Study on the effects and mechanisms of alcohol combined with high-fat diet in promoting enteritis-induced liver injury

Inflammatory hepatic injury associated with inflammatory bowel disease (IBD) is a type of liver disease that occurs in patients with IBD. Up to 30% of IBD patients clinically exhibit abnormal liver function tests. With the increasing incidence of IBD due to economic development and lifestyle changes, the number of patients with IBD complicated by liver injury is on the rise. The mechanism of IBD complicated by liver injury is not yet clear, with unhealthy habits and environmental factors possibly being the main triggers. As a country with a high alcohol consumption rate, statistics show that 30.5% of the population in China drinks alcohol. With lifestyle improvements, people often consume high-calorie foods (such as fats) while drinking, and these combined factors are often key triggers for IBD and liver injury. The simultaneous intake of alcohol and high fat content tends to increase the permeability of the intestinal mucosal barrier, disrupt the gut-liver axis, and exacerbate acute liver damage. It is known that alcohol and high-fat diets are significant potential risk factors for promoting inflammatory liver damage, yet their specific molecular mechanisms remain unknown, and there are currently no effective drugs for treating related inflammatory liver damage clinically. Therefore, clarifying whether alcohol combined with a high-fat diet promotes inflammatory liver damage and exploring its specific mechanisms have important clinical implications for the prevention and treatment of such damage. This study uses DSS-induced colitis mice as subjects to investigate whether alcohol combined with a high-fat diet exacerbates inflammatory liver damage. It also integrates multi-omics data to explore the regulatory mechanisms of alcohol and high-fat diet on inflammatory liver damage, aiming to identify potential intervention targets to provide a theoretical basis for related drug development. Overall design: Mice were administered 2.5% DSS daily to establish a model of colitis. During the modeling period, the weight and Disease Activity Index (DAI) scores of the mice were recorded daily. On day 6, DSS administration was ceased, and the mice were grouped based on average weight and DAI scores. They were then subjected to interventions with either purified high-fat feed or dietary high-fat feed in conjunction with alcohol. During this intervention period, the weight and adverse condition scores of the mice were monitored daily. Liver damage in the colitis mice was assessed using AST/ALT assay kits, and damage to various organs was examined through H&E staining. Damage markers were detected using ELISA and RT-qPCR. Changes in the number of peripheral immune cells in the mice were monitored through blood flow cytometry and routine blood tests. Levels of IL-6, TNF-a, and IL-1ß in the mice's blood were measured using ELISA kits. Immune cell levels in the liver were also assessed through flow cytometry, and liver-related inflammatory factors were measured using ELISA. Key signaling pathways were identified through transcriptome sequencing, and common genes within significant pathways were analyzed using GO gene set analysis. Key metabolites were identified through metabolome sequencing, and their levels in liver tissue were measured using ELISA. Correlative analysis between transcriptome and metabolome sequencing was conducted to explore the connections between highly expressed genes in key signaling pathways and critical metabolites. In vitro cell assays were used to validate the role of these metabolites and differential genes in promoting liver damage.