Antibiotics can cause life-threatening fungal infection, says new study

Each year, fungal infections kill nearly the same number of people as tuberculosis each year. The infection takes hold mostly in vulnerable people because they have a defective immune system caused by an underlying disease, such as a viral infection (HIV or Covid-19), or cancer. Antibiotics can cause immune system defects that increase the risk of fungal infections, a new study has found.

Antibiotics are more likely to cause fungal infections because of disruption to the gut’s immune system, the study conducted by the University of Birmingham (UK) and the National Institutes of Health (US) has found.

The researchers said using immune-boosting drugs alongside antibiotics could reduce the health risks from these complex infections.

A common cause of fungal infections in humans is Candida. It can cause invasive candidiasis, a life-threatening bloodstream infection. One of the risk factors for invasive candidiasis is antibiotics, the study has found. When a patient is prescribed antibiotics, it kills off some of the gut bacteria that can create space for gut fungi (like Candida) to grow.

If the intestine is damaged by surgery or chemotherapy, the Candida can get out of the gut and cause an infection in the bloodstream. The most common way people get invasive candidiasis is not from their gut, but from their skin.

The life-threatening fungal infection is a major complication for hospitalised patients given antibiotics to prevent sepsis or other bacterial infections that quickly spread around hospitals. Treatment for fungal infections can be more difficult than bacterial infections, but the underlying cause of these infections are not well understood.

The researchers discovered that antibiotics disrupted the immune system in the intestines. The team also found that where fungal infections developed, gut bacteria were able to escape, leading to additional risk of bacterial infection.

Published in Cell Host and Microbe, the study demonstrated the potential for immune-boosting drugs. The researchers said their work also highlighted how antibiotics could have additional effects on bodies that affect how humans fought infection and disease. This underscores the importance of careful stewardship of antibiotics.

The team used mice, treated with a broad-spectrum antibiotic cocktail, and infected them with Candida albicans. They found that although their mortality increased, this was caused by infection in the intestine.

The team also pinpointed parts of the immune system were missing from the gut following the antibiotic treatment. The researchers added these back into the mice through immune-boosting drugs similar to those available for humans and found that the approach helped reduce the fungal infection’s severity.

The team followed up the experiment by studying records from hospitals that showed the possibility of similar co-infections in humans after antibiotic treatment.

“Our work highlights the importance of antibiotic stewardship in protecting vulnerable patients from life-threatening infections and provides mechanistic insights into a controllable iatrogenic risk factor for invasive candidiasis,” the authors of the study wrote. 

The above article is for information only and not intended to be a substitute for professional advice. Always seek guidance from a doctor or other qualified medical professional for questions on health.