Hepatobiliary and pancreatic: Multi-donor fecal microbiota transplantation attenuated high-fat diet-induced hepatic steatosis in mice by remodeling the gut microbiota

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.

Gut microbiota in patients with metabolic, dysfunction-associated steatotic liver disease

PURPOSE OF REVIEW

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a highly prevalent condition that can progress to fibrosis, steatohepatitis, and hepatocellular carcinoma. This review examines recent advances concerning the role of gut microbiota in MASLD and microbiota-focused interventions to positively impact disease outcome.

RECENT FINDINGS

Dysbiotic microbiota and a compromised gut barrier facilitate the translocation of microbial-associated molecular patterns and harmful metabolites into the portal circulation and liver, where they exacerbate inflammatory and fibrogenic processes. Conversely, other bacterial metabolites have protective effects in the liver. Therefore, microbiota homeostasis is essential for maintaining liver health.

SUMMARY

Levels of harmful bacterial metabolites including ethanol, NH3, trimethylamine-L-oxide, 2-oleylglycerol, and litocholic acid are often increased in patients with MASLD. Conversely, short-chain fatty acids, indole derivatives, histidine, and the acids taurodeoxycholic, 3-succinylcholic, and hyodeoxycholic are decreased. The main aim of current interventions/treatments is to reduce harmful metabolites and increase beneficial ones. These interventions include drugs (pemafibrate, metformin, obeticholic acid), natural compounds (silymarin, lupeol, dietary fiber, peptides), exogenous bacteria (probiotics, gut symbionts), special diets (Mediterranean diet, time-restricted feeding), as well as microbiota transplantation, and phage therapy. Most improve gut permeability, liver inflammation, and fibrosis through microbiota regulation, and are promising alternatives for MASLFD management. However, most results come from animal studies, while clinical trials in MASLD patients are lacking. Further research is therefore needed in this area.

CCL25 contributes to the pathogenesis of D-Gal/LPS-induced acute liver failure

BACKGROUND AND AIM

Acute liver failure (ALF) is a fatal clinical syndrome of severe hepatic dysfunction. Chemokines promote liver diseases by recruiting and activating immune cells. We aimed to investigate the role of C-C chemokine ligand 25 (CCL25) in ALF.

METHODS

An ALF mouse model induced by D-galactosamine/lipopolysaccharide was evaluated through liver hematoxylin and eosin staining and serum transaminase and cytokine measurement. CCL25 expression in serum was analyzed by ELISA and in liver by immunohistochemical staining and western blot. C-C chemokine receptor 9 (CCR9)-expressing cells in the liver were identified by immunofluorescence staining. The effects of anti-CCL25 on ALF were evaluated in vivo. Cytokine expression and migration of CCL25-stimulated RAW264.7 macrophages were studied. We also investigated the role of anti-CCL25 and BMS-345541, an NF-κB signaling inhibitor, in vitro. NF-κB activation was assessed via western blot, and p65 nuclear translocation was detected using cellular immunofluorescence.

RESULTS

ALF mice showed severe histological damage and high serum levels of aminotransferase and inflammatory cytokines. Elevated CCL25 and NF-κB activation was observed in vivo. CCR9 was expressed on macrophages in ALF mouse liver. ALF was suppressed after anti-CCL25 treatment, with significant NF-κB inhibition. In vitro, CCL25 induced strong migration and cytokine release in RAW264.7 macrophages, which were eliminated by anti-CCL25 and BMS-345541. Furthermore, the NF-κB activation and p65 nuclear translocation induced by CCL25 were also inhibited by anti-CCL25 and BMS-345541.

CONCLUSION

CCL25 contributes to ALF development by inducing macrophage-mediated inflammation via activation of the NF-κB signaling.

Role of the Gut Microbiome in Metabolic Dysfunction-Associated Steatotic Liver Disease

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD)-previously described as nonalcoholic fatty liver disease-continues to rise globally. Despite this, therapeutic measures for MASLD remain limited. Recently, there has been a growing interest in the gut microbiome's role in the pathogenesis of MASLD. Understanding this relationship may allow for the administration of therapeutics that target the gut microbiome and/or its metabolic function to alleviate MASLD development or progression. This review will discuss the interplay between the gut microbiome's structure and function in relation to the development of MASLD, assess the diagnostic yield of gut microbiome-based signatures as a noninvasive tool to identify MASLD severity, and examine current and emerging therapies targeting the gut microbiome-liver axis.

Gut-Liver-Pancreas Axis Crosstalk in Health and Disease: From the Role of Microbial Metabolites to Innovative Microbiota Manipulating Strategies

The functions of the gut are closely related to those of many other organs in the human body. Indeed, the gut microbiota (GM) metabolize several nutrients and compounds that, once released in the bloodstream, can reach distant organs, thus influencing the metabolic and inflammatory tone of the host. The main microbiota-derived metabolites responsible for the modulation of endocrine responses are short-chain fatty acids (SCFAs), bile acids and glucagon-like peptide 1 (GLP-1). These molecules can (i) regulate the pancreatic hormones (insulin and glucagon), (ii) increase glycogen synthesis in the liver, and (iii) boost energy expenditure, especially in skeletal muscles and brown adipose tissue. In other words, they are critical in maintaining glucose and lipid homeostasis. In GM dysbiosis, the imbalance of microbiota-related products can affect the proper endocrine and metabolic functions, including those related to the gut-liver-pancreas axis (GLPA). In addition, the dysbiosis can contribute to the onset of some diseases such as non-alcoholic steatohepatitis (NASH)/non-alcoholic fatty liver disease (NAFLD), hepatocellular carcinoma (HCC), and type 2 diabetes (T2D). In this review, we explored the roles of the gut microbiota-derived metabolites and their involvement in onset and progression of these diseases. In addition, we detailed the main microbiota-modulating strategies that could improve the diseases' development by restoring the healthy balance of the GLPA.

Reduction of product composition variability using pooled microbiome ecosystem therapy and consequence in two infectious murine models

Growing evidence demonstrates the key role of the gut microbiota in human health and disease. The recent success of microbiotherapy products to treat recurrent Clostridioides difficile infection has shed light on its potential in conditions associated with gut dysbiosis, such as acute graft-versus-host disease, intestinal bowel diseases, neurodegenerative diseases, or even cancer. However, the difficulty in defining a "good" donor as well as the intrinsic variability of donor-derived products' taxonomic composition limits the translatability and reproducibility of these studies. Thus, the pooling of donors' feces has been proposed to homogenize product composition and achieve higher taxonomic richness and diversity. In this study, we compared the metagenomic profile of pooled products to corresponding single donor-derived products. We demonstrated that pooled products are more homogeneous, diverse, and enriched in beneficial bacteria known to produce anti-inflammatory short chain fatty acids compared to single donor-derived products. We then evaluated pooled products' efficacy compared to corresponding single donor-derived products in Salmonella and C. difficile infectious mouse models. We were able to demonstrate that pooled products decreased pathogenicity by inducing a structural change in the intestinal microbiota composition. Single donor-derived product efficacy was variable, with some products failing to control disease progression. We further performed in vitro growth inhibition assays of two extremely drug-resistant bacteria, Enterococcus faecium vanA and Klebsiella pneumoniae oxa48, supporting the use of pooled microbiotherapies. Altogether, these results demonstrate that the heterogeneity of donor-derived products is corrected by pooled fecal microbiotherapies in several infectious preclinical models.IMPORTANCEGrowing evidence demonstrates the key role of the gut microbiota in human health and disease. Recent Food and Drug Administration approval of fecal microbiotherapy products to treat recurrent Clostridioides difficile infection has shed light on their potential to treat pathological conditions associated with gut dysbiosis. In this study, we combined metagenomic analysis with in vitro and in vivo studies to compare the efficacy of pooled microbiotherapy products to corresponding single donor-derived products. We demonstrate that pooled products are more homogeneous, diverse, and enriched in beneficial bacteria compared to single donor-derived products. We further reveal that pooled products decreased Salmonella and Clostridioides difficile pathogenicity in mice, while single donor-derived product efficacy was variable, with some products failing to control disease progression. Altogether, these findings support the development of pooled microbiotherapies to overcome donor-dependent treatment efficacy.