


ANN ARBOR—Our bodies are not just passively growing older.


Recent research has shown that signaling between the intestine and brain can regulate a range of biological processes. So far, research has focused mainly on how signals from the gut can affect neurological functions, including some neurodegenerative diseases. Much less is known about how the brain communicates with the gut to affect certain biological process, such as aging.


The researchers discovered that brain-gut communication leads to what Xu calls an "axis of aging," wherein the brain and intestines work together to regulate the worm's longevity. The findings are scheduled for publication Feb. 28 in the journal Genes & Development.

C. elegans roundworms viewed under a microscope. Image credit: Stephanie King, University of Michigan Life Sciences InstituteC. elegans roundworms viewed under a microscope. Image credit: Stephanie King, University of Michigan Life Sciences InstituteUsing different environmental temperatures, which are known to affect roundworms' lifespan, the researchers investigated how neurons process information about external temperature and transmit that information to other parts of the body. They identified two different types of neurons—one that senses warmth and the other coolness—that act on the same protein in the intestine, telling it to either slow down or speed up the aging process.

When the cool-sensing neuron detects a drop in temperature, it sets off a chain of communication that ultimately releases serotonin into the worm's gut. This serotonin prompts a known age-regulating protein, DAF-16, to boost its activity and increase the worm's longevity.


Using these two paths, the brain is able to process cues from the external environment and then use that information to communicate with the intestine about aging. What's more, these signals can be broadcast from the intestine to other parts of the body, allowing the neurons to regulate body-wide aging.


"From our findings, it's clear that the brain and gut can work together to detect aging-related information and then disseminate that information to other parts of the body," Xu said. "We think it's likely that this sort of signaling axis can coordinate aging not only in C. elegans, but in many other organisms as well."

The research was supported by the National Institutes of Health, the Natural Science Foundation of China and the Ministry of Education of China. The study authors are: Jianke Gong and Shawn Xu of U-M; Bi Zhang, Wenyuan Zhang and Jianfeng Liu of Huazhong University of Science and Technology, China; and Rui Xiao of the University of Florida.

The Genes & Development paper is titled "Brain-gut communications via distinct neuroendocrine signals bi-directionally regulate longevity in C. elegans," DOI: 10.1101/gad.309625.117.