Intestinal Microbiome and Psychological Correlates in Irritable Bowel Syndrome and Inflammatory Bowel Disease

Study design is a within-subject design with assessment at 4 points in time. Data will be collected 3-1 month before first GHT session (T1), immediately before first session (T2), at the last session (T3), and 3-6 months after last session (T4).

Study patients will be recruited consecutively at the special outpatient-clinic for psychosomatics at the division of Gastroenterology and Hepatology, department for Internal Medicine III, University Hospital Vienna.

Patients undergo GHT in group setting, which has been shown to reduce irritable bowel syndrome (IBS) symptoms and to increase psychological wellbeing. The GHT protocol used will be the Manchester protocol of gut-directed hypnotherapy and consists of 10 weekly sessions (45 minutes) with six up to eight patients per group over a treatment period of 12 weeks.

The following variables will be assessed using standardized questionnaires: anxiety and depression (HADS-D), perceived stress (PSQ), resilience (CDRISC), and quality of life (visual analogue scales). IBS symptoms will be captured by the IBS Severity Scoring System (IBS-SSS), inflammatory bowel disease (IBD) disease activity via Harvey-Bradshaw-Index. Additionally, medication intake and food supplements will be assessed.

Microbiome data will be gained by frozen stool samples, collected by patients at home. Patients will be provided with a delivery kit to keep the samples frozen. Patients are asked to collect the first stool of the day and not to change diet, medication and intake of pre/probiotics during the hole study period, if possible (documented). At each time point (T1-T4) patients are ask to bring two immediately frozen (stored in their home freezer) double samples (2 stool samples within 1 week) to the hospital to be immediately stored at minus 20 degree Celsius. If patients do not have a home freezer, stool will be collected and frozen at the hospital.

Planned analyses comprise longitudinal and cross-sectional comparisons Intestinal colonization will enter in the analyses according to an algorithm assigning values for an increase or reduction of dysbiosis. Dysbiosis is hereby defined by the following markers: reduction of fecal biodiversity, lowered occurrence of the species Bifidobacterium, Lactobacillus and Faecalibacterium prausnitzi, increased occurrence of Enterobacteriaceae, and a higher quotient Firmicutes:Bacteroidetes.

Inclusion criteria

• Diagnosis of IBS or IBD
• Eligible for gut-directed hypnotherapy
• Adult age (18-89)
• Sufficient knowledge of german language

Exclusion criteria

• Severe somatic or psychiatric illness
• Operations of the GI tract