Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the most common chronic liver disease worldwide. Timely therapeutic intervention for MAFLD is crucial for improving patient prognosis and preventing its progression to liver fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC). Therefore, the discovery of novel drugs for the treatment of MAFLD is of great significance.

Previous clinical studies have shown that calculus bovis sativus, as an adjuvant therapy for icteric hepatitis and chronic hepatitis B, exhibits significant anti-inflammatory and enzyme-reducing effects, improves liver function indicators, and enhances overall clinical outcomes. However, there is currently no clinical research on the therapeutic effects of calculus bovis sativus in patients with MAFLD, and its underlying mechanisms of action remain to be elucidated.

This study proposes a randomized, double-blind, placebo-controlled trial to investigate the effects of calculus bovis sativus in adult patients with MAFLD. The primary objective is to preliminarily explore the clinical efficacy of calculus bovis sativus in treating MAFLD, particularly its impact on liver injury and inflammation. Furthermore, this research will employ a multi-omics approach, integrating metagenomics and metabolomics, to analyze the effects of calculus bovis sativus on the gut microbiota and their metabolites in MAFLD patients. The aim is to uncover its potential mechanisms of action, thereby facilitating its clinical translation and application, and ultimately providing a new therapeutic strategy for patients with MAFLD.

This study is designed as a randomized, double-blind, placebo-controlled trial to investigate calculus bovis sativus in adult subjects with metabolic dysfunction-associated fatty liver disease (MAFLD). The study aims to evaluate the safety of calculus bovis sativus in subjects with MAFLD by monitoring the incidence of adverse events and key laboratory parameters, including routine blood and urine tests, as well as hepatic and renal function, and to preliminarily investigate the potential clinical efficacy of calculus bovis sativus in mitigating MAFLD, liver injury, and inflammation by monitoring various serum biomarkers and non-invasive assessment parameters, such as the controlled attenuation parameter (CAP), liver stiffness measurement (LSM), and magnetic resonance imaging proton density fat fraction (MRI-PDFF). Furthermore, this study will employ a multi-omics approach, combining metagenomics and metabolomics, to explore the effects of calculus bovis sativus on the gut microbiota and its metabolites in patients with MAFLD.

Inclusion Criteria:

1. Has signed the informed consent form (ICF) prior to the study and is fully aware of the study's content, procedures, and potential adverse reactions.

2. Is able to complete the study in accordance with the protocol requirements.

3. The subject (and/or partner) agrees to use effective contraceptive measures voluntarily from the screening period until 6 months after the last dose of the investigational product.

4. At the time of signing the ICF, age is between 18 and 75 years (inclusive), with no restriction on sex.

5. Meets the diagnostic criteria outlined in the "Guidelines for the Prevention and Treatment of Metabolic Dysfunction-Associated (Non-alcoholic) Fatty Liver Disease (2024 Edition)" issued by the Chinese Society of Hepatology, Chinese Medical Association.

6. Confirmed significant hepatic steatosis by transient elastography (Fibroscan) with a Controlled Attenuation Parameter (CAP) value ≥ 240 dB/m.

7. Liver enzyme levels meet the following criteria: 1 × upper limit of normal (ULN) < serum AST and ALT < 5 × ULN.

8. Exclusion of significant liver fibrosis based on non-invasive assessment, meeting at least one of the following four conditions:

   • FIB-4 < 1.3
   • NAFLD Fibrosis Score (NFS) < -1.455
   • LSM < 8.0 kPa
   • FAST score < 0.35

9. Stable body weight for at least 6 weeks prior to screening, defined as a weight change (increase or decrease) of ≤5%.

Exclusion Criteria:

1. Presence of the following chronic diseases: viral hepatitis; positive serology for Human Immunodeficiency Virus (HIV); primary sclerosing cholangitis, primary biliary cholangitis, autoimmune hepatitis, drug-induced liver disease, alcoholic liver disease, or Wilson's disease.

2. Excessive alcohol consumption (defined as >30g of alcohol per day for males or >20g per day for females).

3. History of diabetes other than type 2 diabetes, such as type 1 diabetes, secondary diabetes, etc.

4. History of malignancy (except for those with a tumor-free period of more than 5 years prior to screening), or currently under evaluation for active or suspected malignancy. Exceptions include fully treated basal cell carcinoma, squamous cell skin carcinoma, or cervical carcinoma in situ.

5. History of bariatric surgery within the 5 years prior to screening (inclusive).

6. Use of antibiotics within the last 3 weeks or during the study period.

7. Underwent major surgery within 3 months prior to signing the ICF, or planning to undergo major surgery during the study period. (Major surgery is defined as a procedure with risk to the patient's life, particularly surgery involving the cranium, chest, abdomen, or pelvic organs).

8. Recent history of drug abuse (defined as ≤2 years).

9. Presence of psychosis or any other cognitive impairment, or other conditions that would interfere with the subject's compliance.

10. Currently receiving any approved therapy for MASH. Receiving anticoagulant therapy (e.g., warfarin, heparin), or participated in another interventional clinical trial with a drug product within 3 months prior to screening.

11. Presence of any of the following laboratory exclusion criteria at screening (the study center may repeat the test once for any abnormal value):

    • Serum ALT or AST > 5 × ULN
    • Alkaline phosphatase (ALP) ≥ 2 × ULN
    • eGFR < 60 mL/min
    • Total bilirubin > 1.5 × ULN
    • Platelet count < lower limit of normal (LLN)

12. Received a blood transfusion within ≤2 months prior to screening and/or donated blood within ≤1 month prior to screening. Note: Subjects are not permitted to donate blood throughout the entire study period.

13. Presence of portal hypertension, such as esophageal varices, ascites, or hepatic encephalopathy.

14. Pregnant or lactating females.

15. History of liver transplantation or planned liver transplantation.

16. Presence of any significant systemic or major diseases other than liver disease, including recent (≤6 months prior to screening) congestive heart failure (New York Heart Association [NYHA] Functional Classification III-IV), unstable coronary artery disease, arterial revascularization, respiratory disease, renal failure, stroke, transient ischemic attack, organ transplant, psychiatric disorders, or any other clinically significant disease-related event requiring hospitalization within 6 months prior to screening.

17. Acute or chronic gastrointestinal diseases (including diarrhea, gastrointestinal infections, inflammatory bowel disease, etc.).

18. Any condition that, in the opinion of the investigator, would pose a safety risk to the subject or may interfere with the conduct of the study, or if the investigator believes the subject is unlikely to complete the study or comply with its requirements.