Bifidobacterium pseudolongum-generated acetate suppresses non-alcoholic fatty liver disease-associated hepatocellular carcinoma

Creatine-mediated ferroptosis inhibition is involved in the intestinal radioprotection of daytime-restricted feeding

Ionizing radiation-induced intestinal injury (IRIII) is a catastrophic disease lack of sufficient medical countermeasures currently. Regulation of the gut microbiota through dietary adjustments is a potential strategy to mitigate IRIII. Time-restricted feeding (TRF) is an emerging behavioral nutrition intervention with pleiotropic health benefits. Whether this dietary pattern influences the pathogenesis of IRIII remains vague. We evaluated the impact of TRF on intestinal radiosensitivity in this study and discovered that only daytime TRF (DTRF), not nighttime TRF, could ameliorate intestinal damage in mice that received a high dose of IR. Faecal metagenomic and metabolomic studies revealed that the intestinal creatine level was increased by approximate 9 times by DTRF, to which the Bifidobacterium pseudolongum enrichment contribute. Further investigations showed that creatine could activate the energy sensor AMP-activated protein kinase in irradiated enterocytes and induce phosphorylation of acetyl-CoA carboxylase, resulting in reduced production of polyunsaturated fatty acids and reduced ferroptosis after IR. The administration of creatine mitigated IRIII and reduced bacteremia and proinflammatory responses. Blockade of creatine import compromised the ferroptosis inhibition and mitigation of DTRF on IRIII. Our study demonstrates a radioprotective dietary mode that can reshape the gut microbiota and increase intestinal creatine, which can suppress IR-induced ferroptosis, thereby providing effective countermeasures for IRIII prevention.

Advances in the acting mechanism and treatment of gut microbiota in metabolic dysfunction-associated steatotic liver disease

Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD) is increasing in prevalence worldwide and has become the greatest potential risk for cirrhosis and hepatocellular liver cancer. Currently, the role of gut microbiota in the development of MASLD has become a research hotspot. The development of MASLD can affect the homeostasis of gut microbiota, and significant changes in the composition or abundance of gut microbiota and its metabolite abnormalities can influence disease progression. The regulation of gut microbiota is an important strategy and novel target for the treatment of MASLD with good prospects. In this paper, we summarize the role of gut microbiota and its metabolites in the pathogenesis of MASLD, and describe the potential preventive and therapeutic efficacy of gut microbiota as a noninvasive marker to regulate the pathogenesis of MASLD based on the "gut-hepatic axis", which will provide new therapeutic ideas for the clinic.

Aging and climate change-induced heat stress synergistically increase susceptibility to Vibrio vulnificus infection via an altered gut microbiome-immune axis

Climate change is exacerbating heatwaves, significantly increasing public health risks, including heightened vulnerability to Vibrio vulnificus infections, especially among older adults. While heat stress alone impairs immune regulation and compromises gut integrity, the combined effects of aging and climate-induced heat stress on infectious severity remain insufficiently explored. Using young (12-week-old) and aged (24-month-old) mouse models, we examined how aging and periodic heat stress synergistically influence susceptibility to Vibrio vulnificus by assessing gut microbiome alterations, immune responses, and antibiotic resistance gene dynamics. Heat stress markedly impaired intestinal barrier function, induced significant microbiome shifts, elevated systemic inflammation, and promoted enrichment of antibiotic resistance genes particularly those conferring tetracycline resistance with effects significantly amplified in aged mice. Upon Vibrio vulnificus infection, aged heat-stressed mice demonstrated elevated inflammatory responses, severe intestinal damage, and pronounced immune dysregulation compared to younger counterparts. Gut depletion and probiotic recolonization models further validated microbiota involvement, showing that Roseburia intestinalis significantly reduced heat stress-exacerbated CD4+ T-cell immunosenescence in aged mice. Collectively, this study provides robust experimental evidence highlighting the critical interplay between aging and climate-driven heat stress in intensifying infectious disease severity via microbiome-immune axis disruptions, underscoring the need for microbiota-targeted strategies in climate-vulnerable populations.

Designing live bacterial therapeutics for cancer

Humans are home to a diverse community of bacteria, many of which form symbiotic relationships with their host. Notably, tumors can also harbor their own unique bacterial populations that can influence tumor growth and progression. These bacteria, which selectively colonize hypoxic and acidic tumor microenvironments, present a novel therapeutic strategy to combat cancer. Advancements in synthetic biology enable us to safely and efficiently program therapeutic drug production in bacteria, further enhancing their potential. This review provides a comprehensive guide to utilizing bacteria for cancer treatment. We discuss key considerations for selecting bacterial strains, emphasizing their colonization efficiency, the delicate balance between safety and anti-tumor efficacy, and the availability of tools for genetic engineering. We also delve into strategies for precise spatiotemporal control of drug delivery to minimize adverse effects and maximize therapeutic impact, exploring recent examples of engineered bacteria designed to combat tumors. Finally, we address the underlying challenges and future prospects of bacterial cancer therapy. This review underscores the versatility of bacterial therapies and outlines strategies to fully harness their potential in the fight against cancer.

Effects of Probiotics on Liver Diseases: Current In Vitro and In Vivo Studies

Various types of liver or hepatic diseases cause the death of about 2 million people worldwide every year, of which 1 million die from the complications of cirrhosis and another million from hepatocellular carcinoma and viral hepatitis. Currently, the second most common solid organ transplant is the liver, and the current rate represents less than 10% of global transplant requests. Hence, finding new approaches to treat and prevent liver diseases is essential. In liver diseases, the interaction between the liver, gut, and immune system is crucial, and probiotics positively affect the human microbiota. Probiotics are a non-toxic and biosafe alternative to synthetic chemical compounds. Health promotion by lowering cholesterol levels, stimulating host immunity, the natural gut microbiota, and other functions are some of the activities of probiotics, and their metabolites, including bacteriocins, can exert antimicrobial effects against a broad range of pathogenic bacteria. The present review discusses the available data on the results of preclinical and clinical studies on the effects of probiotic administration on different types of liver diseases.

Exploring tarhana's prebiotic potential using different flours in an in vitro fermentation model

Tarhana, a traditional fermented food important to Turkish and Central Asian cuisines, is known for its unique composition of yoghurt, flour, vegetables, and herbs, and its potential health benefits through fermentation. The aim of this study was to evaluate tarhana's potential prebiotic and postbiotic properties using an in vitro colonic fermentation model. We explored how ingredient variations, particularly flour types and fermentation methods, influence gut microbial diversity and metabolite production. Tarhana was prepared using wheat, chickpea, einkorn, and purple potato flours, fermented with baker's yeast (Saccharomyces cerevisiae) or chickpea sourdough. Gut microbial composition and levels of short-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs) were analysed following in vitro colonic fermentation. Flour type and fermentation method significantly influenced gut microbial composition and metabolite production. Sourdough-fermented tarhana made with purple potato (q = 1.23 × 10-7), chickpea (q = 1.23 × 10-7), and einkorn (q = 2.51 × 10-7) flours reduced Veillonella levels compared to baker's yeast variants. Sourdough purple potato tarhana also decreased Escherichia-Shigella levels in faecal samples, which were higher in baker's yeast-fermented faecal samples (q = 0.003). SCFA levels, particularly acetate and propionate, were higher in chickpea and purple potato tarhana fermented faecal samples, with sourdough variants showing the strongest effects. Bifidobacterium abundance increased in einkorn sourdough tarhana, while chickpea flour tarhana slightly increased isobutyrate levels. This study demonstrates that specific flour types combined with sourdough fermentation enhance tarhana's functional properties by promoting beneficial microbial shifts and increasing SCFA production. These findings suggest tarhana's potential as a personalized functional food to support gut health, warranting further validation through clinical trials.

Intermittent fasting and metabolic dysfunction-associated steatotic liver disease: the potential role of the gut-liver axis

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing public health concern linked to the increasing prevalence of metabolic syndrome, including obesity and type 2 diabetes (T2D). MASLD remains a significant clinical challenge due to the absence of effective therapeutic interventions. Intermittent fasting (IF) has emerged as a promising non-pharmacological strategy for managing MASLD. Although the exact mechanisms underpinning the possible beneficial effects of IF on MASLD are not yet fully elucidated, the gut microbiota and its metabolic byproducts are increasingly recognized as potential mediators of these effects. The gut-liver axis may act as an important conduit through which IF exerts its beneficial influence on hepatic function. This review comprehensively examines the impact of various IF protocols on gut microbiota composition, investigating the resultant alterations in microbial diversity and metabolomic profiles, and their potential implications for liver health and the improvement 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.

Lactitol may improve the prognosis of hepatocellular carcinoma through the proliferation of Megasphaera as well as Bifidobacterium

Background

Increasing evidence suggests that gut microbiota and their metabolites can modulate antitumor immunity. However, sufficient evidence from human studies is lacking. We evaluated the association of lactitol and lactulose as prebiotics with the progression of hepatocellular carcinoma (HCC).

Methods

In Study 1, the effects of lactitol and lactulose on overall survival (OS) of patients with HCC with Child-Pugh scores of B or C were investigated in patients diagnosed at the Nagasaki Medical Center between 2003 and 2020. In Study 2, the effects of these substances on the gut microbiota of patients with cirrhosis were analyzed. Study 3 examined the effect of these substances on serum albumin levels in patients with cirrhosis.

Results

In Study 1, a total of 321 patients were evaluated, and 55 pairs of Lactitol and Non-Lactitol groups and 80 pairs of Lactulose and Non-Lactulose groups were created using one to one propensity score matching. The Lactitol group showed a significant improvement (p < 0.05) in OS compared to the Non-Lactitol group, but the Lactulose group did not show any significance compared to the Non-Lactulose group. In Study 2, the number of Bifidobacterium was higher in the Lactitol group and the Lactulose group than in the Control group, but the number of Megasphaera was significantly higher only in the Lactitol group. In addition, in a study of 10 cases in which the gut microbiota was examined before and after lactitol use, an increase in Bifidobacterium and Megasphaera was observed after lactitol use. Study 3 found that lactitol had no beneficial effect on serum albumin levels.

Conclusion

Lactitol may improve the prognosis of HCC through the proliferation of Megasphaera as well as Bifidobacterium.

Oral Delivery of Ellagic Acid Encapsulated in Milk Exosomes: Sex-Based Differences in Bioavailability, Urolithin Production, and Gut Microbiota Modulation

Milk exosomes (EXOs) enhance polyphenols' bioavailability, but their potential for oral administration remains underexplored. Ellagic acid (EA) is poorly bioavailable. We investigate whether EA encapsulated in EXOs (EXO-EA) consumed orally improves EA bioavailability and (or) modulates gut microbiota. For 2 weeks, BALB/c mice received EXO, non-encapsulated EA (NEA), or EXO-EA (0.27 mg EA/kg bw) orally. Targeted and untargeted metabolomics (UPLC-qTOF-MS), fecal SCFAs (GC-MS), and gut microbiota (PacBio 16S-sequencing) were performed. Additionally, EA plasma and brain kinetics were evaluated in rats following intravenous administration of EXO-EA and NEA. Unlike NEA, EXO-EA quadrupled EA plasma levels in Sprague-Dawley rats and enabled brain detection. However, oral EXO-EA in mice failed to deliver EA systemically due to gastrointestinal instability, confirmed by in vitro digestion. Sex-dependent EXO-EA metabolomic effects were observed. Also, in males only, EXO-EA increased fecal urolithin A and SCFAs and enriched the microbiota with Christensenellaceae R7, Ruminococcus species, and Clostridium fusiformis, among others. In females, both EXO-EA and NEA enriched the microbiota with bifidobacteria, including Bifidobacterium pseudolongum. Oral EXO-EA impacted plasma metabolome, modulated gut microbiota, and increased urolithin A and SCFA production sex-dependently. However, gastrointestinal instability, limited EA encapsulation, and low dose administered prevented systemic delivery.

Gut microbiota in cancer initiation, development and therapy

Cancer has long been associated with genetic and environmental factors, but recent studies reveal the important role of gut microbiota in its initiation and progression. Around 13% of cancers are linked to infectious agents, highlighting the need to identify the specific microorganisms involved. Gut microbiota can either promote or inhibit cancer growth by influencing oncogenic signaling pathways and altering immune responses. Dysbiosis can lead to cancer, while certain probiotics and their metabolites may help reestablish micro-ecological balance and improve anti-tumor immune responses. Research into targeted approaches that enhance therapy with probiotics is promising. However, the effects of probiotics in humans are complex and not yet fully understood. Additionally, methods to counteract harmful bacteria are still in development. Early clinical trials also indicate that modifying gut microbiota may help manage side effects of cancer treatments. Ongoing research is crucial to understand better how gut microbiota can be used to improve cancer prevention and treatment outcomes.

UHPLC-QTOF-MS-based metabolomics joint high-throughput RNA sequencing transcriptomics approach for the analysis of fecal and liver biological samples and application in a case study for the mechanism of Qing-Kai-Ling oral liquid in treating MASLD

Qing-Kai-Ling (QKL) oral liquid has been increasingly used in metabolic dysfunction-associated steatotic liver disease (MASLD). However, the specific metabolic differentials and metabolic pathway mechanisms that affect the MASLD regulated by QKL remained unclear. In this study, serum biochemical analyses and hematoxylin-eosin staining of the liver revealed QKL reduced liver injury and enhanced lipid metabolism ability, respectively. To clarify the therapeutic mechanism of the QKL in the treatment of MASLD, UHPLC-QTOF-MS non-target metabolomics and RNA-Seq high-throughput sequencing analysis were used to explore the mechanism of the QKL in the treatment of MASLD from the perspective of metabolic-gene interactions. UHPLC-QTOF-MS-based untargeted metabolomics further revealed that there were 196 common differentially expressed metabolites identified among 3 groups; QKL significantly up-regulated 44 metabolites, while 11 metabolites (including N-phenylacetylglutamic acid and glycocholic acid) were downregulated significantly. Moreover, the main metabolic pathways regulated by QKL included amino acids, peptides, bile acids, carbohydrates, linoleic acids, etc. Additionally, the result of the RNA sequencing-based transcriptomics showed that a total of 984 differential genes (DEGs) were identified and 9 important DEGs were obtained. The result of the Kyoto Encyclopedia of Genes and Genomes (KEGG) demonstrated that the 984 DEGs were linked to bile acid metabolism, glycerophospholipid metabolism, insulin resistance, AMPK signaling pathway, etc. Overall, this work was the first to show that QKL regulated metabolites and genes to alleviate MASLD by the UHPLC-QTOF-MS-based untargeted metabolomics joint high-throughput RNA sequencing-based transcriptomics analysis, providing the basis and research method for the treatment of metabolic diseases by QKL and other drugs.

PLOD1 promotes the malignancy of hepatocellular carcinoma by facilitating the NF-κB/IL-6/STAT3-dependent TCA cycle

Background & Aims

Procollagen lysyl hydroxylase 1 (PLOD1) is crucial in regulating collagen synthesis and cross-linking. However, its roles and underlying mechanisms in the progression of hepatocellular carcinoma (HCC) remain unclear. Herein, we aimed to investigate the underlying biological functions and mechanisms of PLOD1 in HCC.

Methods

The expression levels of PLOD1 in HCC were measured by qPCR, Western blot, and immunohistochemistry. Cell proliferation, apoptosis, and stemness were examined by CCK8, flow cytometry, sphere formation, and aldehyde dehydrogenase activity assays. The subcutaneous tumorigenicity model, orthotopic tumorigenicity model, and hepatotoxin-induced HCC model were used for in vivo experiments. RNA-sequence and untargeted metabolomics analysis were performed to identify underlying mechanisms.

Results

PLOD1 is found to be highly expressed in both human (p <0.0001) and mouse HCC (p <0.01) and is associated with a poor prognosis (p = 0.047). In vitro and in vivo experiments reveal that overexpression of PLOD1 promotes the proliferation and stemness of HCC cells. Meanwhile, the depletion of PLOD1 attenuates the occurrence and growth of HCC, leading to cell cycle arrest (p <0.01) and apoptosis (p <0.001) in HCC. Mechanistically, PLOD1 positively regulates the NF-κB/IL-6/STAT3 signaling pathway and accelerates TCA cycle metabolic reprogramming. Blocking the NF-κB/IL-6/STAT3 signaling pathway and TCA cycle can effectively mitigate PLOD1-induced proliferation and stemness of HCC cells.

Conclusions

Our study uncovers the PLOD1/NF-κB/IL-6/STAT3 axis as a therapeutic target for inhibiting the progression and stemness of HCC.

Impact and implications

The roles and underlying mechanisms of PLOD1 in the progression of HCC remain unclear. In this study, we report that PLOD1 is highly expressed in patients with HCC and promotes the proliferation and stemness of HCC cells by activating the NF-κB/IL-6/STAT3-dependent TCA cycle. Knocking down hepatic PLOD1 using adeno-associated virus results in reduced progression of HCC in mice, suggesting that PLOD1 may serve as a potential therapeutic target for HCC.

The gut microbiome and cancer: from tumorigenesis to therapy

The gut microbiome has a crucial role in cancer development and therapy through its interactions with the immune system and tumour microenvironment. Although evidence links gut microbiota composition to cancer progression, its precise role in modulating treatment responses remains unclear. In this Review, we summarize current knowledge on the gut microbiome's involvement in cancer, covering its role in tumour initiation and progression, interactions with chemotherapy, radiotherapy and targeted therapies, and its influence on cancer immunotherapy. We discuss the impact of microbial metabolites on immune responses, the relationship between specific bacterial species and treatment outcomes, and potential microbiota-based therapeutic strategies, including dietary interventions, probiotics and faecal microbiota transplantation. Understanding these complex microbiota-immune interactions is critical for optimizing cancer therapies. Future research should focus on defining microbial signatures associated with treatment success and developing targeted microbiome modulation strategies to enhance patient outcomes.

Coculture of Bifidobacterium bifidum G9-1 With Butyrate-Producing Bacteria Promotes Butyrate Production

Supplementation with Bifidobacterium bifidum G9-1 (BBG9-1) has been established to enhance the production of butyrate, a short-chain fatty acid (SCFA) known for its beneficial effects in alleviating constipation. We hypothesized that BBG9-1 alters gut microbiota such that bacteria that produce butyric acid from lactate and acetate become more abundant. In this study, we sought to determine whether BBG9-1 promotes the growth of butyrate-producing bacteria and thereby enhances butyrate production. BBG9-1 was cocultured with different butyrate-producing bacteria to compare differences in the SCFA production of cocultures and monocultures. We indeed detected significant increases in the production of SCFAs in cocultures compared to monocultures. Moreover, lactate and butyrate production increased in a time-dependent manner in the BBG9-1 and Faecalibacterium prausnitzii ID 6052 coculture. In addition, acetate production in cocultures initially increased until 16 h, followed by a decline between 20 and 24 h, and a subsequent significant increase at 48 h. Comparatively, lactate and acetate production in the BBG9-1 and Anaerostipes caccae JCM 13470T coculture peaked at 16 h and declined thereafter, and butyrate production increased in a time-dependent manner. In contrast, lactate, acetate, and butyrate production in the BBG9-1 and Roseburia hominis JCM 17582T coculture increased in a time-dependent manner. These findings indicate that butyrate-producing bacteria increase butyrate production by utilizing BBG9-1-produced lactate and acetate. Thus, the butyrate-mediated physiological activity of BBG9-1 could be attributed to an indirect enhancement of butyrate production.

Understanding the role of Hedgehog signaling pathway and gut dysbiosis in fueling liver cancer

Liver cancer is one of the most prevalent types of cancer worldwide with less than 20% of patients surviving in the past half a decade. Several molecular pathways have been uncovered that may lead to the development of liver cancer but more recently the Hedgehog pathway (HH) and its interactions with the gut microbiota has emerged as an underlying cause of the development of liver cancer. Gut-liver axis is vital to maintaining homeostasis. The HH pathway controls cellular differentiation, proliferation, and apoptosis evasions, its abnormal activation can lead to uncontrolled proliferation of liver cancer stem cells. Additionally, the intricate interplay between HH signaling and the gut microbiota introduces a novel dimension. Recent investigations suggest that potential modulation of HH activity by gut microbiota influence HCC progression. This review explores a crosstalk between HH signaling and the gut microbiota, uncovering intricate mechanisms by which it fuels liver cancer development. This interplay provides insights into gut dysbiosis, HCC etiology and potential therapeutic avenues, highlighting the cooperative role of HH signaling and gut microbiota in shaping the overall HCC landscape.

Intratumoral microbiota for hepatocellular carcinoma: from preclinical mechanisms to clinical cancer treatment

Intratumoral microbiota has been found to be a crucial component of hepatocellular carcinoma (HCC). Due to insufficient recognition, technical limitations, and low biomass of intratumoral microbiota, it is poorly understood. Intratumoral microbiota exhibit significant diversity in HCC tissues. It is involved in the development of HCC through several mechanisms, such as remodeling the immunosuppressive microenvironment, metabolic reprogramming, and genetic alterations. Moreover, intratumoral microbiota is associated with the metastasis of HCC cells. Herein, we reviewed the history of intratumoral microbiota, applied biotechnology to depict the signatures of intratumoral microbiota, investigated the potential sources of intratumoral microbiota, and assessed their functions, mechanisms, and heterogeneity. Furthermore, in this review, we summarized the development of therapeutics that can be used in the treatment of HCC and proposed future perspectives for research in this field.

Diet-microbiome interactions in cancer

Diet impacts cancer in diverse manners. Multiple nutritional effects on tumors are mediated by dietary modulation of commensals, residing in mucosal surfaces and possibly also within the tumor microenvironment. Mechanistically understanding such diet-microbiome-host interactions may enable to develop precision nutritional interventions impacting cancer development, dissemination, and treatment responses. However, data-driven nutritional strategies integrating diet-microbiome interactions are infrequently incorporated into cancer prevention and treatment schemes. Herein, we discuss how dietary composition affects cancer-related processes through alterations exerted by specific nutrients and complex foods on the microbiome. We highlight how dietary timing, including time-restricted feeding, impacts microbial function in modulating cancer and its therapy. We review existing and experimental nutritional approaches aimed at enhancing microbiome-mediated cancer treatment responsiveness while minimizing adverse effects, and address challenges and prospects in integrating diet-microbiome interactions into precision oncology. Collectively, mechanistically understanding diet-microbiome-host interactomes may enable to achieve a personalized and microbiome-informed optimization of nutritional cancer interventions.

Aged Gut Microbiota Contributes to Cognitive Impairment and Hippocampal Synapse Loss in Mice

Gut microbiota alteration during the aging process serves as a causative factor for aging-related cognitive decline, which is characterized by the early hallmark, hippocampal synaptic loss. However, the impact and mechanistic role of gut microbiota in hippocampal synapse loss during aging remains unclear. Here, we observed that the fecal microbiota of naturally aged mice successfully transferred cognitive impairment and hippocampal synapse loss to young recipients. Multi-omics analysis revealed that aged gut microbiota was characterized with obvious change in Bifidobacterium pseudolongum (B.p) and metabolite of tryptophan, indoleacetic acid (IAA) in the periphery and brain. These features were also reproduced in young recipients that were transplanted with aged gut microbiota. Fecal B.p abundance was reduced in patients with cognitive impairment compared to healthy subjects and showed a positive correlation with cognitive scores. Microbiota transplantation from patients who had fewer B.p abundances yielded worse cognitive behavior in mice than those with higher B.p abundances. Meanwhile, supplementation of B.p was capable of producing IAA and enhancing peripheral and brain IAA bioavailability, as well as improving cognitive behaviors and microglia-mediated synapse loss in 5 × FAD transgenic mice. IAA produced from B.p was shown to prevent microglia engulfment of synapses in an aryl hydrocarbon receptor-dependent manner. This study reveals that aged gut microbiota -induced cognitive decline and microglia-mediated synapse loss that is, at least partially, due to the deficiency in B.p and its metabolite, IAA. It provides a proof-of-concept strategy for preventing neurodegenerative diseases by modulating gut probionts and their tryptophan metabolites.

Fasting-mimicking diet-enriched Bifidobacterium pseudolongum suppresses colorectal cancer by inducing memory CD8+ T cells

BACKGROUND

Fasting-mimicking diet (FMD) boosts the antitumour immune response in patients with colorectal cancer (CRC). The gut microbiota is a key host immunity regulator, affecting physiological homeostasis and disease pathogenesis.

OBJECTIVE

We aimed to investigate how FMD protects against CRC via gut microbiota modulation.

DESIGN

We assessed probiotic species enrichment in FMD-treated CRC mice using faecal metagenomic sequencing. The candidate species were verified in antibiotic-treated conventional and germ-free mouse models. Immune landscape alterations were evaluated using single-cell RNA sequencing and multicolour flow cytometry. The microbiota-derived antitumour metabolites were identified using metabolomic profiling.

RESULTS

Faecal metagenomic profiling revealed Bifidobacterium pseudolongum enrichment in FMD-treated CRC mice. B. pseudolongum mediates the FMD antitumour effects by increasing the tissue-resident memory CD8+ T-cell (TRM) population in CRC mice. The level of L-arginine, a B. pseudolongum functional metabolite, increased in FMD-treated CRC mice; furthermore, L-arginine induced the TRM phenotype in vivo and in vitro. Mechanistically, L-arginine is transported by the solute carrier family 7-member 1 (SLC7A1) receptor in CD8+ T cells. Both FMD and B. pseudolongum improved anti-CTLA-4 efficacy in the orthotopic mouse CRC model. In FMD-treated patients with CRC, the CD8+ TRM cell number increased as B. pseudolongum and L-arginine accumulated. The abundance of CD8+ TRM cells and B. pseudolongum was associated with a better prognosis in patients with CRC.

CONCLUSION

B. pseudolongum contributes to the FMD antitumour effects in CRC by producing L-arginine. This promotes CD8+ T-cell differentiation into memory cells. B. pseudolongum administration is a potential CRC therapeutic strategy.

Roles of the gut microbiota in hepatocellular carcinoma: from the gut dysbiosis to the intratumoral microbiota

Hepatocellular carcinoma (HCC) is closely linked to alterations in the gut microbiota. This dysbiosis is characterized by significant changes in the microbial population, which correlate with the progression of HCC. Gut dysbiosis ultimately promotes HCC development in several ways: it damages the integrity of the gut-vascular barrier (GVB), alters the tumor microenvironment (TME), and even affects the intratumoral microbiota. Subsequently, intratumoral microbiota present a characteristic profile and play an essential role in HCC progression mainly by causing DNA damage, mediating tumor-related signaling pathways, altering the TME, promoting HCC metastasis, or through other mechanisms. Both gut microbiota and intratumoral microbiota have dual effects on HCC progression; a comprehensive understanding of their complex biological roles will provide a theoretical foundation for potential clinical applications in HCC treatment.

Gut microbiota-mediated gut-liver axis: a breakthrough point for understanding and treating liver cancer

The trillions of commensal microorganisms living in the gut lumen profoundly influence the physiology and pathophysiology of the liver through a unique gut-liver axis. Disruptions in the gut microbial communities, arising from environmental and genetic factors, can lead to altered microbial metabolism, impaired intestinal barrier and translocation of microbial components to the liver. These alterations collaboratively contribute to the pathogenesis of liver disease, and their continuous impact throughout the disease course plays a critical role in hepatocarcinogenesis. Persistent inflammatory responses, metabolic rearrangements and suppressed immunosurveillance induced by microbial products underlie the pro-carcinogenic mechanisms of gut microbiota. Meanwhile, intrahepatic microbiota derived from the gut also emerges as a novel player in the development and progression of liver cancer. In this review, we first discuss the causes of gut dysbiosis in liver disease, and then specify the pivotal role of gut microbiota in the malignant progression from chronic liver diseases to hepatobiliary cancers. We also delve into the cellular and molecular interactions between microbes and liver cancer microenvironment, aiming to decipher the underlying mechanism for the malignant transition processes. At last, we summarize the current progress in the clinical implications of gut microbiota for liver cancer, shedding light on microbiota-based strategies for liver cancer prevention, diagnosis and therapy.

Gut microbiota metabolism of branched-chain amino acids and their metabolites can improve the physiological function of aging mice

The metabolism of branched-chain amino acids by gut microbiota can improve overall health and may reverse aging. In this study, we investigated Parabacteroides merdae, a gut microbe that is known to catabolise branched-chain amino acids (BCAAs). Three metabolites of BCAAs isovalerate, 2-methylbutyrate, and isobutyrate were used to treat D-gal induced aging mice. The results showed that these treatments could delay aging in mice by providing health benefits in reducing oxidative stress and inflammation, improving muscle capacity, reversing brain acetylcholine levels, and regulating blood glucose. The mechanism was preliminarily explored by combining the gut microbiota metagenome and faecal serum metabolome. Parabacteroides merdae altered the species composition and structure of the gut microbiota in mice. Increasing the abundance of beneficial bacteria, such as Bifidobacterium pseudolongum. Three metabolites affects the gut microbiota and the body's pathways of protein and improves the overall health through a variety of signaling pathways. Overall, regulating the gut microbiota involved in branched-chain amino acid metabolism to bring health benefits may be a new way of reversing aging.

Multi-omics reveal the effects and regulatory mechanism of dietary echinocystic acid supplementation on abdominal fat and liver steatosis in broiler chickens

The accumulation of abdominal fat and the metabolic dysfunction-associated fatty liver disease (MAFLD) are prevalent problems in the poultry industry, and seriously compromise broiler health and reduce economic benefits. Echinocystic acid (EA), a natural product with anti-inflammatory and antioxidant effects, has been demonstrated to reduce abdominal fat deposition and improve intestinal inflammation in mice. However, it has not been reported in poultry research. In this study, we employed chicken hepatocytes (Leghorn male hepatoma cells, LMHs) to construct an oleic acid and palmitic acid (OA/PA)-induced MAFLD model in vitro and 60 male K90 chickens were induced MAFLD by a high-fat diet (HFD) to examine the impact of EA on liver-lipid metabolism and abdominal fat deposition. Moreover, metabolomic analysis, 16S rDNA gene sequencing, and transcriptomic profiling were performed to determine the mechanism of EA. The results showed that EA (10 μM) significantly reduced triglyceride (TG) and total cholesterol (TC) levels in vitro. Moreover, EA reduced abdominal fat deposition without affecting growth performance. EA significantly decreased TC, TG, and low-density lipoprotein-cholesterol (LDL-C) levels, and increased high-density lipoprotein-cholesterol (HDL-C) levels in the blood. Additionally, EA supplementation altered the composition of the intestinal microbiota, particularly by decreasing the ratio of Firmicutes to Bacteroidetes. Furthermore, liver metabolomics analysis revealed that EA increased the abundance of metabolites related to arginine metabolism and mitochondrial oxidation pathways, and these metabolites were predicted to be positively correlated with the gut genera enriched by EA. EA also altered the expression patterns of genes related to liver lipid metabolism and inflammation, particularly CYP7A1, CYP7B1, CYP3A5, and ACAT, which are enriched in the PPAR signaling pathway and steroid hormone metabolism. Moreover, correlation analysis revealed that there was a close correlation between differential gut microbiota, metabolites, and gene expression profiles. Collectively, the results indicated that EA may alleviate MAFLD by regulating steroid hormone metabolism and modulating the gut microbiota. EA may be a candidate feed additive to prevent abdominal fat deposition and MAFLD in the broiler industry.

Metabolic dysfunction-associated steatotic liver disease and the gut microbiome: pathogenic insights and therapeutic innovations

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a major cause of liver disease worldwide, and our understanding of its pathogenesis continues to evolve. MASLD progresses from steatosis to steatohepatitis, fibrosis, and cirrhosis, and this Review explores how the gut microbiome and their metabolites contribute to MASLD pathogenesis. We explore the complexity and importance of the intestinal barrier function and how disruptions of the intestinal barrier and dysbiosis work in concert to promote the onset and progression of MASLD. The Review focuses on specific bacterial, viral, and fungal communities that impact the trajectory of MASLD and how specific metabolites (including ethanol, bile acids, short chain fatty acids, and other metabolites) contribute to disease pathogenesis. Finally, we underscore how knowledge of the interaction between gut microbes and the intestinal barrier may be leveraged for MASLD microbial-based therapeutics. Here, we include a discussion of the therapeutic potential of prebiotics, probiotics, postbiotics, and microbial-derived metabolites.

Gut microbiota differences, metabolite changes, and disease intervention during metabolic - dysfunction - related fatty liver progression

In the current era, metabolic dysfunction-associated steatotic liver disease (MASLD) has gradually developed into a major type of chronic liver disease that is widespread globally. Numerous studies have shown that the gut microbiota plays a crucial and indispensable role in the progression of MASLD. Currently, the gut microbiota has become one of the important entry points for the research of this disease. Therefore, the aim of this review is to elaborate on the further associations between the gut microbiota and MASLD, including the changes and differences in the microbiota between the healthy liver and the diseased liver. Meanwhile, considering that metabolic dysfunction-associated fatty liver and metabolic dysfunction-associated steatohepatitis are abnormal pathological states in the development of the disease and that the liver exhibits different degrees of fibrosis (such as mild fibrosis and severe fibrosis) during the disease progression, we also conduct a comparison of the microbiota in these states and use them as markers of disease progression. It reveals the changes in the production and action mechanisms of short-chain fatty acids and bile acids brought about by changes in the gut microbiota, and the impact of lipopolysaccharide from Gram-negative bacteria on the disease. In addition, the regulation of the gut microbiota in disease and the production and inhibition of related disease factors by the use of probiotics (including new-generation probiotics) will be explored, which will help to monitor the disease progression of patients with different gut microbiota compositions in the future and carry out personalized targeted therapies for the gut microbiota. This will achieve important progress in preventing and combating this disease.

The Role of the Gut-Biliary-Liver Axis in Primary Hepatobiliary Liver Cancers: From Molecular Insights to Clinical Applications

Background: Hepatobiliary liver cancers (HBLCs) represent the sixth most common neoplasm in the world. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) constitute the main HBLC types, with alarming epidemiological projections. Methods: In recent decades, alterations in gut microbiota, with mutual implications on the gut-liver axis and gut-biliary axis permeability status, have been massively investigated and proposed as HBLC pathogenetic deus ex machina. Results: In the HCC setting, elevated intestinal levels of Escherichia coli and other Gram-negative bacteria have been demonstrated, resulting in a close association with increased lipopolysaccharide (LPS) serum levels and, consequently, chronic systemic inflammation. In contrast, the intestinal microbiota of HCC individuals feature reduced levels of Lactobacillus spp., Bifidobacterium spp., and Enterococcus spp. In the CC setting, evidence has revealed an increased expression of Lactobacillus spp., with enhanced levels of Actynomices spp. and Alloscardovia spp. Besides impaired strains/species representation, gut-derived metabolites, including bile acids (BAs), short-chain fatty acids (SCFAs), and oxidative-stress-derived products, configure a network severely impacting the progression of HBLC. Conclusions: In the era of Precision Medicine, the clarification of microbiota composition and functioning in HCC and CC settings can contribute to the identification of individual signatures, potentially providing novel diagnostic markers, therapeutic approaches, and prognostic/predictive tools.

Ruminococcus bromii-generated acetate alleviated Clonorchis sinensis-induced liver fibrosis in mice

Introduction

Infection with Clonorchis sinensis (C. sinensis) has the potential to induce liver fibrosis and significantly alter the gut microbiota. However, it remains unclear how these changes in the gut microbiota, through the gut-liver axis, influence the progression of liver fibrosis. Furthermore, it is uncertain whether targeting the gut microbiota, based on the concept of the gut-liver axis, could be a potential therapeutic strategy for alleviating liver fibrosis.

Methods

The gut microbiota alterations in C. sinensis-infected mice at multiple time points were analyzed through 16S rDNA high-throughput sequencing. Ruminococcus bromii (R.bromii) therapeutic effect on C. sinensis infected mice was evaluated. Metabolic changes following produced by R. bromii were analyzed using short-chain fatty acids (SCFAs) metabolomics. Additionally, R. bromii conditioned medium (R.b CM) or its metabolites were co-cultured with two hepatic stellate cell lines (LX2 and JS1) in vitro to assess their anti-fibrotic effects. Finally, RNA sequencing was employed to investigate the specific mechanism by which acetate inhibits hepatic stellate cells (HSCs) activation.

Results

The abundance of R. bromii increased during the inflammatory stage of C. sinensis infection and decreased significantly during the fibrosis stage. Oral gavage of R. bromii significantly inhibited C. sinensis-induced liver fibrosis while restoring the intestinal barrier. The activation of HSCs was significantly inhibited in vitro upon incubation with R.b CM. Acetate was identified as a key metabolite generated from R. bromii in R.b CM, and acetate attenuated C. sinensis-induced liver fibrosis in vitro and in vivo. Mechanistically, acetate inhibited the activation of HSCs by activating the PI3K/AKT signaling pathway to prevent the progression of liver fibrosis in mice infected with C. sinensis.

Discussion

R. bromii exerted a protective effect on hepatic fibrosis by delivering acetate via the gut-liver axis to active the PI3K/AKT signaling pathway in HSCs. Furthermore, R. bromii can be used as a probiotic therapy to alleviate hepatic fibrosis.

Study on the metastatic mechanism of LINC00115 in adenocarcinoma of the Esophagogastric junction

Adenocarcinoma of the esophagogastric junction (AEG) is a common and deadly cancer, and an in-depth investigation of its molecular mechanisms of metastasis is crucial for discovering new therapeutic targets. This study explores the role of the long non-coding RNA (lncRNA) LINC00115 in AEG metastasis and its underlying mechanisms. Through the analysis of 108 pairs of AEG cancer tissues and matched adjacent tissues, we found a significant upregulation of LINC00115 in AEG tissues, closely associated with TNM staging and lymph node metastasis. Utilizing cell counting kit-8 (CCK-8) assays, colony formation experiments, wound healing assays, flow cytometry for apoptosis and cell cycle analysis, and Transwell assays, we have confirmed that LINC00115 significantly promotes proliferation, migration, and invasion of AEG cells in vitro. Animal experiments further validate the role of LINC00115 in promoting tumor growth and metastasis in vivo. Additionally, our nuclear-cytoplasmic fractionation experiments and RNA fluorescence in situ hybridization (FISH) reveal that LINC00115, along with its interacting protein KH-Type splicing regulatory protein (KHSRP), predominantly localizes to the cell nucleus. By conducting RNA pull-down assays and mass spectrometry (MS) analysis, we have identified a direct interaction between LINC00115 and KHSRP protein and further determined their binding sites through catRAPID and ENCORI databases. This study provides evidence of LINC00115 as a novel biomarker and potential therapeutic target for AEG and offers a fresh perspective on understanding the molecular mechanisms of AEG metastasis.

The microbiome- and metabolome-modulating activity of dietary cholesterol: insights from the small and large intestines

Cholesterol is an important lipid molecule that affects the gut microbiome upon ingestion. We systematically investigated the effects of cholesterol on the microbiota of the large and small intestines using ex vivo and in vivo models, combining flow cytometry, metabolomics, and metagenomics. The results showed that cholesterol directly causes a loss of bacterial membrane polarity and integrity, as well as a reduction in microbial metabolic activity. Cholesterol directly affected the global metabolism of the large and small intestinal microbiota, including amino acid, carbohydrate, and nucleotide metabolism. Ex vivo and in vivo studies shared similar results, showing that cholesterol increased the abundance of the primary bile acid-metabolizing bacteria Clostridium and Dorea in the large intestinal microbiota, confirming the enrichment effect of cholesterol on these bacteria. In the in vivo model, increased conjugated bile acids in the small intestine and decreased abundance of BSH-containing Bifidobacterium were observed due to cholesterol. Only in vivo models have demonstrated that cholesterol increases phosphatidylcholine levels in both the small and large intestines, which may be related to the effects of cholesterol on host metabolism. The pro-inflammatory capacity of the intestinal microbiota was enhanced by cholesterol, as evidenced by the increased levels of IL-1β and TNF-α in THP-1 cells upon stimulation with cholesterol-treated microbiota. This study comprehensively elucidates the effects of cholesterol on the composition and metabolic functions of the microbiota in both the large and small intestines. It offers a novel perspective on the ways in which cholesterol affects host metabolism via the gut microbiome.

Gut microbiome and liver diseases

Symbiotic microbiota plays a crucial role in the education, development, and maintenance of the host immune system, significantly contributing to overall health. Through the gut-liver axis, the gut microbiota and liver have a bidirectional relationship that is becoming increasingly evident as more research highlights the translocation of the gut microbiota and its metabolites. The focus of this narrative review is to examine and discuss the importance of the gut-liver axis and the enterohepatic barrier in maintaining overall health. Additionally, we emphasize the crucial role of the gut microbiome in liver diseases and explore potential therapeutic strategies for liver diseases by manipulating the microbiota.

BefA protein alleviates progression of non-alcoholic fatty liver disease by modulating the AMPK signaling pathway through the gut-liver axis

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver diseases worldwide, necessitating urgent novel oral treatments. In this study, β-cell expansion factor A (BefA) was evaluated in a murine NAFLD model induced by high-fat diet (HFD). Our results revealed that BefA significantly reduced body weight (36.58 ± 1.55 g vs. 42.30 ± 1.96 g, p < 0.01), fat mass-to-body weight ratio (0.023 ± 0.019 vs. 0.300 ± 0.019, p < 0.05), liver weight (1.90 ± 0.07 g vs. 2.31 ± 0.21 g, p < 0.05), and liver function parameters (ALT, AST, ALP levels reduced, p < 0.05). Notably, BefA reversed the pathological features of NAFLD, decreasing hepatic steatosis score from 3.67 ± 0.47 to 1.67 ± 0.47 (p < 0.01). Mechanistically, BefA activated the AMPK signaling pathway, resulting in the suppression of lipogenic gene transcription (ACC, FASN, SREBP-1c) and the enhancement of fatty acid oxidation (CPT-1, PPAR-α). However, AMPK inhibitor and broad-spectrum antibiotics significantly attenuated the benefits observed with BefA treatment, increasing body weight, fat-to-body weight ratio, and liver weight (p < 0.05). Similar detrimental effects were also observed in liver function indices and histopathological characteristics. These findings underscore the pivotal role of both gut microbiota modulation and AMPK signaling in BefA's therapeutic efficacy, making it a promising multitargeted approach for NAFLD treatment.

Pharmacological treatment for metabolic dysfunction-associated steatotic liver disease and related disorders: Current and emerging therapeutic options

Metabolic dysfunction-associated steatotic liver disease (MASLD; formerly known as nonalcoholic fatty liver disease) is a chronic liver disease affecting over a billion individuals worldwide. MASLD can gradually develop into more severe liver pathologies, including metabolic dysfunction-associated steatohepatitis (MASH), cirrhosis, and liver malignancy. Notably, although being a global health problem, there are very limited therapeutic options against MASLD and its related diseases. While a thyroid hormone receptor agonist (resmetirom) is recently approved for MASH treatment, other efforts to control these diseases remain unsatisfactory. Given the projected rise in MASLD and MASH incidence, it is urgent to develop novel and effective therapeutic strategies against these prevalent liver diseases. In this article, the pathogenic mechanisms of MASLD and MASH, including insulin resistance, dysregulated nuclear receptor signaling, and genetic risk factors (eg, patatin-like phospholipase domain-containing 3 and hydroxysteroid 17-β dehydrogenase-13), are introduced. Various therapeutic interventions against MASH are then explored, including approved medication (resmetirom), drugs that are currently in clinical trials (eg, glucagon-like peptide 1 receptor agonist, fibroblast growth factor 21 analog, and PPAR agonist), and those failed in previous trials (eg, obeticholic acid and stearoyl-CoA desaturase 1 antagonist). Moreover, given that the role of gut microbes in MASLD is increasingly acknowledged, alterations in the gut microbiota and microbial mechanisms in MASLD development are elucidated. Therapeutic approaches that target the gut microbiota (eg, dietary intervention and probiotics) against MASLD and related diseases are further explored. With better understanding of the multifaceted pathogenic mechanisms, the development of innovative therapeutics that target the root causes of MASLD and MASH is greatly facilitated. The possibility of alleviating MASH and achieving better patient outcomes is within reach. SIGNIFICANCE STATEMENT: Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease worldwide, and it can progress to more severe pathologies, including steatohepatitis, cirrhosis, and liver cancer. Better understanding of the pathogenic mechanisms of these diseases has facilitated the development of innovative therapeutic strategies. Moreover, increasing evidence has illustrated the crucial role of gut microbiota in the pathogenesis of MASLD and related diseases. It may be clinically feasible to target gut microbes to alleviate MASLD in the future.

Involvement of gut microbiota in chlorpyrifos-induced subchronic toxicity in mice

Chlorpyrifos (CPF) is one of the most widely used organophosphorus pesticides all over the world. Unfortunately, long-term exposure to CPF may cause considerable toxicity to organisms. Some evidence suggests that the intestinal microbial community may be involved in regulating the toxicity of CPF. In this study, we explored if the intestinal microbial community is involved in regulating the toxicity of CPF. Adult mice were continuously exposed to CPF (4 mg/kg body weight /day) for 10 weeks with or without a 2-week pretreatment of antibiotics to change the ecological structure of intestinal microorganisms in advance. Pathological changes in the liver and kidneys were examined and the biochemical parameters in serum for liver and kidney functions were detected, and changes in the intestinal microbial community of the mice were measured. The results showed that subchronic exposure to low-dose CPF caused an ecological imbalance in the intestinal flora and caused pathological damage to the liver and kidneys. Serum biochemical indicators for liver function such as alanine aminotransferase and total bile acids contents and renal biochemical indicators such as urea nitrogen and creatinine were disrupted. Changes in intestinal microbial community structure by using antibiotics in advance can effectively alleviate the pathological and functional damage to the liver and kidneys caused by CPF exposure. Further analysis showed that intestinal microorganisms such as Saccharibacteria (TM7), Odoribacter, Enterococcus and AF12 genera may be involved in managing the toxicity of CPF. Together, our results indicated that long-term low-dose CPF exposure could induce hepatotoxicity and nephrotoxicity, and liver and kidney damage may be mitigated by altering the ecology of intestinal microorganisms.

Simulated digestion and gut microbiota fermentation of polysaccharides from Lactarius hatsudake Tanaka mushroom

Lactarius hatsudake Tanaka is a popular edible mushroom known for its delicious flavor and health benefits. Its polysaccharides (LHP) exhibit significant bioactivity, but their application is limited due to uncertainties in digestion. This study used in vitro simulated models to explore the dynamic changes of LHP during the digestive and fermentation process and validated them through mouse models. Results revealed that LHP cannot be digested by the simulated digestive system, but is primarily degraded into fatty acids by gut microbes, accompanied by reductions in molecular weight, carbohydrate content, and pH. Additionally, LHP promotes the proliferation of beneficial bacteria (Faecalibacterium, Bifidobacterium, Lactobacillus, etc.), while inhibiting harmful bacteria (Escherichia and Shigella). Metabolite analysis in serum indicated that LHP can regulate amino acid and lipid metabolism, enhancing overall health. These findings provide a theoretical foundation for developing LHP as a potential prebiotic, highlighting its considerable promise for disease prevention through improved intestinal health.

Emerging insights into the gut microbiota as a key regulator of immunity and response to immunotherapy in hepatocellular carcinoma

The gut microbiota, a complex microbial ecosystem closely connected to the liver via the portal vein, has emerged as a critical regulator of liver health and disease. Numerous studies have underscored its role in the onset and progression of liver disorders, including alcoholic liver disease, metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction-associated steatohepatitis (MASH), liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). This review provides a comprehensive overview of current insights into the influence of the gut microbiota on HCC progression, particularly its effects on immune cells within the HCC tumor microenvironment (TME). Furthermore, we explore the potential of gut microbiota-targeted interventions, such as antibiotics, probiotics, prebiotics, and fecal microbiota transplantation (FMT), to modulate the immune response and improve outcomes of immunotherapy in HCC. By synthesizing insights from recent studies, this review aims to highlight microbiota-based strategies that may enhance immunotherapy outcomes, advancing personalized approaches in HCC treatment.

Current Therapeutic Landscape for Metabolic Dysfunction-Associated Steatohepatitis

In recent years, "metabolic dysfunction-associated steatotic liver disease" (MASLD) has been proposed to better connect liver disease to metabolic dysfunction, which is the most common chronic liver disease worldwide. MASLD affects more than 30% of individuals globally, and it is diagnosed by the combination of hepatic steatosis and obesity, type 2 diabetes, or two metabolic risk factors. MASLD begins with the buildup of extra fat, often greater than 5%, within the liver, causing liver hepatocytes to become stressed. This can proceed to a more severe form, metabolic dysfunction-associated steatohepatitis (MASH), in 20-30% of people, where inflammation in the liver causes tissue fibrosis, which limits blood flow over time. As fibrosis worsens, MASH may lead to cirrhosis, liver failure, or even liver cancer. While the pathophysiology of MASLD is not fully known, the current "multiple-hits" concept proposes that dietary and lifestyle factors, metabolic factors, and genetic or epigenetic factors contribute to elevated oxidative stress and inflammation, causing liver fibrosis. This review article provides an overview of the pathogenesis of MASLD and evaluates existing therapies as well as pharmacological drugs that are currently being studied in clinical trials for MASLD or MASH.

Hepatocellular carcinoma: signaling pathways and therapeutic advances

Liver cancer represents a major global health concern, with projections indicating that the number of new cases could surpass 1 million annually by 2025. Hepatocellular carcinoma (HCC) constitutes around 90% of liver cancer cases and is primarily linked to factors incluidng aflatoxin, hepatitis B (HBV) and C (HCV), and metabolic disorders. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Therefore, HCC patients usually present with tumors in advanced and incurable stages. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of HCC. Beyond the frequently altered and therapeutically targeted receptor tyrosine kinase (RTK) pathways in HCC, pathways involved in cell differentiation, telomere regulation, epigenetic modification and stress response also provide therapeutic potential. Investigating the key signaling pathways and their inhibitors is pivotal for achieving therapeutic advancements in the management of HCC. At present, the primary therapeutic approaches for advanced HCC are tyrosine kinase inhibitors (TKI), immune checkpoint inhibitors (ICI), and combination regimens. New trials are investigating combination therapies involving ICIs and TKIs or anti-VEGF (endothelial growth factor) therapies, as well as combinations of two immunotherapy regimens. The outcomes of these trials are expected to revolutionize HCC management across all stages. Here, we provide here a comprehensive review of cellular signaling pathways, their therapeutic potential, evidence derived from late-stage clinical trials in HCC and discuss the concepts underlying earlier clinical trials, biomarker identification, and the development of more effective therapeutics for HCC.

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

Could intratumoural microbiota be key to unlocking treatment responses in hepatocellular carcinoma?

Hepatocellular carcinoma (HCC) is the third cause of cancer-related mortality worldwide. Current treatments include surgery and immunotherapy with variable response. Despite aggressive treatment, disease progression remains the biggest contributor to mortality. Thus, there is an urgent unmet need to improve current treatments through a better understanding of HCC tumourigenesis. The gut microbiota has been intensively examined in the context of HCC, with evidence showing gut modulation has the potential to modulate tumourigenesis and prognosis. In addition, recent literature suggests the presence of an intratumoural microbiota that may exert significant impacts on the development of solid tumours including HCC. By drawing parallels between the gut and hepatic/tumoural microbiota, we explore in the present review how the hepatic microbiota is established, its impact on tumourigenesis, and how modulation of the gut and hepatic microbiota may be key to improving current treatments of HCC. In particular, we highlight key bacteria that have been discovered in HCC tumours, and how they may affect the tumour immune microenvironment and HCC tumourigenesis. We then explore current therapies that target the intratumoural microbiota. With a deeper understanding of how the intratumoural microbiota is established, how different bacteria may be involved in HCC tumourigenesis, and how they can be targeted, we hope to spark future research in validating intratumoural microbiota as an avenue for improving treatment responses in HCC.

Characterization of liver, adipose, and fecal microbiome in obese patients with MASLD: links with disease severity and metabolic dysfunction parameters

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) encompasses a range of histological findings from the generally benign simple steatosis to steatohepatitis (MASH) which can progress to fibrosis and cirrhosis. Several factors, including the microbiome, may contribute to disease progression.

RESULTS

Here, we demonstrate links between the presence and abundance of specific bacteria in the adipose and liver tissues, inflammatory genes, immune cell responses, and disease severity. Overall, in MASLD patients, we observed a generalized obesity-induced translocation of gut bacteria to hepatic and adipose tissues. We identified microbial patterns unique to more severely diseased tissues. Specifically, Enterococcus, Granulicatella, and Morganellaceae abundance is positively correlated with immune cell counts and inflammatory gene expression levels, and both genera are significantly enriched in MASH patients. Brevibacterium is enriched in adipose tissues of patients with liver fibrosis.

CONCLUSION

Together, these results provide further insight into the microbial factors that may be driving disease severity. Video Abstract.

The effect of gut microbiome-targeted therapies in nonalcoholic fatty liver disease: a systematic review and network meta-analysis

Background

The incidence of NAFLD is increasing. Preclinical evidences indicate that modulation of the gut microbiome could be a promising target in nonalcoholic fatty liver disease.

Method

A systematic review and network meta-analysis was conducted to compare the effect of probiotics, synbiotics, prebiotics, fecal microbiota transplant, and antibiotics on the liver-enzyme, metabolic effects and liver-specific in patients with NAFLD. The randomized controlled trails (RCTs), limited to English language were searched from database such as Pubmed, Embase, Web of science and Cochrane Library from inception to November 2024. Review Manager 5.3 was used to to draw a Cochrane bias risk. Inconsistency test and publication-bias were assessed by Stata 14.0. Random effect model was used to assemble direct and indirect evidences. The effects of the intervention were presented as mean differences with 95% confidence interval.

Results

A total of 1921 patients from 37 RCTs were eventually included in our study. 23 RCTs evaluated probiotics, 10 RCTs evaluated synbiotics, 4 RCTs evaluated prebiotics, 3 RCTs evaluated FMT and one RCT evaluated antibiotics. Probiotics and synbiotics were associated with a significantly reduction in alanine aminotransferase [ALT, (MD: -5.09; 95%CI: -9.79, -0.39), (MD: -7.38, 95CI%: -11.94, -2.82)] and liver stiffness measurement by elastograph [LSM, (MD: -0.37;95%CI: -0.49, -0.25), (MD: -1.00;95%CI: -1.59, -0.41)]. In addition to, synbiotics was superior to probiotics in reducing LSM. Synbiotics was associated with a significant reduction of Controlled Attenuation Parameter [CAP, (MD: -39.34; 95%CI: -74.73, -3.95)]. Both probiotics and synbiotics were associated with a significant reduction of aspartate transaminase [AST, (MD: -7.81; 95%CI: -15.49, -0.12), (MD: -13.32; 95%CI: -23, -3.64)]. Probiotics and Allogenic FMT was associated with a significant reduction of Homeostatic Model Assessment for Insulin Resistance [HOMA-IR, (MD: -0.7, 95%CI: -1.26, -0.15), (MD: -1.8, 95%CI: -3.53, - 0.07)]. Probiotics was associated with a significant reduction of body mass index [BMI, MD: -1.84, 95%CI: -3.35, -0.33].

Conclusion

The supplement of synbiotics and probiotics maybe a promising way to improve liver-enzyme, LSM, and steatosis in patients with NAFLD. More randomized controlled trials are needed to determine the efficacy of FMT and antibiotics on NAFLD. And the incidence of adverse events of MTTs should be further explored.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, CRD42023450093.

Gut‑liver axis in liver disease: From basic science to clinical treatment (Review)

Incidence of a number of liver diseases has increased. Gut microbiota serves a role in the pathogenesis of hepatitis, cirrhosis and liver cancer. Gut microbiota is considered 'a new virtual metabolic organ'. The interaction between the gut microbiota and liver is termed the gut‑liver axis. The gut‑liver axis provides a novel research direction for mechanism of liver disease development. The present review discusses the role of the gut‑liver axis and how this can be targeted by novel treatments for common liver diseases.

Unraveling Mechanisms of Genetic Risks in Metabolic Dysfunction-Associated Steatotic Liver Diseases: A Pathway to Precision Medicine

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global health problem, affecting ∼1 billion people. This condition is well established to have a heritable component with strong familial clustering. With the extraordinary breakthroughs in genetic research techniques coupled with their application to large-scale biobanks, the field of genetics in MASLD has expanded rapidly. In this review, we summarize evidence regarding genetic predisposition to MASLD drawn from family and twin studies. Significantly, we delve into detailed genetic variations associated with diverse pathogenic mechanisms driving MASLD. We highlight the interplay between these genetic variants and their connections with metabolic factors, the gut microbiome, and metabolites, which collectively influence MASLD progression. These discoveries are paving the way for precise medicine, including noninvasive diagnostics and therapies. The promising landscape of novel genetically informed drug targets such as RNA interference is explored. Many of these therapies are currently under clinical validation, raising hopes for more effective MASLD treatment.

High molecular weight polysaccharides from Ganoderma lucidum attenuates inflammatory responses, gut microbiota, and liver metabolomic in lipopolysaccharide-induced liver injury mice

High molecular weight polysaccharides (GLPH, ≥300 kDa) are the major compounds of Ganoderma lucidum with improving liver function. However, the effect of GLPH on improving acute liver injury (ALI) wasn't revealed. Herein, the ameliorating effects and mechanisms of GLPH were revealed in lipopolysaccharide (LPS)-ALI mice. The results indicated that GLPH intervention (100 mg/kg day) reduced the serum ALT (22.67 ± 6.48 U/L), AST (21.19 ± 7.08 U/L), ALP (56.98 ± 12.71 U/L), GGT (1.48 ± 0.22 U/L) levels in ALI mice (p < 0.01). GLPH activated the hepatic antioxidant enzymes activity [SOD (3.75 ± 1.17 U/mg prot.) and CAT (3.01 ± 0.85 U/mg prot.)] and suppressed the hepatic inflammatory cytokines production [TNF-α (40.14 ± 8.15 pg/mg prot.), IL-1β (35.47 ± 10.90 pg/mg prot.), and IL-6 (8.44 ± 1.71 pg/mg prot.)] by regulating the Nrf2/OH-1 and Tlr4/NF-κB pathway (p < 0.05). Furthermore, GLPH regulated the abundance of Bifidobacterium, Akkermansia, Anaerovorax, and Tyzzerella, which associated with cecal SCFAs, hepatic inflammatory cytokines and antioxidant enzymes. GLPH significantly changed 85 liver metabolites (p < 0.01), which is beneficial for prevent the development of ALI. These results suggested GLPH displayed promising prebiotic properties in relieving ALI, regulating gut microbiota and liver metabolism.

Postbiotics From Lactobacillus Johnsonii Activates Gut Innate Immunity to Mitigate Alcohol-Associated Liver Disease

Prolonged alcohol consumption disrupts the gut microbiota and the immune system, contributing to the pathogenesis of alcohol-associated liver disease (ALD). Probiotic-postbiotic intervention strategies can effectively relieve ALD by maintaining gut homeostasis. Herein, the efficacy of heat-killed Lactobacillus johnsonii (HKLJ) in mitigating alcoholic liver damage is demonstrated in mouse models of ALD. The gut-liver axis is identified as a pivotal pathway for the protective effects of L. johnsonii against ALD. Specifically, HKLJ is found to upregulate the expression of intestinal lysozymes, thereby enhancing the production of immunoregulatory substances from gut bacteria, which subsequently activated the Nucleotide-binding oligomerization domain 2 (NOD2)-interleukin (IL-23)-IL-22 innate immune axis. The elevated IL-22 upregulated the antimicrobial peptide synthesis to maintain intestinal homeostasis and moreover activated the Signal transducer and activator of Transcription3 (STAT3) pathway in the liver to facilitate the repair of hepatic injuries. The heat-killed L. johnsonii provoked immunity helps correct the gut microbiota dysbiosis, specifically by reversing the reduction of butyrate-producing bacteria (such as Faecalibaculum rodentium) and the expansion of opportunistic pathogens (such as Helicobacter sp. and Pichia kudriavzevii) induced by ethanol. The findings provide novel insights into the gut microbiota-liver axis that may be leveraged to enhance the treatment of ALD.

Gut microbial metabolites in cancer therapy

The gut microbiota plays a crucial role in maintaining homeostasis and promoting health. A growing number of studies have indicated that gut microbiota can affect cancer development, prognosis, and treatment through their metabolites. By remodeling the tumor microenvironment and regulating tumor immunity, gut microbial metabolites significantly influence the efficacy of anticancer therapies, including chemo-, radio-, and immunotherapy. Several novel therapies that target gut microbial metabolites have shown great promise in cancer models. In this review, we summarize the current research status of gut microbial metabolites in cancer, aiming to provide new directions for future tumor therapy.

Administration of Alistipes indistinctus prevented the progression from nonalcoholic fatty liver disease to nonalcoholic steatohepatitis by enhancing the gut barrier and increasing Lactobacillus spp

Metabolic-associated fatty liver disease (MAFLD) is an important public health problem, and the gut microbiota has become a new treatment target for MAFLD. Previously, A. indistinctus, a core gut bacterium, was shown to potentially contribute to the prevention of MAFLD. However, the effect and mechanism of A. indistinctus on MAFLD are still unclear and need to be investigated. This study primarily evaluated whether A. indistinctus can improve gut microbiota disorders and prevent the progression from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH) in mice fed a high-fat diet (HFD). First, we observed that A. indistinctus significantly improved lipid metabolism disorders and reduced hepatic inflammation induced by HFD consumption in mice. We found that A. indistinctus improved gut barrier function and inhibited the LPS/TLR4/NF-κB pathway, thereby reducing hepatic inflammation. Moreover, 16S rRNA V3-V4 analyses revealed that A. indistinctus could significantly change the structure of the gut microbiota and increase the abundance of L. johnsonii by promoting its growth. Finally, we showed that L. johnsonii administration significantly improved lipid metabolism disorders and reduced hepatic lipid accumulation induced by HFD consumption in mice. In summary, A. indistinctus administration significantly reduces hepatic inflammation by improving gut barrier function and improves lipid metabolism disorders by promoting the growth of L. johnsonii. Our research improves the understanding of the gut microbiota and provides a basis for future therapeutic use of A. indistinctus.

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.