Synchronizing Calorie Intake Synchronizes Circadian Rhythms Across Multiple Systems

Summary: Time-restricted eating influences gene expression in over 22 regions of the brain and body. The findings have implications for a range of health conditions in which time-restricted eating appears to have potential benefits.

Source: Salk Institute

Numerous studies have shown the health benefits of time-restricted eating, including increased lifespan in lab studies, making practices like intermittent fasting a hot topic in the health industry. welfare.

However, how this affects the body at the molecular level and how these changes interact in multiple organ systems has not been well understood.

Now the Salk scientists are showing in mice how time-restricted feeding influences gene expression in more than 22 regions of the body and brain. Gene expression is the process by which genes are activated and respond to their environment by creating proteins.

The findings, published in Cell metabolism on January 3, 2023, have implications for a wide range of health conditions where time-restricted eating has shown potential benefits, including diabetes, heart disease, hypertension and cancer.

“We found that there is a system-wide molecular impact of time-restricted feeding in mice,” says lead author and Rita and Richard Atkinson Professor Satchidananda Panda at Salk.

“Our findings open the door to further examining how this nutritional intervention activates genes implicated in specific diseases, such as cancer.”

For the study, two groups of mice were fed the same high-calorie diet. One group had free access to food. The other group was restricted to eating within a nine-hour eating window each day.

After seven weeks, tissue samples were taken from 22 organ groups and the brain at different times of the day or night and analyzed for genetic changes. The samples included tissues from the liver, stomach, lungs, heart, adrenal gland, hypothalamus, different parts of the kidney and intestine, and different areas of the brain.

The authors found that 70% of mouse genes respond to time-restricted feeding.

“By altering the timing of food, we were able to alter gene expression not only in the gut or in the liver, but also in thousands of genes in the brain,” Panda explains.

Nearly 40% of genes in the adrenal gland, hypothalamus and pancreas were affected by time-restricted eating. These organs are important for hormonal regulation. Hormones coordinate functions in different parts of the body and brain, and hormonal imbalance has been implicated in many diseases, from diabetes to stress disorders. The findings offer insights into how time-restricted eating can help manage these conditions.

Interestingly, not all sections of the digestive tract were affected equally. While the genes involved in the two upper parts of the small intestine – the duodenum and the jejunum – were activated by time-restricted feeding, the ileum, at the lower end of the small intestine, did not. was not.

It shows an alarm clock and a brain
The authors found that 70% of mouse genes respond to time-restricted feeding. Image is in public domain

This discovery could open a new avenue of research to study how shift jobs, which disrupt our 24-hour biological clock (called circadian rhythm) impact digestive diseases and cancers. Previous research by Panda’s team showed that time-restricted feeding improved the health of firefighters, who are typically shift workers.

The researchers also found that time-restricted eating aligned the circadian rhythms of several organs in the body.

“Circadian rhythms are everywhere in every cell,” says Panda. “We found that time-restricted eating synchronized circadian rhythms to have two main waves: one during fasting and another just after eating. We suspect this allows the body to coordinate different processes.

Next, Panda’s team will take a closer look at the effects of time-restricted feeding on specific conditions or systems involved in the study, such as atherosclerosis, which is hardening of the arteries that is often a precursor to heart disease and stroke, as well as chronic kidney disease.

See also

It shows a revival

About this diet and current genetic research

Author: Press office
Source: Salk Institute
Contact: Press Office – Salk Institute
Image: Image is in public domain

Original research: Free access.
“Diurnal transcriptome landscape of a multi-tissue response to time-restricted feeding in mammals” by Shaunak Deota et al. Cell metabolism


Abstract

Diurnal landscape of the transcriptome of a multi-tissue response to time-restricted feeding in mammals

Strong points

  • 80% of genes are differentially expressed or rhythmic under TRF in at least one tissue
  • TRF decreases genes involved in inflammatory signaling and glycerolipid metabolism
  • TRF increases genes involved in RNA processing, protein folding and autophagy
  • TRF causes multi-tissue rewiring of BCAA, glucose and lipid metabolism

Summary

Time-restricted feeding (TRF) is an emerging behavioral nutritional intervention that involves a daily cycle of eating and fasting. In animals and humans, TRF exhibits pleiotropic health benefits that arise from multiple organ systems, but the molecular basis of TRF-mediated benefits is not well understood.

Here we subjected mice to isocaloric optional diet (ALF) or TRF from a Western diet and examined gene expression changes in samples taken from 22 organs and brain regions taken every 2 h over a 24-h period.

We discovered that TRF has a profound impact on gene expression. Nearly 80% of all genes show differential expression or rhythmicity under TRF in at least one tissue. Functional annotation of these changes revealed tissue- and pathway-specific impacts of TRF.

These findings and resources provide an essential foundation for future mechanistic studies and will help guide time-limited human feeding interventions (TRE) to treat various diseases with or without pharmacotherapies.

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