In recurrent C difficile infection, oral FMT capsules have a pooled cure rate of 82% (low-quality evidence)

In patients with recurrent Clostridioides difficile infection (rCDI), oral fecal microbiota transplantation (FMT) capsules had a pooled cure rate of 82.1% and a low rate of serious adverse events, a systematic review and meta-analysis found. Researchers looked at 12 case series and three randomized controlled trials (RCTs) including a total of 763 participants (median age, 41 to 77 years; 47% to 85% women) with rCDI who received oral FMT capsules. Included studies reported cure rates after eight to 26 weeks of follow-up, with or without a comparison group, and the three RCTs compared FMT with colonoscopy, enema, or placebo.

The study was published online on Jan. 19 by the Journal of Clinical Gastroenterology. The following commentary by Laura C. Horton, MD, and Joseph D. Feuerstein, MD, was published in the ACP Journal Club section of Annals of Internal Medicine on June 1.

FMT plays a key role in the therapeutic approach for patients with rCDI. Although delivery by colonoscopy is the most well-studied route, oral administration of FMT is an attractive option that reduces procedural risks and costly resources. However, there are concerns about adequate delivery of transplanted microbiota per os to the colon, including survival of microbiota through gastric acid, dosage of inoculum, optimal encapsulation material, and the theoretical risk for aspiration given the large number of capsules required for oral FMT. Few large, prospective, well-controlled studies have compared oral capsules with more well-established colonoscopy-based FMT.

In this systematic review and meta-analysis assessing the safety and efficacy of oral FMT formulations, Du and colleagues found oral FMT has an estimated 82% efficacy for rCDI, which is similar to that achieved with colonoscopy-based FMT, although noninferiority could not be assessed due to the heterogeneity of the included studies. Studies were heterogenous in key domains, including relevant patient inclusion criteria (e.g., inflammatory bowel disease, immunocompromise, and definition of rCDI), donor characteristics, pre-FMT and FMT protocols (e.g., use of proton-pump inhibitors to suppress gastric acid and number of capsules and dosage of inoculum), and duration of follow-up. Secondary analysis found no difference in efficacy between various formulations of oral FMT (lyophilized and frozen fecal preparations), but no studies compared these directly.

Oral FMT avoids the risks associated with colonoscopy and allows for a simpler delivery route of FMT for health care providers and patients. Although the primary finding of this study is promising for oral FMT becoming the standard of care for FMT management of rCDI, the heterogeneity of included patients and FMT protocols limit the clinical applicability of this meta-analysis. Additional well-designed RCTs that use standardized protocols are needed before routine use of oral FMT for rCDI.