New guidelines support probiotics for C. difficile prevention, but few other uses

The American Gastroenterological Association recently issued clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders.

The guidelines were based on an accompanying technical review that reviewed the evidence to answer eight specific questions. The guideline writers focused on conditions where probiotics are commonly considered and outcomes that are important to patients, such as induction and maintenance of disease, treatment of disease, and prevention of sepsis and all-cause mortality. The guidelines and review were published by Gastroenterology on June 9.

The guidelines found little evidence to support probiotics in a number of the conditions assessed and recommended their use for treatment only in the context of a clinical trial for patients with Clostridioides difficile infection, Crohn's disease, ulcerative colitis, or irritable bowel syndrome.

The guidelines suggested specific probiotics (over others or none) for prevention of C. difficile in patients on antibiotic treatment: Saccharomyces boulardii; the two-strain combination of Lactobacillus acidophilus CL1285 and L. casei LBC80R; the three-strain combination of L. acidophilus, L. delbrueckii subsp. bulgaricus, and Bifidobacterium bifidum; or the four-strain combination of L. acidophilus, L. delbrueckii subsp. bulgaricus, B. bifidum, and Streptococcus salivarius subsp. thermophilus. However, the guidelines noted that patients who place a high value on the potential harms or avoidance of the associated cost and a low value on the small risk of C. difficile development (particularly in the outpatient setting) would reasonably select no probiotics.

For adults and children with pouchitis, the guidelines suggested the eight-strain combination of L. paracasei subsp. paracasei DSM 24733, L. plantarum DSM 24730, L. acidophilus DSM 24735, L. delbrueckii subsp. bulgaricus DSM 24734, B. longum subsp. longum DSM 24736, B. breve DSM 24732, B. longum subsp. infantis DSM 24737, and S. salivarius subsp. thermophilus DSM 24731 over no or other probiotics. Again, the authors noted that patients for whom the feasibility and cost of using this combination are problematic may reasonably select no probiotics. Two additional guidelines addressed use of probiotics in children and newborns.

The guideline authors noted a variety of causes for the current knowledge gaps “in this very promising and important area of research,” including significant heterogeneity between studies, variability in the probiotic strains studied, lack of consistent harms reporting, and unavailability of product manufacturing details. “Future high-quality studies are urgently needed which address these pitfalls,” they wrote. The guidelines may be updated in three to five years or if practice-changing evidence is published.