Effect of Asian Diet on Metabolic Parameters, Gut Microbiota Profile, and Liver Histology: Study on The NASH Rat Model

Non-alcoholic fatty liver disease (NAFLD) is a widespread condition posing significant mortality risks from cirrhosis and hepatocellular carcinoma (HCC). In Asia, particularly in rural areas adhering to Asian diets (AD), there's a rising incidence of NAFLD. This study aimed to investigate the relationship between AD and the occurrence of Non-alcoholic steatohepatitis (NASH) in Rats (Rattus norvegicus strain Wistar) by measuring metabolic parameters, gut microbiota profile, and liver histology. Experimental research was conducted with fourteen male rats, which were divided into two groups: Chow Diet (CD, n=7) and AD (n=7) for 12 weeks. Liver enzymes, blood sugar, and lipid profiles were measured by enzyme-linked immunosorbent assay (ELISA). Analysis of the gut microbiota was performed using 16S rRNA gene sequencing targeting the V3-V4 variables region. Liver histology was obtained by biopsy and stained with Hematoxylin Eosin (HE). Furthermore, it was interpreted using NAS (NAFLD Activity Score). AD-treated rats displayed lower body weight than CD (p = 0.001). We found a significantly higher number of Lactobacillus reuteri, Romboutsia ilealis, andPrevotellaceae bacterium in AD than in CD (p= 0.00058; p= 0.026; p= 0.026), likewise the genus Lactobacillus (p= 0.004), phylum Bacteroidota and Firmicutes (p= 0.001; p= 0.0005). Alkaline phosphatase (ALP) was higher in AD than in CD (p = 0.003). However, both groups did not have a significant difference in total bilirubin, alanine transaminase (ALT), aspartate transaminase (AST), blood sugar, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (p = 0.069; p = 0.098; p = 0.773; p = 0.538; p = 0.640; p = 0.475; p = 0.104; p = 0.775). The NAS between the two groups indicated non-NAFLD rats. Despite the high-calorie type of Asian diet, it did not produce significant changes in metabolic parameters and liver histology to NASH. This may be influenced by the gut microbiota protective effect.

非酒精性脂肪性肝病（Non-alcoholic fatty liver disease, NAFLD）是一种广泛流行的疾病，可因肝硬化和肝细胞癌（hepatocellular carcinoma, HCC）带来显著的死亡风险。在亚洲，尤其是遵循亚洲饮食（Asian diets, AD）的农村地区，NAFLD的发病率正逐年上升。本研究旨在通过检测代谢参数、肠道菌群谱及肝脏组织学特征，探究亚洲饮食与大鼠（Wistar品系褐家鼠，Rattus norvegicus strain Wistar）非酒精性脂肪性肝炎（Non-alcoholic steatohepatitis, NASH）发生的关联。本实验选取14只雄性大鼠，随机分为基础饲料饮食组（Chow Diet, CD，n=7）与亚洲饮食组（n=7），干预周期为12周。采用酶联免疫吸附测定（enzyme-linked immunosorbent assay, ELISA）检测肝脏酶学指标、血糖及血脂谱；针对16S rRNA基因V3-V4可变区进行测序，以分析肠道菌群组成；通过肝脏活检获取组织样本，经苏木精-伊红（Hematoxylin Eosin, HE）染色后，采用NAFLD活动度评分（NAFLD Activity Score, NAS）进行组织学解读。与基础饲料饮食组相比，亚洲饮食组大鼠的体重显著更低（p=0.001）。亚洲饮食组大鼠的罗伊氏乳杆菌（Lactobacillus reuteri）、回肠罗姆布茨菌（Romboutsia ilealis）及普雷沃氏菌科细菌（Prevotellaceae bacterium）的相对丰度显著升高（分别为p=0.00058、p=0.026、p=0.026），乳杆菌属（Lactobacillus）相对丰度亦显著升高（p=0.004），拟杆菌门（Bacteroidota）与厚壁菌门（Firmicutes）的相对丰度同样显著升高（p=0.001、p=0.0005）。亚洲饮食组大鼠的碱性磷酸酶（Alkaline phosphatase, ALP）水平显著高于基础饲料饮食组（p=0.003）。但两组在总胆红素、丙氨酸氨基转移酶（alanine transaminase, ALT）、天冬氨酸氨基转移酶（aspartate transaminase, AST）、血糖、总胆固醇、高密度脂蛋白（high-density lipoprotein, HDL）、低密度脂蛋白（low-density lipoprotein, LDL）及甘油三酯水平上均无显著差异（分别为p=0.069、p=0.098、p=0.773、p=0.538、p=0.640、p=0.475、p=0.104、p=0.775）。两组的NAFLD活动度评分均提示大鼠未发生非酒精性脂肪性肝病。尽管亚洲饮食为高能量膳食模式，但其并未使代谢参数与肝脏组织学特征发生足以诱发非酒精性脂肪性肝炎的显著改变，这一现象可能与肠道菌群的保护作用有关。