Orally fecal gavage enriched Lachnospiraceae and butylate to mitigate acetaminophen-induced liver injury

Background:Gut dysbiosis significantly impacts acetaminophen-induced liver injury (AILI) in mice. Fecal microbiota transplantation (FMT) has sparked great interest in treating human diseases. It is intriguing to target gut microbes for treating AILI.Purpose: We aimed to elucidate how gut microbes impact the severity of AILI and to identify the microbes or their metabolites potentially treating AILI clinically.Methods: AILI was created in conventionally housed and germ-free C57BL/6 mice by peritoneal injection of sublethal and lethal doses of acetaminophen. Fecal microbiota and metabolites before and after FMT were assayed using 16S rDNA sequencing and metabolomics platforms, respectively. Mechanistic studies were performed in cultured hepatocytes and verified in mice with AILI.Results: Regardless inconsistent impacts on AILI by antibiotics treatments, orally fecal transplantation (OFT) constantly mitigated the severity and lethality of AILI in mice. Following acetaminophen-overdose, oral gavage with frest (OFG) or pasteurized feces (OPG) mitigated AILI. Microbiota profiling and metabolomic assays revealed that Lachnospiraceae (butyrate producers), butyrate biosynthesis pathways, and short-chain fatty acides (SCFAs) were enriched in feces after OFT. SCFAs alleviated AILI in mice. Mechanistically, butyrate blocked acetaminophen-instigated mitochondrial damage, oxidative stress, and ferroptosis by activating the AMPK-ULK1-p62 axis to provoke the Nrf2 anti-stress responses and mitophagy. Cotreatment with butyrate and N-acetylcysteine significantly improved the survival rate of AILI in mice.Conclusion: Orally fecal gavage enriched Lachnospiraceae and butyrate, which induced the Nrf2 anti-stress responses and mitophagy to mitigate AILI. Our findings highlight distinct microbial and biological impacts via orally fecal administration from commensal gut microbes or colonic fecal transplantation and underline the potential of microbial metabolites for new drug development.