The goal of this clinical trial is to learn if thyme supplement enhances the effects of a low FODAMP diet on reducing clinical symptoms and improving the quality of life of patients with irritable bowel syndrome or not.

The main questions it aims to answer are:

1. Does consumption of thyme reduce the severity score of clinical symptoms in patients with irritable bowel syndrome?
2. Does consumption of thyme increase the quality of life score in patients with irritable bowel syndrome? Researchers will compare thyme supplementation with placebo to see if thyme supplement enhances the effects of a low FODAMP diet on clinical symptoms and quality of life in patients with irritable bowel syndrome.

Participants will:

1. Receive thyme supplement plus a low FODMAP diet or placebo with low FODMAP diet for 8 weeks.
2. Recorde 3 days (1weekend and 2 workday) dietary recalls at week 4 and week 8 to assess adherence to the low FODMP diet.
3. Visit the clinic at the beginning of the study and the end of the study for a check-up and score record

Inclusion Criteria:

• Ages 18-65;
• Patients with irritable bowel syndrome;
• Body Mass Index in the range of 18-25 kg/m2

Exclusion Criteria:

• Any organic intestinal disease;
• Medical history of chronic gastrointestinal and colorectal disease;
• Any major bowel surgery;
• Medical history of liver and kidney disorders;
• Regular use of laxative, anti-diarrhea and anti inflammatory medications.