PYY peptides are antifungal and maintain intestinal microbial health

When the team detected this form of C. albicans using PYY, the data showed that PYY effectively stopped the growth of these bacteria, killing more fungal forms of C. albicans and retaining the symbiotic yeast form of C. albicans.

Eugene Chang’s group at the University of Chicago has published a paper in the journal Science entitled: Peptide YY: A Paneth cell antimicrobial peptide that maintains Candida gut commensalism.

YY peptide (PYY) It is an intestinal hormone expressed and secreted by enteroendocrine cells (ECC) to control appetite by generating satiety. Recent studies have found that the intestinal non-specific PanethCell also expresses a form of PYY, which can act as an antimicrobial peptide (AMP), which also plays a crucial role in keeping the intestinal microbiota healthy and preventing Candida albicans from becoming a dangerous pathogenic mode.

Little is known about the regulation of these bacteria by our gut microbiome. We just know that the bacteria are out there, but we don’t know what makes them good for our health. Recent studies have shown that YY peptides are actually important for maintaining intestinal bacterial symbiosis.

At the outset, the team was not ready to study bacteria in the gut microbiome. When Joseph Pierre, the first author of the paper, was studying the intestinal endocrine cells of PYY producing mice, Dr. Joseph Pierre noticed that PYY also has Panethcells, which are important immune system defenses in the mammalian gut and prevent the multiplication of dangerous bacteria by metabolizing several bacterosuppressive compounds. This does not seem reasonable because PYY was previously thought to be only an appetite hormone. When the team detected a variety of bacteria, PYY was found to be bad at killing them.

PYY peptides are antifungal and maintain intestinal microbial health

However, when they searched for other types of structurally similar peptides, they found a PYY-like peptide -Magainin2, an antimicrobial peptide present on Xenopus skin that protects against bacterial and fungal infections. Therefore, the team set out to test the antifungal properties of PYY. In fact, PYY is not only a highly effective antifungal agent but also a very specific antifungal agent.

Intact, unmodified PYY has 36 amino acids (PYY1-36) and is a potent antifungal peptide when Paneth cells metabolise it into the gut. But when endocrine cells produce PYY, it is stripped of two amino acids (PYY3-36) and converted into an intestinal hormone that can travel through the bloodstream to create a sense of fullness that tells the brain you’re not hungry.

Candida albicans (C.albicans), also known as Candida albicans, is a bacterium that generally grows in the mouth, skin and intestine. It is commensal in the body in a basic yeast shape, but under moderate conditions it converts to a so-called fungal shape, which allows it to grow in large amounts, leading to thrups, mouth and throat infections, vaginal infections, or more severe systemic infections.

When the team detected this form of C. albicans using PYY, the data showed that PYY effectively stopped the growth of these bacteria, killing more fungal forms of C. albicans and retaining the symbiotic yeast form of C. albicans.