Abstract
Chronic intestinal pseudo-obstruction (CIPO) is characterized by bowel dilation and obstructive symptoms without any structural blockage. Although the microbiota is known to affect gastrointestinal function, its role in CIPO is poorly understood. We aimed to characterize the CIPO microbiota, investigate its role in disease expression and explore the therapeutic role of fecal microbiota transplantation (FMT). CIPO patients (n = 14) and healthy controls (HC, n = 12) were recruited from Italy and Canada. Microbiota profiles and functions were assessed by 16S rRNA sequencing and PICRUSt. Germ-free NIH Swiss mice were colonized with HC and CIPO microbiota, their intestinal transit and bowel distension were assessed by videofluoroscopy and computed tomography (CT), and the expression of host genes by NanoString®. The CIPO microbiota exhibited reduced microbial diversity with dominance of Proteobacteria and altered metabolic function. Mice with CIPO microbiota developed marked bowel distension and slow intestinal transit associated with altered expression of multiple genes related to immunity, the intestinal barrier and neuromuscular function. FMT from a HC improved the microbiota profile, intestinal transit and bowel distension in both CIPO mice and a selected CIPO patient, in whom a marked clinical improvement was sustained for 8 y. Thus, our findings support the use of microbiota-directed therapies to induce clinical improvement in CIPO patients.