Giving mice a diet with lots of fat and few carbohydrates seemed to boost certain immune cells, which protected them from the flu
Source:
https://www.newscientist.com/article/2223688-eating-a-keto-diet-may-give-some-protection-against-the-flu/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home