C. Diff Infection: Microbiota Changes Predict Treatment Failure

Infection with C. difficile is associated with several adverse outcomes including treatment failure (5% to 35%) but researchers do not know what clinical factors can predict this failure.

Reporting at the American College of Gastroenterology Scientific Meeting in Honolulu, a Mayo Clinic team of researchers looked at which gut microbiota signatures might be useful in determining whether patients will get better.

They defined treatment failure as a non-response to treatment with vancomycin for four days or metronidazole for five days. They looked at 889 patients with primary C. dif in infection (CDI) of whom 60.2% were women and the median age was 54 years. Of these 7% had severe CDI, 70.5% had been treated with metronidazole, 23.8% with vancomycin, and 5.6% with a combination.

Overall 12.5% failed treatment and the rates were similar with each drug.

The researchers looked at clinical factors that might have predicted the failures--age, sex, obesity, prior antibiotic use, and other factors. They found no correlation between having those factors and failing treatment. They did find that patients who responded to treatment had higher quantities of certain bacteria, for instance Faecalibacterium and Bacteroides.

Conversely, the patients who failed treatment had more Streptococcus and Clostridium.

The authors suggest that analyzing these changes in microbiota could be useful. "Gut microbiota signatures may be used to predict treatment response in the absence of reliable clinical predictors," said Sahil Khanna, MBBS, M S in presenting the study.

These patients may be candidates for other therapies, such as fecal microbiota transplant, or defined microbial consortia, she said.