolic burden (such as cardiovascular and metabolic consequences), it represents a worrying phenomenon needing a more comprehensive and successful management. Laboratory tests and classical imaging techniques play a pivotal role in NAFLD diagnosis, but novel noninvasive alternative methods to diagnose and monitor NAFLD have been investigated. Currently, lifestyle modifications remain the mainstay treatment, although its efficacy is poor because of the lack of compliance. Pediatric research is focusing on multiple alternative treatments targeting the main pathogenic factors such as insulin-resistance, dyslipidemia, gut-liver axis and microbiota, oxidative stress, and proinflammatory pathways. Results from these studies are promising but larger validation is needed. Innovative therapeutic approaches might add an important piece in the complex knowledge of pediatric NAFLD. We aimed to summarize recent insights into NAFLD diagnosis and treatment in children, with a focus on possible future perspectives in pediatric research.

High potency multistrain probiotic improves liver histology in non-alcoholic fatty liver disease (NAFLD): a randomised, double-blind, proof of concept study

Objective

Pharmacological treatment of non-alcoholic fatty liver disease (NAFLD) is still evolving. Probiotics could be a promising treatment option, but their effectiveness needs to be established. The present study aimed to evaluate the efficacy of a high potency multistrain probiotic in adult patients with NAFLD.

Methods

Thirty-nine liver biopsy-proven patients with NAFLD were randomised in a double-blind fashion to either lifestyle modifications plus an oral multistrain probiotic (675 billion bacteria daily, n=19) or identical placebo (n=20) for 1 year. Lifestyle modifications included regular exercise for all and control of overweight/obesity (with additional dietary restrictions), hypertension and hyperlipidaemia in those with these risk factors. Primary objective of the study was the histological improvement in NAFLD activity score (NAS) and its components and secondary objectives were improvement in alanine transaminase (ALT) and cytokine profile.

Results

Thirty (76.9%) out of 39 patients with NAFLD completed the study with 1 year of follow-up. A repeat liver biopsy at 1 year could be done in 10 patients (52.6%) in probiotic group and five patients (25%) in placebo group. In comparison to baseline, hepatocyte ballooning (p=0.036), lobular inflammation (p=0.003) and NAS score (p=0.007) improved significantly at 1 year in the probiotic group. When compared with placebo, the NAS score improved significantly in the probiotic group (p=0.004), along with improvements in hepatocyte ballooning (p=0.05) and hepatic fibrosis (p=0.018). A significant improvement in levels of ALT (p=0.046), leptin (p=0.006), tumour necrosis factor-α (p=0.016) and endotoxins (p=0.017) was observed in probiotic group in comparison to placebo at 1 year. No significant adverse events were reported in the study.

Conclusion

Patients with NAFLD managed with lifestyle modifications and multistrain probiotic showed significant improvement in liver histology, ALT and cytokines.

Trial registration number

The clinical trial is registered with CLINICAL TRIAL REGISTRYINDIA (CTRI); http://ctri.nic.in, No. CTRI/2008/091/000074

Effects of probiotic supplementation on the regulation of blood lipid levels in overweight or obese subjects: a meta-analysis

BACKGROUND

Obesity is a risk factor for many deadly diseases. Meanwhile, the prevalence of obesity has been continuously increasing in many countries. Probiotics are defined as live microorganisms that confer health benefits on hosts. Probiotic supplementation could reduce body weight, body mass index (BMI) and fat percentage. However, it is unclear whether supplementation with probiotics is beneficial to lower blood lipid levels for obese or overweight people.

METHODS

In this study, a comprehensive search across multiple databases was performed to identify studies that focused on the effects of probiotics on blood lipid levels in overweight or obese subjects. The meta-analysis included studies that compared the variations in blood lipid (total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglyceride (TG)) concentrations between overweight and obese subjects who were supplemented with probiotics versus the controls who were not supplemented with probiotics.

RESULTS

Our findings indicated that probiotic supplementation in obese or overweight people was associated with significantly larger reductions in TC and LDL levels compared to a lack of probiotic supplementation in the control subjects. However, there was no significant difference in the variations between HDL and TG concentrations.

CONCLUSION

Probiotic supplementation reduced TC and LDL concentrations in obese or overweight people. Additional data from large clinical trials are required to confirm the efficacy and safety of probiotics in the regulation of blood lipid levels in obese or overweight people.

The role of the gut microbiome in chronic liver disease: the clinical evidence revised

Recent research has suggested a role for the intestinal microbiota in the pathogenesis and potential treatment of a wide range of liver diseases. The intestinal microbiota and bacterial products may contribute to the development of liver diseases through multiple mechanisms including increased intestinal permeability, chronic systemic inflammation, production of short-chain fatty acids and changes in metabolism. This suggests a potential role for pre-, pro- and synbiotic products in the prevention or treatment of some liver diseases. In addition, there is emerging evidence on the effects of faecal microbial transplant. Herein, we discuss the relationship between the intestinal microbiota and liver diseases, as well as reviewing intestinal microbiota-based treatment options that are currently being investigated.