Speeding up your metabolism may be more complex than eating spicy foods or drinking green tea. Researchers from The Scripps Research Institute (TSRI) took a microscopic look into the factors beyond food that influence metabolism, and found genes may play a role as well.

For the study, published in the journal Cell Reports, researchers looked at a group of related genes that play a role in processing information from the environment, including through hearing, vision, taste, smell, and touch. They deleted each of these genes from a roundworm organism called C. elegans until they were left with two that specifically influenced fat metabolism — one specifically regulated a group of neurons that were responsible for metabolism and sensing oxygen in the environment.

Senior author Supriya Srinivasan, an assistant professor at TSRI, and her research team believe this gene exists to detect food because the worm eats bacteria, which consume oxygen. If the worm squirms into an environment that has slightly lower levels of oxygen, it may serve as a signal that bacteria is nearby.

The team decided to test this theory by increasing oxygen levels in the worms’ environment, thereby simulating an area where there’s no bacteria to eat. The worms reacted by speeding up their metabolism and burning stored fat for energy. When oxygen levels were slightly lower (simulating bacteria nearby), the worms burned fat more slowly, supposedly because they expected to find a meal within reach.

"This is an interesting, previously unknown role for these neurons," said the study’s co-author Emily Witham, a research associate at TSRI, in a press release. "We think that this is a self-preservation system, which prevents a fat-burning signal from the neurons in conditions of depleted fat reserves."

When they took a closer look to figure out how the worms’ metabolism was activated, the team found their intestines could communicate with the oxygen-sensing neurons. When fat reserves were low, the neuron’s signal to burn fat declined.

It’s too early to know if human metabolism works in a similar way, but if there is a genetic root, then it could lead to new approaches in obesity research. The team’s next step is to identify exactly how the intestines communicate with the neurons.

"That implies that our metabolism is not a simple consequence of food intake," Srinivasan said. "A lightbulb went off in my head — there could be a connection between sensing oxygen and burning fat. We think a hormone-like factor is secreted. We're chasing down that signal."

Source: Srinivasan S, Ratanpal H, Comunian C, Witham E, Skora S, and Zimmer M. C. elegans Body Cavity Neurons are Homeostatic Sensors That Integrate Fluctuations In Oxygen Availability And Internal Nutrient Reserves . Cell Reports. 2016.