Immune-boosting drugs with antibiotics may reduce the health risks of fungal infections

Patients are more susceptible to fungal infections because the immune system in the gut is disrupted when patients are given antibiotics in the hospital.

Using immune-boosting drugs with antibiotics, according to a recent study from the University of Birmingham and the National Institutes of Health, might reduce the health risks associated with these complex infections.

Invasive candidiasis, a life-threatening fungal infection, is a serious consequence for hospitalized patients who are given antibiotics to combat sepsis and other bacterial diseases that spread rapidly throughout hospitals (such as C. diff). Fungal infections are harder to treat than bacterial infections, yet the causes of fungal diseases are poorly known.

Antibiotics affect the immune system in the intestines, which means fungal infections are poorly managed in that location, according to experts from the University’s Institute of Immunology and Immunotherapy and the National Institutes of Health. Surprisingly, the researchers discovered that when fungal infections grew, gut bacteria were able to escape as well, increasing the chance of bacterial infection.

These factors can add up to a complicated clinical situation—and by understanding these underlying causes, doctors will be better able to treat these patients effectively.”

Dr Rebecca Drummond, Study Lead Author, Institute of Immunology and Immunotherapy, University of Birmingham

The study, which was published in Cell Host and Microbe, shows the promise of immune-boosting drugs, but the researchers also point out that antibiotics can have side effects that influence how they fight infection and diseases. This emphasizes the significance of careful antibiotic stewardship.

We knew that antibiotics make fungal infections worse, but the discovery that bacterial co-infections can also develop through these interactions in the gut was surprising. These factors can add up to a complicated clinical situation—and by understanding these underlying causes, doctors will be better able to treat these patients effectively.”

Dr Rebecca Drummond, Study Lead Author, Institute of Immunology and Immunotherapy, University of Birmingham

The researchers infected animals with Candida albicans, the most prevalent fungus that causes invasive candidiasis in people, after treating mice with a broad-spectrum antibiotic cocktail. Although infected mice died more frequently, researchers discovered that this was due to infection in the intestine rather than the kidneys or other organs.

In a further phase, the researchers identified which immune system components were missing from the gut following antibiotic treatment, and then employed immune-boosting drugs identical to those used in people to replace them in the mice. Scientists discovered that taking this method reduced the severity of the fungal infection.

The researchers followed up on the experiment by examining hospital records, where scientists discovered that identical co-infections can arise in humans following antibiotic treatment.

These findings demonstrate the possible consequences of using antibiotics in patients who are at risk of developing fungal infections. If we limit or change how we prescribe antibiotics we can help reduce the number of people who become very ill from these additional infections—as well as tackling the huge and growing problem of antibiotic resistance.”

Dr Rebecca Drummond, Study Lead Author, Institute of Immunology and Immunotherapy, University of Birmingham