The goal of this clinical trial is to:

1. promote and optimize standardized diagnostic and treatment pathways for polycystic ovary syndrome (PCOS) and to investigate the clinical phenotypic characteristics of PCOS;
2. establish a bidirectional referral system and standardized referral pathways for PCOS;
3. comprehensively evaluate the effectiveness of standardized PCOS care pathways based on a bidirectional referral system;
4. collaborate with technical partners to develop an information-based clinical management platform for PCOS suitable for use in primary healthcare settings; and
5. investigate the effects of combined lifestyle intervention and prebiotic supplementation on insulin resistance and glucose-lipid metabolism in patients with PCOS.

The main questions this study aims to answer are:

1. What are the clinical phenotypic characteristics of PCOS, and how effective are standardized diagnostic and treatment pathways for PCOS?
2. What are the effects of combined lifestyle intervention and prebiotic supplementation, implemented within standardized diagnostic and treatment pathways for PCOS, on insulin resistance and glucose-lipid metabolism in patients with PCOS?

Researchers will compare standardized diagnostic and treatment pathways for PCOS before and after implementation to assess improvements in clinical outcomes in patients with PCOS, and will also compare lifestyle intervention with and without prebiotic supplementation to determine whether prebiotic supplementation can improve insulin resistance and glucos-lipid metabolism in patients with PCOS.

All participants will first undergo a 12-week run-in phase, during which standardized diagnostic and treatment pathways for PCOS combined with lifestyle intervention will be implemented uniformly. After completion of the run-in phase and randomization at Week 12, participants will be assigned to one of two parallel intervention arms. Participants in the control arm will continue to receive lifestyle intervention alone for an additional 8 weeks, without additional prebiotic supplementation. Participants in the intervention arm will continue to receive lifestyle intervention and will additionally receive prebiotic supplementation for 8 weeks.

Inclusion Criteria:

1. Female participants aged 18-50 years.
2. A diagnosis of PCOS based on the 2003 Rotterdam consensus, meeting at least two of the following three criteria: (i) oligo-ovulation and/or anovulation;(ii) clinical and/or biochemical signs of hyperandrogenism; or(iii) polycystic ovarian morphology on ultrasonography, defined as the presence of ≥12 follicles measuring 2-9 mm in diameter in each ovary and/or an ovarian volume ≥10 cm³.

Exclusion Criteria:

1. Patients with other serious medical conditions, including coronary heart disease (e.g., angina pectoris, myocardial infarction, history of coronary revascularization, or abnormal Q waves on electrocardiography), stroke (ischemic or hemorrhagic, including transient ischemic attack), or severe hepatic or renal dysfunction.
2. Patients with eating disorders or severe gastrointestinal diseases that may affect nutritional intervention outcomes.
3. Patients with any other medical condition associated with an estimated life expectancy of less than 5 years.
4. Patients with drug abuse, chronic alcoholism, alcohol dependence, or other addictive tendencies.
5. Patients who are unable to comply with dietary modification or lifestyle intervention or who are unlikely to adhere to follow-up visits.
6. Pregnant or lactating women, or those who have used oral contraceptives or glucagon-like peptide-1 (GLP-1) receptor agonists within the past 3 months.
7. Patients with a known allergy to prebiotics, those who have taken probiotics, prebiotics, or synbiotic supplements within the past 3 months, or those who have used antibiotics within the past 1 month.

Individual participant data will not be shared due to concerns regarding participant privacy and confidentiality, and because no formal plan for external data sharing has been established at this time.