Unrecognized Antiplatelet Effect of Mushroom Coffee: A Case of Postoperative Bleeding Following Colonic Surgery

Mushroom coffee—blends of coffee with “functional” mushroom powders—has surged in popularity, yet its hemostatic effects are poorly appreciated in perioperative care. We report a postoperative hemorrhage likely potentiated by a commercial mushroom coffee. A 62-year-old man with HIV, hepatitis C, and insulin-treated diabetes underwent colostomy reversal. On postoperative day 9, he developed brisk bleeding at the colonic anastomosis requiring angiography and embolization. Recurrent hemorrhage prompted a detailed supplement history, revealing daily use of mushroom coffee for two months preoperatively. The product’s labeled ingredients include an organic mushroom blend of cordyceps, lion’s mane (Hericium), reishi (Ganoderma), shiitake, turkey tail, and king trumpet, combined with arabica coffee, MCT oil, and coconut milk. Several constituents—reishi, cordyceps, lion’s mane, and chaga (Inonotus obliquus, used in some mushroom blends)—have published antiplatelet or antithrombotic activity in vitro and/or in vivo. After counseling, the patient discontinued mushroom coffee; no further bleeding occurred, and he recovered without additional intervention. This case highlights a clinically important but underrecognized risk: mushroom-based beverages can exert antiplatelet effects comparable to herbal supplements traditionally flagged in preoperative screening. We recommend that preoperative medication reconciliation explicitly query mushroom coffees and “adaptogenic” blends and that such products be held similarly to other agents with antiplatelet properties. Greater awareness among surgeons, anesthesiologists, and internists is needed as functional foods proliferate. Controlled studies are warranted to quantify bleeding risk from multi-mushroom products and to inform evidence-based perioperative guidance