Scientists cast new light on how fasting impacts the immune system
New research from The University of Manchester may reshape our understanding of what happens to the immune system when we fast.
Funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the study on mice shows that the brain青瓜视频檚 hypothalamus controls how the immune system adapts during fasting, through a handful of highly specialized neurons responsible for making animals hungry.
Published today (04/04/25) in 青瓜视频攐ne of the world青瓜视频檚 leading immunology journals青瓜视频攖he study shows the brain青瓜视频檚 perception of hunger or fullness, rather than actual eating or caloric restriction, is enough to drive changes in the body青瓜视频檚 immune cells.
The findings cast doubt on the current view that a lack of nutrients alone controls how the immune system responds to fasting, indicating the brain has a critical role, beyond the simple absence of food.
By artificially switching on specific brain neurons in mice青瓜视频攚hich typically signal low energy levels青瓜视频攕cientists induced a synthetic sense of hunger. Remarkably, within hours, they saw a fast reorganization of immune cells in the blood, with a noticeable drop in inflammatory monocytes. These artificially hungry mice looked, from an immune perspective, just like mice that had fasted for real.
Our perceptions can shape our bodies in ways we don青瓜视频檛 always notice. It青瓜视频檚 easy to see how thoughts guide our actions, but this study reminds us that even our internal body adjustments that are not under conscious control respond to the brain青瓜视频檚 signals
This discovery could have important implications for developing new therapies to treat a range of inflammatory diseases as well as for treating wasting syndromes seen in cancer, in which individuals lose weight despite eating normally.
It may also explain why obesity often accompanies inflammatory conditions and why malnourished individuals are more prone to infections and inflammation.
The lead senior researcher, Dr Giuseppe D青瓜视频橝gostino, who coordinated the study, said: 青瓜视频淥ur perceptions can shape our bodies in ways we don青瓜视频檛 always notice. It青瓜视频檚 easy to see how thoughts guide our actions, but this study reminds us that even our internal body adjustments that are not under conscious control respond to the brain青瓜视频檚 signals.
青瓜视频淭his study underlines how important the brain is in regulating the immune system. But if internal or external factors alter the brain青瓜视频檚 perception, these processes can go awry, reminding us how deeply the mind and body are青瓜视频攁nd should remain青瓜视频攃onnected.
"In addition to BBSRC who funded the work, we are grateful to the Medical Research Council for providing early-stage seed funding that helped the lab explore completely novel areas 青瓜视频� a small but truly visionary contribution that still resonates today."
Collaborator and Manchester immunologist Professor Matt Hepworth added: 青瓜视频淭his work challenges the long-standing view that fasting青瓜视频檚 immunological impact is driven purely by nutrient levels. It highlights the nervous system青瓜视频檚 profound influence on how the immune system adapts during fasting.青瓜视频�
Lead author Dr Cavalcanti de Albuquerque said: 青瓜视频淏y showing how the brain exerts top-down control over immune cells, we can further explore when and how fasting might deliver health benefits. It also opens up potential ways to treat infectious, inflammatory, metabolic, and psychiatric conditions.青瓜视频�
The paper Brain Sensing of Metabolic State Regulates Circulating Monocytes is available