Concurrent and Subsequent Co-Infections of Colitis in the Era of Gut Microbiota and Expanding Treatment Options.

We narratively reviewed the physiopathology, epidemiology, and management of co-infections in colitis (CDI) by searching the following keywords in Embase, MedLine, and PubMed: "", "co-infection", "blood-stream infection" (BSI), "fungemia", "", "", "probiotics", "microbial translocation" (MT). Bacterial BSIs (mainly by and ) and fungemia (mainly by ) may occur in up to 20% and 9% of CDI, increasing mortality and length of hospitalization. Up to 68% of the isolates are multi-drug-resistant bacteria. A pivotal role is played by gut dysbiosis, intestinal barrier leakage, and MT. Specific risk factors are represented by CDI-inducing broad-spectrum antibiotics, oral vancomycin use, and CDI severity. Probiotics administration (mainly and ) during moderate/severe CDI may favor probiotics superinfection. Other co-infections (such as or protozoa) can complicate limited and specific cases. There is mounting evidence that fidaxomicin, bezlotoxumab, and fecal microbiota transplantation can significantly reduce the rate of co-infections compared to historical therapies by interrupting the vicious circle between CDI, treatments, and MT. Bacterial BSIs and candidemia represent the most common co-infections in CDI. Physicians should be aware of this complication to promptly diagnose and treat it and enforce preventive strategies that include a more comprehensive consideration of newer treatment options.