Role of the Gut Microbiota in Regulating Non-alcoholic Fatty Liver Disease in Children and Adolescents

Polyethylene microplastics impair chicken growth through gut microbiota-induced hepatic fatty acid metabolism dysfunction

Microplastics (MPs) negatively impact various terrestrial animals, but their comprehensive effects on Gallus gallus domesticus, key agricultural and ecological species connecting people and the environment, are not well-documented. This study investigates the effects of polyethylene (PE) MPs and phthalate esters (PAEs) on chicken growth, liver metabolism, and gut microbiota using multi-omics and 16S rRNA sequencing technology. Results show that PE MPs, particularly those containing PAEs, significantly reduced body weight gain and hepatic triglyceride levels by up to 71.2 % and 50.1 %, respectively (p < 0.05). The clean MPs affected energy metabolism, while PAE-spiked MPs disrupted fatty acid metabolism and triggered immune and inflammatory responses in the liver. Key genes related to fatty acid metabolism such as FAN, SCD and ELOVL5 were significantly downregulated, leading to imbalances in lipid metabolism. These disruptions in PAE-spiked MPs exposure were associated with the altered gut microbiota balance, including increased Firmicutes/Bacteroidetes ratios and changes in Actinobacteriota and Proteobacteria abundance. Totally, the study highlights a "Trojan Horse" effect, where MPs act as carriers for PAEs, intensifying toxicity through gut-liver axis interactions. The findings emphasize the role of gut microbiota in mediating liver dysfunction and impaired growth.

Personalized Dietary Approaches to Optimizing Intestinal Microbial Health and Homeostasis

Diet has a profound impact in human health, which is partly driven by changes in the intestinal microbiota. Several associations between dietary intake and the intestinal microbiota composition and function have been described. Namely, the Mediterranean diet is associated with beneficial bacteria, while the intake of ultraprocessed foods is linked to dysbiosis. It is, therefore, very tempting to tailor dietary approaches to the individual needs of the microbiota; however, high-quality prospective data are lacking. Provisionally, a diet rich in fruits and vegetables and low in ultraprocessed foods is recommended to improve the intestinal microbiota composition and function.

Epithelial barrier hypothesis in the context of nutrition, microbial dysbiosis, and immune dysregulation in metabolic dysfunction-associated steatotic liver

In recent years, the prevalence of chronic liver diseases, particularly Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), has increased significantly. This upward trend is largely associated with lifestyle-related factors such as unhealthy dietary habits, physical inactivity, and various environmental influences. Among the key elements contributing to the pathogenesis of MASLD, the integrity of the intestinal epithelial barrier emerges as a critical determinant, given its central role in maintaining immune homeostasis along the gut-liver axis. Disruption of this barrier, often driven by excessive consumption of saturated fats and refined carbohydrates in combination with low dietary fiber intake, can lead to microbial dysbiosis. This imbalance in the gut microbiota triggers immune dysregulation and promotes systemic inflammation, thereby exacerbating hepatic injury. This review discusses the contribution of epithelial barrier dysfunction to the development and progression of MASLD, with a particular focus on how increased intestinal permeability may initiate and sustain chronic liver inflammation. Additionally, the influence of dietary and environmental factors on epithelial integrity, immune responses, and the inflammatory cascade is addressed. A better understanding of the complex interplay between gut barrier impairment, immune modulation, and liver pathology may offer valuable insights into MASLD pathophysiology and contribute to the development of more targeted therapeutic strategies.

Role of short-chain fatty acids in non-alcoholic fatty liver disease and potential therapeutic targets

Non-alcoholic fatty liver disease (NAFLD) is increasing worldwide and has become the greatest potential risk for cirrhosis and hepatocellular carcinoma. The metabolites produced by the gut microbiota act as signal molecules that mediate the interaction between microorganisms and the host and have biphasic effects on human health. The gut microbiota and its metabolites, short-chain fatty acids (SCFAs), have been discovered to ameliorate many prevalent liver diseases, including NAFLD. Currently, SCFAs have attracted widespread attention as potential therapeutic targets for NAFLD, but the mechanism of action has not been fully elucidated. This article summarizes the mechanisms of short-chain fatty acids of gut microbiota metabolites to regulate the metabolism of glucose and lipid, maintain the intestinal barrier, alleviate the inflammatory response, and improve the oxidative stress to improve NAFLD, in order to provide a reference for clinical application.

The Role of Short-Chain Fatty Acids in Metabolic Dysfunction-Associated Steatotic Liver Disease and Other Metabolic Diseases

With its increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a major global public health concern over the past few decades. Growing evidence has proposed the microbiota-derived metabolites short-chain fatty acids (SCFAs) as a potential factor in the pathophysiology of MASLD and related metabolic conditions, such as obesity and type 2 diabetes mellitus (T2DM). By influencing key pathways involved in energy homeostasis, insulin sensitivity, and inflammation, SCFAs play an important role in gut microbiota composition, intestinal barrier function, immune modulation, and direct metabolic signaling. Furthermore, recent animal and human studies on therapeutic strategies targeting SCFAs demonstrate their potential for treating these metabolic disorders.

Macronutrient Modulation in Metabolic Dysfunction-Associated Steatotic Liver Disease-the Molecular Role of Fatty Acids compared with Sugars in Human Metabolism and Disease Progression

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a significant public health concern, with its progression to metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis leading to severe outcomes including cirrhosis, hepatocellular carcinoma, and liver failure. Whereas obesity and excess energy intake are well-established contributors to the development and progression of MASLD, the distinct role of specific macronutrients is less clear. This review examines the mechanistic pathways through which dietary fatty acids and sugars contribute to the development of hepatic inflammation and fibrosis, offering a nuanced understanding of their respective roles in MASLD progression. In terms of addressing potential therapeutic options, human intervention studies that investigate whether modifying the intake of dietary fats and carbohydrates affects MASLD progression are reviewed. By integrating this evidence, this review seeks to bridge the gap in the understanding between the mechanisms of macronutrient-driven MASLD progression and the effect of altering the intake of these nutrients in the clinical setting and presents a foundation for future research into targeted dietary strategies for the treatment of the disease.

The gut microbiome across the lifespan: how diet modulates our microbial ecosystem from infancy to the elderly

This comprehensive review examines the impact of dietary patterns on gut microbiome composition and diversity from infancy to old age, linking these changes to age-related health outcomes. It investigates how the gut microbiome develops and changes across life stages, focusing on the influence of dietary factors. The review explores how early-life feeding practices, including breastfeeding and formula feeding, shape the infant gut microbiota and have lasting effects. In elderly individuals, alterations in the gut microbiome are associated with increased susceptibility to infections, chronic inflammation, metabolic disorders and cognitive decline. The critical role of diet in modulating the gut microbiome throughout life is emphasised, particularly the potential benefits of probiotics and fortified foods in promoting healthy ageing. By elucidating the mechanisms connecting food systems to gut health, this review provides insights into interventions that could enhance gut microbiome resilience and improve health outcomes across the lifespan.

Dietary index for gut microbiota and its protective role against kidney stones: evidence of diabetes as a mediator from NHANES cross-sectional data

Background

The dietary index for gut microbiota (DI-GM) reflects dietary patterns that support gut microbial health and may influence kidney stone (KS) risk. The role of DI-GM and its mediation by diabetes in KS pathogenesis remains unclear.

Objective

To investigate the association between DI-GM and KS prevalence, assess the mediation effect of diabetes, and explore subgroup-specific effects and underlying mechanisms.

Methods

A cross-sectional analysis of NHANES (2007-2018) data was conducted using a stratified, multistage probability sampling design. A total of 19,841 participants were included in the final analysis. Data entry and statistical analysis were performed using Empower version 4.2 (X&Y Solutions, Inc., Boston, MA, United States) and R version 3.4.3 (R Foundation). Multivariable logistic regression was employed to assess the association between DI-GM and KS prevalence, with statistical significance set at p < 0.05. Mediation analysis evaluated diabetes's contribution to this relationship, and subgroup analyses were conducted based on sex, race/ethnicity, and alcohol consumption.

Results

Higher DI-GM scores were associated with lower KS prevalence (adjusted OR: 0.78, 95% CI: 0.65-0.92 per SD increase). Diabetes mediated 9.27% of this relationship. Subgroup analyses revealed stronger protective effects among females, non-Hispanic Black individuals, and heavy drinkers. Mechanistically, DI-GM may reduce KS risk through gut microbial modulation of oxalate metabolism, urinary citrate excretion, and systemic inflammation.

Conclusion and recommendations

Higher DI-GM scores are associated with reduced KS prevalence, partially mediated by diabetes. These findings highlight the role of dietary interventions targeting gut microbiota in KS prevention and call for longitudinal studies to confirm these results and develop tailored dietary strategies.

Mechanisms underpinning the effect of exercise on the non-alcoholic fatty liver disease: review

Non-alcoholic Fatty Liver Disease (NAFLD) - whose terminology was recently replaced by metabolic liver disease (MAFLD) - is an accumulation of triglycerides in the liver of >5 % of its weight. Epidemiological studies indicated an association between NAFLD and reduced physical activity. In addition, exercise has been shown to improve NAFLD independently of weight loss. In this paper, we aim to systematically review molecular changes in sedentary experimental NAFLD models vs. those subjected to exercise. We utilized the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and standard review techniques. Studies were considered for inclusion if they addressed the primary question: the mechanisms by which exercise influenced NAFLD. This review summarized experimental evidence of improvements in NAFLD with exercise in the absence of weight loss. The pathways involved appeared to have AMPK as a common denominator. See also the graphical abstract(Fig. 1).

Dietary Influences on Gut Microbiota and Their Role in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major contributor to liver-related morbidity, cardiovascular disease, and metabolic complications. Lifestyle interventions, including diet and exercise, are first line in treating MASLD. Dietary approaches such as the low-glycemic-index Mediterranean diet, the ketogenic diet, intermittent fasting, and high fiber diets have demonstrated potential in addressing the metabolic dysfunction underlying this condition. The development and progression of MASLD are closely associated with taxonomic shifts in gut microbial communities, a relationship well-documented in the literature. Given the importance of diet as a primary treatment for MASLD, it is important to understand how gut microbiota and their metabolic byproducts mediate favorable outcomes induced by healthy dietary patterns. Conversely, microbiota changes conferred by unhealthy dietary patterns such as the Western diet may induce dysbiosis and influence steatotic liver disease through promoting hepatic inflammation, up-regulating lipogenesis, dysregulating bile acid metabolism, increasing insulin resistance, and causing oxidative damage in hepatocytes. Although emerging evidence has identified links between diet, microbiota, and development of MASLD, significant gaps remain in understanding specific microbial roles, metabolite pathways, host interactions, and causal relationships. Therefore, this review aims to provide mechanistic insights into the role of microbiota-mediated processes through the analysis of both healthy and unhealthy dietary patterns and their contribution to MASLD pathophysiology. By better elucidating the interplay between dietary nutrients, microbiota-mediated processes, and the onset and progression of steatotic liver disease, this work aims to identify new opportunities for targeted dietary interventions to treat MASLD efficiently.

Association between hepatocyte TM4SF5 expression and gut microbiome dysbiosis during non-alcoholic fatty liver disease development

Gut microbiome dysbiosis is involved in non-alcoholic fatty liver disease (NAFLD) development. Hepatic transmembrane 4 L six family member 5 (TM4SF5) overexpression promotes NAFLD. However, how gut microbiota are associated with TM4SF5-mediated NAFLD remains unexplored. We analyzed the gut microbiome using feces from hepatocyte-specific TM4SF5-overexpressing transgenic (Alb-TGTm4sf5-Flag, TG) or Tm4sf5-/- knock-out (KO) mice fed a normal chow diet (NCD), high-fat diet (HFD) for 2 weeks (HFD2W), or methionine-choline-deficient diet (MCD) for 4 weeks to investigate associations among Tm4sf5 expression, diet, and the gut microbiome. TG-NCD mice showed a higher Firmicutes-to-Bacteroidetes (F/B) ratio, with less enrichment of Akkermansia muciniphila and Lactobacillus reuteri. NASH-related microbiomes in feces were more abundant in TG-HFD2w mice than in KO-HFD2w mice. Further, TG-MCD showed a higher F/B ratio than TG-NCD or KO mice, with decreases or increases in microbiomes beneficial or detrimental to the liver, respectively. Such effects in TG-MCD animals were correlated with functional pathways producing short-chain fatty acids (SCFAs). Furthermore, potential functional pathways of the gut microbiome were metabolically parallel to NAFLD features in TG-MCD mice. These results suggest that hepatocyte Tm4sf5 supports gut microbiome dysbiosis and metabolic activity, leading to SCFA production and hepatic inflammation during NAFLD development.

Gut microbiome and NAFLD: impact and therapeutic potential

Non-Alcoholic Fatty Liver Disease (NAFLD) affects approximately 32.4% of the global population and poses a significant health concern. Emerging evidence underscores the pivotal role of the gut microbiota-including bacteria, viruses, fungi, and parasites-in the development and progression of NAFLD. Dysbiosis among gut bacteria alters key biological pathways that contribute to liver fat accumulation and inflammation. The gut virome, comprising bacteriophages and eukaryotic viruses, significantly shapes microbial community dynamics and impacts host metabolism through complex interactions. Similarly, gut fungi maintain a symbiotic relationship with bacteria; the relationship between gut fungi and bacteria is crucial for overall host health, with certain fungal species such as Candida in NAFLD patients showing detrimental associations with metabolic markers and liver function. Additionally, the "hygiene hypothesis" suggests that reduced exposure to gut parasites may affect immune regulation and metabolic processes, potentially influencing conditions like obesity and insulin resistance. This review synthesizes current knowledge on the intricate interactions within the gut microbiota and their associations with NAFLD. We highlight the therapeutic potential of targeting these microbial communities through interventions such as probiotics, prebiotics, and fecal microbiota transplantation. Addressing the complexities of NAFLD requires comprehensive strategies that consider the multifaceted roles of gut microorganisms in disease pathology.

Comparative genomic and metabolomic analysis reveals the potential of a newly isolated Enterococcus faecium B6 involved in lipogenic effects

Evidence has indicated that Enterococcus plays a vital role in non-alcoholic fatty liver disease (NAFLD) development. However, the microbial genetic basis and metabolic potential in the disease are yet unknown. We previously isolated a bacteria Enterococcus faecium B6 (E. faecium B6) from children with NAFLD for the first time. Here, we aim to systematically investigate the potential of strain B6 in lipogenic effects. The lipogenic effects of strain B6 were explored in vitro and in vivo. The genomic and functional characterizations were investigated by whole-genome sequencing and comparative genomic analysis. Moreover, the metabolite profiles were unraveled by an untargeted metabolomic analysis. We demonstrated that strain B6 could effectively induce lipogenic effects in the liver of mice. Strain B6 contained a circular chromosome and two circular plasmids and posed various functions. Compared to the other two probiotic strains of E. faecium, strain B6 exhibited unique functions in pathways of ABC transporters, phosphotransferase system, and amino sugar and nucleotide sugar metabolism. Moreover, strain B6 produced several metabolites, mainly enriched in the protein digestion and absorption pathway. The unique potential of strain B6 in lipogenic effects was probably associated with glycolysis, fatty acid synthesis, and glutamine and choline transport. This study pioneeringly revealed the metabolic characteristics and specific detrimental traits of strain B6. The findings provided new insights into the underlying mechanisms of E. faecium in lipogenic effects, and laid essential foundations for further understanding of E. faecium-related disease.

NAFLD-associated hepatocellular carcinoma (HCC) - A compelling case for repositioning of existing mTORc1 inhibitors

The increasing prevalence of non-alcoholic fatty liver disease (NAFLD) is a growing concern for the high incidence rate of hepatocellular carcinoma (HCC) globally. The progression of NAFLD to HCC is heterogeneous and non-linear, involving intermediate stages of non-alcoholic steatohepatitis (NASH), liver fibrosis, and cirrhosis. There is a high unmet clinical need for appropriate diagnostic, prognostic, and therapeutic options to tackle this emerging epidemic. Unfortunately, at present, there is no validated marker to identify the risk of developing HCC in patients suffering from NAFLD or NASH. Additionally, the current treatment protocols for HCC don't differentiate between viral infection or NAFLD-specific etiology of the HCC and have a limited success rate. The mammalian target of rapamycin complex 1 (mTORc1) is an important protein involved in many vital cellular processes like lipid metabolism, glucose homeostasis, and inflammation. These cellular processes are highly implicated in NAFLD and its progression to severe liver manifestations. Additionally, hyperactivation of mTORc1 is known to promote cell proliferation, which can contribute to the genesis and progression of tumors. Many mTORc1 inhibitors are being evaluated for different types of cancers under various phases of clinical trials. This paper deliberates on the strong pathological implication of the mTORc1 signaling pathway in NAFLD and its progression to NASH and HCC and advocates for a systematic investigation of known mTORc1 inhibitors in suitable pre-clinical models of HCC having NAFLD/NASH-specific etiology.

Pediatric metabolic (dysfunction)-associated fatty liver disease: current insights and future perspectives

The historical use of the term non-alcoholic fatty liver disease (NAFLD) in obese/overweight children has been controversial as to the appropriateness of this terminology in children, and lately, in adults too. Newer game-changer terminology, metabolic (dysfunction)-associated fatty liver disease (MAFLD), for this condition signifies a positive step forward that addresses the limitations of the previous definition for both adults and children. The prevalence of MAFLD has surged in tandem with the global rise in obesity rates, establishing itself as a predominant cause of chronic liver disease in both adult and pediatric populations. The adoption of the recently proposed nomenclature reflects a more encompassing comprehension of the disease and its etiology compared to its predecessor, NAFLD. Notably, the revised terminology facilitates the recognition of MAFLD as an autonomous condition while acknowledging the potential coexistence of other systemic fatty liver disorders. Particularly in children, this includes various paediatric-onset genetic and inherited metabolic disorders, necessitating thorough exclusion, especially in cases where weight loss interventions yield no improvement or in the absence of obesity. MAFLD presents as a multifaceted disorder; evidence suggests its origins lie in a complex interplay of nutritional, genetic, hormonal, and environmental factors. Despite advancements, current non-invasive diagnostic biomarkers exhibit limitations in accuracy, often necessitating imaging and histological evaluations for definitive diagnosis. While dietary and lifestyle modifications stand as cornerstone measures for MAFLD prevention and management, ongoing evaluation of therapeutic agents continues. This article provides an overview of the latest developments and emerging therapies in the realm of paediatric MAFLD.

Deciphering the Gut–Liver Axis: A Comprehensive Scientific Review of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant global health issue. The condition is closely linked to metabolic dysfunctions such as obesity and type 2 diabetes. The gut–liver axis, a bidirectional communication pathway between the liver and the gut, plays a crucial role in the pathogenesis of NAFLD. This review delves into the mechanisms underlying the gut–liver axis, exploring the influence of gut microbiota, intestinal permeability, and inflammatory pathways. This review also explores the potential therapeutic strategies centered on modulating gut microbiota such as fecal microbiota transplantation; phage therapy; and the use of specific probiotics, prebiotics, and postbiotics in managing NAFLD. By understanding these interactions, we can better comprehend the development and advancement of NAFLD and identify potential therapeutic targets.

Aluminum-induced oxidative stress promotes changes in the structure of the gut microbiota and liver deficiency

As a low-toxicity metal, aluminum has garnered increasing attention in relation to its impact on the human body; however, the specific mechanism of action remains unclear. To bridge this knowledge gap and facilitate practical applications, this study took 8-week-old ICR mice as the research object to study the effects of dietary addition of aluminum potassium sulfate on intestinal flora structure and liver. As the concentration of aluminum increased, it inhibited mice weight growth rate and significantly altered the composition of white blood cells in their bloodstream. Histological examination revealed liver inflammation through HE staining sections. The oxidative stress markers MDA increased, GSH-PX and CAT decreased significantly. And liver function index MAO increased, TC and ALP decreased first and then increased. Moreover, there was a significant increase in pro-inflammatory factor TNF-α content. Further 16S rRNA sequencing analysis demonstrated substantial changes in both composition and structure of mouse intestinal microbiota induced by aluminum exposure; microbial phenotype prediction indicated that aluminum-induced oxidative stress promoted an increase in abundance of oxidation-resistant microbial types. Alterations in gut flora structure also influenced the liver via the gut-liver axis. These findings lay a foundation for further research on the regulation and interaction of aluminum on intestinal flora.

Soybean oil-based HFD induces gut dysbiosis that leads to steatosis, hepatic inflammation and insulin resistance in mice

High-fat diets (HFDs) shape the gut microbiome and promote obesity, inflammation, and liver steatosis. Fish and soybean are part of a healthy diet; however, the impact of these fats, in the absence of sucrose, on gut microbial dysbiosis and its association with liver steatosis remains unclear. Here, we investigated the effect of sucrose-free soybean oil-and fish oil-based high fat diets (HFDs) (SF-Soy-HFD and SF-Fish-HFD, respectively) on gut dysbiosis, obesity, steatosis, hepatic inflammation, and insulin resistance. C57BL/6 mice were fed these HFDs for 24 weeks. Both diets had comparable effects on liver and total body weights. But 16S-rRNA sequencing of the gut content revealed induction of gut dysbiosis at different taxonomic levels. The microbial communities were clearly separated, showing differential dysbiosis between the two HFDs. Compared with the SF-Fish-HFD control group, the SF-Soy-HFD group had an increased abundance of Bacteroidetes, Firmicutes, and Deferribacteres, but a lower abundance of Verrucomicrobia. The Clostridia/Bacteroidia (C/B) ratio was higher in the SF-Soy-HFD group (3.11) than in the SF-Fish-HFD group (2.5). Conversely, the Verrucomicrobiacae/S24_7 (also known as Muribaculaceae family) ratio was lower in the SF-Soy-HFD group (0.02) than that in the SF-Fish-HFD group (0.75). The SF-Soy-HFD group had a positive association with S24_7, Clostridiales, Allobaculum, Coriobacteriaceae, Adlercreutzia, Christensenellaceae, Lactococcus, and Oscillospira, but was related to a lower abundance of Akkermansia, which maintains gut barrier integrity. The gut microbiota in the SF-Soy-HFD group had predicted associations with host genes related to fatty liver and inflammatory pathways. Mice fed the SF-Soy-HFD developed liver steatosis and showed increased transcript levels of genes associated with de novo lipogenesis (Acaca, Fasn, Scd1, Elovl6) and cholesterol synthesis (Hmgcr) pathways compared to those in the SF-Fish-HFD-group. No differences were observed in the expression of fat uptake genes (Cd36 and Fabp1). The expression of the fat efflux gene (Mttp) was reduced in the SF-Soy-HFD group. Moreover, hepatic inflammation markers (Tnfa and Il1b) were notably expressed in SF-Soy-HFD-fed mice. In conclusion, SF-Soy-HFD feeding induced gut dysbiosis in mice, leading to steatosis, hepatic inflammation, and impaired glucose homeostasis.

Alteration of Gut Microbiota Composition in the Progression of Liver Damage in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the microbiota-gut-liver axis impact the liver damaging processes toward fibrosis. Gut microbiota status is shaped by dietary and lifestyle factors, depending on geographic location. We aimed to identify microbial signatures in a group of Chilean MASLD patients. Forty subjects were recruited, including healthy controls (HCs), overweight/obese subjects (Ow/Ob), patients with MASLD without fibrosis (MASLD/F-), and MASLD with fibrosis (MASLD/F+). Both MASLD and fibrosis were detected through elastography and/or biopsy, and fecal microbiota were analyzed through deep sequencing. Despite no differences in α- and β-diversity among all groups, a higher abundance of Bilophila and a lower presence of Defluviitaleaceae, Lachnospiraceae ND3007, and Coprobacter was found in MASLD/F- and MASLD/F+, compared to HC. Ruminococcaceae UCG-013 and Sellimonas were more abundant in MASLD/F+ than in Ow/Ob; both significantly differed between MASLD/F- and MASLD/F+, compared to HC. Significant positive correlations were observed between liver stiffness and Bifidobacterium, Prevotella, Sarcina, and Acidaminococcus abundance. Our results show that MASLD is associated with changes in bacterial taxa that are known to be involved in bile acid metabolism and SCFA production, with some of them being more specifically linked to fibrosis.

Tangshen formula targets the gut microbiota to treat non-alcoholic fatty liver disease in HFD mice: A 16S rRNA and non-targeted metabolomics analyses

BACKGROUND

Tangshen formula (TSF) has an ameliorative effect on hepatic lipid metabolism in non-alcoholic fatty liver disease (NAFLD), but the role played by the gut microbiota in this process is unknown.

METHOD

We conducted three batches of experiments to explore the role played by the gut microbiota: TSF administration, antibiotic treatment, and fecal microbial transplantation. NAFLD mice were induced with a high-fat diet to investigate the ameliorative effects of TSF on NAFLD features and intestinal barrier function. 16S rRNA sequencing and serum untargeted metabolomics were performed to further investigate the modulatory effects of TSF on the gut microbiota and metabolic dysregulation in the body.

RESULTS

TSF ameliorated insulin resistance, hypercholesterolemia, lipid metabolism disorders, inflammation, and impairment of intestinal barrier function. 16S rRNA sequencing analysis revealed that TSF regulated the composition of the gut microbiota and increased the abundance of beneficial bacteria. Antibiotic treatment and fecal microbiota transplantation confirmed the importance of the gut microbiota in the treatment of NAFLD with TSF. Subsequently, untargeted metabolomics identified 172 differential metabolites due to the treatment of TSF. Functional predictions suggest that metabolisms of choline, glycerophospholipid, linoleic acid, alpha-linolenic acid, and arachidonic acid are the key metabolic pathways by which TSF ameliorates NAFLD and this may be influenced by the gut microbiota.

CONCLUSION

TSF treats the NAFLD phenotype by remodeling the gut microbiota and improving metabolic profile, suggesting that TSF is a functional gut microbial and metabolic modulator for the treatment of NAFLD.

Cultivated Enterococcus faecium B6 from children with obesity promotes nonalcoholic fatty liver disease by the bioactive metabolite tyramine

Gut microbiota plays an essential role in nonalcoholic fatty liver disease (NAFLD). However, the contribution of individual bacterial strains and their metabolites to childhood NAFLD pathogenesis remains poorly understood. Herein, the critical bacteria in children with obesity accompanied by NAFLD were identified by microbiome analysis. Bacteria abundant in the NAFLD group were systematically assessed for their lipogenic effects. The underlying mechanisms and microbial-derived metabolites in NAFLD pathogenesis were investigated using multi-omics and LC-MS/MS analysis. The roles of the crucial metabolite in NAFLD were validated in vitro and in vivo as well as in an additional cohort. The results showed that Enterococcus spp. was enriched in children with obesity and NAFLD. The patient-derived Enterococcus faecium B6 (E. faecium B6) significantly contributed to NAFLD symptoms in mice. E. faecium B6 produced a crucial bioactive metabolite, tyramine, which probably activated PPAR-γ, leading to lipid accumulation, inflammation, and fibrosis in the liver. Moreover, these findings were successfully validated in an additional cohort. This pioneering study elucidated the important functions of cultivated E. faecium B6 and its bioactive metabolite (tyramine) in exacerbating NAFLD. These findings advance the comprehensive understanding of NAFLD pathogenesis and provide new insights for the development of microbe/metabolite-based therapeutic strategies.

Altered gut microbiome associated with metabolic-associated fatty liver disease in Chinese children

BACKGROUND & AIM

Limited studies have investigated the association between gut microbiota and metabolic dysfunction-associated fatty liver disease (MAFLD) in children and adolescents. We aimed to identify differences in gut microbiota composition and diversity between children with MAFLD and healthy counterparts.

METHODS

Data were collected from a nested case-control study (October to December, 2021) of the "Huantai Childhood Cardiovascular Health Cohort Study" in Huantai County, Zibo City, China. The study included 52 children aged 5-11 years with new-onset MAFLD and 52 healthy children matched by age and sex. Stool samples were collected and analyzed using 16S rRNA gene sequencing. Shannon index and Chao index were used to assess the α diversity of gut microbiota and Principal coordinates analysis (PCoA) was performed to evaluate β diversity between the two groups. The differences in the relative abundance of gut microbiota between MAFLD group and control group were compared by the Wilcoxon rank-sum test after false discovery rate (FDR) correction. Additionally, the gut-microbial metabolic pathways were identified using the phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt).

RESULTS

We found that children with MAFLD had significant different gut microbiota composition and reduced α diversity compared with the control group. PCoA showed that the two groups can be significantly distinguished based on the unweighted unifrac distance algorithm. Gut microbiota at the phylum level such as Verrucomicrobia and Desulfobacterial, genus level such as Blautia, Lachnospiraceae_NK4A136_group, Coprococcus, Erysipelotrichaceae_UCG-003, UCG-002 and Akkermansia, and species level such as Bifidobacterium_longum abundances were significantly decreased in children with MAFLD compared with that in children without MAFLD. Notably, the abundance of these bacteria were found to be associated with HDL-C, SBP, DBP, WC, BMI, etc. In addition, our analysis of gut-microbial metabolic pathways identified differences in carbohydrate transport and metabolism, as well as amino acid transport and metabolism between the two groups.

CONCLUSION

Significant differences in gut microbiota composition are observed between children with and without MAFLD, which indicate that gut microbiota may be a potential contributor to the development of MAFLD in childhood.

Nutritional Interventions, Probiotics, Synbiotics and Fecal Microbiota Transplantation in Steatotic Liver Disease : Pediatric Fatty Liver and Probiotics

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major health problem worldwide, and the strongest determinant of liver disease in children. The possible influence of high-fat/low-fiber dietary patterns with microbiota (e.g., increased Firmicutes/Bacteroidetes ratio), and ultimately with MASLD occurrence and progression has been elucidated by several association studies. The possible mechanisms through which microbes exert their detrimental effects on MASLD include gut vascular barrier damage, a shift towards non-tolerogenic immunologic environment, and the detrimental metabolic changes, including a relative reduction of propionate and butyrate in favor of acetate, endogenous ethanol production, and impairment of the unconjugated bile acid-driven FXR-mediated gut-liver axis. The impact of nutritional and probiotic interventions in children with MASLD is described.

Breaking the barriers: the role of gut homeostasis in Metabolic-Associated Steatotic Liver Disease (MASLD)

Obesity, insulin resistance (IR), and the gut microbiome intricately interplay in Metabolic-associated Steatotic Liver Disease (MASLD), previously known as Non-Alcoholic Fatty Liver Disease (NAFLD), a growing health concern. The complex progression of MASLD extends beyond the liver, driven by "gut-liver axis," where diet, genetics, and gut-liver interactions influence disease development. The pathophysiology of MASLD involves excessive liver fat accumulation, hepatocyte dysfunction, inflammation, and fibrosis, with subsequent risk of hepatocellular carcinoma (HCC). The gut, a tripartite barrier, with mechanical, immune, and microbial components, engages in a constant communication with the liver. Recent evidence links dysbiosis and disrupted barriers to systemic inflammation and disease progression. Toll-like receptors (TLRs) mediate immunological crosstalk between the gut and liver, recognizing microbial structures and triggering immune responses. The "multiple hit model" of MASLD development involves factors like fat accumulation, insulin resistance, gut dysbiosis, and genetics/environmental elements disrupting the gut-liver axis, leading to impaired intestinal barrier function and increased gut permeability. Clinical management strategies encompass dietary interventions, physical exercise, pharmacotherapy targeting bile acid (BA) metabolism, and microbiome modulation approaches through prebiotics, probiotics, symbiotics, and fecal microbiota transplantation (FMT). This review underscores the complex interactions between diet, metabolism, microbiome, and their impact on MASLD pathophysiology and therapeutic prospects.

Unveiling the role of gut dysbiosis in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial complicated condition, reflected by the accumulation of extra fat in the liver. A detailed study of literature throws light on the fascinating connection between gut dysbiosis and NAFLD. The term 'gut dysbiosis' describes an imbalance in the harmony and operation of the gut microflora, which can upshoot a number of metabolic disorders. To recognize the underlying mechanisms and determine treatment options, it is essential to comprehend the connection between gut dysbiosis and NAFLD. This in-depth review discusses the normal gut microflora composition and its role in health, alterations in the gut microflora composition that leads to disease state focusing on NAFLD. The potential mechanisms influencing the advent and aggravation of NAFLD suggested disturbance of microbial metabolites, changes in gut barrier integrity, and imbalances in the composition of the gut microflora. Furthermore, it was discovered that gut dysbiosis affected immune responses, liver inflammation, and metabolic pathways, aggravating NAFLD.

Dietary and Nutritional Interventions in Nonalcoholic Fatty Liver Disease in Pediatrics

Nonalcoholic fatty liver disease (NAFLD) is pediatrics' most common chronic liver disease. The incidence is high in children and adolescents with obesity, which is associated with an increased risk of disease progression. Currently, there is no effective drug therapy in pediatrics; therefore, lifestyle interventions remain the first line of treatment. This review aims to present an updated compilation of the scientific evidence for treating this pathology, including lifestyle modifications, such as exercise and dietary changes, highlighting specific nutritional strategies. The bibliographic review was carried out in different databases, including studies within the pediatric population where dietary and/or nutritional interventions were used to treat NAFLD. Main interventions include diets low in carbohydrates, free sugars, fructose, and lipids, in addition to healthy eating patterns and possible nutritional interventions with n-3 polyunsaturated fatty acids (EPA and DHA), amino acids (cysteine, L-carnitine), cysteamine, vitamins, and probiotics (one strain or multi-strain). Lifestyle changes remain the main recommendation for children with NAFLD. Nevertheless, more studies are required to elucidate the effectiveness of specific nutrients and bioactive compounds in this population.

Alterations in gut microbiota and metabolite profiles in patients with infantile cholestasis

BACKGROUND

Infantile cholestasis (IC) is the most common hepatobiliary disease in infants, resulting in elevated direct bilirubin levels. Indeed, hepatointestinal circulation impacts bile acid and bilirubin metabolism. This study evaluates changes in the gut microbiota composition in children with IC and identifies abnormal metabolite profiles associated with microbial alterations.

RESULTS

The gut microbiota in the IC group exhibits the higher abundance of Veillonella, Streptococcus and Clostridium spp. (P < 0.05), compared to healthy infants (CON) group. Moreover, the abundance of Ruminococcus, Vibrio butyricum, Eubacterium coprostanogenes group, Intestinibacter, and Faecalibacterium were lower (P < 0.05). In terms of microbiota-derived metabolites, the levels of fatty acids (palmitoleic, α-linolenic, arachidonic, and linoleic) (P < 0.05) increased and the levels of amino acids decreased in IC group. Furthermore, the abundances of Ruminococcus, Eubacterium coprostanoligenes group, Intestinibacter and Butyrivibrio are positively correlated with proline, asparagine and aspartic acid, but negatively correlated with the α-linolenic acid, linoleic acid, palmitoleic acid and arachidonic acid. For analysis of the relationship between the microbiota and clinical index, it was found that the abundance of Veillonella and Streptococcus was positively correlated with serum bile acid content (P < 0.05), while APTT, PT and INR were negatively correlated with Faecalibalum and Ruminococcus (P < 0.05).

CONCLUSION

Microbiota dysbiosis happened in IC children, which also can lead to the abnormal metabolism, thus obstructing the absorption of enteral nutrition and aggravating liver cell damage. Veillonella, Ruminococcus and Butyrivibrio may be important microbiome related with IC and need further research.

Microbiome and Genetic Factors in the Pathogenesis of Liver Diseases

Our genetic background has not changed over the past century, but chronic diseases are on the rise globally. In addition to the genetic component, among the critical factors for many diseases are inhabitants of our intestines (gut microbiota) as a crucial environmental factor. Dysbiosis has been described in liver diseases with different etiologies like non-alcoholic fatty liver disease (NAFLD), alcohol-related liver disease (ALD), viral hepatitis, autoimmune hepatitis (AIH), primary sclerosing cholangitis (PSC), primary biliary cholangitis (PBC), cirrhosis, hepatocellular carcinoma (HCC). On the other hand, new technologies have increased our understanding of liver disease genetics and treatment options. Genome-wide association studies (GWAS) identify unknown genetic risk factors, positional cloning of unknown genes associated with different diseases, gene tests for single nucleotide variations (SNVs), and next-generation sequencing (NGS) of selected genes or the complete genome. NGS also allowed studying the microbiome and its role in various liver diseases has begun. These genes have proven their effect on microbiome composition in host genome–microbiome association studies. We focus on altering the intestinal microbiota, and supplementing some bacterial metabolites could be considered a potential therapeutic strategy. The literature data promote probiotics/synbiotics role in reducing proinflammatory cytokines such as TNF-α and the interleukins (IL-1, IL-6, IL-8), therefore improving transaminase levels, hepatic steatosis, and NAFLD activity score. However, even though microbial therapy appears to be risk-free, evaluating side effects related to probiotics or synbiotics is imperative. In addition, safety profiles for long-term usage should be researched. Thus, this review focuses on the human microbiome and liver diseases, recent GWASs on liver disease, the gut-liver axis, and the associations with the microbiome and microbiome during/after liver disease therapy.

The chronic consumption of dietary fructose promotes the gut Clostridium species imbalance and bile acid alterations in developing nonalcoholic fatty liver disease

Excessive fructose intake is associated with the rising prevalence of nonalcoholic fatty liver disease (NAFLD). The gut microbiome (GM) and bile acids (BAs) are involved in the pathogenesis of NAFLD, but the impact of fructose on their cross-talk is unclear. In this study, adult male C57BL/6J mice were fed a normal diet with tap water (ND) or with 4% fructose in the drinking water (Fru), 60% high-fat diet with tap water (HF) or with 4% fructose solution (HFF) for 12 weeks. Targeted BA analysis was performed in five anatomical sites including the liver, ileum contents, portal serum, cecum contents, and feces. Metagenomic sequencing was performed to explore gut dysbiosis. Within 12 weeks, the 4% fructose diet could initially stimulate gut dysbiosis and BA upregulation in the ileum, portal serum, and cecum when the intestinal and hepatic transport system remained stable without hepatic lipid accumulation. However, the chronic consumption of fructose promoted HF-induced NAFLD, with significantly increased body weight, impaired glucose tolerance, and advanced liver steatosis. BA transporters were inhibited in HFF, causing the block of internal BA circulation and increased BA secretion via cecum contents and feces. Notably, lithocholic acid (LCA) and its taurine conjugates were elevated within the enterohepatic circulation. Meanwhile, the Clostridium species were significantly altered in both Fru and HFF groups and were closely associated with fructose and BA metabolism. In summary, excessive fructose caused gut dysbiosis and BA alterations, promoting HF-induced NAFLD. The crosstalk between Clostridium sp. and LCA species were potential targets in fructose-mediated NAFLD.

Therapeutics for Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD)

Metabolic dysfunction associated fatty liver disease (MAFLD) has been recently recognized as a new global chronic liver disease entity with non-alcoholic fatty liver disease (NAFLD) associated with overweight/obesity or type 2 diabetes mellitus (T2DM) and evidence of metabolic dysregulation. Due to the rising rates of obesity and diabetes, MAFLD is considered a rapidly emerging chronic liver disease globally. Nearly 25–30% of the global population poses health issues due to MAFLD with a substantial economic burden to societies. Disease progression depends on the persistence of risk factors and etiological agents, from simple steatosis, hepatitis, fibrosis, to cirrhosis, and if untreated, leads to hepatocellular carcinoma. In this review article we summarize various risk and etiological factors, diagnostic techniques, and therapeutic evaluation of pharmacological agents developed for MAFLD. Effective pharmaceutical agents for the treatment of MAFLD (and NAFLD) are lacking, and research is ongoing to search for effective medications in this direction. Currently, pioglitazone is advised for MAFLD patients, whereas Vitamin E is advised for non-diabetic MAFLD patients with ≥F2 non-cirrhosis. Current approaches to disease management emphasize diet control, lifestyle changes, and weight loss. In this review, we summarized the pharmacological agents currently being developed and their current status to treat patients with MAFLD.

Cross-talk between gut microbiota and liver steatosis: Complications and therapeutic target

Liver steatosis is the most widespread chronic liver condition. Its global incidence is rising swiftly and is currently estimated to be 24%. Liver steatosis is strongly related with numerous metabolic syndrome characteristics, like obesity, insulin resistance, hyperlipidemia, and hypertension. The gastrointestinal tract contains about 100 trillion commensal organisms and more than 7,000 distinct bacterial strains. Fat deposition in the liver without secondary causes is known as liver steatosis. Dysregulation of the gut flora is one of the factors connected to the onset of fatty liver disease. Dietary choices may alter constitution of the microbiome and cause gut microbiome dysbiosis, particularly due to the intake of food high in fructose sugars, animal products, and saturated fats. Various gut bacteria cause nutrient metabolism in multiple ways, setting off different inflammatory cascades that encourage liver disease and pathways that help fat build up in the liver. Due to their relatively stable nature, genetic factors may not be responsible for the constant increase in liver steatosis incidence. Genetic factors set the stage for liver steatosis pathogenesis. This review will offer an overview of our present knowledge of the roles played by gut microbiota in regulating the development of liver steatosis, potential side effects, and potential treatment targets.

Malattia grassa del fegato: tra fattori ambientali e predisposizione genetica

Nonalcoholic fatty liver disease (NAFLD) is now recognized as the hepatic manifestation of the metabolic syndrome and is the most common cause of chronic liver disease in both adults and children. It is assumed that a genetic predisposition associated with epigenetic factors participates in the evolution of this condition. Visceral obesity and insulin-resistence (IR) have always been considered as key factors linking Metabolic Syndrome (MetS) and NAFLD, but a multifactorial pathogenesis characterized by the interaction between genetic background and environmental factors is increasingly recognized as a key point in the development of metabolic disorders associated with NAFLD. In fact, in patients with NAFLD, insulin resistance, arterial hypertension, abdominal obesity, dyslipidemia and reduced intestinal permeability have often been found, as well as a higher prevalence of comorbidities such as coronary artery disease, obstructive sleep apnea, polycystic ovary syndrome and osteopenia, which define a MetS framework. Early diagnosis is needed to prevent disease progression through primarily lifestyle interventions. Unfortunately, to date, there is no recommended pharmacological intervention in a pediatric setting. However, a variety of new pharmacological agents are under clinical study. To achieve this, studies on the pathways that link the genetic background to the environment before and after birth to the development of NAFLD and MetS and on the molecular mechanisms that define NASH should be increased. Therefore, it is desirable that future studies may be useful in terms of population screening to identify individuals at risk for NAFLD and Mets.

Gut Microbiome in the Progression of NAFLD, NASH and Cirrhosis, and Its Connection with Biotics: A Bibliometric Study Using Dimensions Scientific Research Database

There is growing evidence that gut microbiota dysbiosis is linked to the etiopathogenesis of nonalcoholic fatty liver disease (NAFLD), from the initial stage of disease until the progressive stage of nonalcoholic steatohepatitis (NASH) and the final stage of cirrhosis. Conversely, probiotics, prebiotics, and synbiotics have shown promise in restoring dysbiosis and lowering clinical indicators of disease in a number of both preclinical and clinical studies. Additionally, postbiotics and parabiotics have recently garnered some attention. The purpose of this bibliometric analysis is to assess recent publishing trends concerning the role of the gut microbiome in the progression of NAFLD, NASH and cirrhosis and its connection with biotics. The free access version of the Dimensions scientific research database was used to find publications in this field from 2002 to 2022. VOSviewer and Dimensions' integrated tools were used to analyze current research trends. Research into the following topics is expected to emerge in this field: (1) evaluation of risk factors which are correlated with the progression of NAFLD, such as obesity and metabolic syndrome; (2) pathogenic mechanisms, such as liver inflammation through toll-like receptors activation, or alteration of short-chain fatty acids metabolisms, which contribute to NAFLD development and its progression in more severe forms, such as cirrhosis; (3) therapy for cirrhosis through dysbiosis reduction, and research on hepatic encephalopathy a common consequence of cirrhosis; (4) evaluation of diversity, and composition of gut microbiome under NAFLD, and as it varies under NASH and cirrhosis by rRNA gene sequencing, a tool which can also be used for the development of new probiotics and explore into the impact of biotics on the gut microbiome; (5) treatments to reduce dysbiosis with new probiotics, such as Akkermansia, or with fecal microbiome transplantation.

Gut microbiome as a therapeutic target for liver diseases

The prominent role of gut in regulating the physiology of different organs in a human body is increasingly acknowledged, to which the bidirectional communication between gut and liver is no exception. Liver health is modulated via different key components of gut-liver axis. The gut-derived products mainly generated from dietary components, microbial metabolites, toxins, or other antigens are sensed and transported to the liver through portal vein to which liver responds by secreting bile acids and antibodies. Therefore, maintaining a healthy gut microbiome can promote homeostasis of this gut-liver axis by regulating the intestinal barrier function and reducing the antigenic molecules. Conversely, liver secretions also regulate the gut microbiome composition. Disturbed homeostasis allows luminal antigens to reach liver leading to impaired liver functioning and instigating liver disorders. The perturbations in gut microbiome, permeability, and bile acid pool have been associated with several liver disorders, although precise mechanisms remain largely unresolved. Herein, we discuss functional fingerprints of a healthy gut-liver axis while contemplating mechanistic understanding of pathophysiology of liver diseases and plausible role of gut dysbiosis in different diseased states of liver. Further, novel therapeutic approaches to prevent the severity of liver disorders are discussed in this review.

Gut Microbiota in Non-Alcoholic Fatty Liver Disease Patients with Inflammatory Bowel Diseases: A Complex Interplay

The intestinal microbiota represents the microbial community that colonizes the gastrointestinal tract and constitutes the most complex ecosystem present in nature. The main intestinal microbial phyla are Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria, Fusobacteria, and Verrucromicrobia, with a clear predominance of the two phyla Firmicutes and Bacteroidetes which account for about 90% of the intestinal phyla. Intestinal microbiota alteration, or dysbiosis, has been proven to be involved in the development of various syndromes, such as non-alcoholic fatty liver disease, Crohn's disease, and ulcerative colitis. The present review underlines the most recurrent changes in the intestinal microbiota of patients with NAFLD, Crohn's disease, and ulcerative colitis.

Clearing Steatosis Prior to Liver Surgery for Colorectal Metastasis: A Narrative Review and Case Illustration

Over recent years, non-alcoholic fatty liver disease (NAFLD) has become the most common liver disorder in the developed world, accounting for 20% to 46% of liver abnormalities. Steatosis is the hallmark of NAFLD and is recognized as an important risk factor for complication and death after general surgery, even more so after liver resection. Similarly, liver steatosis also impacts the safety of live liver donation and transplantation. We aim to review surgical outcomes after liver resection for colorectal metastases in patients with steatosis and discuss the most common pre-operative strategies to reduce steatosis. Finally, as illustration, we report the favorable effect of a low-caloric, hyper-protein diet during a two-stage liver resection for colorectal metastases in a patient with severe steatosis.

Weil's Disease-Immunopathogenesis, Multiple Organ Failure, and Potential Role of Gut Microbiota

Leptospirosis is an important zoonotic disease, causing about 60,000 deaths annually. In this review, we have described in detail the immunopathogenesis of leptospirosis, the influence of cytokines, genetic susceptibility on the course of the disease, and the evasion of the immune response. These data are combined with information about immunological and pathomorphological changes in the kidneys, liver, and lungs, which are most affected by Weil's disease. The review also suggests a possible role of the gut microbiota in the clinical course of leptospirosis, the main mechanisms of the influence of gut dysbiosis on damage in the liver, kidneys, and lungs through several axes, i.e., gut-liver, gut-kidney, and gut-lungs. Modulation of gut microbiota by probiotics and/or fecal microbiota transplantation in leptospirosis may become an important area of scientific research.

Interplay of Lymphocytes with the Intestinal Microbiota in Children with Nonalcoholic Fatty Liver Disease

Abnormally high lymphocyte counts are seen in persons with nonalcoholic fatty liver disease (NAFLD). Gut microbiota dysbiosis is a risk factor for NAFLD. We assessed the gut microbiota of 63 healthy children and 63 children with NAFLD using 16S rRNA gene and metagenomic sequencing to explore the relationships. Compared with healthy children (HC group), the Bacteroidetes, Verrucomicrobia, and Akkermansia were less abundant, while the Actinobacteria were more abundant in children with NAFLD (FLD group). To understand the effect of lymphocytes on the gut microbiota of children with NAFLD, we compared the microbiota of 41 children with NAFLD and high numbers of lymphocytes (FLD_HL group) and 22 children with NAFLD and low numbers of lymphocytes (FLD_LL group). The abundances of Bacteroidetes, Verrucobacterium, and Akkermansia increased and Actinobacteria decreased in the FLD_LL group compared to the FLD_HL group. Akkermansia was negatively correlated with lymphocyte count. NAFLD may disturb the gut microbiota in children through reducing the abundance of Akkermansia and increasing the abundance of proinflammatory bacteria, such as Escherichia-Shigella. Conclusions: High lymphocyte counts are associated with disturbances of gut microbiota and emergence of opportunistic pathogens in children with NAFLD.

Benefits of Physical Exercise as Approach to Prevention and Reversion of Non-Alcoholic Fatty Liver Disease in Children and Adolescents with Obesity

Non-alcoholic fatty liver disease (NAFLD) is an important health concern during childhood; indeed, it is the most frequent cause of chronic liver diseases in obese children. No valid pharmacological therapies for children affected by this condition are available, and the recommended treatment is lifestyle modification, usually including nutrition and exercise interventions. In this narrative review, we summarized up-to-date information on the benefits of physical exercise on NAFLD in children and adolescents with obesity. The role of exercise as non-pharmacological treatment was emphasized in order to provide recent advances on this topic for clinicians not deeply involved in the field. Several studies on obese children and adults confirm the positive role of physical activity (PA) in the treatment of NAFLD, but to date, there are no pediatric randomized clinical trials on exercise versus usual care. Among the pathogenic mechanisms involved in the PA effects on NAFLD, the main players seem to be insulin resistance and related inflammation, oxidative stress, and gut dysbiosis, but further evaluations are necessary to deeply understand whether these factors are correlated and how they synergistically act. Thus, a deeper research on this theme is needed, and it would be extremely interesting.

Oral administration of branched-chain amino acids ameliorates high-fat diet-induced metabolic-associated fatty liver disease via gut microbiota-associated mechanisms

Branched-chain amino acids (BCAAs), essential amino acids for the human body, are mainly obtained from food. High levels of BCAAs in circulation are considered as potential markers of metabolic-associated fatty liver disease (MAFLD) in humans. However, there are conflicting reports about the effects of supplement of BCAAs on MAFLD, and research on BCAAs and gut microbiota is not comprehensive. Here, C57BL/6J mice were fed with a high-fat diet with or without BCAAs to elucidate the effects of BCAAs on the gut microbiota and metabolic functions in a mouse model of MAFLD. Compared to high-fat diet (HFD) feeding, BCAA supplementation significantly reduced the mouse body weight, ratio of liver/body weight, hepatic lipid accumulation, serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and alanine aminotransferase (ALT), and the expressions of the lipogenesis-related enzymes Fas, Acc, and Scd-1 and increased expressions of the lipolysis-related enzymes Cpt1A and Atgl in the liver. BCAAs supplementation also counteracted HFD-induced elevations in serum BCAAs levels by stimulating the enzymatic activity of BCKDH. Furthermore, BCAAs supplementation markedly improved the gut bacterial diversity and altered the gut microbiota composition and abundances, especially those of genera, in association with MAFLD and BCAAs metabolism. These data suggest that BCAA treatment improves HFD-induced MAFLD through mechanisms involving intestinal microbes.

Effects of Multispecies Synbiotic Supplementation on Anthropometric Measurements, Glucose and Lipid Parameters in Children With Exogenous Obesity: A Randomized, Double Blind, Placebo-Controlled Clinical Trial (Probesity-2 Trial)

Studies on the effects of synbiotics on obesity in children are limited. The objective of this randomized double-blind placebo-controlled trial was to test the effects of a multispecies synbiotic during 12 weeks on anthropometric measurements, glucose metabolism and lipid parameters in 61 children with exogenous obesity. All children were treated with a standard diet and increased physical activity and received once daily a synbiotic supplement (probiotic mixture including Lactobacillus acidophilus, Lacticaseibacillus rhamnosus, Bifidobacterium bifidum, Bifidobacterium longum, Enterococcus faecium and fructo-oligosaccharides) or daily placebo for 12 weeks. At baseline, no statistically significant differences existed in anthropometric measurements, glucose and lipid parameters between both groups. We observed changes for anthropometric measures (% reduction comparing to baseline) in both synbiotic and placebo groups. After 12 weeks; changes (% reduction comparing to baseline) in weight (p < 0.01), BMI (p < 0.05), waist circumference (p < 0.05) and waist circumference to height ratio (p < 0.05) were significantly higher in the children receiving the synbiotic supplement. There is no difference in glucose metabolism, lipid parameters, presence of non-alcoholic fatty liver disease between both groups after 12 weeks. The daily intake of a multispecies synbiotic in addition to diet and increased physical activity did improve anthropometric measurements: body weight, BMI, waist circumference and waist/height ratio. The supplementation of this synbiotic is an efficient weight-loss strategy above diet and exercise in pediatric obesity (Trial identifier: NCT05162209).

Multi-Omics Reveals Inhibitory Effect of Baicalein on Non-Alcoholic Fatty Liver Disease in Mice

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, whose etiology is poorly understood. Accumulating evidence indicates that gut microbiota plays an important role in the occurrence and progression of various human diseases, including NAFLD. In this study, NAFLD mouse models were established by feeding a high-fat diet (HFD). Baicalein, a natural flavonoid with multiple biological activities, was administered by gavage, and its protective effect on NAFLD was analyzed by histopathological and blood factor analysis. Gut microbiota analysis demonstrated that baicalein could remodel the overall structure of the gut microbiota from NAFLD model mice, especially Anaerotruncus, Lachnoclostridium, and Mucispirillum. Transcriptomic analysis showed baicalein restored the expressions of numerous genes that were upregulated in hepatocytes of NAFLD mice, such as Apoa4, Pla2g12a, Elovl7, Slc27a4, Hilpda, Fabp4, Vldlr, Gpld1, and Apom. Metabolomics analysis proved that baicalein mainly regulated the processes associated with lipid metabolism, such as alpha-Linolenic acid, 2-Oxocarboxylic acid, Pantothenate and CoA biosynthesis, and bile secretion. Multi-omics analysis revealed that numerous genes regulated by baicalein were significantly correlated with pathways related to lipid metabolism and biosynthesis and secrection of bile acid, and baicalein might affect lipid metabolism in liver via regulating the ecological structure of gut microbiota in NAFLD mice. Our results elucidated the correlated network among diet, gut microbiota, metabolomic, and transcriptional profiling in the liver. This knowledge may help explore novel therapeutic approaches against NAFLD.

Trust Your Gut: The Association of Gut Microbiota and Liver Disease

The gut microbiota composition is important for nutrient metabolism, mucosal barrier function, immunomodulation, and defense against pathogens. Alterations in the gut microbiome can disturb the gut ecosystem. These changes may lead to the loss of beneficial bacteria or an increase in potentially pathogenic bacteria. Furthermore, these have been shown to contribute to the pathophysiology of gastrointestinal and extra-intestinal diseases. Pathologies of the liver, such as non-alcoholic liver disease, alcoholic liver disease, cirrhosis, hepatocellular carcinoma, autoimmune hepatitis, viral hepatitis, and primary sclerosing cholangitis have all been linked to changes in the gut microbiome composition. There is substantial evidence that links gut dysbiosis to the progression and complications of these pathologies. This review article aimed to describe the changes seen in the gut microbiome in liver diseases and the association between gut dysbiosis and liver disease, and finally, explore treatment options that may improve gut dysbiosis in patients with liver disease.

Rural-Urban differentials in prevalence, spectrum and determinants of Non-alcoholic Fatty Liver Disease in North Indian population

Background

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of disease ranging from simple steatosis, non-alcoholic steatohepatitis (NASH), through to advanced fibrosis and cirrhosis. We assessed the prevalence, spectrum, and determinants of NAFLD among adults in urban and rural North India.

Methods

A representative sample of adults aged 30–60 years were recruited from urban Delhi and rural Ballabhgarh during 2017–2019. Participants underwent abdominal ultrasonography (USG) and vibration controlled transient elastography (VCTE) with FibroScan to assess fatty liver and fibrosis, respectively. We estimated the age- and sex-standardised prevalence of NAFLD and its spectrum. The factors associated with ‘ultrasound-diagnosed NAFLD’ were identified using multivariate logistic regression.

Results

A total of 828 urban (mean ± SD age: 45.5 ± 8.0 years; women: 52.7%) and 832 rural (mean ± SD age: 45.1 ± 7.9 years; women: 62.4%) participants were recruited. The age- and sex-standardized prevalence of ultrasound-diagnosed NAFLD was 65.7% (95%CI: 60.3–71.2) in the urban and 61.1% (55.8–66.5) in the rural areas, respectively. The prevalence of NAFLD with elevated alanine transaminase (≥40IU/L) was 23.2% (19.8–26.6), and 22.5% (19.0–26.0) and any fibrosis by liver stiffness measurement on transient elastography (≥6.9 kPa) was 16.5% (13.8–19.8) and 5.2% (3.8–6.7) in urban and rural participants, respectively. In both urban and rural areas, diabetes, central obesity and insulin resistance were significantly associated with NAFLD.

Conclusion

NAFLD prevalence was high among rural and urban North Indian adults, including fibrosis or raised hepatic enzymes. The strong association of metabolic determinants confirms its linkage with metabolic syndrome.

The Origins of NAFLD: The Potential Implication of Intrauterine Life and Early Postnatal Period

Fetal life and the first few months after birth represent a plastic age, defined as a "window of opportunity", as the organism is particularly susceptible to environmental pressures and has to adapt to environmental conditions. Several perturbations in pregnancy, such as excessive weight gain, obesity, gestational diabetes mellitus and an inadequate or high-fat diet, have been associated with long-term metabolic consequences in offspring, even without affecting birth weight. Moreover, great interest has also been focused on the relationship between the gut microbiome of early infants and health status in later life. Consistently, in various epidemiological studies, a condition of dysbiosis has been associated with an increased inflammatory response and metabolic alterations in the host, with important consequences on the intestinal and systemic health of the unborn child. This review aims to summarize the current knowledge on the origins of NAFLD, with particular attention to the potential implications of intrauterine life and the early postnatal period. Due to the well-known association between gut microbiota and the risk of NAFLD, a specific focus will be devoted to factors affecting early microbiota formation/composition.

Diet-Induced Non-alcoholic Fatty Liver Disease and Associated Gut Dysbiosis Are Exacerbated by Oral Infection

Increasing evidence indicates that chronic inflammation due to periodontal disease is associated with progression of non-alcoholic fatty liver disease (NAFLD) caused by a Western diet. NAFLD has also been associated with oral infection with the etiological agent of periodontal disease, Porphyromonas gingivalis. P. gingivalis oral infection has been shown to induce cardiometabolic disease features including hepatic lipid accumulation while also leading to dysbiosis of the gut microbiome. However, the impact of P. gingivalis infection on the gut microbiota of mice with diet-induced NAFLD and the potential for those changes to mediate NAFLD progression has yet to be determined. In the current study, we have demonstrated that P. gingivalis infection induced sustained alterations of the gut microbiota composition and predicted functions, which was associated with the promotion of NAFLD in steatotic mice. Reduced abundance of short-chain fatty acid-producing microbiota was observed after both acute and chronic P. gingivalis infection. Collectively, our findings demonstrate that P. gingivalis infection produces a persistent change in the gut microbiota composition and predicted functions that promotes steatosis and metabolic disease.

Roles of gut microbiota and metabolites in overweight and obesity of children

The prevalence of overweight and obesity in children and adolescents is an increasing public health problem. Pediatric overweight and obesity result from multiple factors, including genetic background, diet, and lifestyle. In addition, the gut microbiota and their metabolites play crucial roles in the progression of overweight and obesity of children. Therefore, we reviewed the roles of gut microbiota in overweight/obese children. The relationship between pediatric overweight/obesity and gut metabolites, such as short-chain fatty acids, medium-chain fatty acids, amino acids, amines, and bile acids, are also summarized. Targeting gut microbiota and metabolites might be a promising strategy for interventions aimed at reducing pediatric overweight/obesity.

The Gut-Liver Axis in Health and Disease: The Role of Gut Microbiota-Derived Signals in Liver Injury and Regeneration

Diverse liver diseases undergo a similar pathophysiological process in which liver regeneration follows a liver injury. Given the important role of the gut-liver axis in health and diseases, the role of gut microbiota-derived signals in liver injury and regeneration has attracted much attention. It has been observed that the composition of gut microbiota dynamically changes in the process of liver regeneration after partial hepatectomy, and gut microbiota modulation by antibiotics or probiotics affects both liver injury and regeneration. Mechanically, through the portal vein, the liver is constantly exposed to gut microbial components and metabolites, which have immense effects on the immunity and metabolism of the host. Emerging data demonstrate that gut-derived lipopolysaccharide, gut microbiota-associated bile acids, and other bacterial metabolites, such as short-chain fatty acids and tryptophan metabolites, may play multifaceted roles in liver injury and regeneration. In this perspective, we provide an overview of the possible molecular mechanisms by which gut microbiota-derived signals modulate liver injury and regeneration, highlighting the potential roles of gut microbiota in the development of gut microbiota-based therapies to alleviate liver injury and promote liver regeneration.

Efficacy of probiotic adjuvant therapy for irritable bowel syndrome in children: A systematic review and meta-analysis

Objective

Irritable bowel syndrome (IBS) affects children’s quality of life and learning. The purpose of this research was to systematically evaluate the efficacy of probiotic adjuvant therapy for IBS in children.

Methods

The Web of Science, PubMed, Cochrane Library, EMBASE and Clinical Trials databases were electronically searched for randomized controlled trials (RCTs) published prior to January 2021 exploring the use of probiotic adjuvant therapy for IBS in children. Strict screening and quality evaluations of the eligible articles were performed independently by 2 researchers. Outcome indexes were extracted, and a meta-analysis of the data was performed using RevMan 5.4.1 and STATA 16 software. Finally, the risk of bias in the included studies was assessed with the RCT bias risk assessment tool recommended in the Cochrane Handbook for Systematic Reviews of Interventions (5.1.0).

Results

A total of nine RCTs were included. In children, probiotics significantly reduced the abdominal pain score (I² = 95%, SMD = -1.15, 95% (-2.05, -0.24), P = 0.01) and Subject’s Global Assessment of Relief (SGARC) score (I² = 95%, MD = -3.84, 95% (-6.49, -1.20), P = 0.004), increased the rate of abdominal pain treatment success (I² = 0%, RR = 3.44, 95% (1.73, 6.87), P = 0.0005) and abdominal pain relief (I² = 40%, RR = 1.48, 95% (0.96, 2.28), P = 0.08), and reduced the frequency of abdominal pain (I² = 2%, MD = -0.82, 95% (-1.57, -0.07), P = 0.03). However, we found that it might not be possible to relieve abdominal pain by increasing the daily intake of probiotics.

Conclusions

Probiotics are effective at treating abdominal pain caused by IBS in children, however, there was no significant correlation between abdominal pain and the amount of probiotics ingested. More attention should be given to IBS in children, and a standardized evaluation should be adopted.