Role of gut/liver metabolites and gut microbiota in liver fibrosis caused by cholestasis

p16INK4a Deletion Alleviated Obesity-Associated Kidney Fibrosis by Regulating Metabolic Reprogramming and the Inflammasome Pathway

Recent research has revealed a close association between obesity and various metabolic disorders, including renal metabolic diseases, but the mechanism is still unknown. This study explored the role of p16INK4a in obesity-related kidney fibrosis and evaluated its potential as a therapeutic target. Using wild-type (WT) mice and p16 KO mice, we fed both groups a high-fat diet (HFD) for 6 months. Our results showed that an HFD led to significant weight gain and increased p16INK4a expression in WT mouse kidneys. Notably, p16 KO mice presented reduced fibrosis, as indicated by decreased levels of profibrotic proteins (α-SMA and collagen I) and improved histological outcomes, including reduced fibrosis in the glomeruli and renal tubules. P16 KO also suppressed the levels of several proinflammatory biomarkers (MMP1, MMP3, IL-1β, TNF-α and IL-6) and inhibited the NLRP3 inflammasome pathway. The administration of ABT263 further validated these findings by decreasing fibrosis and inflammation in HFD-fed mice, suggesting that p16INK4a contributes to both fibrotic and inflammatory processes. Metabolomic analyses revealed that p16 knockout influenced various metabolic pathways, including linoleic acid and pyrimidine metabolism, in HFD-induced kidneys. Additionally, p16INK4a over-expression was observed in the kidneys of chronic kidney disease patients with long-term hyperlipidaemia. These results highlight the critical role of p16INK4a in obesity-induced kidney damage and suggest that targeting p16INK4a may be a promising approach for treating obesity-related kidney fibrosis and inflammation.

Mechanisms of Dihydromyricetin for Improving Hepatic Fibrosis through the Integration of Metabolomics and Gut Microbiota

It is crucial to prevent and treat liver fibrosis in patients with chronic liver disease. Dihydromyricetin (DMY) is a natural flavonoid compound from traditional Chinese medicine, known to alleviate chronic liver injury. However, its role in regulating inflammatory responses through gut microbiota and metabolic changes remains unclear. In this study, a mouse model of liver fibrosis was induced with carbon tetrachloride (CCl4), and DMY was administered via gavage. Histopathology, immunohistochemistry, Reverse Transcription Polymerase Chain Reaction (RT-PCR), 16S rRNA sequencing, and untargeted metabolomics were employed to evaluate DMY's pharmacological effects on CCl4-induced liver fibrosis and explore its underlying mechanisms. Our results show that DMY reduced the aspartate transaminase (AST) and alanine transaminase (ALT) serum levels in liver fibrosis model mice, and lowered the mRNA expression of pro-inflammatory cytokines and fibrosis markers. Additionally, DMY restored the richness and diversity of the gut microbiota, with several microbiota taxa significantly correlating with inflammatory markers. Metabolomic analysis of serum and liver tissue revealed that DMY significantly altered the liver metabolite disturbances induced by CCl4. Pearson correlation analysis demonstrated a strong relationship between microbial composition and liver metabolites. These results suggest that DMY alleviates liver fibrosis in mice by reshaping the gut microbiota and host metabolism, thereby improving the inflammatory response.

The impact of traditional Chinese medicine and dietary compounds on modulating gut microbiota in hepatic fibrosis: A review

Traditional Chinese medicine (TCM) and dietary compounds have a profound influence on the regulation of gut microbiota (GM) in hepatic fibrosis (HF). Certain substances found in both food and herbs that are edible and medicinal, such as dietary fiber, polyphenols, and polysaccharides, can generate beneficial metabolites like short-chain fatty acids (SCFAs), bile acids (BAs), and tryptophan (Trp). These compounds contribute to regulate the GM, reduce levels of endotoxins in the liver, and alleviate fibrosis and inflammation in the liver. Furthermore, they enhance the composition and functionality of GM, promoting the growth of beneficial bacteria while inhibiting the proliferation of harmful bacteria. These mechanisms mitigate the inflammatory response in the intestines and maintain the integrity of the intestinal barrier. The purpose of this review is to analyze how the GM regulates the pathogenesis of HF, evaluate the regulatory effect of TCM and dietary compounds on the intestinal microflora, with a particular emphasis on modulating flora structure, enhancing gut barrier function, and addressing associated pathogenic factors, thereby provide new insights for the treatment of HF.