Molecular phenomics and metagenomics of hepatic steatosis in non-diabetic obese women

Identifying the location-dependent adipose tissue bacterial DNA signatures in obese patients that predict body weight loss

Recent sets of evidence have described profiles of 16S rDNA sequences in host tissues, notably in fat pads that are significantly overrepresented and can serve as signatures of metabolic disease. However, these recent and original observations need to be further detailed and functionally defined. Here, using state-of-the-art targeted DNA sequencing and discriminant predictive approaches, we describe, from the longitudinal FLORINASH cohort of patients who underwent bariatric surgery, visceral, and subcutaneous fat pad-specific bacterial 16SrRNA signatures. The corresponding Porphyromonadaceae, Campylobacteraceae, Prevotellaceae, Actimomycetaceae, Veillonellaceae, Anaerivoracaceae, Fusobacteriaceae, and the Clostridium family XI 16SrRNA DNA segment profiles are signatures of the subcutaneous adipose depot while Pseudomonadaceae and Micrococcacecae, 16SrRNA DNA sequence profiles characterize the visceral adipose depot. In addition, we have further identified that a specific pre-bariatric surgery adipose tissue bacterial DNA signature predicts the efficacy of body weight loss in obese patients 5-10 years after the surgery. 16SrRNA signatures discriminate (ROC ~ 1) the patients who did not maintain bodyweight loss and those who did. Second, from the 16SrRNA sequences we infer potential pathways suggestive of catabolic biochemical activities that could be signatures of subcutaneous adipose depots that predict body weight loss.

Auricularia auriculaPolysaccharides Exert Anti-inflammatory Effects in Hepatic Fibrosis by the Gut-Liver Axis and Enhancing SCFA Metabolism

Auricularia auricula, esteemed in Chinese culture for their culinary and medicinal properties, exhibits notable metabolic and immunomodulatory effects. The principal active constituents are indigestible fermentable polysaccharides, which not only exhibit anti-inflammatory activities but also facilitate the proliferation of beneficial gut microbiota. However, the influence of gut-derived components on liver-regulated metabolic products remains insufficiently understood. This item offers insights into the therapeutic potential of wood ear mushrooms for treating hepatic fibrosis and the associated mechanisms. Following 8 weeks of treatment, a substantial reduction in ECM deposition was recorded, linked to modulation of the NLRP3 inflammasome activation. This study aims to reveal the potential microbiome-mediated mechanisms behind its therapeutic effects. Insights from antibiotic combination treatments indicate that the protective effects against ECM deposition rely on the presence of specific gut microbiota. This fecal microbiota intervention enhances key physiological mechanisms, underscoring the contributions of Lactobacillales, Rikenellaceae, and Bacteroidaceae in potentially mitigating fibrosis. Collectively, these findings suggest that interventions utilizing wood ear mushrooms may reduce inflammation and ECM deposition, mediated by the TLR4/NF-κB pathway.

Intrahepatic levels of microbiome-derived hippurate associates with improved metabolic dysfunction-associated steatotic liver disease

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterised by lipid accumulation in the liver and is often associated with obesity and type 2 diabetes. The gut microbiome recently emerged as a significant player in liver metabolism and health. Hippurate, a host-microbial co-metabolite has been associated with human gut microbial gene richness and with metabolic health. However, its role on liver metabolism and homeostasis is poorly understood.

METHODS

We characterised liver biospies from 318 patients with obesity using RNAseq and metabolomics in liver and plasma to derive associations among hepatic hippurate, hepatic gene expression and MASLD and phenotypes. To test a potential beneficial role for hippurate in hepatic insulin resistance, we profile the metabolome of (IHH) using ultra-high-performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC-MS/MS), and characterised intracellular triglyceride accumulation and glucose internalisation after a 24 h insulin exposure.

RESULTS

We first report significant associations among MASLD traits, plasma and hepatic hippurate. Further analysis of the hepatic transcriptome shows that liver and plasma hippurate are inversely associated with MASLD, implicating lipid metabolism and regulation of inflammatory responses pathways. Hippurate treatment inhibits lipid accumulation and rescues insulin resistance induced by 24-hour chronic insulin in IHH. Hippurate also improves hepatocyte metabolic profiles by increasing the abundance of metabolites involved in energy homeostasis that are depleted by chronic insulin treatment while decreasing those involved in inflammation.

CONCLUSIONS

Altogether, our results further highlight hippurate as a mechanistic marker of metabolic health, by its ability to improve metabolic homeostasis as a postbiotic candidate.

The gut-brain axis underlying hepatic encephalopathy in liver cirrhosis

Up to 50-70% of patients with liver cirrhosis develop hepatic encephalopathy (HE), which is closely related to gut microbiota dysbiosis, with an unclear mechanism. Here, by constructing gut-brain modules to assess bacterial neurotoxins from metagenomic datasets, we found that phenylalanine decarboxylase (PDC) genes, mainly from Ruminococcus gnavus, increased approximately tenfold in patients with cirrhosis and higher in patients with HE. Cirrhotic, not healthy, mice colonized with R. gnavus showed brain phenylethylamine (PEA) accumulation, along with memory impairment, symmetrical tremors and cortex-specific neuron loss, typically found in patients with HE. This accumulation of PEA was primarily driven by decreased monoamine oxidase-B activity in both the liver and serum due to cirrhosis. Targeting PDC or PEA reversed the neurological symptoms induced by R. gnavus. Furthermore, fecal microbiota transplantation from patients with HE to germ-free cirrhotic mice replicated these symptoms and further corroborated the efficacy of targeting PDC or PEA. Clinically, high baseline PEA levels were linked to a sevenfold increased risk of HE after intrahepatic portosystemic shunt procedures. Our findings expand the understanding of the gut-liver-brain axis and identify a promising therapeutic and predictive target for HE.

The gut-liver axis links the associations between serum carotenoids and non-alcoholic fatty liver in a 7.8-year prospective study

Background

Many studies have shown that carotenoids are beneficial to non-alcoholic fatty liver disease (NAFLD). Therefore, we explored potential biomarkers of gut microbiota and fecal and serum metabolites linking the association between serum carotenoids and NAFLD in adults.

Methods

This 7.8-year prospective study included 2921 participants with serum carotenoids at baseline and determined NAFLD by ultrasonography (ULS-NAFLD) every 3 years. A total of 828 subjects additionally underwent magnetic resonance imaging to identify NAFLD (MRI-NAFLD). Gut microbiota was analyzed by 16S rRNA sequencing in 1,661 participants, and targeted metabolomics profiling in 893 feces and 896 serum samples was performed by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in the middle term.

Results

A total of 2,522 participants finished follow-up visits. Of these participants, 770, 301, 474, and 977 were categorized into NAFLD-free, improved, new-onset, and persistent NAFLD groups based on their ULS-NAFLD status changes, respectively, and 342/828 were MRI-verified NALFD. Longitudinal analyses showed an inverse association between carotenoids and NALFD risk/presence (P-trend <0.05). Multivariable-adjusted odds ratios (ORs)/hazard ratio (HR) [95% confidence intervals (CIs)] of NAFLD for quartile 4 (vs. quartile 1) of total carotenoids were 0.63 (0.50, 0.80) for incident ULS-NAFLD, 0.20 (0.15, 0.27) for persistent ULS-NAFLD, 1.53 (1.10, 2.12) for improved-NAFLD, and 0.58 (0.39, 0.87) for MRI-NAFLD. The biomarkers in the gut-liver axis significantly associated with both serum carotenoids and NAFLD included sixteen microbial genera mainly in Ruminococcaceae and Veillonellaceae family, nineteen fecal metabolites containing medium-chain fatty acids (MCFAs), bile acids, and carnitines, and sixteen serum metabolites belonging to organic acids and amino acids. The total carotenoids-related scores of significant microbial genera, fecal and serum metabolites mediated the carotenoids-NAFLD association by 8.72%, 12.30%, and 16.83% (all P<0.05) for persistent NAFLD and 9.46%, 8.74%, and 15.7% for incident-NAFLD, respectively.

Conclusions

Our study reveals a beneficial association of serum carotenoids and incident and persistent NAFLD. The identified gut-liver axis biomarkers provided mechanistic linkage for the epidemiological association.

A narrative review about cognitive impairment in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Another matter to face through a holistic approach

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic hepatic disorder worldwide in both adults and children. It is well established that MASLD represents the hepatic manifestation of the metabolic syndrome whose definition includes the presence of obesity, type 2 diabetes (T2D), dyslipidemia, hypertension and hypercoagulability. All these conditions contribute to a chronic inflammatory status which may impact on blood brain barrier (BBB) integrity leading to an impaired function of central nervous system (CNS).

AIM OF REVIEW

Since the mechanisms underlying the brain-liver-gut axis derangement are still inconclusive, the present narrative review aims to make a roundup of the most recent studies regarding the cognitive decline in MASLD also highlighting possible therapeutic strategies to reach a holistic advantage for the patients.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Due to its ever-growing prevalence, the MASLD-related mental dysfunction represents an enormous socio-economic burden since it largely impacts on the quality of life of patients as well as on their working productivity. Indeed, cognitive decline in MASLD translates in low concentration and processing speed, reduced memory, sleepiness but also anxiety and depression. Chronic systemic inflammation, hyperammonemia, genetic background and intestinal dysbiosis possibly contribute to the cognitive decline in MASLD patients. However, its diagnosis is still underestimated since the leading mechanisms are multi-faceted and unexplained and do not exist standardized diagnostic tools or cognitive test strategies. In this scenario, nutritional and lifestyle interventions as well as intestinal microbiota manipulation (probiotics, fecal transplantation) may represent new approaches to counteract mental impairment in these subjects. In sum, to face the "mental aspect" of this multifactorial disease which is almost unexplored, cognitive tools should be introduced in the management of MASLD patients.

Multi-omics analysis reveals toxicity and gut-liver axis disruption induced by polychlorinated biphenyls exposure in Yellowfin Seabream (Acanthopagrus latus)

Polychlorinated biphenyls (PCBs) are persistent organic pollutants known for their environmental persistence and bioaccumulation, posing significant health risks. This study examines the toxic effects of a representative PCBs (Aroclor 1254) on yellowfin seabream (Acanthopagrus latus) exposured for 30 days through a multi-omics approach. Histopathological examinations revealed structural damage to the intestinal structure and hepatic steatosis, along with elevated serum lipopolysaccharide levels, indicating compromised intestinal barrier integrity and liver inflammation. Metabolomic profiling showed significant alterations in lipid metabolites, including elevated lysophosphatidylcholines and arachidonic acid derivatives. Transcriptomic analysis unveiled 2272 differentially expressed genes in the liver, with notable changes in immune response and metabolic pathways. Gut microbiome analysis showed dysbiosis characterized by an increase in Proteobacteria and a decrease in Firmicutes and Actinobacteria. Remarkably, Tetranor-12S-HETE and LPC 15:1 emerged as key biomarkers for the disruption of the gut-liver axis, correlating with immune gene expression and gut microbiota composition. The integration of transcriptomic, metabolomic, and microbiome data highlighted the complex interplay between A1254 exposure and the gut-liver axis, emphasizing the central role played by PPAR signaling in mediating these effects. Collectively, these results indicate that exposure to A1254 results in bioaccumulation in the liver and gut, leading to severe tissue injury, microbiota dysbiosis, and dysregulation of the gut-liver axis, ultimately disrupting lipid metabolism. These findings underscore the metabolic health risks posed by PCBs exposure in aquatic environments.

Gut microbiota may modify the association between dietary polyphenol intake and serum concentrations of hippuric acid: results from a 1-year longitudinal study in China

BACKGROUND

Hippuric acid (HA), a host-microbe cometabolite, normally derives from gut microbial catabolism of dietary polyphenols.

OBJECTIVES

We investigated the potential interplay between dietary polyphenols and gut microbiota on circulating HA concentrations and examined the associations between serum concentrations of HA and cardiometabolic risk markers.

METHODS

In a 1-y cohort of 754 community-dwelling adults, serum HA and its precursor [benzoic acid (BA)], and fecal microbiota were assayed using liquid chromatography-tandem mass spectrometry and 16S ribosomal RNA sequencing, respectively. Diet, blood pressure, blood glucose, and lipid concentrations were measured twice, 1 y apart. Arterial stiffness [indicated by brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index] and liver fat accumulation [indicated by controlled attenuation parameter (CAP)] were measured after 1 y.

RESULTS

We identified 27 microbial genera whose relative abundance was positively associated with serum HA concentrations (PFDR < 0.05) and constructed a microbial score to reflect the overall HA-producing potential. In multivariate-adjusted linear models, dietary intake of catechins and chlorogenic acids was positively associated with serum HA concentrations among participants with a higher microbial score (β = 0.26, P = 0.03) but not among those with a lower score (β = -0.13, P = 0.30, Pinteraction = 0.03). Participants with higher intake of dietary catechins and chlorogenic acids had lower triglyceride concentrations (Percentage change = -5.9%, P < 0.05). Each 1 μmol/L increase in serum HA, but not in BA, was associated with 5.7%, 1.5%, 1.7%, 1.7%, and 1.7% decrease in triglyceride, systolic blood pressure, diastolic blood pressure, baPWV, and CAP, respectively (all P < 0.05).

CONCLUSIONS

The gut microbial genera that predicted circulating HA concentrations might modify the association between dietary polyphenol intake and circulating HA concentrations, and elevated serum HA concentrations are favorably associated with multiple cardiometabolic risk markers.

Integrative multi-omics analysis reveals liver-gut axis adaptation in high-altitude goats

The liver-gut axis is an important regulatory axis for the host's metabolic functions. The study of liver gene expression, changes in metabolic products and the regulation of gut microbial communities in plateau animals under harsh environments can reveal the mechanisms by which Tibetan goats adapt to the plateau environment. This study employs transcriptome, metabolome and metagenomic analyses to reveal the differences in genes, metabolism, and gut microbiota between Jianzhou big-eared goats (JBG) and Xizang cashmere goats (TCG), which is of significant importance for improving survival models of high-altitude ruminants. The results showed that there were 553 DEGs in the liver of JBG and TCG. Hepatic metabolomic analysis revealed significant differences in metabolic activity between the JBG and TCG groups, with notable increases in glycerophospholipid and retinol metabolic pathways. The gut microbiota, including Andreesenia, Dielma, Oscillibacter, Agrobacterium, Hyella and Thermosinus, interact with liver metabolites and can regulate the high-altitude adaptability of goats. This study reveals that TCG enhance immune regulation and energy utilization efficiency by regulating liver gene expression, modulating metabolic pathways, and improving gut microbiota, thereby helping TCG maintain healthy survival capabilities in hypoxic and high-radiation environments.

Core microbe Bifidobacterium in the hindgut of calves improves the growth phenotype of young hosts by regulating microbial functions and host metabolism

BACKGROUND

The growth and health of young ruminants are regulated by their gut microbiome, which can have lifelong consequences. Compared with subjective grouping, phenotypic clustering might be a more comprehensive approach to revealing the relationship between calf growth state and core gut microbes. However, the identification of beneficial gut bacteria and its internal mechanisms of shaping host phenotype differentiation remains unclear.

RESULTS

In this study, calves were divided into two clusters, cluster1 and cluster2, based on 29 phenotypic indicators using cluster analysis. Calves in cluster2 showed better growth performance, including higher body weight (BW), average daily gain (ADG), and dry matter intake (DMI), as well as better serum indicators with a high level of total superoxide dismutase (T-SOD), interleukin-6 (IL-6), and insulin-like growth factor-1 (IGF-1) compared to those in cluster1. Multi-omics was used to detect microbial features among calves in different phenotypic clusters. Distinct differences were observed between the two clustered gut microbiomes, including microbial diversity and composition. The close relationships between growth performance, blood metabolites, and microbiome were also confirmed. In cluster2, Bifidobacterium members were the dominant contributors to microbial metabolic functions with a higher abundance. Furthermore, pathways involved in carbohydrate degradation, glycolysis, and biosynthesis of propionate and proteins were active, while methane production was inhibited. In addition, the diversity and richness of hindgut resistome in cluster2 were lower than those in cluster1. The isolation and culture of Bifidobacterium strain, as well as the mice experiment, indicated that B. longum 1109 from calf feces in cluster2 could promote the growth of young hosts, enhance their blood immunity and antioxidation, and improve the development of hindgut.

CONCLUSIONS

In summary, cluster analysis has proved to be a feasible and reliable approach for identifying phenotypic subgroups of calves, prompting further exploration of host-microbiome interactions. Bifidobacterium as a core microbe in the hindgut of calves may play a crucial probiotic role in host phenotypic differentiation. This study enhances our comprehension of how gut core microbe shapes the host phenotype and provides new insights into the manipulation of beneficial gut colonizers to improve the growth performance and productivity of young ruminants. Video Abstract.

The Gut Microbiota-Related Antihyperglycemic Effect of Metformin

It is critical to sustain the diversity of the microbiota to maintain host homeostasis and health. Growing evidence indicates that changes in gut microbial biodiversity may be associated with the development of several pathologies, including type 2 diabetes mellitus (T2DM). Metformin is still the first-line drug for treatment of T2DM unless there are contra-indications. The drug primarily inhibits hepatic gluconeogenesis and increases the sensitivity of target cells (hepatocytes, adipocytes and myocytes) to insulin; however, increasing evidence suggests that it may also influence the gut. As T2DM patients exhibit gut dysbiosis, the intestinal microbiome has gained interest as a key target for metabolic diseases. Interestingly, changes in the gut microbiome were also observed in T2DM patients treated with metformin compared to those who were not. Therefore, the aim of this review is to present the current state of knowledge regarding the association of the gut microbiome with the antihyperglycemic effect of metformin. Numerous studies indicate that the reduction in glucose concentration observed in T2DM patients treated with metformin is due in part to changes in the biodiversity of the gut microbiota. These changes contribute to improved intestinal barrier integrity, increased production of short-chain fatty acids (SCFAs), regulation of bile acid metabolism, and enhanced glucose absorption. Therefore, in addition to the well-recognized reduction of gluconeogenesis, metformin also appears to exert its glucose-lowering effect by influencing gut microbiome biodiversity. However, we are only beginning to understand how metformin acts on specific microorganisms in the intestine, and further research is needed to understand its role in regulating glucose metabolism, including the impact of this remarkable drug on specific microorganisms in the gut.

Microbiome and metabolomics reveal the effect of gut microbiota on liver regeneration of fatty liver disease

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is associated with impaired regenerative capacity and poor postoperative prognosis following hepatectomy. Previous research has highlighted the importance of the gut-liver axis in the physiological and pathological processes of the liver. However, the contribution of gut bacteria to the regeneration of livers with MAFLD and its metabolic regulatory mechanisms remain elusive.

METHODS

Partial hepatectomy (PHx) was performed on C57Bl/6J mice fed with high-fat diet (HFD) for 12 weeks. Pathological examination, immunohistochemistry, and qRT-PCR analysis were performed to assess the severity of steatosis and proliferative potential. The gut microbiome was examined by 16S rRNA gene sequencing and shotgun metagenomics, whereas liver metabolomics was analysed via untargeted and targeted metabolomics using liquid chromatography-tandem mass spectrometry (LC-MS).

FINDINGS

HFD-induced hepatic steatosis in mice led to impaired liver regeneration following PHx. The gut microbiota and liver metabolites were altered along with the liver regeneration process. Longitudinal time-series analysis revealed dynamic alterations in these data, whereas correlation analysis screened out bacterial candidates that potentially influence liver regeneration in MAFLD by modulating metabolic pathways. Among these bacteria, the dominant bacterium Akkermansia was selected for subsequent investigation. MAFLD mice gavaged with Akkermansia muciniphila (A. muciniphila) exhibited reduced liver lipid accumulation and accelerated liver regeneration, possibly through the regulation of the tricarboxylic acid (TCA) cycle.

INTERPRETATION

These data demonstrated the interplay between the gut microbiome, liver metabolomics, and liver regeneration in mice with MAFLD. A. muciniphila has the potential to serve as a clinical intervention agent to accelerate postoperative recovery in MAFLD.

FUNDING

This work was supported by the Research Project of Jinan Microecological Biomedicine Shandong Laboratory [JNL-2022008B]; the Zhejiang Provincial Natural Science Foundation of China [LZ21H180001]; the Fundamental Research Funds for the Central Universities [No. 2022ZFJH003].

New Insights into AMPK, as a Potential Therapeutic Target in Metabolic Dysfunction-Associated Steatotic Liver Disease and Hepatic Fibrosis

AMP-activated protein kinase (AMPK) activators have garnered significant attention for their potential to prevent the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) into liver fibrosis and to fundamentally improve liver function. The broad spectrum of pathways regulated by AMPK activators makes them promising alternatives to conventional liver replacement therapies and the limited pharmacological treatments currently available. In this study, we aim to illustrate the newly detailed multiple mechanisms of MASLD progression based on the multiple-hit hypothesis. This model posits that impaired lipid metabolism, combined with insulin resistance and metabolic imbalance, initiates inflammatory cascades, gut dysbiosis, and the accumulation of toxic metabolites, ultimately promoting fibrosis and accelerating MASLD progression to irreversible hepatocellular carcinoma (HCC). AMPK plays a multifaceted protective role against these pathological conditions by regulating several key downstream signaling pathways. It regulates biological effectors critical to metabolic and inflammatory responses, such as SIRT1, Nrf2, mTOR, and TGF-β, through complex and interrelated mechanisms. Due to these intricate connections, AMPK's role is pivotal in managing metabolic and inflammatory disorders. In this review, we demonstrate the specific roles of AMPK and its related pathways. Several agents directly activate AMPK by binding as agonists, while some others indirectly activate AMPK by modulating upstream molecules, including adiponectin, LKB1, and the AMP: ATP ratio. As AMPK activators can target each stage of MASLD progression, the development of AMPK activators offers immense potential to expand therapeutic strategies for liver diseases such as MASH, MASLD, and liver fibrosis.

Gut microbiome synthesizes important core metabolites to prevent cognitive decline and mitigate onset and progression of Alzheimer's disease

Background

This study explores how gut metabolites, produced through bacterial metabolism in the gut, influence neurological conditions like Alzheimer's disease (AD). Key metabolites such as succinate and short-chain fatty acids signal through the autonomic nervous system and can cross the blood-brain barrier, impacting central nervous system functions.

Objective

The aim is to examine the role of the gut microbiota in compensating for metabolic deficiencies in AD. By analyzing wild-type (WT) and APP/PS1 mice, the study investigates how the microbiome affects key metabolic processes and whether it can slow AD progression.

Methods

High-throughput sequencing data from the gut microbiomes of APP/PS1 transgenic AD model mice and age-matched WT C57BL/6 male mice were analyzed for microbial and metabolite profiles.

Results

Alpha and beta diversity analyses showed differences in microbial composition between groups. Partial least squares discriminant analysis and Anosim confirmed distinct microbiome profiles in WT and APP/PS1 mice. At the genus level, Vescimonas was more abundant in WT mice, while Odoribacter, Lacrimispora, Helicobacter, Bacteroides, and Alloprevotella were more prevalent in APP/PS1 mice.

Conclusions

While taxonomic differences did not directly link specific microorganisms to AD, functional analysis identified key metabolites-acetyl-CoA, glucose, succinate, lipids, choline, and acetylcholine-that may alleviate energy deficits and synaptic dysfunction. This study suggests that the microbiome may help compensate for AD-related impairments, opening avenues for microbiome-based therapies.

ABL1‒YAP1 axis in intestinal stem cell activated by deoxycholic acid contributes to hepatic steatosis

BACKGROUND

Yes-associated protein 1 (YAP1) regulates the survival, proliferation, and stemness of cells, and contributes to the development of metabolic dysfunction associated fatty liver disease (MAFLD). However, the regulatory role of intestinal YAP1 in MAFLD still remains unclear.

METHODS

Terminal ileal specimens were used to compare intestinal YAP1 activation in patients with and without MAFLD. Mice targeted for knocking out YAP1 in the intestinal epithelium were fed a high-fat diet (HFD) for 8 consecutive weeks. In a separate group, the mice were fed an HFD supplemented with the bile acid binder cholestyramine (CHO) or a low-fat diet with deoxycholic acid (DCA). Immunofluorescence, Immunohistochemistry, Western blot, RT-qPCR, ELISA, 16S rDNA sequencing, tissue and enteroid culture techniques were used to evaluate the effects of an HFD or DCA on the gut‒liver axis in mice or humans.

RESULTS

Intestinal YAP1 was activated in both humans with MAFLD and mice fed an HFD. In in vivo studies, YAP1 knockout in intestinal epithelial cells of mice alleviated the hepatic steatosis induced by an HFD, and mitigated the adverse effects of HFD on the gut‒liver axis, including the upregulation of lipopolysaccharide (LPS) and inflammation levels, enrichment of intestinal Gram-negative bacteria, and inhibition of intestinal stem cell (ISC) differentiation into the goblet and Paneth cells. High-fat feeding (HFF) produced high concentrations of DCA. The consumption of DCA mimics these HFF-induced changes, and is accompanied by the activation of Abelson tyrosine-protein kinase 1 (ABL1) and its direct substrate, YAP1, in the terminal ileum. In vitro studies further confirmed that DCA upregulated the tyrosine phosphorylation of YAP1Y357 in ISC by activating ABL1, which inhibited the differentiation of ISCs into secretory cells.

CONCLUSIONS

Our findings reveal that the activation of the ABL1‒YAP1 axis in ISCs by DCA contributes to hepatic steatosis through the gut‒liver axis, which may provide a potential intestinal therapeutic target for MAFLD.

Gut microbiota mediated T cells regulation and autoimmune diseases

Gut microbiota regulates the immune system, the development and progression of autoimmune diseases (AIDs) and overall health. Recent studies have played a crucial part in understanding the specific role of different gut bacterial strains and their metabolites in different AIDs. Microbial signatures in AIDs are revealed by advanced sequencing and metabolomics studies. Microbes such as Faecalibacterium prausnitzii, Akkermansia muciniphila, Anaerostipes caccae, Bacteroides sp., Roseburia sp., Blautia sp., Blautia faecis, Clostridium lavalense, Christensenellaceae sp., Coprococcus sp., Firmicutes sp., Ruminococcaceae sp., Lachnospiraceae sp., Megamonas sp., Monoglobus sp., Streptococcus pneumoniae and Bifidobacterium sp. help maintain immune homeostasis; whereas, Prevotella copri, Ruminococcus gnavus, Lactobacillus salivarius, Enterococcus gallinarum, Elizabeth menigoseptica, Collinsella sp., Escherichia sp., Fusobacterium sp., Enterobacter ludwigii, Enterobacteriaceae sp., Proteobacteria, Porphyromonas gingivalis, Porphyromonas nigrescens, Dorea sp., and Clostridium sp. cause immuno-pathogenesis. A complex web of interactions is revealed by understanding the influence of gut microbiota on immune cells and various T cell subsets such as CD4+ T cells, CD8+ T cells, natural killer T cells, γδ T cells, etc. Certain AIDs, including rheumatoid arthritis, diabetes mellitus, atopic asthma, inflammatory bowel disease and non-alcoholic fatty liver disease exhibit a state of dysbiosis, characterized by alterations in microbial diversity and relative abundance of specific taxa. This review summarizes recent developments in understanding the role of certain microbiota composition in specific AIDs, and the factors affecting specific regulatory T cells through certain microbial metabolites and also focuses the potential application and therapeutic significance of gut microbiota-based interventions as novel adjunctive therapies for AIDs. Further research to determine the precise association of each gut bacterial strain in specific diseases is required.

Utilizing Lactic Acid Bacteria to Improve Hyperlipidemia: A Comprehensive Analysis from Gut Microbiota to Metabolic Pathways

Hyperlipidemia poses significant risks for cardiovascular diseases, with emerging evidence underscoring the critical role of gut microbiota in metabolic regulation. This study explores Lactobacillus casei CAAS36, a probiotic strain with promising cholesterol-lowering capabilities, assessing its impact on hyperlipidemic hamsters. Utilizing 1H NMR-based metabolomics and 16S rRNA gene sequencing, we observed that L. casei CAAS36 treatment not only altered metabolic pathways but also reshaped gut microbiota composition. Notably, the treatment restored the balance between Firmicutes and Bacteroidetes and significantly increased the abundance of propionate-producing Muribaculaceae. Metabolically, L. casei CAAS36 administration led to the normalization of key lipid markers, including reductions in total cholesterol, LDL-C, and triglycerides (29.9%, 29.4% and 32.6%), while enhancing the protective HDL-C levels. These effects were accompanied by significant increases in beneficial metabolites such as propionate and succinate, which are known for their roles in preventing metabolic disorders. These findings highlight the dual regulatory effects of L. casei CAAS36 on the metabolic profile and gut microbiota, suggesting a substantial potential for this probiotic in the management of hyperlipidemia and possibly other metabolic diseases. Future applications may include its use as a natural therapeutic agent in clinical settings, aiming to reduce reliance on conventional pharmaceuticals and their associated side effects.

Metabolic disorders, inter-organ crosstalk, and inflammation in the progression of metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease (MASLD) represents a global health concern, affecting over 30 % of adults. It is a principal driver in the development of cirrhosis and hepatocellular carcinoma. The complex pathogenesis of MASLD involves an excessive accumulation of lipids, subsequently disrupting lipid metabolism and prompting inflammation within the liver. This review synthesizes the recent research progress in understanding the mechanisms contributing to MASLD progression, with particular emphasis on metabolic disorders and interorgan crosstalk. We highlight the molecular mechanisms linked to these factors and explore their potential as novel targets for pharmacological intervention. The insights gleaned from this article have important implications for both the prevention and therapeutic management of MASLD.

Interplay between gut microbiome, host genetic and epigenetic modifications in MASLD and MASLD-related hepatocellular carcinoma

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a wide spectrum of liver injuries, ranging from hepatic steatosis, metabolic dysfunction-associated steatohepatitis (MASH), fibrosis, cirrhosis to MASLD-associated hepatocellular carcinoma (MASLD-HCC). Recent studies have highlighted the bidirectional impacts between host genetics/epigenetics and the gut microbial community. Host genetics influence the composition of gut microbiome, while the gut microbiota and their derived metabolites can induce host epigenetic modifications to affect the development of MASLD. The exploration of the intricate relationship between the gut microbiome and the genetic/epigenetic makeup of the host is anticipated to yield promising avenues for therapeutic interventions targeting MASLD and its associated conditions. In this review, we summarise the effects of gut microbiome, host genetics and epigenetic alterations in MASLD and MASLD-HCC. We further discuss research findings demonstrating the bidirectional impacts between gut microbiome and host genetics/epigenetics, emphasising the significance of this interconnection in MASLD prevention and treatment.

Prebiotics targeting gut-liver axis to treat non-alcoholic fatty liver disease

Non-alcoholic steatohepatitis (NASH) is a high-prevalence, rapidly growing form of non-alcoholic fatty liver disease (NAFLD), which is closely linked to obesity and metabolic disorders. Gut microbiota has been increasingly recognized as a key factor in the onset of NAFLD in recent years. The liver can be strongly influenced by changes in the gut microbiota through the portal vein, giving the gut-liver axis a very important role in understanding the pathophysiology of liver diseases. A healthy intestinal barrier is characterized by selective permeability to nutrients, metabolites, water and bacterial products and its impairment may be a predisposing or aggravating condition for the progression of NAFLD. In most cases, NAFLD patients follow a Western diet pattern, which is closely linked to obesity and associated metabolic diseases, promoting inflammation, structural and behavioral changes in the gut microbiota. In fact, factors such as age, gender, genetic or environmental factors may induce a dysbiotic microbiota that promotes epithelial barrier dysfunction and increased intestinal permeability, favoring the progression of NAFLD. In this context, new dietary approaches, such as prebiotics, are emerging to prevent disease and maintain health. In this review, we reported the role of the gut-liver axis in the pathogenesis of NAFLD and investigated the potential therapeutic effect of prebiotics on the enhancement of intestinal barrier dysfunction, hepatic steatosis and, consequently, the progression of NAFLD.

Metabolic signatures of metabolic dysfunction-associated steatotic liver disease in severely obese patients

BACKROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) can lead to liver fibrosis, cirrhosis, and hepatocellular carcinoma. Still, most patients with MASLD die from cardiovascular diseases indicating metabolic alterations related to both liver and cardiovascular pathology.

AIMS AND METHODS

The aim of this study was to assess biologic pathways behind MASLD progression from steatosis to metabolic dysfunction-associated steatohepatitis (MASH) using non-targeted liquid chromatography-mass spectrometry analysis in 106 severely obese individuals (78 women, mean age 47.7 7 ± 9.2 years, body mass index 41.8 ± 4.3 kg/m²) undergoing laparoscopic Roux-en-Y gastric bypass.

RESULTS

We identified several metabolites that are associated with MASLD progression. Most importantly, we observed a decrease of lysophosphatidylcholines LPC(18:2), LPC(18:3), and LPC(20:3) and increase of xanthine when comparing those with steatosis to those with MASH. We found that indole propionic acid and threonine were negatively correlated to fibrosis, but not with the metabolic disturbances associated with cardiovascular risk. Xanthine, ketoleucine, and tryptophan were positively correlated to lobular inflammation and ballooning but also with insulin resistance, and dyslipidemia, respectively. The results did not change when taking into account the most important genetic risk factors of MASLD.

CONCLUSIONS

Our findings suggest that there are several separate biological pathways, some of them independent of insulin resistance and dyslipidemia, associating with MASLD.

Ruminococcus gnavus in the gut: driver, contributor, or innocent bystander in steatotic liver disease?

The human gut microbiome plays a crucial role in regulating intestinal and systemic health, impacting host immune response and metabolic function. Dysbiosis of the gut microbiome is linked to various diseases, including steatotic liver diseases. Metabolic dysfunction-associated steatotic liver disease (MASLD), a chronic liver disease characterized by excess hepatic lipid content and impaired metabolism, is the leading cause of liver disease worldwide. Among the gut microbes, Ruminococcus gnavus (R. gnavus) has garnered attention for its association with inflammatory and metabolic diseases. While R. gnavus abundance correlates to liver fat accumulation, further research is needed to identify a causal role or therapeutic intervention in steatotic liver disease. This review surveys our current understanding of R. gnavus in the development and progression of steatotic liver diseases, highlighting its potential mechanisms through metabolite secretion, and emphasizes the need for comprehensive microbiome analyses and longitudinal studies to better understand R. gnavus' impact on liver health. This knowledge could pave the way for targeted interventions aimed at modulating gut microbiota to treat and prevent MASLD and its comorbidities.

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.

Integrated serum metabolomics, 16S rRNA sequencing and bile acid profiling to reveal the potential mechanism of gentiopicroside against nonalcoholic steatohepatitis in lean mice

ETHNOPHARMACOLOGICAL RELEVANCE

Lean nonalcoholic steatohepatitis (NASH) poses a serious threat to public health worldwide. Herbs of the genus Gentiana have been used for centuries to treat hepatic disease or have been consumed for hepatic protection efficiency. Gentiopicroside (GPS), the main bioactive component of Gentiana herbs, has been shown to be beneficial for protecting the liver, improving intestinal disorders, modulating bile acid profiles, ameliorating alcoholic hepatosteatosis, and so on. It is plausible to speculate that GPS may hold potential as a therapeutic strategy for lean NASH. However, no related studies have been conducted thus far.

AIM OF THE STUDY

The present work aimed to investigate the benefit of GPS on NASH in a lean mouse model.

MATERIALS AND METHODS

NASH in a lean mouse model was successfully established via a published method. GPS of 50 and 100 mg/kg were orally administered to verify the effect. Untargeted metabolomics, 16S rDNA sequencing and bile acid (BA) profiling, as well as qPCR and Western blotting analysis were employed to investigate the mechanism underlying the alleviating effect.

RESULTS

GPS significantly reduced the increase in serum biochemicals and liver index, and attenuated the accumulation of fat in the livers of lean mice with NASH. Forty-two potential biomarkers were identified by metabolomics analysis, leading to abnormal metabolic pathways of primary bile acid biosynthesis and fatty acid biosynthesis, which were subsequently rebalanced by GPS. A decreased Firmicutes/Bacteroidetes (F/B) ratio and disturbed BA related GM profiles were revealed in lean mice with NASH but were partially recovered by GPS. Furthermore, serum profiling of 23 BAs confirmed that serum BA levels were elevated in the lean model but downregulated by GPS treatment. Pearson correlation analysis validated associations between BA profiles, serum biochemical indices and related GM. qPCR and Western blotting analysis further elucidated the regulation of genes associated with liver lipid synthesis and bile acid metabolism.

CONCLUSIONS

GPS may ameliorate steatosis in lean mice with NASH, regulating the metabolomic profile, BA metabolism, fatty acid biosynthesis, and BA-related GM. All these factors may contribute to its beneficial effect.

Piperlongumine, a natural alkaloid from Piper longum L. ameliorates metabolic-associated fatty liver disease by antagonizing the thromboxane A2 receptor

Metabolic dysfunction-associated fatty liver disease (MAFLD) encompasses a broad spectrum of hepatic disorders, including hyperglycemia, hepatic steatosis, and insulin resistance. Piperlongumine (PL), a natural amide alkaloid extracted from the fruits of Piper longum L., exhibited hepatoprotective effects in zebrafish and liver injury mice. This study aimed to investigate the therapeutic potential of PL on MAFLD and its underlying mechanisms. The findings demonstrate that PL effectively combats MAFLD induced by a high-fat diet (HFD) and improves metabolic characteristics in mice. Additionally, our results suggest that the anti-MAFLD effect of PL is attributed to the suppression of excessive hepatic gluconeogenesis, inhibition of de novo lipogenesis, and alleviation of insulin resistance. Importantly, the results indicate that, on the one hand, the hypoglycemic effect of PL is closely associated with CREB-regulated transcriptional coactivators (CRTC2)-dependent cyclic AMP response element binding protein (CREB) phosphorylation; on the other hand, the lipid-lowering effect of PL is attributed to reducing the nuclear localization of sterol regulatory element-binding proteins 1c (Srebp-1c). Mechanistically, PL could alleviate insulin resistance induced by endoplasmic reticulum stress by antagonizing the thromboxane A2 receptor (TP)/Ca2+ signaling, and the TP receptor serves as the potential target for PL in the treatment of MAFLD. Therefore, our results suggested PL effectively improved the major hallmarks of MAFLD induced by HFD, highlighting a potential therapeutic strategy for MAFLD.

Gut microbes, diet, and genetics as drivers of metabolic liver disease: a narrative review outlining implications for precision medicine

Metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing in prevalence, impacting over a third of the global population. The advanced form of MASLD, Metabolic dysfunction-associated steatohepatitis (MASH), is on track to become the number one indication for liver transplant. FDA-approved pharmacological agents are limited for MASH, despite over 400 ongoing clinical trials, with only a single drug (resmetirom) currently on the market. This is likely due to the heterogeneous nature of disease pathophysiology, which involves interactions between highly individualized genetic and environmental factors. To apply precision medicine approaches that overcome interpersonal variability, in-depth insights into interactions between genetics, nutrition, and the gut microbiome are needed, given that each have emerged as dynamic contributors to MASLD and MASH pathogenesis. Here, we discuss the associations and molecular underpinnings of several of these factors individually and outline their interactions in the context of both patient-based studies and preclinical animal model systems. Finally, we highlight gaps in knowledge that will require further investigation to aid in successfully implementing precision medicine to prevent and alleviate MASLD and MASH.

The role of the gut microbiome in the development of hepatobiliary cancers

Hepatobiliary cancers, including hepatocellular carcinoma and cancers of the biliary tract, share high mortality and rising incidence rates. They may also share several risk factors related to unhealthy western-type dietary and lifestyle patterns as well as increasing body weights and rates of obesity. Recent data also suggest a role for the gut microbiome in the development of hepatobiliary cancer and other liver pathologies. The gut microbiome and the liver interact bidirectionally through the "gut-liver axis," which describes the interactive relationship between the gut, its microbiota, and the liver. Here, we review the gut-liver interactions within the context of hepatobiliary carcinogenesis by outlining the experimental and observational evidence for the roles of gut microbiome dysbiosis, reduced gut barrier function, and exposure to inflammatory compounds as well as metabolic dysfunction as contributors to hepatobiliary cancer development. We also outline the latest findings regarding the impact of dietary and lifestyle factors on liver pathologies as mediated by the gut microbiome. Finally, we highlight some emerging gut microbiome editing techniques currently being investigated in the context of hepatobiliary diseases. Although much work remains to be done in determining the relationships between the gut microbiome and hepatobiliary cancers, emerging mechanistic insights are informing treatments, such as potential microbiota manipulation strategies and guiding public health advice on dietary/lifestyle patterns for the prevention of these lethal tumors.

The gut microbiome and dietary fibres: implications in obesity, cardiometabolic diseases and cancer

Dietary fibres constitute a heterogeneous class of nutrients that are key in the prevention of various chronic diseases. Most dietary fibres are fermented by the gut microbiome and may, thereby, modulate the gut microbial ecology and metabolism, impacting human health. Dietary fibres may influence the occurrence of specific bacterial taxa, with this effect varying between individuals. The effect of dietary fibres on microbial diversity is a matter of debate. Most intervention studies with dietary fibres in the context of obesity and related metabolic disorders reveal the need for an accurate assessment of the microbiome to better understand the variable response to dietary fibres. Epidemiological studies confirm that a high dietary fibre intake is strongly associated with a reduced occurrence of many types of cancer. However, there is a need to determine the impact of intervention with specific dietary fibres on cancer risk, therapy efficacy and toxicity, as well as in cancer cachexia. In this Review, we summarize the mechanisms by which the gut microbiome can mediate the physiological benefits of dietary fibres in the contexts of obesity, cardiometabolic diseases and cancer, their incidence being clearly linked to low dietary fibre intake.

Gut microbiome alterations at acute myeloid leukemia diagnosis are associated with muscle weakness and anorexia

The gut microbiota makes critical contributions to host homeostasis, and its role in the treatment of acute myeloid leukemia (AML) has attracted attention. We investigated whether the gut microbiome is affected by AML, and whether such changes are associated with hallmarks of cachexia. Biological samples and clinical data were collected from 30 antibiotic- free AML patients at diagnosis and matched volunteers (1:1) in a multicenter, cross-sectional, prospective study. The composition and functional potential of the fecal microbiota were analyzed using shotgun metagenomics. Fecal, blood, and urinary metabolomics analyses were performed. AML patients displayed muscle weakness, anorexia, signs of altered gut function, and glycemic disorders. The composition of the fecal microbiota differed between patients with AML and control subjects, with an increase in oral bacteria. Alterations in bacterial functions and fecal metabolome support an altered redox status in the gut microbiota, which may contribute to the altered redox status observed in patients with AML. Eubacterium eligens, reduced 3-fold in AML patients, was strongly correlated with muscle strength and citrulline, a marker of enterocyte mass and function. Blautia and Parabacteroides, increased in patients with AML, were correlated with anorexia. Several bacterial taxa and metabolites (e.g., Blautia, Prevotella, phenylacetate, and hippurate) previously associated with glycemic disorders were altered. Our work revealed important perturbations in the gut microbiome of AML patients at diagnosis, which are associated with muscle strength, altered redox status, and anorexia. These findings pave the way for future mechanistic work to explore the function and therapeutic potential of the bacteria identified in this study.

Review of current and new drugs for the treatment of metabolic-associated fatty liver disease

In the past 3 decades, metabolic-associated fatty liver disease (MAFLD) has emerged as a widespread liver condition, with its global prevalence on the rise. It ranks as a leading contributor to hepatocellular carcinoma (HCC) and necessitates liver transplantation. Under the multiple parallel hits model, the pathogenesis of MAFLD stems from various liver stressors, notably nutrient overload and sedentary lifestyles. While medical management for MAFLD is well-established, encompassing non-pharmaceutical and pharmaceutical interventions, determining the most effective pharmaceutical therapy has remained elusive. This review discusses diabetic medications for MAFLD treatment, emphasizing recent studies and emerging drugs while reviewing other nondiabetic agents. Emerging evidence suggests that combination therapies hold promise for resolving MAFLD and metabolic steatohepatitis (MASH) while managing side effects. Ongoing trials play a pivotal role in elucidating the effects of mono, dual, and triple receptor agonists in individuals with MASH. With the rising burden of MAFLD/MASH and its severe consequences, the need for effective treatments is more pressing than ever. This review provides a comprehensive overview of the current landscape of pharmaceutical interventions for MAFLD and MASH, shedding light on the potential of newer drugs especially diabetic medications and the importance of ongoing research in this field.

Altered gut microbial profile accompanied by abnormal short chain fatty acid metabolism exacerbates nonalcoholic fatty liver disease progression

Dysregulation of the gut microbiome has associated with the occurrence and progression of non-alcoholic fatty liver disease (NAFLD). To determine the diagnostic capacity of this association, we compared fecal microbiomes across 104 participants including non-NAFLD controls and NAFLD subtypes patients that were distinguished by magnetic resonance imaging. We measured their blood biochemical parameters, 16 S rRNA-based gut microbiota and fecal short-chain fatty acids (SCFAs). Multi-omic analyses revealed that NAFLD patients exhibited specific changes in gut microbiota and fecal SCFAs as compared to non-NAFLD subjects. Four bacterial genera (Faecalibacterium, Subdoligranulum, Haemophilus, and Roseburia) and two fecal SCFAs profiles (acetic acid, and butyric acid) were closely related to NAFLD phenotypes and could accurately distinguish NAFLD patients from healthy non-NAFLD subjects. Twelve genera belonging to Faecalibacterium, Subdoligranulum, Haemophilus, Intestinibacter, Agathobacter, Lachnospiraceae_UCG-004, Roseburia, Butyricicoccus, Actinomycetales_unclassified, [Eubacterium]_ventriosum_group, Rothia, and Rhodococcus were effective to distinguish NAFLD subtypes. Of them, combination of five genera can distinguish effectively mild NAFLD from non-NAFLD with an area under curve (AUC) of 0.84. Seven genera distinguish moderate NAFLD with an AUC of 0.83. Eight genera distinguish severe NAFLD with an AUC of 0.90. In our study, butyric acid distinguished mild-NAFLD from non-NAFLD with AUC value of 0.83. And acetic acid distinguished moderate-NAFLD and severe-NAFLD from non-NAFLD with AUC value of 0.84 and 0.70. In summary, our study and further analysis showed that gut microbiota and fecal SCFAs maybe a method with convenient detection advantages and invasive manner that are not only a good prediction model for early warning of NAFLD occurrence, but also have a strong ability to distinguish NAFLD subtypes.

Probiotics and Non-Alcoholic Fatty Liver Disease: Unveiling the Mechanisms of Lactobacillus plantarum and Bifidobacterium bifidum in Modulating Lipid Metabolism, Inflammation, and Intestinal Barrier Integrity

In recent years, the prevalence of non-alcoholic fatty liver disease (NAFLD) has risen annually, yet due to the intricacies of its pathogenesis and therapeutic challenges, there remains no definitive medication for this condition. This review explores the intricate relationship between the intestinal microbiome and the pathogenesis of NAFLD, emphasizing the substantial roles played by Lactobacillus plantarum and Bifidobacterium bifidum. These probiotics manipulate lipid synthesis genes and phosphorylated proteins through pathways such as the AMPK/Nrf2, LPS-TLR4-NF-κB, AMPKα/PGC-1α, SREBP-1/FAS, and SREBP-1/ACC signaling pathways to reduce hepatic lipid accumulation and oxidative stress, key components of NAFLD progression. By modifying the intestinal microbial composition and abundance, they combat the overgrowth of harmful bacteria, alleviating the inflammatory response precipitated by dysbiosis and bolstering the intestinal mucosal barrier. Furthermore, they participate in cellular immune regulation, including CD4+ T cells and Treg cells, to suppress systemic inflammation. L. plantarum and B. bifidum also modulate lipid metabolism and immune reactions by adjusting gut metabolites, including propionic and butyric acids, which inhibit liver inflammation and fat deposition. The capacity of probiotics to modulate lipid metabolism, immune responses, and gut microbiota presents an innovative therapeutic strategy. With a global increase in NAFLD prevalence, these insights propose a promising natural method to decelerate disease progression, avert liver damage, and tackle associated metabolic issues, significantly advancing microbiome-focused treatments for NAFLD.

Gut Microbiota-Metabolite-Brain Axis Reconstitution Reverses Sevoflurane-Induced Social and Synaptic Deficits in Neonatal Mice

Background: The mechanisms underlying social dysfunction caused by repeated sevoflurane in early life remain unclear. Whether the gut microbiota-metabolite-brain axis is involved in the mechanism of sevoflurane developmental neurotoxicity still lacks report. Methods: Mice received 3% sevoflurane at postnatal day (PND) 6, 7, and 8 for 2 h per day. Metagenomic sequencing and untargeted metabolomic analysis were applied to investigate the effects of sevoflurane on gut microbiota and metabolism. The animal social behavior and the synaptic development were analyzed during PND 35. Subsequently, fecal microbiota transplantation (FMT) from the control group and bile acid administration were performed to see the expected rescuing effect on socially related behaviors that were impaired by repeated sevoflurane exposure in the mice. Results: In the 3-chamber test, sevoflurane-exposed mice spent less time with stranger mice compared with the control group. The density of both the apical and basal spine decreased in mice exposed to sevoflurane. In addition, repeated sevoflurane exposure led to a notable alteration in the gut microbiota and metabolite synthesis, particularly bile acid. FMT reduced the production of intestinal bile acid and attenuated the effect of sevoflurane exposure on social function and synaptic development. Cholestyramine treatment mimics the protective effects of FMT. Conclusions: The gut microbiota-metabolite-brain axis underlies social dysfunction caused by sevoflurane exposure in early age, and bile acid regulation may be a promising intervention to this impairment.

Investigating the efficacy of acupuncture in treating patients with metabolic-associated fatty liver disease: a protocol for a randomised controlled clinical trial

INTRODUCTION

Acupuncture is widely used for metabolic-associated fatty liver disease (MAFLD) treatment; however, the clinical efficacy has not been confirmed due to the lack of high-level evidence-based clinical practice. The purpose of this study is to design a research protocol that will be used to determine the efficacy of acupuncture versus sham acupuncture (SHA) for MAFLD treatment.

METHODS AND ANALYSIS

This will be a multicentre, randomised and sham-controlled trial. Ninety-eight participants with MAFLD will be enrolled in this trial. Participants will be randomly assigned in a 1:1 ratio to receive acupuncture or SHA for 12 weeks. The primary outcome is the rate of patients with a 30% relative decline in liver fat after 12 weeks of treatment in MRI-proton density fat fraction (MRI-PDFF), which will be obtained by quantitative chemical shift imaging such as the multipoint Dixon method at 0, 12 and 24 weeks. Secondary outcomes include the changes in the relative liver fat content measured by MRI-PDFF, magnetic resonance elastography, liver function, lipid metabolism, homeostatic model assessment for insulin resistance (HOMA-IR) and serum high sensitivity C reactive protein, which will be obtained at 0, 6, 12 and 24 weeks. Body measurement indicators (body mass index, waist circumference, hip circumference and waist-to-hip ratio) will be obtained at 0, 3, 6, 9, 12 and 24 weeks. The alteration in the gut microbiota composition and its metabolism will be assessed by 16S ribosomal RNA sequencing and liquid chromatography-mass spectrometry at 0 and 12 weeks.

ETHICS AND DISSEMINATION

This study protocol has been approved by the ethics committee of Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine (2023-1347-114-01). The results of this study will be published in a peer-reviewed journal and presented at academic conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2300075701.

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.

Systems Biology of Human Microbiome for the Prediction of Personal Glycaemic Response

The human gut microbiota is increasingly recognized as a pivotal factor in diabetes management, playing a significant role in the body's response to treatment. However, it is important to understand that long-term usage of medicines like metformin and other diabetic treatments can result in problems, gastrointestinal discomfort, and dysbiosis of the gut flora. Advanced sequencing technologies have improved our understanding of the gut microbiome's role in diabetes, uncovering complex interactions between microbial composition and metabolic health. We explore how the gut microbiota affects glucose metabolism and insulin sensitivity by examining a variety of -omics data, including genomics, transcriptomics, epigenomics, proteomics, metabolomics, and metagenomics. Machine learning algorithms and genome-scale modeling are now being applied to find microbiological biomarkers associated with diabetes risk, predicted disease progression, and guide customized therapy. This study holds promise for specialized diabetic therapy. Despite significant advances, some concerns remain unanswered, including understanding the complex relationship between diabetes etiology and gut microbiota, as well as developing user-friendly technological innovations. This mini-review explores the relationship between multiomics, precision medicine, and machine learning to improve our understanding of the gut microbiome's function in diabetes. In the era of precision medicine, the ultimate goal is to improve patient outcomes through personalized treatments.

Beneficial Effects of the Ketogenic Diet on Nonalcoholic Fatty Liver Disease (NAFLD/MAFLD)

The prevalence of nonalcoholic fatty liver disease (NAFLD) is likely to be approaching 38% of the world's population. It is predicted to become worse and is the main cause of morbidity and mortality due to hepatic pathologies. It is particularly worrying that NAFLD is increasingly diagnosed in children and is closely related, among other conditions, to insulin resistance and metabolic syndrome. Against this background is the concern that the awareness of patients with NAFLD is low; in one study, almost 96% of adult patients with NAFLD in the USA were not aware of their disease. Thus, studies on the therapeutic tools used to treat NAFLD are extremely important. One promising treatment is a well-formulated ketogenic diet (KD). The aim of this paper is to present a review of the available publications and the current state of knowledge of the effect of the KD on NAFLD. This paper includes characteristics of the key factors (from the point of view of NAFLD regression), on which ketogenic diet exerts its effects, i.e., reduction in insulin resistance and body weight, elimination of fructose and monosaccharides, limitation of the total carbohydrate intake, anti-inflammatory ketosis state, or modulation of gut microbiome and metabolome. In the context of the evidence for the effectiveness of the KD in the regression of NAFLD, this paper also suggests the important role of taking responsibility for one's own health through increasing self-monitoring and self-education.

A microbial metabolite inhibits the HIF-2α-ceramide pathway to mediate the beneficial effects of time-restricted feeding on MASH

Time-restricted feeding (TRF) is a potent dietary intervention for improving metabolic diseases, including metabolic dysfunction-associated steatotic liver disease/metabolic dysfunction-associated steatohepatitis (MASLD/MASH). However, the mechanism of this efficacy has remained elusive. Here, we show that TRF improves MASLD, which is associated with a significant enrichment of Ruminococcus torques (R. torques). Mechanistically, R. torques suppresses the intestinal HIF-2α-ceramide pathway via the production of 2-hydroxy-4-methylpentanoic acid (HMP). We identify rtMor as a 4-methyl-2-oxopentanoate reductase that synthesizes HMP in R. torques. Finally, we show that either the colonization of R. torques or oral HMP supplementation can ameliorate inflammation and fibrosis in a MASH mouse model. These findings identify R. torques and HMP as potential TRF mimetics for the treatment of metabolic disorders.

Exploring non-invasive diagnostics for metabolic dysfunction-associated fatty liver disease

The population with metabolic dysfunction-associated fatty liver disease (MAFLD) is increasingly common worldwide. Identification of people at risk of progression to advanced stages is necessary to timely offer interventions and appropriate care. Liver biopsy is currently considered the gold standard for the diagnosis and staging of MAFLD, but it has associated risks and limitations. This has spurred the exploration of non-invasive diagnostics for MAFLD, especially for steatohepatitis and fibrosis. These non-invasive approaches mostly include biomarkers and algorithms derived from anthropometric measurements, serum tests, imaging or stool metagenome profiling. However, they still need rigorous and widespread clinical validation for the diagnostic performance.

Christensenella minuta Alleviates Acetaminophen-Induced Hepatotoxicity by Regulating Phenylalanine Metabolism

Acetaminophen (APAP)-induced liver injury (AILI), even liver failure, is a significant challenge due to the limited availability of therapeutic medicine. Christensenella minuta (C. minuta), as a probiotic therapy, has shown promising prospects in metabolism and inflammatory diseases. Our research aimed to examine the influence of C. minuta on AILI and explore the molecular pathways underlying it. We found that administration of C. minuta remarkably alleviated AILI in a mouse model, as evidenced by decreased levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) and improvements in the histopathological features of liver sections. Additionally, there was a notable decrease in malondialdehyde (MDA), accompanied by restoration of the reduced glutathione/oxidized glutathione (GSH/GSSG) balance, and superoxide dismutase (SOD) activity. Furthermore, there was a significant reduction in inflammatory markers (IL6, IL1β, TNF-α). C. minuta regulated phenylalanine metabolism. No significant difference in intestinal permeability was observed in either the model group or the treatment group. High levels of phenylalanine aggravated liver damage, which may be linked to phenylalanine-induced dysbiosis and dysregulation in cytochrome P450 metabolism, sphingolipid metabolism, the PI3K-AKT pathway, and the Integrin pathway. Furthermore, C. minuta restored the diversity of the microbiota, modulated metabolic pathways and MAPK pathway. Overall, this research demonstrates that supplementing with C. minuta offers both preventive and remedial benefits against AILI by modulating the gut microbiota, phenylalanine metabolism, oxidative stress, and the MAPK pathway, with high phenylalanine supplementation being identified as a risk factor exacerbating liver injury.

Acupuncture influences multiple diseases by regulating gut microbiota

Acupuncture, an important green and side effect-free therapy in traditional Chinese medicine, is widely use both domestically and internationally. Acupuncture can interact with the gut microbiota and influence various diseases, including metabolic diseases, gastrointestinal diseases, mental disorders, nervous system diseases, and other diseases. This review presents a thorough analysis of these interactions and their impacts and examines the alterations in the gut microbiota and the potential clinical outcomes following acupuncture intervention to establish a basis for the future utilization of acupuncture in clinical treatments.

Mendelian randomization reveals association of gut microbiota with Henoch-Schönlein purpura and immune thrombocytopenia

Gut microbiota have been linked to immune thrombocytopenia (ITP) and Henoch-Schönlein purpura (HSP) in recent studies, but a cause-and-effect relationship is unclear. We used Mendelian randomization (MR) to assess causal relationships between gut microbiota and HSP/ITP using summary statistics from the GWAS dataset of the international MiBioGen and FinnGen consortium. The IVW method was used as the main evaluation indicator. MR analysis of 196 intestinal flora and HSP/ITP/sTP phenotypes showed that 12 flora were potentially causally associated with ITP, 6 with HSP, and 9 with sTP. The genes predicted that genus Coprococcus3 (p = 0.0264, OR = 2.05, 95% CI 1.09-3.88)and genus Gordonibacter (p = 0.0073, OR = 1.38; 95% CI 1.09-1.75) were linked to a higher likelihood of developing ITP. Additionally, family Actinomycetaceae (p = 0.02, OR = 0.51, 95% CI 0.28-0.90) and order Actinomycetales (p = 0.0199, OR = 0.50, 95% CI 0.28-0.90) linked to reduced HSP risk. Genus Ruminococcaceae UCG013 (p = 0.0426, OR = 0.44, 95% CI 0.20-0.97) negatively correlated with sTP risk. Our MR analyses offer evidence of a possible cause-and-effect connection between certain gut microbiota species and the likelihood of HSP/ITP.

Human Gut Microbiota in Cardiovascular Disease

The gut ecosystem, termed microbiota, is composed of bacteria, archaea, viruses, protozoa, and fungi and is estimated to outnumber human cells. Microbiota can affect the host by multiple mechanisms, including the synthesis of metabolites and toxins, modulating inflammation and interaction with other organisms. Advances in understanding commensal organisms' effect on human conditions have also elucidated the importance of this community for cardiovascular disease (CVD). This effect is driven by both direct CV effects and conditions known to increase CV risk, such as obesity, diabetes mellitus (DM), hypertension, and renal and liver diseases. Cardioactive metabolites, such as trimethylamine N -oxide (TMAO), short-chain fatty acids (SCFA), lipopolysaccharides, bile acids, and uremic toxins, can affect atherosclerosis, platelet activation, and inflammation, resulting in increased CV incidence. Interestingly, this interaction is bidirectional with microbiota affected by multiple host conditions including diet, bile acid secretion, and multiple diseases affecting the gut barrier. This interdependence makes manipulating microbiota an attractive option to reduce CV risk. Indeed, evolving data suggest that the benefits observed from low red meat and Mediterranean diet consumption can be explained, at least partially, by the changes that these diets may have on the gut microbiota. In this article, we depict the current epidemiological and mechanistic understanding of the role of microbiota and CVD. Finally, we discuss the potential therapeutic approaches aimed at manipulating gut microbiota to improve CV outcomes. © 2024 American Physiological Society. Compr Physiol 14:5449-5490, 2024.

Lactobacillus acidophilus CICC 6075 attenuates high-fat diet-induced obesity by improving gut microbiota composition and histidine biosynthesis

This study aimed to investigate the potential anti-obesity efficacy of Lactobacillus acidophilus CICC 6075. The study analyzed fecal metagenomic data from 120 obese and 100 non-obese individuals. C57BL/6 mice on normal diet or high-fat diet (HFD) were treated with L. acidophilus CICC 6075 by daily oral gavage for 12 weeks, followed by evaluations of the obesity phenotype. Metagenomic analysis revealed depletion of L. acidophilus in obese individuals. Administration of L. acidophilus CICC 6075 attenuated excessive weight gain and fat accumulation and maintained the intestinal barrier in HFD-induced obese mice. Sequencing results showed that HFD hindered α- and β-diversity while reducing the relative abundance of Lactobacillus and norank_f_Muribaculaceae and significantly increasing the relative abundance of Ileibacterium. L. acidophilus CICC 6075 reversed these results and reduced the Firmicutes/Bacteroidetes ratio. Supplementation of L. acidophilus CICC 6075 enhanced histidine biosynthesis, inhibited the NF-κB pathway, and significantly reduced the expression levels of inflammatory factors in adipose tissue. These results indicate that L. acidophilus CICC 6075 alleviates HFD-induced obesity in mice by inhibiting the activation of the NF-κB pathway and enhancing gut microbiota functionality. This suggests that L. acidophilus CICC 6075 may be a good candidate probiotic for preventing obesity.

Gut Microbiota and Sinusoidal Vasoregulation in MASLD: A Portal Perspective

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common condition with heterogeneous outcomes difficult to predict at the individual level. Feared complications of advanced MASLD are linked to clinically significant portal hypertension and are initiated by functional and mechanical changes in the unique sinusoidal capillary network of the liver. Early sinusoidal vasoregulatory changes in MASLD lead to increased intrahepatic vascular resistance and represent the beginning of portal hypertension. In addition, the composition and function of gut microbiota in MASLD are distinctly different from the healthy state, and multiple lines of evidence demonstrate the association of dysbiosis with these vasoregulatory changes. The gut microbiota is involved in the biotransformation of nutrients, production of de novo metabolites, release of microbial structural components, and impairment of the intestinal barrier with impact on innate immune responses, metabolism, inflammation, fibrosis, and vasoregulation in the liver and beyond. The gut-liver axis is a conceptual framework in which portal circulation is the primary connection between gut microbiota and the liver. Accordingly, biochemical and hemodynamic attributes of portal circulation may hold the key to better understanding and predicting disease progression in MASLD. However, many specific details remain hidden due to limited access to the portal circulation, indicating a major unmet need for the development of innovative diagnostic tools to analyze portal metabolites and explore their effect on health and disease. We also need to safely and reliably monitor portal hemodynamics with the goal of providing preventive and curative interventions in all stages of MASLD. Here, we review recent advances that link portal metabolomics to altered sinusoidal vasoregulation and may allow for new insights into the development of portal hypertension in MASLD.

Stiffness sensing via Piezo1 enhances macrophage efferocytosis and promotes the resolution of liver fibrosis

Tissue stiffening is a predominant feature of fibrotic disorders, but the response of macrophages to changes in tissue stiffness and cellular context in fibrotic diseases remains unclear. Here, we found that the mechanosensitive ion channel Piezo1 was up-regulated in hepatic fibrosis. Macrophages lacking Piezo1 showed sustained inflammation and impaired spontaneous resolution of early liver fibrosis. Further analysis revealed an impairment of clearance of apoptotic cells by macrophages in the fibrotic liver. Macrophages showed enhanced efferocytosis when cultured on rigid substrates but not soft ones, suggesting stiffness-dependent efferocytosis of macrophages required Piezo1 activation. Besides, Piezo1 was involved in the efficient acidification of the engulfed cargo in the phagolysosomes and affected the subsequent expression of anti-inflammation genes after efferocytosis. Pharmacological activation of Piezo1 increased the efferocytosis capacity of macrophages and accelerated the resolution of inflammation and fibrosis. Our study supports the antifibrotic role of Piezo1-mediated mechanical sensation in liver fibrosis, suggesting that targeting PIEZO1 to enhance macrophage efferocytosis could induce fibrosis regression.

Berberine promotes the degradation of phenylacetic acid to prevent thrombosis by modulating gut microbiota

BACKGROUND

Berberine is the main bioactive constituent of Coptis chinensis, a quaternary ammonium alkaloid. While berberine's cardiovascular benefits are well-documented, its impact on thrombosis remains not fully understood.

PURPOSE

This study investigates the potential of intestinal microbiota as a novel target for preventing thrombosis, with a focus on berberine, a natural compound known for its effectiveness in managing cardiovascular conditions.

METHODS

Intraperitoneal injection of carrageenan induces the secretion of chemical mediators such as histamine and serotonin from mast cells to promote thrombosis. This model can directly and visually observe the progression of thrombosis in a time-dependent manner. Thrombosis was induced by intravenous injection of 1 % carrageenan solution (20 mg/kg) to all mice except the vehicle control group. Quantitative analysis of gut microbiota metabolites through LC/MS. Then, the gut microbiota of mice was analyzed using 16S rRNA sequencing to assess the changes. Finally, the effects of gut microbiota on thrombosis were explored by fecal microbiota transplantation.

RESULTS

Our research shows that berberine inhibits thrombosis by altering intestinal microbiota composition and related metabolites. Notably, berberine curtails the biosynthesis of phenylacetylglycine, a thrombosis-promoting coproduct of the host-intestinal microbiota, by promoting phenylacetic acid degradation. This research underscores the significance of phenylacetylglycine as a thrombosis-promoting risk factor, as evidenced by the ability of intraperitoneal phenylacetylglycine injection to reverse berberine's efficacy. Fecal microbiota transplantation experiment confirms the crucial role of intestinal microbiota in thrombus formation.

CONCLUSION

Initiating our investigation from the perspective of the gut microbiota, we have, for the first time, unveiled that berberine inhibits thrombus formation by promoting the degradation of phenylacetic acid, consequently suppressing the biosynthesis of PAG. This discovery further substantiates the intricate interplay between the gut microbiota and thrombosis. Our study advances the understanding that intestinal microbiota plays a crucial role in thrombosis development and highlights berberine-mediated intestinal microbiota modulation as a promising therapeutic approach for thrombosis prevention.

Influence of gut microbiome on metabolic diseases: a new perspective based on microgravity

Purpose

Microgravity, characterized by gravity levels of 10-3-10-6g, has been found to significantly impair various physiological systems in astronauts, including cardiovascular function, bone density, and metabolism. With the recent surge in human spaceflight, understanding the impact of microgravity on biological health has become paramount.

Methods

A comprehensive literature search was performed using the PubMed database to identify relevant publications pertaining to the interplay between gut microbiome, microgravity, space environment, and metabolic diseases.

Results

This comprehensive review primarily focuses on the progress made in investigating the gut microbiome and its association with metabolic diseases under microgravity conditions. Microgravity induces notable alterations in the composition, diversity, and functionality of the gut microbiome. These changes hold direct implications for metabolic disorders such as cardiovascular disease (CVD), bone metabolism disorders, energy metabolism dysregulation, liver dysfunction, and complications during pregnancy.

Conclusion

This novel perspective is crucial for preparing for deep space exploration and interstellar migration, where understanding the complex interplay between the gut microbiome and metabolic health becomes indispensable.

Gut-liver axis: Potential mechanisms of action of food-derived extracellular vesicles

Food-derived extracellular vesicles (FEVs) are nanoscale membrane vesicles obtained from dietary materials such as breast milk, plants and probiotics. Distinct from other EVs, FEVs can survive the harsh degrading conditions in the gastrointestinal tract and reach the intestines. This unique feature allows FEVs to be promising prebiotics in health and oral nanomedicine for gut disorders, such as inflammatory bowel disease. Interestingly, therapeutic effects of FEVs have recently also been observed in non-gastrointestinal diseases. However, the mechanisms remain unclear or even mysterious. It is speculated that orally administered FEVs could enter the bloodstream, reach remote organs, and thus exert therapeutic effects therein. However, emerging evidence suggests that the amount of FEVs reaching organs beyond the gastrointestinal tract is marginal and may be insufficient to account for the significant therapeutic effects achieved regarding diseases involving remote organs such as the liver. Thus, we herein propose that FEVs primarily act locally in the intestine by modulating intestinal microenvironments such as barrier integrity and microbiota, thereby eliciting therapeutic impact remotely on the liver in non-gastrointestinal diseases via the gut-liver axis. Likewise, drugs delivered to the gastrointestinal system through FEVs may act via the gut-liver axis. As the liver is the main metabolic hub, the intestinal microenvironment may be implicated in other metabolic diseases. In fact, many patients with non-alcoholic fatty liver disease, obesity, diabetes and cardiovascular disease suffer from a leaky gut and dysbiosis. In this review, we provide an overview of the recent progress in FEVs and discuss their biomedical applications as therapeutic agents and drug delivery systems, highlighting the pivotal role of the gut-liver axis in the mechanisms of action of FEVs for the treatment of gut disorders and metabolic diseases.

Apelin and the gut microbiome: Potential interaction in human MASLD

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of chronic liver disease with increasing numbers worldwide. Adipokines like apelin (APLN) can act as key players in the complex pathophysiology of MASLD.

AIMS

Investigating the role of APLN in MASLD.

METHODS

Fecal and blood samples were collected in a MASLD cohort and healthy controls (HC). MASLD patients with liver fibrosis and MASLD-associated hepatocellular carcinoma (HCC) were included into the study. Systemic concentration of Apelin, Apelin receptor (APLNR) and circulating cytokines were measured in serum samples.

RESULTS

Apelin concentration correlated with the Fib-4 score and was elevated in MASLD patients (mild fibrosis, mF (Fib-4 <3.25) and severe fibrosis, sF (Fib-4 >3.25)) as well as in MASLD-associated HCC patients compared to HC. In accordance APLNR and circulating cytokines were also elevated in mF and sF. In contrast apelin levels were negatively associated with liver survival at three and five years. Changes in taxa composition at phylum level showed an increase of Enterobactericae, Prevotellaceae and Lactobacillaceae in patients with sF compared to mF. We could also observe an association between apelin concentrations and bacterial lineages (phyla).

CONCLUSIONS

Circulating apelin is associated with liver fibrosis and HCC. In addition, there might exist an interaction between systemic apelin and the gut microbiome.