Testing two different strategies for weight loss intervention and revealing possible changes in composition of gut microbiota, in order to provide more insight in the effect of dietary changes and weight loss treatments on gut microbiome in overweight and obese women with polycystic ovary syndrome (PCOS). The two strategies are:

• dietary advice plus myo-inositol and folic acid
• dietary advice plus liraglutide, glucagon-like peptide-1 (GLP-1) receptor agonist Primary outcome will be weight loss. Secondary outcomes are longitudinal changes in clinical features associated with PCOS and metabolic syndrome, longitudinal changes in gut microbiome with interventions.

Subjects will be treated during 16 weeks and follow-up will take 16 weeks after stop of treatment.

Inclusion Criteria:

• PCOS according to ROtterdam criteria
• BMI ≥ 27 kg/m2 and at risk of metabolic syndrome or BMI ≥ 30 kg/m2

Exclusion Criteria:

• pregnancy
• pancreatitis (in the past)
• oral contraceptive pill use
• inflammatory bowel disease
• auto-immune disease
• immuno-modulatory drugs
• antidiabetic drugs
• anti-inflammatory drugs