Antibiotics favor certain fungal infections

Antibiotics favor certain fungal infections

Antibiotics are essential for treating common infections. But this class of drugs is not without drawbacks. Besides antibiotic resistance, they could promote Candida fungal infections.

Against bacteria-related infections, we have molecules named antibiotics. Their discovery revolutionized medicine! These molecules have been widely used in recent decades. It turns out that more and more bacteria manage to circumvent the modes of action of antibiotics and that it is becoming more and more difficult to develop new classes of antibiotics. Besides the antibiotic resistance, misuse of this family of drugs has other consequences. Antibiotics can lead to dysfunctions in the immune system of patients, particularly in the intestine, and promote fungal infections.

Antibiotics promote fungal infections…

The results were published in Cell Host and Microbe. The authors looked at people who were hospitalized and on antibiotics with invasive candidiasis – a particularly severe fungal infection. Invasive candidiasis is linked to the passage in the blood of mushroom candida.

Animal tests have been conducted. Antibiotic administration has been shown to increase the risk of developing an invasive Candida fungal infection. But what is the mechanism underlying this observation? It would seem that the antibiotics would modify the functioning of the immune system of the patient’s intestine, in particular by reducing the production of cytokines (IL-17 and GM-CSF). Thus, the cells of the intestine would find themselves unable to defend themselves against the fungal infection, or even allow the passage of bacteria from the intestine to the bloodstream. A bacterial and fungal co-infection would set in.

Some very serious infections require the prescription of antibiotics, despite the risk of secondary fungal infection.  © patrikslezak, Adobe Stock

…but a parry is possible!

To confirm their hypothesis, the authors gave the animals treated with antibiotics the defective cytokines, IL-17 and GM-CSF. The system is reversible ! In case of co-administration of antibiotics and cytokines, the number of fungal infections was significantly reduced compared to the group treated only with antibiotics. Even if additional work is necessary to confirm these results, they represent a glimmer of hope in situations where the prescription of antibiotics is unavoidable in patients who are already very fragile.

In addition, the authors mention another observation, not yet published. The use of antibiotics would increase the risk of inflammatory bowel diseases such as Crohn’s disease. So there you have it, two new arguments in favor of sparing use of antibiotics.

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