ObjectiveFaecal microbiota transplantation (FMT) from healthy donors to patients with irritable bowel syndrome (IBS) has been attempted in two previous double-blind, placebo-controlled studies. While one of those studies found improvement of the IBS symptoms, the other found no effect. The present study was conducted to clarify these contradictory findings.DesignThis randomised, double-blind, placebo-controlled study randomised 165 patients with IBS to placebo (own faeces), 30 g FMT or 60 g FMT at a ratio of 1:1:1. The material for FMT was obtained from one healthy, well-characterised donor, frozen and administered via gastroscope. The primary outcome was a reduction in the IBS symptoms at 3 months after FMT (response). A response was defined as a decrease of 50 or more points in the total IBS symptom score. The secondary outcome was a reduction in the dysbiosis index (DI) and a change in the intestinal bacterial profile, analysed by 16S rRNA gene sequencing, at 1 month following FMT.ResultsResponses occurred in 23.6%, 76.9% (p<0.0001) and 89.1% (p<00.0001) of the patients who received placebo, 30 g FMT and 60 g FMT, respectively. These were accompanied by significant improvements in fatigue and the quality of life in patients who received FMT. The intestinal bacterial profiles changed also significantly in the groups received FMT. The FMT adverse events were mild self-limiting gastrointestinal symptoms.ConclusionsFMT is an effective treatment for patients with IBS. Utilising a well-defined donor with a normal DI and favourable specific microbial signature is essential for successful FMT. The response to FMT increases with the dose.Trial registrationwww.clinicaltrials.gov (NCT03822299) and www.cristin.no (ID657402).

In patients with functional dyspepsia, scanning by a novel ultrasonographic method was carried out to investigate postprandial accommodation of the proximal stomach. Twenty patients with functional dyspepsia and 20 controls were scanned fasting in a sitting position after drinking 500 ml meat soup. Images were recorded up to 25 min after the ingestion period using an ultrasound sector scanner with a 3.25-MHz transducer. The area in a sagittal section and the maximal diameter in a oblique frontal section were chosen as the main variables for calculating the emptying fraction of the proximal stomach, defined as: (aV2.5min - aVactual/aV2.5min. All subjects were asked to score total symptoms (1-9) provoked by the meal. From 7.5 to 25 min after the ingestion period the patients exhibited both smaller area in the sagittal section (P < 0.018) and shorter diameter in the frontal section (P < 0.046) compared with the healthy controls, and they suffered more symptoms in response to the meal (P = 0.002). Dyspeptic patients revealed higher emptying fractions (P = 0.0005, ANOVA), and H. pylori status did not influence the emptying fractions. Diagnostic sensitivity of the method at 20 min postprandially was 70% and the specificity was 65%. Patients with functional dyspepsia have impaired accommodation of the proximal stomach to a meal, temporarily related to symptom induction.

Our findings support the efficacy of a LFD in alleviating IBS symptoms, and show changes in inflammatory cytokines, microbiota profile, and SCFAs, which may have consequences for gut health.