Clinical Study of Zuogui Jiangtang Shuluo Formula in Treating Diabetic Peripheral Neuropathy

DSPN inclusion criteria: 1. Meet the diagnostic criteria for type 2 diabetes mellitus with distal symmetric polyneuropathy (DSPN) according to Western medicine standards. 2. Meet the TCM syndrome differentiation criteria for consumptive thirst complicated with arthromyodynia of the pattern of Qi-Yin deficiency with blood stasis. 3. Glycated hemoglobin (HbA1c) between 6.5% and 9.0% (inclusive). 4. Aged 35 to 75 years (inclusive) at the time of screening, regardless of gender. 5. Have not participated in any other clinical trial within 2 weeks prior to the start of treatment, and have not taken lipid-lowering agents, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants, immunosuppressants, or other traditional Chinese medicines that may affect metabolomic and lipidomic profiles. 6. Willing to voluntarily participate in the trial and adhere to the 4-week traditional Chinese medicine treatment regimen. 7. Right-handed. 8. Provide written informed consent and are able to understand and comply with the study protocol requirements, including dietary and exercise recommendations and blood glucose monitoring. DSPN exclusion criteria 1. Patients with type 1 diabetes mellitus or other specific types of diabetes mellitus. 2. Women who are pregnant, breastfeeding, planning pregnancy, or taking oral contraceptives long-term. 3. Neuropathies caused by other conditions, including but not limited to multiple sclerosis, Parkinson's disease, Guillain-Barré syndrome, epilepsy, spinal cord injury, cervical or lumbar spine lesions (nerve root compression, spinal stenosis, cervical or lumbar degenerative diseases), neuromuscular diseases, severe arterial or venous vascular diseases (venous thrombosis, lymphangitis, etc.), sequelae of cerebrovascular disease, or post-surgical status of lower extremity vasculature. 4. History of stroke, transient ischemic attack, unstable angina, or myocardial infarction within 3 months prior to study enrollment. 5. History of acute diabetic complications (diabetic ketoacidosis, lactic acidosis, or hyperosmolar hyperglycemic state) within 3 months prior to study enrollment. 6. Concomitant severe complications of diabetes, such as end-stage diabetic kidney disease, or proliferative diabetic retinopathy. 7. Concomitant severe diseases of the heart, liver, kidney, cerebrovascular system, or malignant tumors, defined as serum creatinine \>200 μmol/L, blood urea nitrogen \>1.5 times the upper limit of normal, or alanine aminotransferase or aspartate aminotransferase \>3 times the upper limit of normal. 8. Any infection that, in the investigator's opinion, makes the patient unsuitable for participation prior to study enrollment, including but not limited to urinary tract infection, respiratory infection, or diabetic foot with infection requiring further treatment. 9. Patients with psychiatric disorders, cognitive impairment, or inability to cooperate with the study procedures; or individuals with a history of alcohol abuse or drug addiction. Healthy volunteer inclusion criteria: 1. Aged 18 to 55 years (inclusive) at the time of screening, regardless of gender. 2. Body mass index (BMI) within the range of 19.0 to 26.0 kg/m² (inclusive). No severe diseases of the heart, liver, kidney, cerebrovascular system, or malignant tumors; routine laboratory tests, electrocardiogram, and chest X-ray are essentially within normal limits. 3. Have not participated in any other clinical trial within 2 weeks prior to the start of treatment, and have not taken lipid-lowering agents, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants, immunosuppressants, or other traditional Chinese medicines that may affect metabolomic and lipidomic profiles. 4. Voluntarily sign the informed consent form and are willing and able to cooperate with the investigators to complete the clinical study. Healthy volunteer exclusion criteria: 1. Women who are pregnant, breastfeeding, planning pregnancy, or taking oral contraceptives long-term. 2. Patients with psychiatric disorders, cognitive impairment, or inability to cooperate with the study procedures. 3. Individuals with a history of alcohol abuse or drug addiction.