The goal of this observational study is to learn about the molecular characteristics of colorectal polyps in patients with metabolic dysfunction-associated steatohepatitis (MASH) compared to individuals without fatty liver, and to identify potential transcriptomic biomarkers for high-risk polyps. The main questions it aims to answer are: What are the key gene expression differences in adenomatous polyps between MASH patients and non-fatty liver individuals? Can specific high-risk transcriptional molecules in plasma and polyp tissue serve as biomarkers for MASH-related colorectal polyps? Participants already scheduled for colonoscopic polypectomy as part of their routine care will provide a small portion of their polyp tissue, residual plasma from standard blood tests, and allow use of their stored pathological slides for research; they will also be followed up every six months.

I. Research Methods

1. Research Content

1. Recruit 6 inpatients scheduled for endoscopic treatment of colonic polyps, including 3 without fatty liver and 3 with MASH. During colonoscopic treatment, completely remove the colonic polyp and submit a portion of the tissue for single-cell RNA sequencing analysis.
2. Establish a MASH-associated colonic polyp cohort. Recruit 94 inpatients scheduled for endoscopic treatment of colonic polyps. Assess steatosis and liver fibrosis degree using FibroScan. Collect 2ml of residual plasma from routine blood tests performed upon admission from the clinical laboratory. After pathological results are available, borrow 3 paraffin sections from the pathology department for validation of high-risk transcriptional molecule expression.
3. Statistically analyze the expression levels of high-risk transcriptional molecules and evaluate their association with MASH-related colonic polyps and their diagnostic value.

2. Study Procedures:

1. Recruit inpatients scheduled for colonoscopic polypectomy, with polyp sizes of 1-2cm.
2. Select eligible patients according to the inclusion and exclusion criteria, explain the specific study protocol, and obtain informed consent.
3. Record patient basic information, such as: name, sex, age, ethnicity, date of birth, height, weight, date of initial symptom onset, contact information (phone, permanent address).
4. Upon admission, inquire about liver ultrasound results within the past three months, alcohol consumption history, and history of viral hepatitis. For patients with fatty liver, perform elastography on the day of admission. For patients who cannot provide a liver ultrasound report, perform a fasting ultrasound on the second day of admission. Categorize patients into the non-fatty liver group and the MASH group based on liver ultrasound, ultrasound elastography results, and liver function tests.
5. Collect as detailed a medical history and relevant auxiliary examination/laboratory results as possible. Routine blood tests, biochemistry (ALT, AST, TBIL, TG, Ch, Glu, total protein, albumin), blood pressure, BMI, abdominal ultrasound, and elastography (FibroScan) are mandatory items.
6. For patients enrolled in the single-cell RNA sequencing cohort, perform colonoscopic treatment on the second day after admission. Select an adenomatous polyp of 1-2cm for single-cell RNA sequencing analysis. During the colonoscopic procedure, completely remove the polyp. Quickly rinse the sample in a dressing bowl with saline to remove blood and debris, then place it on dry gauze. Use a sterile scalpel blade to bisect the polyp along the vertical axis. Take a piece approximately the size of a mung bean (about 0.5cm) and send it for sequencing. Submit the remaining portion for pathological examination to confirm the pathological type (ensure a pathological report is issued for the patient). Place the sample for testing into a centrifuge tube containing 1ml of pre-cooled tissue preservation solution. Check the centrifuge tube containing the tissue sample and preservation solution to ensure the tissue sample is completely submerged. Confirm that the relevant sample information is clearly marked on the outer surface of the tube and seal with parafilm. Place the centrifuge tube in a foam box, surrounded by cushioning material for protection. Before shipping, add sufficient -20℃ ice packs to ensure a low-temperature environment during transport, then seal the box and ship on the same day.
7. For patients enrolled in the MASH-associated colonic polyp cohort, complete liver function blood tests on the day of admission. Collect 2ml of residual plasma remaining after routine testing from the clinical laboratory and store at -80℃ or below. Perform colonoscopic treatment on the second day after admission and send the polyp for pathological biopsy. After pathological results are available, borrow 3 paraffin sections of polyps pathologically diagnosed as adenomatous from the pathology department. Plasma and pathological sections will be used for validation of high-risk transcriptional molecule expression.

II. Inclusion and Exclusion Criteria

Inclusion Criteria:

1. Diagnosis of MAFLD conforms to the "Guidelines for the Prevention and Treatment of Non-alcoholic Fatty Liver Disease" (2018 Edition);
2. Male or female patients aged 18-70 years;
3. Signed informed consent form and explanation of the specific study protocol.

Exclusion Criteria:

1. Chronic liver disease due to other etiologies (alcoholic, viral, autoimmune, drug-induced, etc.), decompensated cirrhosis, primary liver cancer;
2. Underlying diseases of other vital organs (heart, kidney, lung, etc.) and bleeding disorders;
3. Individuals lacking legal capacity or with poor insight. III. Risks and Adverse Effects The investigators will adhere to clinical standards and operate cautiously. [In the event of serious complications, active management will be provided according to clinical routine diagnosis and treatment protocols, and free treatment will be offered]{.underline}. Potential issues from blood draws mainly include local pain at the puncture site, bleeding, swelling, and infection. We will manage these actively according to clinical routine. Painless electronic colonoscopic polypectomy is an invasive procedure but is a routine clinical operation. Potential risks and complications include bleeding, perforation, infection, abdominal pain, bloating, bowel obstruction, anesthesia accidents, etc.

IV. Withdrawal Conditions

1. If a patient experiences a severe adverse reaction or complication requiring immediate withdrawal from the study, they will receive appropriate treatment and care.
2. If a patient experiences significant physical or psychological discomfort during the study that prevents them from continuing participation, they may choose to withdraw.
3. If a patient voluntarily chooses to withdraw from the study, their wishes shall be respected, and necessary support and assistance provided.
4. If unforeseen risks or problems arise during the study that make it impossible to continue, patients shall be permitted to withdraw.

Inclusion Criteria:

1. Diagnosis of MAFLD conforms to the "Guidelines for the Prevention and Treatment of Non-alcoholic Fatty Liver Disease" (2018 Edition);
2. Male or female patients aged 18-70 years;
3. Signed informed consent form and explanation of the specific study protocol.

Exclusion Criteria:

1. Chronic liver disease due to other etiologies (alcoholic, viral, autoimmune, drug-induced, etc.), decompensated cirrhosis, primary liver cancer;
2. Underlying diseases of other vital organs (heart, kidney, lung, etc.) and bleeding disorders;
3. Individuals lacking legal capacity or with poor insight.

Recruit inpatients scheduled for colonoscopic polypectomy, with polyp sizes of 1~2cm.