A mushroom species native to Asia may boost immunity when eaten daily, a new study has claimed. Researchers from the University of Florida found increased immunity in people who ate a cooked shiitake mushroom every day for four weeks. In the study led by UF Food Science and Human Nutrition Professor Sue Percival, 52 healthy adults, age 21 to 41, were given a four-week supply of dry shiitake mushrooms, popular in countries like Japan and China. Participants took the mushrooms home, cleaned and cooked them. Then they ate one, 4-ounce serving of mushrooms each day during the experiment. Through blood tests before and after the experiment, researchers saw better-functioning gamma delta T-cells and reductions in inflammatory proteins. "If you eat a shiitake mushroom every day, you could see changes in their immune system that are beneficial," said Percival. "We're enhancing the immune system, but we're also reducing the inflammation that the immune system produces," Percival said. To be eligible for the study, participants could not be vegans or vegetarians. They also could not drink tea, take antioxidant supplements or probiotics before the study. They also could not consume more than 14 glasses of alcoholic beverages per week or eat more than seven servings of fruits and vegetables per day during the experiment. Percival said the dietary restrictions were imposed because fibre, tea and probiotics help the body's immune system, so researchers didn't want to start with people who already had a strong immune system. Additionally, alcohol could suppress immunity, Percival said. The study was published in the Journal of the American College of Nutrition.