Axial spondyloarthritis (SpA) is a chronic inflammatory disease primarily affecting the sacroiliac and spinal joints that usually begins in young adults and is a major cause of chronic pain and disability that profoundly alter the quality of life of patients. Besides non-steroidal anti-inflammatory drugs, the development of anti-tumor necrosis factor-α (TNFα) and anti-interleukin (IL-17) biotherapies and of JAK inhibitors, has improved the management of these patients. However only half of the patients respond to these treatments and many of them are only partially relieved. Remarkably, this disorder frequently combines with overt inflammatory bowel disease (IBD) -i.e. Crohn's disease (CD) or ulcerative colitis (UC)- and even more frequently with subclinical gut inflammation, leading to suspect a role of the gut microbiota as a possible trigger. Consistently, recent studies evidenced an alteration of gut microbiota composition -or dysbiosis- in the course of SpA that appeared all the more pronounced that disease was more active. It was notably shown a restriction of bacterial diversity and an expansion of species considered as potentially pro-inflammatory, including Ruminococcus gnavus. Given its potential involvement in the pathogenesis of SpA, gut microbiota could be considéred as a promising therapeutic target. Fecal microbiota transplantation (FMT) is a technic consisting in thorough replacement of dysbiotic microbiota by healthy dondor's microbiota that has recently been developped to correct dysbiosis. It has been validated for the treatment of intractable colitis due to Clostridium difficile and its efficacy has been reported in CD or UC. The current trial, aims to evaluate efficacy of FMT in drug-resistant axial SpA.
Current pharmacological management of inflammatory rheumatism and in particular axial SpA remains imperfect. Only 50% of patients respond to the most effective biotherapies, and many of them are only partially relieved. In addition, these are extremely expensive treatments that expose them to the risk of potentially serious side effects. Compelling evidence indicates that gut dybiosis could be a critical trigger of inflammation in axial SpA and thus correcting dysbiosis represents an attractive way of reversing the pathogenic process.The efficacy of FMT in patients with axial SpA has never been studied. This randomized double-blind study will be the first to assess feasability of FMT in axial SpA, the capacity of this procedure to restore healthy microbiome, its tolerance and its potential efficacy on disease activity. If sucessfull, this trial would set the path to larger-scale clinical trials of FMT to treat axial SpA.