A new research shows that the immune system kill bacteria more actively at night as compare to the day time. Shirasu-Hiza and her colleague David Schneider conducted the study on laboratory model organism, Drosophila melanogaster and found that the specific immune response known as phagocytosis oscillates with the body's circadian rhythm.

Study on fruit flies revealed that those sick with bacterial infections lost their healthy circadian rhythms, which paces the human body's healthy eating and sleeping cycle.

Mimi Shirasu-Hiza, a researcher at Stanford University said, "These results suggest that immunity is stronger at night, consistent with the hypothesis that circadian proteins regulate the restorative functions such as specific immune responses during sleep, when animals are not engaged in metabolically costly activities."

Researchers found that the infected flies with a bacterial infection at night had a better chance of survival than the flies infected during the day. They also found that human's immune responses such as phagocytosis not only involved in clearing bacterial infection but also are implicated in a growing number of human diseases such as cancer and neurodegenerative disorders.