Abstract: Objective The aim of this study was to explore the correlation between intestinal flora changes and the severity of hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD). Methods A cohort of 50 patients with NAFLD and 38 healthy individuals were recruited in our hospital between July 2024 and July 2025, and all patients with NAFLD underwent FibroScan for controlled attenuation parameter (CAP), by which hepatic steatosis was stratified as mild, moderate and severe degree. The composition of intestinal microbiota was analyzed by utilizing 16S rRNA gene high-throughput sequencing. Results Of the 50 patients with NAFLD, mild liver steatosis was found in 16 cases, moderate in 19 cases and severe in 15 cases; the abundances of Firmicutes, Faecalibacterium prausnitzii, Bifidobacterium, Anaerorhabdus and Blautia in patients with NAFLD were (5.1±1.2) %, (6.5±1.3) %, (7.1±1.9) %, (9.2±2.1) % and (11.8±2.9) %, all significantly lower than [(7.4±1.5) %, (10.4±2.1) %, (9.6±2.0) %, (12.3±2.6) % and (15.7±3.1) %, respectively, P<0.05], while abundances of Bacteroidetes and Proteobacteria were (40.3±3.2) % and (7.4±1.5) %, both significantly higher than [(33.5±2.8) % and (4.6±1.1) %, respectively, P<0.05] in healthy controls; the abundances of Firmicutes, Faecalibacterium prausnitzii, Bifidobacterium, Anaerorhabdus and Blautia in patients with severe NAFLD were (3.1±0.9) %, (5.1±1.0) %, (5.6±1.7) %, (7.4±1.5) % and (8.8±2.3) %, all significantly lower than [(5.3±1.3) %, (6.4±1.2) %, (7.1±1.9) %, (9.3±2.2) % and (12.1±3.1) %, respectively, P<0.05] in those with moderate NAFLD or [(6.7±1.4) %, (7.9±1.7) %, (8.5±2.1) %, (10.8±2.5) % and (14.3±3.2) %, respectively, P<0.05] in those with mild NAFLD, while abundances of Bacteroidetes and Proteobacteria were (44.4±3.2) % and (9.7±1.7) %, both significantly higher than [(41.2±3.3) % and (7.2±1.6) %, P<0.05] in those with moderate NAFLD or [(35.4±3.1) % and (5.5±1.2) %, P<0.05] in mild NAFLD. Conclusion There is a significant imbalance of intestinal flora in patients with NAFLD, which is manifested as decreased abundances of Firmicutes, Faecalibacterium prausnitzii, Bifidobacterium, Anaerorhabdus and Blautia, and increased abundances of Bacteroides and Proteobacteria, which needs further clarification.

Key words: Non-alcoholic fatty liver disease, Intestinal flora, Liver steatosis, Controlled attenuation parameter