Resolution of long-term severe irritable bowel syndrome following fecal microbiota transplantation: A case report and microbiota analysis.

The diagnosis and management of irritable bowel syndrome (IBS) is challenging due to its complex symptoms and inconsistent treatment responses. Given the important role of gut microbiota in gastrointestinal health, fecal microbiota transplantation (FMT) is a promising intervention. We describe the case of a 55-y-old woman without prior gastrointestinal issues who, following severe depression, developed multiple gastrointestinal symptoms, including abdominal pain, fluctuating bowel habits, and a persistent burning sensation in her mouth and upper gastrointestinal tract. At Lausanne University Hospital, she was diagnosed with IBS resistant to multiple lines of treatment and a multidisciplinary team proposed multiple oral FMTs. One-month post-FMT, her gastrointestinal symptoms significantly improved and remained better after a year, with only the burning sensation persisting. Analysis of pre- and post-FMT samples and donor material, using 16S rRNA amplicon metagenomics, revealed a 90% genus-level taxonomic overlap between the patient and the donor. The observed changes in the relative abundance of these genera, including the enrichment of beneficial gut commensals, as well as the elimination of IBS-associated genera likely supported her recovery. Overall, FMT led to substantial improvement in her long-standing gastrointestinal symptoms.