The smell of food controls cellular recycling and affects life expectancy

February 21, 2019, University of Cologne
The smell of food controls cellular recycling and affects life expectancy
C. elegans' sense of smell depends on olfactory neurons (red); loss of function in odor perception results in deteriorations of the intestinal recycling system, visualized by the accumulation of green fluorescent protein (GFP). Credit: Fabian Finger

The smell of food induces a variety of physiological processes in our body. Thus, the production of saliva and digestive enzymes is stimulated before the actual food intake in order to prepare the gastrointestinal tract for the upcoming digestive process. In a healthy organism, this coordination depends on a dynamic balance between formation and degradation of proteins (proteostasis). This plays an important role for the recycling of cells and during the aging process.

Scientists of Thorsten Hoppe's lab at the University of Cologne have has demonstrated the influence of food odours on proteostasis. The experimental investigations were carried out in the roundworm Caenorhabditis elegans, a fundamental model organism in biomedical research. Their finding: two of the 358 neurons that form the nematode are part of the olfactory system, and thus important for perception.

The researchers were able to uncover the influence of smell on the physiology of the digestive tract by investigating the recycling of green fluorescent proteins in the intestine. The brighter the green fluorescent signal within the worms, the more severe the accumulation of cellular waste, strongly correlating with defective protein degradation.

The underlying processes are mediated by the regulatory microRNA molecule mir-71. This molecule regulates the genetic programme of olfactory neurons and subsequent degradation processes in the digestive tract. However, if this mechanism is blocked, cellular recycling processes are diminished and the animal's lifespan is reduced. In other words, roundworms with a non-functional sense of smell have shorter lives—a strong indication for its physiological significance.

This mechanism is central for the proper processing of odour signals and mediates adjustments in the intestinal cells. "We assume that the organism coordinates food intake and effective degradation this way," said first author Dr. Fabian Finger, who was recently awarded with the Klaus Liebrecht Prize of the UoC for his work.

"The impact of odours at the is a poorly investigated field," says Thorsten Hoppe. "It is well known that malfunctions in odour perception are associated with neurodegenerative diseases. We will further investigate the influence of the perception of odours on aging-associated disorders such as Alzheimer's or Parkinson's disease."

Explore further: It's not just what you eat, it's what's eating you

More information: Fabian Finger et al, Olfaction regulates organismal proteostasis and longevity via microRNA-dependent signalling, Nature Metabolism (2019). DOI: 10.1038/s42255-019-0033-z

Related Stories

It's not just what you eat, it's what's eating you

August 2, 2017

Restricting how much you eat without starving has been shown to robustly extend lifespan in more than 20 species of animals including primates. How this works is still unclear. In a new study published in PLOS Genetics, neuroscientists ...

Better odour recognition in odour-colour synaesthesia

August 21, 2017

People who see colours while perceiving smells are better at distinguishing between different smells and different colours, and are better at naming odours, compared to a group without synaesthesia. Researchers from Radboud ...

Label descriptions affect odour perception

February 12, 2014

According to Simona Manescu and Johannes Frasnelli of the University of Montreal's Department of Psychology, an odour is judged differently depending on whether it is accompanied by a positive or negative description when ...

On the immortality of stem cells

March 7, 2018

Stem cells are considered to be immortal in culture and, therefore, of great interest for aging research. This immortality is regulated by increased proteostasis, which controls the quality of proteins. A team of researchers ...

Recommended for you

Semimetals are high conductors

March 18, 2019

Researchers in China and at UC Davis have measured high conductivity in very thin layers of niobium arsenide, a type of material called a Weyl semimetal. The material has about three times the conductivity of copper at room ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.