Yogurt: Eating at least a cup of fresh yogurt a day will help fight the bad bacteria in your digestive tract.

Cleaning your digestive tract of infections can give you immunity from stomach disorders like upset stomach and illnesses like fever, lethargy and cold.

Carrots: Carrots contain beta carotene, which boosts the immune system's production of infection fighting cells. It protects our bodies from cancer.

It also contains vitamin B6 which boosts the production of antibodies. Some other food sources of vitamin B6 are bananas, sunflower seeds, lentils etc.

Try to add at least half a cup of fresh carrots to your diet daily. Although cooked carrots are good for you, the heat from cooking can destroy some of the beta carotene in it.