Effects of the Multispecies Probiotic Ecologic Barrier in IBS Patients With Upper GI Symptoms and Anxiety, Depression, or Stress

The aim of this clinical trial is to find out whether Ecologic Barrier is effective in supporting the treatment of irritable bowel syndrome (IBS) in adults. The main questions that this trial aims to answer are: * Does Ecologic Barrier help improve IBS severity when added to standard IBS treatment? * Does Ecologic Barrier help improve symptoms of anxiety, depression, and stress in patients with IBS? * Does Ecologic Barrier help improve upper gastrointestinal symptoms when added to standard IBS treatment? * What adverse events may occur when using Ecologic Barrier? The researchers will compare a group receiving standard symptom-based treatment with another group receiving standard treatment plus Ecologic Barrier. Participants will: * Receive IBS treatment for 2 months, with Ecologic Barrier added during either the first month or the second month, depending on random assignment. * Attend a follow-up visit after 1 month of treatment. * Take part in interviews about IBS severity, symptom improvement, adverse events, and symptoms of depression and anxiety at baseline, 2 weeks, 4 weeks, 8 weeks, and 12 weeks.