Research on Probiotic Yeasts and Drug-Resistant Fungal Infections

Overview of Probiotics

Researchers in the United States and India are exploring the potential of certain probiotic yeasts to prevent and treat serious drug-resistant fungal infections. Probiotics are live bacteria and yeasts that contribute positively to health. Commonly found in foods like yogurt, they are also available as dietary supplements. Probiotics are known for enhancing digestive health and may offer additional benefits, including the treatment of allergies, type 2 diabetes, and the prevention of various infections.

Research Institutions and Publication

A collaborative study between Worcester Polytechnic Institute in Massachusetts, U.S., and the Central Food Technological Research Institute in Mysore, India, focuses on the ability of specific probiotic yeasts to combat life-threatening fungal infections in hospital patients. Their findings were recently published in the journal mBio.

Fungal Infections in Immunocompromised Patients

Concerns with Candida Infections

Candida albicans is a leading cause of fungal infections among hospital patients; however, non-albicans Candida species are becoming increasingly concerning due to their ability to cause severe infections and resistance to antifungal treatments. These infections pose significant risks, especially for patients with weakened immune systems or those with implanted medical devices, catheters, or intravenous lines. Antifungal drugs, while sometimes effective, can also have serious side effects, damaging human cells and tissues.

Potential of Probiotic Yeasts

Certain probiotic yeasts may provide a novel approach to preventing or treating non-albicans fungal infections.

Mechanisms of Action of Probiotic Yeasts

Adhesion and Biofilm Formation

The ability of non-albicans fungi to adhere to surfaces and form biofilms is a key factor in their pathogenicity and resistance to treatment. These biofilms create a physical barrier against antifungal agents. Researchers conducted laboratory experiments to determine whether specific probiotic yeasts could inhibit adhesion and biofilm formation of non-albicans Candida species on non-biological surfaces, similar to those found in catheters and intravenous lines, as well as on human gut cells.

Laboratory Findings

In one experiment, the application of probiotic yeasts on non-biological plastic surfaces reduced the adherence of non-albicans Candida by up to 53% and decreased biofilm formation by as much as 70%. Other studies demonstrated that these probiotic yeasts could lower the adhesion of non-albicans Candida to human gut epithelial cells.

Animal Model Studies

To evaluate the effects in living organisms, researchers studied nematode worms, which share several key characteristics with the human intestinal system. They discovered that nematodes pre-treated with probiotic yeasts were protected from non-albicans Candida infections compared to untreated worms. Furthermore, administering probiotic yeasts to infected nematodes helped alleviate the gut infection.

Implications for Treatment of Drug-Resistant Fungal Infections

Future Directions

These laboratory investigations suggest that certain probiotic yeasts could serve as effective alternatives to antifungal medications for preventing and treating non-albicans Candida infections.

Expert Commentary

“As the rate of deadly infections by non-albicans fungi species increases, there is a pressing need for more effective and safer medications to both prevent and treat these intractable illnesses,” stated Prof. Reeta Rao, a lead author of the study. “This study has shown that probiotic yeast may be the alternative we have been looking for and certainly warrants further investigation,” she added.

References

Kunyeit L, Kurrey NK, Anu-Appaiah KA, et al. Probiotic yeasts inhibit virulence of non-albicans Candida species. mBio Doi:1128/mBio.02307-19. Published online 15 October 2019. Worcester Polytechnic Institute, Press release 10 Dec 2019. “Probiotic yeast may offer an effective treatment for drug-resistant fungal infections.” https://www.eurekalert.org/pub_releases/2019-12/wpi-pym121019.php