DEC 02, 2021 9:04 AM PST

Antibodies Seem to Keep Gut Fungi in Check, Except in Crohn's Patients

WRITTEN BY: Carmen Leitch

The bacteria that live in the gut microbiome have gotten a lot of attention, and for good reason; gut bacteria have been associated with different diseases, and have a significant influence on their host in many ways. But other microbes like viruses and fungi live in the gut microbiome too, and they can also have a major impact on host health.

Candida albicans. / Credit: CDC/ Dr. Stuart Brown

New research has shown that in some patients with the intestinal disorder Crohn's disease, the antibodies that are supposed to be tamping down the growth of harmful fungi that live in the gut are disrupted. While research has indicated that the host immune system can help maintain the healthy balance of bacteria in the microbiome, this study has suggested that the immune system is involved in controlling gut fungi, sometimes called the mycobiome, too. The research has been reported in Nature Microbiology.

Different stuff in the environment, like cold temperatures or the wrong pH, can cause fungi to change their shape. The common yeast Candida albicans can transform into a pathogenic form that grows appendages called hyphae, which can cause damage and invade other tissues, because of environmental conditions.

The immune system is quite active in the gut, and antibodies that are released there can influence the pathogenicity of C. albicans. This normal situation may be disrupted in Crohn's, a chronic inflammatory condition. Excessive growth of C. albicans has been linked to several conditions that involve the gastrointestinal tract.

In this study, the researchers identified an antibody, secretory immunoglobulin A (slgA), in mouse fecal matter. The antibody could specifically bind hyphae on C. albicans, preventing it from spreading. Those antibodies also attached to hyphae on C. albicans from human samples. Since they selectively attach to hyphae that cause virulence, and not harmless forms of C. albincans, the researchers suggested that antibodies are helping to maintain the right balance of microbes in the gut.

Crohn's disease patients were found to be carrying many antifungal antibodies compared to healthy individuals. But these antibodies don't seem to work against the hyphae, there were also high levels of hyphae in the patients.

"An impairment in this mechanism of control in mice and in patients with Crohn's disease might be a contributing factor to the increased hyphal growth in the gut," said senior study author Dr. Iliyan Iliev, an associate professor of immunology in medicine at Weill Cornell Medicine .

Additional work showed that antifungal antibodies could reduce hyphae production on C. albicans when the yeast was grown with human cells. "It seems that these antifungal antibodies disarm hyphae to a degree," said first study author and graduate student Itai Doron.

This research could open up new treatment options for C. albicans overgrowth.

"The community of gut fungi in the gut, specifically C. albicans, is shaping our immunity," Iliev said. "We develop these antibodies, and it seems they have a protective role in a specific context."

Sources: Cornell University, Nature Microbiology

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
NOV 09, 2021
Microbiology
Can This Cat Parasite Become a Tumor Treatment?
NOV 09, 2021
Can This Cat Parasite Become a Tumor Treatment?
You may have heard of Toxoplasma gondii because it is so common. Cats carry this parasite, and anyone that cleans a litt ...
DEC 06, 2021
Clinical & Molecular DX
Bacterial Toxins and Advances in Detecting Bloodstream Infections
DEC 06, 2021
Bacterial Toxins and Advances in Detecting Bloodstream Infections
Sepsis describes the uncontrolled inflammatory response when the host cell is attacked by bloodstream infections. Sepsis ...
NOV 19, 2021
Cell & Molecular Biology
Viral RNA Can Hijack the Host by Assuming a tRNA-Like Structure
NOV 19, 2021
Viral RNA Can Hijack the Host by Assuming a tRNA-Like Structure
Many viruses have genomes made of RNA. In human cells, messenger RNA (mRNA) molecules act as intermediates; cellular mac ...
NOV 28, 2021
Microbiology
A Gut Microbe That Improves Bees' Memory
NOV 28, 2021
A Gut Microbe That Improves Bees' Memory
Accumulating evidence has suggested that the community of microbes in the gastrointestinal tracts of most organisms have ...
DEC 08, 2021
Genetics & Genomics
Expanding the Gene-Editing Toolbox
DEC 08, 2021
Expanding the Gene-Editing Toolbox
The CRISPR-Cas9 gene-editing technology sparked a veritable revolution in the biomedical sciences, taking genetic engine ...
DEC 23, 2021
Cell & Molecular Biology
Toxoplasma Parasites Can Manipulate Host Brain Cells
DEC 23, 2021
Toxoplasma Parasites Can Manipulate Host Brain Cells
The parasite that causes Toxoplasmosis, Toxoplasma gondii is common, and is found in undercooked or contaminated meat, a ...
Loading Comments...