Coordinated changes of gut microbiome and lipidome differentiates nonalcoholic steatohepatitis (NASH) from isolated steatosis.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease encompasses isolated steatosis or nonalcoholic fatty liver and nonalcoholic steatohepatitis (NASH). NASH develops from isolated steatosis with obscure driving forces. We aim to identify key factors promoting this transition. METHODS: Following 21-week of high-fat diet feeding, obese mice were classified into two groups termed as isolated steatosis and NASH based on hematoxylin-eosin staining of liver histology. The integrated multi-omics analysis of lipidome, transcriptome and gut microbiome were performed in mice with isolated steatosis and NASH, and confirmed in human samples. RESULTS: Livers in mice with NASH lost most lipids, and the transcriptional landscape was also changed dramatically in mice with NASH in relative to mice with isolated steatosis. Plasma lipidome analysis demonstrated a very clear difference between these two groups of mice, which was partially recapitulated in serum of patients with isolated steatosis and NASH. The microbiota composition revealed that Bacteroides genus and Bacteroides uniformis species decreased while Mucispirillum genus and Mucispirillum schaedleri species increased largely in mice with NASH. More importantly, we found that Bacteroides uniformis correlated positively with triglycerides (TGs) and negatively with free fatty acids (FFAs) and PE(18:1/20:4), while Mucispirillum schaedleri correlated positively with FFAs, LysoPC(20:3), LysoPC(20:4) and DG(16:1/18:2). Mechanically, administration of Bacteroides uniformis increased specific TGs, and decreased hepatic injury and inflammation in diet-induced mice. CONCLUSIONS: Overall, through multi-omics integration, we identified a microbiota-lipid axis promoting the initiation of NASH from isolated steatosis, which might provide a novel perspective on NASH pathogenesis and treatment.

WZ66, a novel acetyl-CoA carboxylase inhibitor, alleviates nonalcoholic steatohepatitis (NASH) in mice.

The global prevalence of nonalcoholic steatohepatitis (NASH) increases incredibly. NASH ends up to advanced liver disease, which is highly threatening to human health. Currently, treatment of NASH is very limited. Acetyl-CoA carboxylases (ACC1/ACC2) are proved as effective drug targets for NASH. We aimed to develop novel ACC inhibitors and evaluate their therapeutic value for NASH prevention. ACC inhibitors were obtained through structure-based drug design, synthesized, screened from ACC enzymatic measurement platform and elucidated in cell culture-based assays and animal models. The lipidome and microbiome analysis were integrated to assess the effects of WZ66 on lipids profiles in liver and plasma as well as gut microbiota in the intestine. WZ66 was identified as a novel ACC1/2 inhibitor. It entered systemic circulation rapidly and could accumulate in liver. WZ66 alleviated NASH-related liver features including steatosis, Kupffer cells and hepatic stellate cells activation in diet-induced obese mice. The triglycerides (TGs) and other lipids including diglycerides (DGs), phosphatidylcholine (PC) and sphingomyelin (SM) were decreased in WZ66-treated mice as evidenced by lipidome analysis in livers. The lipids profiles in plasma were also altered with WZ66 treatment. Plasma TG were moderately increased, while the activation of SREBP1c was not detected. WZ66 also downregulated the abundance of Allobaculum, Mucispirillum and Prevotella genera as well as Mucispirillum schaedleri species in gut microbiota. WZ66 is an ideal lead compound and a potential drug candidate deserving further investigation in the therapeutics of NASH.

Chitosan Oligosaccharide Ameliorates Nonalcoholic Fatty Liver Disease (NAFLD) in Diet-Induced Obese Mice.

Nonalcoholic fatty liver disease (NAFLD) is a global epidemic, and there is no standard and efficient therapy for it. Chitosan oligosaccharide (COS) is widely known to have various biological effects, and in this study we aimed to evaluate the liver-protective effect in diet-induced obese mice for an enzymatically digested product of COS called COS23 which is mainly composed of dimers and trimers. An integrated analysis of the lipidome and gut microbiome were performed to assess the effects of COS23 on lipids in plasma and the liver as well as on intestinal microbiota. Our results revealed that COS23 obviously attenuated hepatic steatosis and ameliorated liver injury in diet-induced obese mice. The hepatic toxic lipids-especially triglycerides (TGs) and free fatty acids (FFAs)-were decreased dramatically after COS23 treatment. COS23 regulated lipid-related pathways, especially inhibiting the expressions of FFA-synthesis-related genes and inflammation-related genes. Furthermore, COS23 could alter lipid profiles in plasma. More importantly, COS23 also decreased the abundance of Mucispirillum and increased the abundance of Coprococcus in gut microbiota and protected the intestinal barrier by up-regulating the expression of tight-junction-related genes. In conclusion, COS23, an enzymatically digested product of COS, might serve as a promising candidate in the clinical treatment of NAFLD.

Amlodipine, an anti-hypertensive drug, alleviates non-alcoholic fatty liver disease by modulating gut microbiota.

BACKGROUND AND PURPOSE: Non-alcoholic fatty liver disease (NAFLD) represents a severe public health problem. It often coexists with hypertension in the context of metabolic syndrome. We investigated the effects of amlodipine on NAFLD combined with hypertension and investigated the underlying mechanism/s. EXPERIMENTAL APPROACH: Mice were fed with high-fat diet (HFD) and 0.05% N-nitro-L-arginine methylester sterile water to induce NAFLD with hypertension. Gut microbiota composition and function were assessed by 16S ribosomal DNA and metagenomic sequencing. Untargeted metabolome profiles were applied to identify differential metabolites in mice caecum. KEY RESULTS: Amlodipine besylate and amlodipine aspartate significantly decreased liver injury and hepatic steatosis, and improved lipid metabolism with a concomitant reduction in the expression of lipogenic genes in mice with NAFLD and hypertension. Mechanistically, amlodipine besylate and amlodipine aspartate have potential to restore intestinal barrier integrity and improve antimicrobial defence, along with the elevated abundances of Akkermansia, Bacteroides and Lactobacillus. Noteworthily, the gut microbiota in amlodipine besylate- and amlodipine aspartate-treated mice had higher abundance of functional genes involved in taurine and hypotaurine metabolism. Consistently, the strengthened taurine and hypotaurine metabolism was confirmed by untargeted metabolome analysis. Based on the correlation and causal analysis, the altered gut microbiota composition and the enhancement of taurine and hypotaurine metabolism may synergistically decreased alanine aminotransferase, liver triglycerides, lipogenic genes and plasma cholesterol in HFD-fed hypertensive mice. CONCLUSION AND IMPLICATIONS: Amlodipine besylate and amlodipine aspartate exert multifactorial improvements in NAFLD and hypertension by modulating gut microbiota. They may serve as promising therapeutic agents for treating these diseases.