Peptide YY reduces cytotoxicity of Candida albicans in alcohol-associated liver disease

<h2>Abstract</h2><h3>Background & Aims</h3> Transitioning from yeast to hyphal morphology enables <i>Candida albicans</i> to secrete candidalysin, invade the intestinal mucosa and translocate to the blood stream. Patients with alcohol-associated hepatitis have increased abundance of <i>C. albicans</i> in the intestinal microbiome and the gene encoding candidalysin<i>,</i> is associated with reduced survival. Paneth cell derived peptide YY (PC-PYY), inhibits hyphal growth of <i>C. albicans</i>. In this study, we evaluated the potential of different <i>C. albicans</i> strains isolated from patients with alcohol-associated hepatitis to cause systemic infections and explored the therapeutic potential of PC-PYY in ethanol-induced liver disease in mice. <h3>Methods</h3> <i>C.albicans</i> strains isolated from fecal samples of patients (n=105) with alcohol-associated hepatitis were co-cultured with intestinal epithelial Caco-2 cells to assess in vitro cytotoxicity. Caco-2 cells and primary mouse hepatocytes were incubated with <i>C. albicans</i> and PC-PYY. Mice were subjected to chronic plus binge ethanol feeding. <h3>Results</h3> <i>C.albicans</i> strains isolated from stool of patients with alcohol-associated hepatitis induced significant cytotoxicity in Caco-2 cells, and high cytotoxicity was associated with worse 30-day survival (log-rank p=0.032). This functional cytotoxicity is primarily associated with the hyphal form, largely driven by candidalysin. PC-PYY, significantly reduced <i>C. albicans</i>-induced cytotoxicity in Caco-2 cells (Wilcoxon rank sum test, p=0.015) and primary mouse hepatocytes (p=0.03) compared with a scrambled peptide as control by inhibiting hyphal morphology. <i>Peptide YY</i> to <i>chromogranin A</i> ratio in intestinal crypts was significantly elevated in ethanol-fed mice compared with both isocaloric (p=0.005) and antifungal-treated controls (p=0.009), indicating that fungal overgrowth in ethanol-fed mice stimulates PC-PYY release. In ethanol-fed mice, PC-PYY administration attenuated liver injury (p=0.032) and steatosis (p=0.0498), and reduced hyphae formation in the feces (p=0.0159). <h3>Conclusion</h3> PYY inhibits filamentous growth of <i>C. albicans</i> in vitro and alleviates ethanol-induced liver disease in mice, highlighting its potential as a therapy for patients with alcohol-associated liver disease. <h3>Impact and Implications</h3> <i>C. albicans</i> and especially its toxin candidalysin are associated with poor outcome in patients with alcohol-associated hepatitis but the extent to which the cytotoxicity of individual <i>C. albicans</i> strains influence patient survival, and the role of Paneth-cell derived PYY (PC-PYY) in this context remains elusive. This study identifies a link between the cytotoxic effect of patient-derived <i>C. albicans</i> strains and survival in patients with alcohol-associated hepatitis and demonstrates that PC-PYY plays a protective role in ethanol-induced liver disease by limiting candidalysin-producing hyphae. Our work provides insight into why some patients with alcohol-associated liver disease have worse outcomes and highlights the potential of PC-PYY as therapy for patients with alcohol-associated liver disease.