Zebrafish help reveal how probiotics can sooth stress

More research shows that probiotics may help soothe our anxiety. Previous studies have suggested that the helpful bugs can reduce stress. The new study comes from University of Missouri research conducted on zebrafish, the new darlings of modeling human neurobehavior.

"Zebrafish are an emerging model species for neurobehavioral studies and their use is well-established in drug-screening," Aaron Ericsson, director of the MU Metagenomics Center and a research assistant professor in the Department of Veterinary Pathobiology, said in a university release. "Our study has shown that simple probiotics that we normally use to keep our digestive tract in sync, could be beneficial to reducing our stress levels as well."

How did the fish reveal the microbes’ power? Researchers studied the fish’s behavior after some of the fish in the study received doses of Lactobacillus plantarum, a common bacteria found in yogurt. A control group did not receive the bacteria. Then, the researchers stressed the fish. How do you stress out a zebrafish? Do things like draining small amounts of water from the tank or overcrowd their community.

By analyzing the gene pathways of both groups of fish, the researchers found that zebrafish that were given the supplements showed a reduction in the metabolic pathways associated with stress.

"By measuring the genes associated with stress and anxiety, our tests were able to predict how this common probiotic is able to benefit behavioral responses in these fish,” Daniel Davis, assistant director of the MU Animal Modeling Core, said in the release. "Essentially, bacteria in the gut altered the gene expression associated with stress- and anxiety-related pathways in the fish allowing for increased signaling of particular neurotransmitters."

Scientific Reports published the study results. The researchers say that zebrafish could be a relatively inexpensive platform for testing other species of probiotics and finding out their potential benefits on other systems of the body, as well as the nervous system.