Livers

After the first release of synthalin B (dodecamethylenbiguanide) in 1928 and its later retraction in the 1940s in Germany, the retraction of phenformin (N-Phenethylbiguanide) and of Buformin in the USA (but not outside) because of the lethal complication of acidosis seemed to have put an end to the era of the biguanides as oral antidiabetics. The strongly hygroscopic metformin (1-1-dimethylbiguanide), first synthesized 1922 and resuscitated as an oral antidiabetic (type 2 of the elderly) compound first released in 1959 in France and in other European countries, was used in the first large multicenter prospective long-term trial in England in the UKPDS (1977–1997). It was then released in the USA after a short-term prospective trial in healthy overweight “young” type 2 diabetics (mean age 53 years) in 1995 for oral treatment of type 2 diabetes. It was, however, prescribed to mostly multimorbid older patients (above 60–65 years of age). Metformin is now the most used oral drug for type 2 diabetes worldwide. While intravenous administration of biguanides does not have any glucose-lowering effect, their oral administration leads to enormous increase in their intestinal concentration (up to 300-fold compared to that measured in the blood), to reduced absorption of glucose from the diet, to increased excretion of glucose through the stool, and to decrease in insulin serum level through increased hepatic uptake and decreased production. Intravenously injected F18-labeled glucose in metformin-treated type 2 diabetics accumulates in the small and even more in the large intestine. The densitometry picture observed in metformin-treated overweight diabetics is like that observed in patients after bowel-cleansing or chronically taking different types of laxatives, where the accumulated radioactivity can even reach values observed in colon cancer. The glucose-lowering mechanism of action of metformin is therefore not only due to inhibition of glucose uptake in the small intestine but also to “attraction” of glucose from the hepatocyte into the intestine, possibly through the insulin-mediated uptake in the hepatocyte and its secretion into the bile. Furthermore, these compounds have also a diuretic effect (loss of sodium and water in the urine) Acute gastrointestinal side effects accompanied by fluid loss often lead to the drugs’ dose reduction and strongly limit adherence to therapy. Main long-term consequences are “chronic” dehydration, deficiency of vitamin B12 and of iron, and, as observed for all the biguanides, to “chronic” increase in fasting and postprandial lactate plasma level as a laboratory marker of a clinical condition characterized by hypotension, oliguria, adynamia, and evident lactic acidosis. Metformin is not different from the other biguanides: synthalin B, buformin, and phenformin. The mechanism of action of the biguanides as antihyperglycemic substances and their side effects are comparable if not even stronger (abdominal pain, nausea, vomiting, diarrhea, fluid loss) to those of laxatives. Full article

Metabolic dysfunction-associated steatohepatitis (MASH) and atherosclerosis are cardiometabolic twin disorders with shared underlying pathophysiological mechanisms such as insulin resistance and chronic inflammation. This review explores the salient role of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in linking hepatic dysfunction to cardiovascular disease. Findings in mice with genetic modulation of Ceacam1 gene established a critical role for CEACAM1 protein in regulating insulin and lipid metabolism and endothelial integrity and modulating immune response. Loss of CEACAM1 in hepatocytes impairs insulin clearance, causing chronic hyperinsulinemia, a process that ultimately leads to insulin resistance and hepatic and extra-hepatic fat accumulation, which in turn causes inflammatory infiltration. This prompts a paradigm shift that positions impaired hepatic CEACAM1 function as a mechanistic underpinning of the link between insulin resistance, MASH, and atherosclerosis. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the leading cause of chronic liver disease worldwide, affecting approximately 25–30% of the global adult population and highlighting the urgent need for effective therapeutics and prevention strategies. MASLD is characterized by excessive hepatic lipid accumulation and can progress, in a subset of patients, to metabolic dysfunction-associated steatohepatitis (MASH), a pro-inflammatory and pro-fibrotic condition associated with increased risk of liver cirrhosis and hepatocellular carcinoma. Although the molecular drivers of MASLD progression remain incompletely understood, several key metabolic pathways—such as triglyceride handling, cholesterol catabolism, bile acid metabolism, mitochondrial function, and autophagy—are consistently dysregulated in MASLD livers. This narrative review summarizes primary literature and highlights insights from recent reviews on the multifaceted role of the mRNA-binding protein Human antigen R (HuR) in the post-transcriptional regulation of critical cellular processes, including nutrient metabolism, cell survival, and stress responses. Emerging evidence underscores HuR’s essential role in maintaining liver homeostasis, particularly under metabolic stress conditions characteristic of MASLD, with hepatocyte-specific HuR depletion associated with exacerbated disease severity. Moreover, comorbid conditions such as obesity, type 2 diabetes mellitus, and cardiovascular disease not only exacerbate MASLD progression but also involve HuR dysregulation in extrahepatic tissues, further contributing to liver dysfunction. A deeper understanding of HuR-regulated post-transcriptional networks across metabolic organs may enable the development of targeted therapies aimed at halting or reversing MASLD progression. Full article

Background: Breast cancer is a widespread disease and, when metastatic, has a bleak prognosis. The surgical approach for BCLM has had a limited role, but robotic surgery could find an important place. Methods: Data were collected from a multicenter retrospective database that includes 1070 consecutive robotic liver resections performed in nine European hospital centers from 2011 to 2023. Of the entire series, 35 were performed for BCLM in five European hospital centers. Results: The post-operative complication rate was 11.44%, but no severe complications occurred. The mean hospital stay was 4.65 days. One patient (2.85%) was readmitted to the hospital within 90 days after discharge and died due to heart failure, with a 90-day mortality of 2.85%. Conclusions: Robotic liver resection for BCLM is feasible and safe when performed in experienced centers by surgeons who have completed the learning curve. Full article

Background: Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as the most prevalent chronic liver condition. Its prevalence is estimated to further increase. The gut–liver axis, which represents both anatomical and functional connections, contributes significantly to the development of MASLD. Dysbiosis, characterized by an imbalance in gut microbiota, can exacerbate the disease by increasing intestinal permeability, which permits harmful bacteria and their components to enter the bloodstream. This review sought to explore the impact of probiotics, prebiotics, and synbiotics on the treatment of MASLD. Method: The methodology for scoping reviews in accordance with Prisma-ScR guidelines was followed. A comprehensive search was conducted in databases such as PubMed, Scopus, and Medline. Out of 1390 studies screened, 25 were selected for the final analysis. Results: The findings of this scoping review highlight the therapeutic potential of probiotics, prebiotics, and synbiotics in the management and treatment of MASLD, as showcased by the existing literature. Conclusions: This scoping review offers important insights into the advantages of probiotics, prebiotics, and synbiotics in the treatment of MASLD. The limitations identified in this study emphasize the necessity for larger, long-term, and geographically diverse studies in order to obtain more solid scientific results. Full article

Background. To meet the WHO’s viral hepatitis elimination goal by 2030, the Minister of Health (Italy) introduced free HCV screening among people born between 1969 and 1989 and those at greater risk (people in the care of the addiction services and detained). Aims. To estimate the following: (i) the prevalence of HCV in hospitalized patients born before 1969 not included in the free HCV screening, (ii) the prevalence of transaminase values outside the range, and (iii) the HBV prevalence in a subgroup of patients. Methods. Anti-HCV antibodies and transaminase values were prospectively evaluated in patients born before 1969 and admitted to the Santa Maria alle Scotte Hospital in Siena. The first screening (October 2021–July 2022) was conducted in the Internal Medicine Division (cohort 0), and the second one (May 2024–October 2024) in Internal Medicine, Gastroenterology, and Geriatric Units (cohorts 1–3), including clinical features and HBV markers in a subgroup of patients. Results. Overall, 774 subjects underwent HCV screening. In the first screening period, 1.4% (8/567) of patients were anti-HCV+, of whom 0.7% were HCV RNA+ (4/567). In the second, 3.9% of patients (8/207) were anti-HCV+ and 0.9% were viremic (2/207). Overall, HCV prevalence was 0.8%. Of 96 patients in the gastroenterology cohort, 8 patients were at risk for occult HBV infection (8.3%). Conclusions. Our study demonstrates a chronic HCV infection prevalence of 0.8% in hospitalised patients born before 1969 and a prevalence of 8.3% of people at risk for occult HBV infection in a subgroup of patients residing in South-Eastern Tuscany, confirming that an opportunistic screening can identify the unrecognized people affected by viral hepatitis. Full article

Hepatosplenomegaly can occur in extrahepatic diseases such as Philadelphia-negative chronic myeloproliferative neoplasms (MPNs), which may involve the liver and vasculature. In myelofibrosis, extramedullary hematopoiesis can be present in the liver, even within hepatic sinusoids. Liver biopsies in MPN patients have shown platelet aggregates obstructing these sinusoids. Both liver and spleen stiffness are significantly higher in myelofibrosis, correlating with the severity of bone marrow fibrosis. Spleen stiffness is also elevated in myelofibrosis and polycythemia Vera compared to essential thrombocythemia. MPNs are a leading cause of splanchnic vein thrombosis in the absence of cirrhosis or local malignancy, especially in the presence of the JAK2V617F mutation. This mutation promotes thrombosis through endothelial dysfunction and inflammation. It is found in endothelial cells, where it enhances leukocyte adhesion and upregulates thrombogenic and inflammatory genes. Hepatic sinusoidal microthromboses in MPNs may contribute to portal hypertension and liver dysfunction. MPN therapies can also affect liver function. While hepatocytolysis has been reported, agents such as Hydroxycarbamide and Ruxolitinib exhibit antifibrotic hepatic effects in experimental models. Overall, MPNs are linked to chronic inflammation, increased thrombotic risk—particularly splanchnic thrombosis—and atherogenesis. Full article

Liver cirrhosis poses major challenges for both individual health and global healthcare systems. Recent studies have challenged the traditional and predictable linear course of cirrhosis, demonstrating marked heterogeneity in the patterns of the first decompensating events. This review presents an updated epidemiology of cirrhosis and its main causes, outlines an overview of the clinical features, and explores the evolving concepts of the spectrum of decompensation. It further delineates recent advancements in the diagnosis, prognostic scoring, and management of decompensated cirrhosis and the subsequent clinically challenging complications of portal hypertension. Emerging innovations in non-invasive imaging, diagnostic serum biomarkers, and etiology-specific therapies, together with the development of novel liver support systems, underscore a paradigm shift toward a multimodal approach for cirrhosis care. Furthermore, the integration of precision medicine into clinical practice holds promise for reshaping the future of liver cirrhosis management in the coming decades. Full article

Albumin is the most abundant protein synthesized exclusively by the hepatocytes in the liver. Once secreted into plasma, it helps in the maintenance of osmotic pressure, as well as the exertion of defensive roles such as anti-oxidative and anti-inflammatory functions. Dysregulation in the synthesis and clearance of albumin is observed in various hepatic and extra-hepatic diseases. Abnormal levels of albumin could be either a cause or an effect of various pathological ailments, including hepatic, cardiac, renal, neurological, etc. Owing to its long half-life and multiple binding sites in its heart-shaped structure, it interacts with various internal agents, such as hormones, or external substances like drugs, which is why transportation can be one of its many functions. Additionally, albumin’s drug interactions, as well as displacement of albumin–drug binding, could have serious clinical consequences, and careful considerations should be made in determining an appropriate drug regimen to achieve a desired therapeutic outcome with minimal side effects. Moreover, albumin also undergoes several post-translational modifications that can influence its physiological roles, including drug binding and antioxidant functions. Furthermore, it has a complicated role in physiology, where it can help in maintaining plasma oncotic pressure and prevent endothelial cell apoptosis but can have adverse effects on the lungs and kidneys. These adverse effects are mainly attributed to ER stress and inflammasome activation. This narrative review provides an overview of the general biology of albumin and its effects in physiology, with a focus on its beneficial and adverse effects and the underlying molecular mechanisms. Full article

Background: De novo malignancies (DNMs) after liver transplantation (LT) are a major cause of long-term mortality. However, no definitive screening protocol has been established due to their diversity. This study aimed to evaluate DNM diagnosis methods, screening protocols, and prognoses. Methods: This retrospective study included 231 adult LT recipients from April 1997 to March 2021. Disease-specific survival (DSS) was analyzed to assess the impact of screening on prognosis. Most recipients underwent serum tests every three months, annual gastrointestinal endoscopy, and chest-abdominal CT as part of routine surveillance. Results: Twenty-five DNMs were diagnosed in 22 patients, with median age of 61 years (range, 23–72), of whom 13 (59.1%) were female. The duration from transplantation to DNM diagnosis of DNM was 88 months (range, 4–195). DNM was diagnosed as follows: seven patients (31.8%) through screening (screening group) and 15 patients (68.2%) by other means (non-screening group). Curative treatment was achieved in all of the patients diagnosed by screening, whereas it was possible in only 60.0% of patients diagnosed by other means (p = 0.026). DSS in the screening group was significantly longer than that in the non-screening group (p = 0.024). Conclusions: While screening was associated with earlier-stage diagnosis and improved outcomes in some patients, the overall efficacy of the protocol requires further validation in larger studies. Full article

Background: Sarcopenia, defined as the progressive loss of skeletal muscle mass and strength, is a critical predictor of morbidity and mortality in patients with cirrhosis. In chronic liver disease, sarcopenia exacerbates adverse clinical outcomes and deteriorates quality of life. Physical activity, particularly resistance training, has demonstrated beneficial effects in reversing muscle depletion in various chronic conditions. Aim: This systematic review aimed to evaluate the impact of resistance training on sarcopenia among cirrhotic patients, with a focus on both pre-liver transplant and post-liver transplant populations, to improve clinical outcomes and enhance quality of life. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed/MEDLINE databases were searched for randomized controlled trials (RCTs) using a standardized search command combining MESH terms and Boolean operators. Studies meeting eligibility criteria and reporting improvements in sarcopenia following resistance training were selected for data extraction. Results: Out of 109 references identified, 12 RCTs were included—10 in pre-transplant and 2 in post-transplant populations. Across studies, resistance training led to measurable improvements in key outcomes: peak VO₂ increased by up to 5.3 mL/kg/min, 6 min walk distance improved by 18–97 m, quadriceps muscle thickness increased by up to 1.05 cm, and grip strength gains ranged from 0.4 to 3.8 kg. Postoperative studies reported reductions in fatigue severity scores and length of hospital stay, along with improvements in respiratory pressures and peripheral muscle strength. Conclusions: Resistance training is effective in ameliorating sarcopenia in cirrhotic patients, thereby enhancing pre-transplant status and postoperative quality of life. Clinically, structured exercise programs should be routinely implemented. Full article

Bisphenol analogs and their derivatives have been identified in human tissue and our living environment. There are major concerns over exposure to bisphenol analogs, especially the low-dose- and mixture-related toxicities, as they are considered potential endocrine-disrupting chemicals that may cause adverse effects in multiple organ systems. The liver is a critical organ responsible for an array of functions, e.g., metabolism, immunity, digestion, detoxification and vitamin storage, in addition to being a leading chemical target site. In this literature review of multiple species, we discussed the metabolism of bisphenol analogs in the liver, which was followed by discussions of bisphenol analog-induced liver toxicity in various species, including humans, rodents (mice and rats) and other species (chicken, pig, sheep, etc.). Further, the mechanisms of action and markers of liver damage such as oxidative stress, apoptosis, inflammation and fibrosis were discussed. It was concluded that bisphenol analogs can produce toxic effects on the liver in different species through various mechanisms, including epigenetic modifications and disruptions of the cell signaling pathways, gene expression, microbiome and metabolome. More research should be conducted to study the toxicity of bisphenol analogs other than bisphenol A and the underlying mechanisms of action, and in particular the potential for causing dysbiosis. Understanding the mechanisms of liver injury holds promise for improving the prediction of liver toxicity from bisphenol analogs and other environmental chemicals, and their risk assessment and legislation. Full article

Background: Hepatitis delta virus (HDV) was recently proven to be directly carcinogenic on hepatocytes via different mechanisms compared to hepatitis B virus (HBV). Our study evaluated the differences between hepatocellular carcinoma (HCC) behaviour in both cases. Methods: A retrospective tertiary care centre study was conducted and included all HBsAg-positive adult patients admitted from the 1st of January 2021 to the 31st of December 2022. IBM SPSS 29.0 was used for statistics. Patients were split into a control group, HBV + HCC, and a study group, HBV + HDV + HCC. Results: A total of 679 patients were included, with an estimated prevalence of HCC in the HDV population of 20.8% versus 9.1% in the control group, p < 0.001, with an OR = 2.263 and a CI 95% of (1.536–3.333), p = 0.001. Younger patients developed HCC in the HBV monoinfection group (mean ± SD, 50.65 ± 12.302 years vs. 51.4 ± 13.708, p = 0.457). Study group patients had smaller tumours (maximum diameter: 32.66 ± 23.181 mm vs. 56.75 ± 38.09 mm, p = 0.002), lower AFP values (177.24 ± 364.8 ng/mL vs. 183.07 ± 336.77 ng/mL, p = 0.941) and predominantly loco-regional treatment. BCLC classification (p = 0.001) and the AFP-Duvoux score (p = 0.001) showed more advanced HCC in HBV monoinfection, with access to mainly systemic therapies (p < 0.001). Conclusions: HCC is more frequent in HDV-infected patients, leading to a different HCC pattern, with smaller tumours, less advanced neoplasia and less access to curative treatment compared to HBV-monoinfection-associated HCC. Full article

Autoimmune hepatitis (AIH) and drug-induced liver injury (DILI) are major causes of liver inflammation with distinct pathophysiology but overlapping clinical features. Among acute cases, DILI is a key differential diagnosis for AIH, especially when drug history is unclear or the injury is non-dose-dependent. Mechanisms of DILI include direct toxicity, metabolic idiosyncrasies, and immune-mediated responses that can mimic AIH. Moreover, certain drugs can induce AIH-like syndromes, further complicating the diagnosis. While causality assessment tools aid initial evaluations, liver biopsy remains valuable for distinguishing AIH from DILI; given these complexities, hepatologist consultation is often essential to ensure appropriate diagnosis and treatment management. Full article

The term “plastics” is an umbrella term generally referring to any material containing a high level of polymer content as an essential ingredient. Micro(nano)plastics (MNPs) are derived from the degradation of plastics, representing exogenous substances whose exposure can potentially interfere with different physiological processes. In this scenario, even considering the relative paramount detoxification role, the liver emerges as a key active organ in the relationship between plastic exposure and human disease. In industrialized countries, where plastics constitute largely diffused components of objects routinely adopted in daily/social life, including food packaging, Metabolic dysfunction-associated Steatotic Liver Disease (MASLD) represents the predominant hepatopathy and is progressively becoming the leading cause of cirrhosis and liver cancer, with an incompletely elucidated multifactorial pathogenesis. Notably, oral exposure to MNPs has been revealed to impact the gut–liver axis by influencing gut microbiota composition, gastrointestinal absorption, and, ultimately, determining hepatic accumulation. At the hepatic level, MNPs can contribute to the onset and worsening of steatosis by inducing metabolic dysfunction and inflammation. Plastics can also serve as vectors for different potentially toxic additives, with specific MNPs constituting a persistent source of release of bisphenol A (BPA), a well-recognized exogenous etiological factor contributing to MASLD genesis and worsening. Recently, exposure to MNPs and additives has demonstrated significant impacts on the immune system, oxidative stress, and metabolism. In particular, polystyrene-derived MNPs impair the mechanisms regulating hepatic lipid metabolism, simultaneously acting as antigens abnormally triggering the innate immune response. At the same time, environmental BPA exposure has been revealed to trigger trained immunity-related pathways, configuring novel pathogenetic drivers potentially promoting the progression of MASLD. The present review, after rapidly overviewing the main sources and toxicological properties of MNPs and related additives, explores plastic-related exposure’s potential implications in the genesis and progression of hepatic steatosis, highlighting the urgent need for further clarification of relative pathogenetic mechanisms. Full article

N-acetyl para-aminophenol was suggested as a safer alternative to other drugs on the market for pain and fever in 1948. It was given the generic name “acetaminophen” in 1951 and the trade name “Tylenol” when it was put on the market in the USA in 1955 as a prescription drug to treat pediatric fever. It also received the generic name “paracetamol” in the UK where it was initially marketed in 1956 under the name “Panadol.” Toxicity from overdose of acetaminophen was reported in 1966. Research at the US National Institutes of Health uncovered the mechanisms of toxicity and proposed a treatment in a foundational series of papers in 1973 and 1974. A nomogram was developed in 1973 and published in 1975 to guide estimation of patient risk of hepatic toxicity. Rapid development followed utilizing acetylcysteine given both orally and intravenously. Various protocols and methods of administration have been employed over time with the primary use today of acetylcysteine intravenously as the therapeutic method. The nomogram has been revised over time to the current version, published in 2023, which allows stratification of patients to a high-risk group over 300 mg/L at 4 h and standard risk above 150 mg/L at 4 h, except in the UK where the standard risk is defined very conservatively with a line above 100 mg/L at 4 h. Adjunct therapy with fomepizole in patients with massive ingestions, delay until arrival in a health care facility or renal injury has been proposed. The mortality rate with treatment has been substantially reduced and recovery from hepatic injury is achieved in almost all patients. Full article

Background and aims: The CC5, CXC3, and CC2 chemokines (CK) are known to play a role in the pathogenesis of autoimmune hepatitis (AIH). However, no data are available on their potential utility as markers of disease progression or response to treatment. Material and methods: We analyzed their role as markers of remission in a population of patients with AIH. We retrospectively investigated the kinetics of RANTES (CCL5), IP-10 (CXCL10), and MCP-1 (CCL2) in 48 patients with AIH at the time of treatment initiation and also in 32 at biochemical, clinical and histological remission. Forty-nine healthy donors (HDs) served as controls. Results: At baseline, IP-10 and MCP-1 levels were higher in AIH patients than in HDs (261 vs. 101 pg/mL and 689 vs. 330 pg/mL, p < 0.01), and RANTES levels showed no differences. Correlations were observed between RANTES and IgG concentrations (r = 0.36 p = 0.04) and between IP-10 and Ishak’s grade (r = 0.52 p = 0.02). At remission, in 32 patients, while IP-10 and MCP-1 values showed a significant decrease from baseline reaching HD levels (261 vs. 106 pg/mL and 689 vs. 387 pg/mL, p < 0.01), RANTES did not. However, two kinetics patterns emerged, with 20 patients showing lower and 12 higher baseline RANTES values compared to HDs (29,450 pg/mL and 70,960 pg/mL vs. 52,010 pg/mL, p < 0.01). The former required longer treatment to reach remission and had higher Ishak’s grades than the latter (p < 0.01). Conclusions: RANTES, IP-10, and MCP-1 may help in predicting response to treatment and stable remission and in supporting the decision if and when to discontinue immune suppressive therapy. Full article

Background/Objectives: Hepatitis B virus (HBV) infection is a worldwide health problem responsible for chronic liver disease and hepatocellular carcinoma. Both innate immunity and the adaptive immune response play central roles in the development of chronic hepatitis and liver cancer. We previously performed a comprehensive analysis of gene expression in the livers of HBV-infected chimeric mice and found that several genes associated with cell growth or carcinogenesis via hypoxia and KRAS signaling were upregulated by HBV infection. However, due to the absence of adaptive immunity in uPA/SCID chimeric mice, we were unable to analyze the effect of the host immune response. Methods: In this study, we compared gene expression profiles in the livers obtained from HBV-infected chimeric mice with those of HBV carriers. Results: After HBV infection, the expression of genes associated with inflammation and immune response, especially involving the Th1 and Th2 activation pathways, was altered as HBV-specific intracellular immune responses both in vivo and in clinical samples. Interestingly, the proinflammatory gene IL12A was induced by HBV infection in the chimeric mouse livers but not in the human livers, and associated genes, such as SRDA5A2, AR, and CCR3, showed differential alteration by HBV infection between the chimeric mouse and human livers. Conclusions: These results suggest that hepatocarcinogenesis may be suppressed by host immunity in HBV carriers. This study highlights potential new implications for inhibiting the progression of HBV-related liver diseases, including hepatocarcinogenesis. Full article

Metabolic dysfunction–associated steatotic liver disease (MASLD) is a multifactorial condition linked to liver injury, insulin resistance, and disrupted gut–liver interactions. A key aspect of MASLD pathogenesis is the dysfunction of intestinal barriers, including mechanical, immunological, and microbial alterations that amplify liver damage. The disruption of tight junctions and increased intestinal permeability allow microbial products, such as lipopolysaccharides, to enter the bloodstream, triggering liver inflammation via Kupffer cell activation. In MASLD, the gut vascular barrier is also compromised, marked by increased expression of PV-1. Additionally, dysbiosis, driven by high-fat, high-sugar diets, shifts the gut microbiota toward pro-inflammatory species, exacerbating systemic inflammation and intestinal permeability. This imbalance activates Toll-like receptor signaling, which promotes endotoxin-induced liver injury. Gut dysbiosis further impairs lipid metabolism, contributing to hepatic steatosis and MASLD progression. The gut–liver axis plays a critical role, with factors like altered bile acid metabolism and toxic metabolites such as hydrogen sulfide worsening intestinal barrier function and fueling chronic inflammation. This review aims to explore the complex role of the gut–liver axis in MASLD progression, highlighting the mechanisms of intestinal barrier dysfunction, dysbiosis, and microbial contributions to liver injury. It also discusses therapeutic strategies targeting intestinal barriers, including dietary and microbiota-based interventions, while acknowledging the challenges of personalized treatment approaches. Future research should focus on multi-omics technologies and the safety and efficacy of microbiota-targeted therapies in MASLD management. Full article