January 2026
To critically evaluate the literature over the past year on microbial therapeutics in the management of disorders of the large intestine. The primary focus is on disorders where the microbiome has been implicated in pathophysiology, and its modulation has been a therapeutic target.
Though widely consumed, data on the impact of probiotics and prebiotics in gastrointestinal disorders continue to pose challenges in interpretation due to shortcomings in study design; postbiotics, meanwhile, because of some logistical and regulatory advantages, are attracting attention. Though time-honored for its role in infections due to Clostridioides difficile (CDI), FMT has encountered challenges in relation to regulation leading to the appearance of highly standardized, extensively screened and rigorously prepared microbial products [defined as live biotherapeutic products (LBP)], which show great promise; two have been approved by the FDA for prevention of recurrent CDI. Outside of CDI, efforts to define a role for FMT in the management of various diseases have met with mixed results.
The translation of findings in studies of microbiome composition to successful therapies has proven disappointing to date, though attempts to develop selective and targeted microbial consortia show promise and may lead the way to personalized bacteriotherapy.