Irritable bowel syndrom (IBS) is a common chronic gastrointestinal disorder that affects 10-20% of the world population. The prevalence of IBS in Norway is between 8% and 25%. The pathophysiology of IBS is incompletely understood, and there is no effective treatment for this condition. Imbalance (dysbiosis) of the gut microbiome has been found in patients with IBS. In the absence of effective method to restore the dysbiosis, transplantation of a microbiome from healthy individuals with well-functioning gut (FMT) to those with IBS has been performed. Two randomized double blind placebo-controlled (RCT) studies have been published recently. Whereas it was reported in one study that FMT reduced symptom and improved quality of life in patients with IBS, FMT had no effect in the other study. In order to clarify these contradictory results, a new RCT study that enrolled larger number of patients is required. In this study, the investigators intend to recruit 170 IBS patients from those attending outdoor clinic at Stord hospital in a randomized, double blind placebo trial. A single healthy donor with well-characterized microbiome is going to be used. The effects on symptoms, quality of life, fatigue as well as dysbiosis before and after FMT are going to be investigated. The possible mechanisms behind the effects if any of FMT such as changes in intestinal stem cells, enteroendocrine cells and local immune defense shall be also investigated. The patients are going to be randomized either to placebo (own faces), 30 g or 60 g of the donor faces in ratio 1:1:1.

Study design Patients One hundred and seventy patients who fulfill the following inclusion criteria and lack the exclusion criteria shall be included. In addition, the patients are examined physically, and blood tests are taken to exclude inflammation, and liver, kidney and thyroid diseases. They undergo further gastroscopy with duodenal biopsies to exclude coeliac disease. They undergo also colonoscopy to exclude malignity, or inflammatory bowel disease (IBD). Microscopic colitis is excluded by examining tissue obtained by colonoscopy with segmental biopsy sampling.

Donor selection and screening:

A single donor shall be selected and screened according to the European and international guidelines. The donor should not be a first-degree relative to any of the patients, as the intestinal microbiota is affected by the genetic composition, and similarity between the donor and recipient in the fecal microbiota may occur.

Protocol

Feces collection, preparation and administration:

Feces from both the donors and recipients were collected and stored at - 80•. Frozen feces (30 or 60g) from the donor or patients (placebo), thawed at 5° C and were dissolved in 50 mL of 0.9% sterile saline per 30 g feces. The dissolved stool is administrated to the patients, after overnight fast, through working channel of gastroduodeno-scope in pars descendent duodenum distal to the papilla of Vater.

Sigmoidoscopy: After administration of faeces, a sigmoidoscopy is performed during which 4 biopsies from the sigmoid colon about 30 cm from anus, and 4 biopsies from the rectum about 15 cm from anus are taken. Sigmoidoscopy is repeated in the same way 1 month after FMT.

Methods Questionnaires

1. IBS symptom severity Scale (IBS-SSS) questionnaire.
2. Birmingham Symptom scale questionnaires.
3. IBSQoL questionnaire.
4. Short form of Nepean Dyspepsia Index (SF-NDI) questionnaire.
5. Fatigue Assessment Scale (FAS).

Microbiome analysis Gut microbiota analysis was performed using the GA-mapTM Dysbiosis test (Genetic Analysis AS, Oslo, Norway) by algorithmically assessing fecal bacterial abundance and profile (dysbiosis index, DI), and potential deviation in the microbiome from normobiosis. GA-map test is based on fecal homogenization, mechanical bacterial cell disruption and automated total bacterial genomic DNA extraction using magnetic beads. DI is based on 54 DNA probes targeting more than 300 bacterial strains based on their 16S rRNA sequence in seven variable regions (V3-V9). Twenty-six bacteria probes are species specific, 19 detect bacteria on genus level, and 9 probes detect bacteria at higher taxonomic levels. Probe labeling is by single nucleotide extension and hybridization to complementary probes coupled to magnetic beads, and signal detection by using Bio Code 1000A 128-Plex Analyzer (Applied Bio Code, Santa Fe Springs, CA, USA). A DI above 2 shows a microbiota profile that differs from that of the normobiotic reference collection (DI 1-2: non-dysbiosis, DI: moderate, DI 4-5: severe dysbiosis).

Inclusion criteria:

1. Patients between who fulfill Rome IV criteria for the diagnosis of IBS.
2. Patients with moderate to severe IBS symptoms (IBS-SSS ≥ 175).

Exclusion criteria:

1. Pregnant, planning pregnancy or lactating women.
2. The use of antibiotics or probiotics within 1 month prior to FMT.
3. Patients who had undergone any abdominal surgery, with the exception of appendectomy, cholecystectomy, Caesarean section or hysterectomy.

All data are stored at Helse Vest server. Anonymous patients data is available to other research on demand.

A research nurse, not involved in the trial, create the allocation sequence using a website. This was done in blocks of 21 patients.