Nav: Home

Dietary restriction increases lifespan through effects on the gut

July 14, 2016

La Jolla, Calif., July 14, 2016 (embargoed until 2:00 P.M. EST) -- Dietary restriction, or limited food intake without malnutrition, has beneficial effects on longevity in many species, including humans. A new study from the Sanford Burnham Prebys Medical Discovery Institute (SBP), published today in PLoS Genetics, represents a major advance in understanding how dietary restriction leads to these advantages.

"In this study, we used the small roundworm C. elegans as a model to show that autophagy in the intestine is critical for lifespan extension," said Malene Hansen, Ph.D., associate professor in SBP's Development, Aging, and Regeneration Program and senior author of the study. "We found that the gut of dietary-restricted worms has a higher than normal rate of autophagy, which appears to improve fitness in multiple ways--preserving intestinal integrity and maintaining the animal's ability to move around."

Autophagy, or cellular recycling, is well known to play a role in lifespan extension. Autophagy involves breaking down the cell's parts--its protein-making, power-generating, and transport systems--into small molecules. This both eliminates unnecessary or broken cell machinery and provides building blocks to make new cell components, which is especially important when starting materials are not provided by the diet.

In this study the research team wanted to understand how dietary restriction impacts autophagy in the intestine, whose proper function is already known to be important for long life.

"The strain of worms we used, called eat-2, is genetically predisposed to eat less, and they live longer than normal worms, so they provide an ideal model in which to investigate how dietary restriction extends lifespan," said Sara Gelino, Ph.D., research associate in Hansen's lab and lead author of the study. "We found that blocking autophagy in their intestines significantly shortened their lifespans, showing that autophagy in this organ is key for longevity.

"These results led us to examine how inhibiting autophagy impacts the function of the intestine. We found that while normal worms' gut barriers become leaky as they get older, those of eat-2 worms remain intact. Preventing autophagy eliminated this benefit, which indicates that a non-leaky intestine is an important factor for long life."

"How intestinal integrity relates to longevity is not clearly understood," Hansen commented. "It's possible that the decline in the gut's barrier function associated with normal aging might let damaging substances or pathogens into the body."

The research team also observed that turning off autophagy in the intestine made the slow-eating, long-lived worms move around less.

"The decrease in physical activity indicates that autophagy in one organ can have a major impact on other organs, in this case probably muscle or motor neurons," said Hansen. "Finding the link between motility and autophagy in the intestine will require further research, but we speculate that inhibiting autophagy in the gut may impair the gut's ability to metabolize nutrients or secrete hormones important for the function of other organs."

While these results suggest that boosting autophagy in the gut is generally beneficial, Hansen cautions that further research is needed: "Before we can consider regulating autophagy to manage disease, we need to learn a lot more about how the process works both in a single cell as well as in the whole organism."

Many of these future studies will also employ C. elegans. "Even though worms are much simpler than humans, many of the same basic mechanisms drive their biology. The knowledge we gain from this fast-paced research could eventually contribute to the development of new treatments that help people live longer, healthier lives," added Hansen.
-end-
This research was performed in collaboration with Siler Panowski in the laboratory of Andrew Dillin, Ph.D., at the Salk Institute for Biological Studies, and was financially supported by the National Institutes of Health, the Ellison Medical Foundation and the American Federation for Aging Research.

About SBP

Sanford Burnham Prebys Medical Discovery Institute (SBP) is an independent nonprofit medical research organization that conducts world-class, collaborative, biological research and translates its discoveries for the benefit of patients. SBP focuses its research on cancer, immunity, neurodegeneration, metabolic disorders and rare children's diseases. The Institute invests in talent, technology and partnerships to accelerate the translation of laboratory discoveries that will have the greatest impact on patients. Recognized for its world-class NCI-designated Cancer Center and the Conrad Prebys Center for Chemical Genomics, SBP employs about 1,100 scientists and staff in San Diego (La Jolla), Calif., and Orlando (Lake Nona), Fla. For more information, visit us at SBPdiscovery.org or on Facebook at facebook.com/SBPdiscovery and on Twitter @SBPdiscovery.

Sanford-Burnham Prebys Medical Discovery Institute

Related Aging Articles:

Brain development and aging
The brain is a complex organ -- a network of nerve cells, or neurons, producing thought, memory, action, and feeling.
Aging gracefully in the rainforest
In an article that appears in the current issue of Evolutionary Anthropology, researchers synthesize over 15 years of theoretical and empirical findings from long-term study of the Tsimane forager-farmers.
Reversing aging now possible!
DGIST's research team identified the mechanism of reversible recovery of aging cells by inducing lysosomal activation.
Brain-aging gene discovered
Researchers at Columbia University Medical Center have discovered a common genetic variant that greatly affects normal brain aging in older adults.
Aging can be good for you (if you're a yeast)
It's a cheering thought for anyone heading towards their golden years.
How eating less can slow the aging process
New research shows why calorie restriction made mice live longer and healthier lives.
Turning back the aging clock
By boosting genes that destroy defective mitochondrial DNA, researchers can slow down and potentially reverse an important part of the aging process.
Insilico Medicine launches a deep learned biomarker of aging, Aging.AI 2.0 for testing
Insilico Medicine, Inc., a company applying latest advances in deep learning to biomarker development, drug discovery and aging research, launched Aging.AI 2.0.
Substance with the potential to postpone aging
The coenzyme NAD+ plays a main role in aging processes.
What does a healthy aging cat look like?
Just as improved diet and medical care have resulted in increased life expectancy in humans, advances in nutrition and veterinary care have increased the life span of pet cats.

Related Aging Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...