Today, I review, link to, and excerpt from The Curbsiders‘ #494 C. diff, Diarrhea, the Microbiome, and New Therapies with Dr. Cynthia Sears. Live from Johns Hopkins Grand Rounds.*
*Watto MF, Sears C, Williams PN. “494 C. diff diarrhea, the Microbiome, and New Therapies with Dr. Cynthia Sears. Live from Johns Hopkins Grand Rounds”. The Curbsiders Internal Medicine Podcast. thecurbsiders.com/category/curbsiders-podcast Final publishing date August 11, 2025.
All that follows is from the above resource.
Show Segments
- 00:00 Intro
- 03:00 Guest bio and hobby
- 04:25 Case of Charles Fleur Fontaine
- 06:00 Risk factors and epidemiology
- 08:00 Antibiotic hierarchy of risk
- 10:00 Diagnosis, testing strategies
- 14:00 Defining severity
- 17:30 Treatment options
- 20:00 Microbiome recovery strategies
- 24:00 Probiotics and postbiotics
- 27:00 Infection control counseling
- 30:00 C. diff and colon cancer
- 32:00 Recurrent C. diff strategies
- 35:00 Why some FMT and bezlotoxumab were discontinued
- 38:00 Microbiota replacement therapies
- 43:00 Prophylaxis strategies
- 45:00 Future therapies and ongoing research
- 47:00 Audience Q&A
- 52:00 Outro
Dominate C. diff! Learn to distinguish colonization from infection, select first-line therapies, and counsel patients on recurrence prevention and microbiome recovery. We’re joined by IDSA past president and expert on foodborne and intestinal infections, Dr. Cindy Sears (Johns Hopkins University) for a comprehensive update on Clostridioides difficile (C. diff, Cdiff, CDAD, CDI).
Claim CME for this episode at curbsiders.vcuhealth.org!
Transcript available via YouTube
Disclosures
Dr. Sears reports no relevant financial disclosures. Dr. Williams financial relationships disclosed include a Merck grant or research support. This relationship has not ended.
C. diff Pearls
- Confirm true diarrhea with ≥3 watery stools/day that run to the edge of the container.
- PCR tests (NAAT) are sensitive; combine them with EIA for toxin B antigen for specificity (Guh, 2018).
- First C. diff infection: Vancomycin remains widely used due to cost, but fidaxomicin is preferred due to less microbiome disruption and decreased risk of recurrence (Louie, 2011, IDSA CPG 2021). Metronidazole is associated with higher mortality in patients 65 and older (Haley, 2019).
- Probiotic supplements may delay microbiome reassembly post-treatment—generally not recommended (Suez, 2018). Psyllium fiber (prebiotic) or kefir (a fermented, probiotic yogurt drink) are reasonable to trial.
- Prevent spread at home through hand hygiene and 10% bleach for infection control (expert opinion). Use separate bathrooms if able. The spores are resilient and easily spread.
- Two new microbiome restoration therapies are now available. One is a live, branded rectal suspension, and the other live, oral fecal microbiota spore capsules.
- Traditional FMT is no longer available without an investigational new drug application as of December 31, 2024.
- Bezlotoxomab is no longer available for treatment of C. diff as off January 31, 2025 (empr.com/news Story on C. diff prevention accessed July 2025).
- Antibiotic exposure, even as little as 15 days, as long as 10 years prior to diagnosis is associated with an increased risk of colon cancer, and risk increases with greater exposure. (Boursi, 2015; Zhang, 2019; Liu, 2025).
