Dietary butyrate was added to fish food to see if it could help Nile tilapia grow better and fight off infections. The fish were fed different amounts of butyrate for 90 days and then injected with harmful bacteria. The fish that ate more butyrate had better growth, immune responses, and were more resistant to the bacteria. Fish that had 7.5-10.0 grams of butyrate per kilogram of food had no deaths from the infection, while those on a regular diet had an 85% mortality rate. Adding 6.25 grams of butyrate per kilogram of food could be a good way to boost the health and immunity of Nile tilapia.