Objective: To investigate the effect ofBifidobacterium triple viable capsules on treatment efficacy and carotid atherosclerosis risk in patients with chronic hepatitis B (CHB) complicated by non-alcoholic fatty liver disease (NAFLD), based on the gut-liver axis and immunomodulation mechanisms.Methods: A total of 130 CHB patients with NAFLD were divided into an observation group and a control group according to different treatment methods, with 65 cases in each group. The control group received conventional comprehensive treatment, while the observation group receivedBifidobacterium triple viable capsules in addition to the control group's regimen. After 6 months of continuous intervention, the following indicators were compared between the two groups:Virological response: HBV DNA levels.Liver function: Alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (GGT), and total bilirubin (TBIL).Liver steatosis and fibrosis: Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM).Intestinal flora indices: Relative abundance ofBifidobacterium andEnterobacteriaceae, and flora α-diversity (Shannon index).Intestinal mucosal barrier indices: Endotoxin (LPS), diamine oxidase (DAO), and intestinal fatty acid-binding protein (I-FABP).Inflammation and immune indices: High-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), CD4+/CD8+ ratio, and regulatory T cell (Treg) proportion.Carotid atherosclerosis risk indices: Carotid intima-media thickness (CIMT), carotid plaque detection rate, maximum area of carotid plaque, and carotid hemodynamic parameters [peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI)].Results:Virological & Liver Function: The HBV DNA level in the observation group after treatment was significantly lower than in the control group (P0.05).Gut Microbiota & Barrier: The abundance ofBifidobacterium and the Shannon index were higher in the observation group, while the abundance ofEnterobacteriaceae was lower compared to the control group (P0.05).Conclusion: The addition ofBifidobacterium triple viable capsules to standard antiviral therapy can regulate intestinal flora balance, repair the intestinal mucosal barrier, inhibit systemic inflammatory responses, and improve immune disorders. Consequently, this adjunctive therapy enhances virological response in CHB-NAFLD patients, improves liver function, reduces liver steatosis and fibrosis, and helps delay the early progression of carotid atherosclerosis.