The aim of the study is to demonstrate a beneficial effect in reducing symptoms that negatively affect the quality of life of IBS patients, and to demonstrate a positive effect on inflammatory and intestinal function markers.

The double-blind, randomized, placebo-controlled study will be conducted on 48 patients (18-55 years old) with Irritable Bowel Syndrome (IBS). The study will consist of 2 months of supplementation with three parallel arms: 1) probiotic strains and prebiotic (Partially Hydrolyzed Guar Gum); 2) probiotic strains, prebiotic (Partially Hydrolyzed Guar Gum) and elderberry and chokeberry fruit extract; 3) placebo.The study will assess symptoms associated with IBS, using the IBS-QOL questionnaire and the Bristol Stool Formation Scale. Markers of inflammation and intestinal barrier permeability , will be determined in blood and stool samples collected from patients.

Inclusion Criteria:

• Diagnosed Irritable Bowel Syndrome.
• Women and men, 18-55 years old.
• Signed informed consent.

Exclusion Criteria:

• Intake of supplements containing plant extracts, polyphenols or anthocyanins, and supplements containing fiber, probiotics and prebiotics.
• Participation in another clinical trial.
• Inability to swallow an oral study drug/placebo.
• Oncological disease, autoimmune disease, severe liver dysfunction, tuberculosis, leukemia, multiple sclerosis, AIDS, rheumatoid arthritis, organ transplant and other gastrointestinal diseases that may affect the results of the study.
• Women who are pregnant, planning to become pregnant during the study, or breastfeeding,