Mushrooms. They contain proteins called cytokines that could assist the body in defending itself against viruses. These beneficial effects you may find in ordinary button mushrooms, available at your local supermarket.
Probiotic Yogurt. Researchers have found that a daily probiotic yoghurt drink prevents diarrhea, one of the symptoms of gastroenteritis, otherwise known as stomach flu.
Chamomile Tea. Scientists from London found that men who drank five cups of the herbal tea each day had significantly higher levels of phenols - antibacterial substances which assist in fighting the colds and diseases.
Brazil Nuts. The micronutrient selenium provides you with all-round protection against influenza. Three Brazil nuts per day will give you the recommended daily amount.