Probiotic Mixture Ameliorates a Diet-Induced MASLD/MASH Murine Model through the Regulation of Hepatic Lipid Metabolism and the Gut Microbiome

Alpha-aminobutyric acid ameliorates diet-induced metabolic dysfunction-associated steatotic liver disease (MASLD) progression in mice via enhancing AMPK/SIRT1 pathway and modulating the gut-liver axis

Alpha-aminobutyric acid (ABA) is a nonproteinogenic amino acid, a metabolite which could be generated from the metabolism of methionine, threonine, serine and glycine or as a gut-microbiome-derived metabolite. Changes in ABA levels have been embroiled in metabolic dysfunction-associated steatotic liver disease (MASLD) intervention studies, but their relation to MASLD pathogenesis remains unclear. Hence, this present study aimed to investigate the effect of oral ABA supplementation on the progression of a high fat/high cholesterol diet (HFD) induced MASLD mice model. ABA was found to remodel the gut microbiome composition and ameliorate MASLD parameters in HFD-fed mice. ABA mitigated HFD-induced gain in liver weight, hepatic steatosis, insulin resistance, serum and hepatic triglyceride levels, and liver cholesterol levels. Modulation of lipid metabolism was observed in the liver, in which expression of proteins and/or genes involved in de novo lipogenesis were suppressed, while those involved in fatty acid oxidation and autophagy were upregulated together with cellular antioxidant capacity, in addition to the enhancement of the AMPK/SIRT1 pathway. ABA reshaped the gut composition by enriching nine bacterial species, including Helicobacter hepaticus, Desulfovibrio sp. G11, Parabacteroides distasonis, and Bacteroides fragilis, while diminishing the abundance of 16 species, which included four Helicobacter species. KEGG pathway analysis of microbial functions found that ABA impeded secondary bile acid biosynthesis - which was reflected in the faecal BA composition analysis. Notably, ABA also inhibited ileal FXR-Fgf15 signaling, allowing for increased hepatic Cyp7a1 expression to eliminate cholesterol buildup in the liver. Overall, our findings indicate that ABA could be used as a promising therapeutic approach for the intervention of MASLD.

Probiotics Mixture, Prohep: a Potential Adjuvant for Low-Dose Sorafenib in Metabolic Dysfunction-Associated Steatotic Liver Disease-Associated Hepatocellular Carcinoma Suppression Through Modulating Gut Microbiota

Targeting gut microbiota is an innovative approach to mitigate the development of metabolic dysfunction-associated steatotic liver disease-associated hepatocellular carcinoma (MASLD-HCC). This study aims to investigate the effects of Prohep, a probiotic mixture, both as a prophylactic measure and as an adjuvant therapy for low-dose sorafenib. A MASLD-HCC mice model was established by diethylnitrosamine (DEN) injection with feeding of a high-fat high-cholesterol (HFHC) diet. Gut microbiome profiles were later identified through shotgun sequencing. Our findings demonstrated that Prohep supplementation effectively suppressed MASLD-HCC development in mice. This protective effect was attributed to the modulation of gut microbiota and the increased production of short-chain fatty acids (SCFAs), propionate, and valerate. Prohep also activated AMPK, which decreased lipogenesis, reduced lipid uptake, and enhanced antioxidant enzyme expressions. Additionally, the cancer proliferation pathway PI3K/mTOR was inhibited in response to Prohep treatment. As an adjuvant therapy, Prohep improved the efficacy of low-dose sorafenib, as indicated by reduced tumor counts, alleviated inflammation, and increased hepatic superoxide dismutase (SOD) expression. The combination led to enhanced butyrate production, contributing to the overall therapeutic effects, thanks to the gut microbiota modulatory effects of Prohep. These results underscore Prohep's anti-tumorigenic properties and its potential to enhance the therapeutic outcomes of low-dose sorafenib in MASLD-HCC treatment. The study highlights the importance of gut microbiota modulation for developing effective neoadjuvant therapies and long-term management strategies for MASLD-HCC.

The Gut Microbiome in Hepatocellular Carcinoma: Proliferation, Inhibition, Diagnosis, and Immunotherapy

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. Major causes of HCC include hepatitis B and C viral infections, alcoholic hepatitis, and liver cirrhosis. Additionally, conditions such as obesity, diabetes, and metabolic syndrome have been identified as contributing factors to HCC development. In recent years, research on gut microbiota has expanded significantly, resulting in numerous studies exploring the relationship between HCC and gut microbiota. Thus, in this review, we highlight the association between gut microbiota and HCC, focusing on microbiota-related proliferation, inhibition, diagnosis, and immunotherapy. The gut microbiota is proposed to play a crucial role in both the diagnosis and treatment of HCC, paving the way for the development of novel diagnostic and therapeutic approaches for this disease.

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

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

Alpha-aminobutyric acid administration suppressed visceral obesity and modulated hepatic oxidized PUFA metabolism via gut microbiota modulation

BACKGROUND

High-fat diet (HFD) is associated with visceral obesity due to disruption in the lipid metabolism and gut dysbiosis. These symptoms may contribute to hepatic steatosis and the formation of oxidized polyunsaturated fatty acids (PUFAs). Alpha-aminobutyric acid (ABA) is an amino-acid derived metabolite, and its concentration has been correlated with several metabolic conditions and gut microbiome diversity while its direct effects on visceral obesity, lipid metabolism and the gut microbiota are not well understood. This study was designed to investigate the effect of physiological dose of ABA on diet-induced visceral obesity and lipid metabolism dysregulation by examining the fatty acids and oxidized PUFAs profile in the liver as well as the gut microbiota.

RESULTS

ABA administration reduced visceral obesity by 28 % and lessened adipocyte hypertrophy. The expression of liver Cd36 was lowered by more than 50 % as well as the saturated and monounsaturated FA concentration. Notably, the desaturation index for C16 and C18 FAs that are correlated with adiposity were reduced. The concentration of several DHA-derived oxidized PUFAs were also enhanced. Faecal metagenomics sequencing revealed enriched abundance of Leptogranulimonas caecicola and Bacteroides sp. ZJ-18 and were positively correlated with several DHA- and ALA-derived oxidized PUFAs in ABA group.

CONCLUSION

Our study revealed the modulatory effect of physiological dose of ABA on attenuating visceral obesity, reducing hepatic steatosis, and promoting the production of anti-inflammatory oxidized PUFAs that were potentially mediated by the gut microbiota.

Human Gut Microbiome: A Connecting Organ Between Nutrition, Metabolism, and Health

The gut microbiome plays a vital role in human health, functioning as a metabolic organ that influences nutrient absorption and overall well-being. With growing evidence that dietary interventions can modulate the microbiome and improve health, this review examines whether healthcare systems should prioritize personalized microbiome-targeted therapies, such as probiotics, prebiotics, and microbiota transplants, over traditional pharmaceutical treatments for chronic diseases like obesity, diabetes, cardiovascular risk, and inflammatory conditions. A systematic review using Web of Science and Scopus databases was conducted, followed by a scientometric analysis. Key metabolic pathways, such as dietary fiber fermentation and short-chain fatty acid production, were explored, focusing on their impact on lipid and glucose metabolism. The interactions between microbial metabolites and the immune system were also investigated. Dietary interventions, including increased fiber and probiotic intake, show potential for addressing dysbiosis linked to conditions, such as type 2 diabetes, obesity, and autoimmune diseases. The review emphasizes the need to incorporate microbiome modulation strategies into clinical practice and research, calling for a multidisciplinary approach that integrates nutrition, microbiology, and biochemistry to better understand the gut microbiome's complex role in health.

Differential effects of ellagic acid on non-alcoholic fatty liver disease in mice: grouped by urolithin A-producing capacity

Ellagic acid (EA) exhibits protective effects on non-alcoholic fatty liver disease (NAFLD). However, the ability to produce urolithins and the health benefits associated with EA consumption differ considerably among individuals. Therefore, the different effects of EA on high-fat and high-fructose diet (HFFD)-induced NAFLD, considering variability in urolithin-producing ability, were explored. Our results showed that EA could effectively reduce body weight, lipid accumulation and insulin resistance, and improve oxidative stress and inflammation in NAFLD mice. The metabolomics analysis indicated that liver metabolism disorder induced by HFFD was obviously improved by EA mainly through the regulation of unsaturated fatty acid biosynthesis and amino acid metabolism. In particular, the improvement effect of EA on NAFLD in mice with high urolithin A production was better than that in their low counterparts. Moreover, EA treatment reshaped the gut microbiota imbalance caused by HFFD. Specifically, compared to the model group, the lower abundances of Faecalibaculum (by 95.11%), Ruminococcus_torques_group (by 208.14%), Clostridium_sensu_stricto_1 (by 449.37%), and Ileibacterium (by 172.64%), while higher abundances of Verrucomicrobia and Akkermansia (by 425.0%) were observed in the high-UroA-producing group (p < 0.05). This study provided new insights into EA's anti-NAFLD effectiveness and suggested that the response capacity of the gut microbiota to EA greatly determined the performance of EA in alleviating the development of NAFLD.

Special correlation between diet and MASLD: positive or negative?

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic and systemic metabolic liver disease characterized by the presence of hepatic steatosis and at least one cardiometabolic risk factor (CMRF). The pathogenesis of MASLD involves multiple mechanisms, including lipid metabolism disorders, insulin resistance, inflammatory responses, and the hepato-intestinal axis of metabolic dysfunction. Among these factors, diet serves as both an inducement and a potential remedy in the disease's development. Notably, a high-lipid diet exacerbates fat accumulation, oxidative stress, and inflammatory responses, thereby promoting the progression of MASLD. Consequently, dietary induction models have become vital tools for studying the pathological mechanisms of MASLD, providing a foundation for identifying potential therapeutic targets. Additionally, we summarize the therapeutic effects of dietary optimization on MASLD and elucidate the role of specific dietary components in regulating the hepato-intestinal axis, lipid metabolism, and inhibiting inflammatory responses. In conclusion, studies utilizing animal models of MASLD offer significant insights into dietary therapy, particularly concerning the regulation of lipid metabolism-related and hepatoenteric axis-related signaling pathways as well as the beneficial mechanism of probiotics in hepatoenteric regulation. By understanding the specific mechanisms by which different dietary patterns affect MASLD, we can assess the clinical applicability of current dietary strategies and provide new directions for research and treatment aimed at disease modification.

Lactobacillus delbrueckii subsp. lactis CKDB001 Ameliorates Metabolic Complications in High-Fat Diet-Induced Obese Mice

BACKGROUND/OBJECTIVES

Functional probiotics, particularly Lactobacillus delbrueckii subsp. lactis CKDB001, have shown potential as a therapeutic option for metabolic dysfunction-associated steatotic liver disease (MASLD). However, their effects have not been confirmed in in vivo systems. Here, we investigated the effects of L. delbrueckii subsp. lactis CKDB001 on insulin resistance, dyslipidemia, MASLD, and lipid metabolism in a murine model of high-fat diet (HFD)-induced obesity.

METHODS

The mice were divided into four groups (n = 12 per group)-normal chow diet (NCD), high fat diet (HFD), HFD with L. delbrueckii subsp. lactis CKDB001 (LL), and HFD with resmetirom (positive control (PC), a thyroid receptor β agonist). The experimental animals were fed NCD or HFD for 12 weeks, followed by an additional 12-week oral treatment with LL or resmetirom.

RESULTS

LL supplementation reduced body weight, insulin levels, and HOMA-IR compared with those in the HFD group, indicating improved insulin sensitivity. Additionally, LL reduced serum triglyceride (TG) levels without affecting total cholesterol (TC) levels. HFD consumption increased liver weight and hepatic TG and TC levels, indicating ectopic fat accumulation; however, LL supplementation reversed these changes, indicating a liver-specific effect on cholesterol metabolism. Furthermore, LL administration attenuated NAFLD activity scores, reduced hepatic fibrosis, improved liver function markers (aspartate aminotransferase), and enhanced Adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. However, LL did not considerably affect the expression of genes related to lipid metabolism. In epididymal adipose tissue, LL treatment reduced leptin levels but had no effect on adiponectin; additionally, histological analysis showed an increase in adipocyte size, potentially linked to enhanced energy metabolism.

CONCLUSIONS

Collectively, these findings suggest that LL could be a promising therapeutic candidate for improving insulin sensitivity, reducing hepatic lipid accumulation, and mitigating MASLD.

Probiotic Mixture Attenuates Colorectal Tumorigenesis in Murine AOM/DSS Model by Suppressing STAT3, Inducing Apoptotic p53 and Modulating Gut Microbiota

Colorectal cancer (CRC) is one of the most common cancers worldwide. The standard CRC chemo drug, 5-Fluorouracil (5-FU), has a poor response rate and chemoresistance, prompting the need for a more effective and affordable treatment. In this study, we aimed to evaluate whether Prohep, a novel probiotic mixture, would alleviate azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colorectal tumorigenesis and enhance 5-FU efficacy and its mechanism. Our results suggested that Prohep showed stronger anti-tumorigenesis effects than 5-FU alone or when combined in the AOM/DSS model. Prohep significantly reduced the total tumor count, total tumor size, caecum weight, colonic crypt depth, colonic inflammation, and collagen fibrosis. Prohep downregulated pro-inflammatory TNF-α and proliferative p-STAT3 and upregulated apoptotic p53. Metagenomics analysis indicated that Prohep-enriched Helicobacter ganmani, Desulfovibrio porci, Helicobacter hepaticus, and Candidatus Borkfalkia ceftriaxoniphila were inversely correlated to the total tumor count. In addition, Prohep-enriched Prevotella sp. PTAC and Desulfovibrio porci were negatively correlated to AOM/DSS enriched bacteria, while forming a co-existing community with other beneficial bacteria. From KEGG analysis, Prohep downregulated CRC-related pathways and enhanced pathways related to metabolites suppressing CRC like menaquinone, tetrapyrrole, aminolevulinic acid, and tetrahydrofolate. From Metacyc analysis, Prohep downregulated CRC-related peptidoglycan, LPS, and uric acid biosynthesis, and conversion. Prohep elevated the biosynthesis of the beneficial L-lysine, lipoic acid, pyrimidine, and palmitate. Prohep also elevated metabolic pathways related to energy utilization of lactic acid-producing bacteria (LAB) and acetate producers. Similarly, fecal acetate concentration was upregulated by Prohep. To sum up, Prohep demonstrated exceptional anti-tumorigenesis effects in the AOM/DSS model, which revealed its potential to develop into a novel CRC therapeutic in the future.

Low-dose valine attenuates diet-induced metabolic dysfunction-associated steatotic liver disease (MASLD) in mice by enhancing leptin sensitivity and modulating the gut microbiome

OBJECTIVES

Elevated circulating branched-chain amino acids (BCAAs) have been associated with obesity, insulin resistance, and MASLD. Nonetheless, BCAA supplementation has been shown to provide protective outcomes towards the intervention of MASLD. Currently, there is a lack of study towards the contribution of the BCAA: valine on MASLD. Herein, the effect of low-dose valine supplementation was investigated for its role in the progression of MASLD.

METHODS

C57BL/6J mice were fed a high-fat/high-cholesterol diet (HFD) to induce MASLD. Upon the establishment of MASLD, valine was supplemented via voluntary oral administration. Clinical and biochemical parameters associated with MASLD were measured, and molecular mechanism and gut microbiota modulation from the effect of valine were investigated.

RESULTS

Low-dose valine was found to attenuate the progression of MASLD, significantly reducing the gain in body weight, liver weight, and epididymal white adipose tissue (eWAT) weight, while also attenuating hyperglycemia and hyperleptinemia, and improving serum lipid profiles. Mechanistically, in the liver, genes related to hepatic lipogenesis and cholesterol biosynthesis were downregulated, while those associated with fatty acid oxidation, autophagy, and antioxidant capacity were upregulated, and AMPK pathway activity was enhanced. Liver and hypothalamic leptin resistance and inflammation were also attenuated, allowing better appetite control in mice fed a HFD and leading to reduced food intake. Additionally, metabolic flexibility in the eWAT was improved, and the gut microbiome was modulated by low-dose valine supplementation.

CONCLUSION

Low-dose valine supplementation attenuates MASLD by enhancing systemic leptin sensitivity and modulating the gut microbiome.