Probiotics are live bacteria that are found in yogurt and supplements (among other sources). Probiotics improve the immune system and promote digestive health.
Researchers at the University of Virginia School of Medicine have conducted studies which show reduced symptoms of depression on a significant cognitive level when feeding mice yogurt enriched with probiotics.
Yogurt contains Lactobacillus, a probiotic bacterium found in live cultures. It has been found that when taken, Lactobacillus has positive effects on moods.
Treating Depression Using Probiotics
Depression is said to be among the United States’ most profound mental health conditions in the recent years.
About 7% of America's population experiences a depressive episode at some point in their lifetime.
There has been a lot of research on the mini ecosystem of bacteria found in the gut-also known as the microbiome.
The research tries to find the relationship to how depression and other mental conditions occur within the microbiome.
Gaultier, a neurologist at UVA Department of Neuroscience and its Center for Brain Immunology and Glia, set out to establish whether there is a link between depression and gut health by conducting tests on mice.
Results From Experiments On Mice
In order the discover the connection between gut bacteria and mood, researchers exposed mice to a variety of conditions.
Researchers compared their digestive systems from before and after stress tests were conducted.
The bacteria Lactobacillus was very low after mice dealt with the stressful conditions.
Marin, a study's co-author, said in a press release, "We see Lactobacillus levels correlate directly with the behavior of these mice."
In another test, mice were directly fed Lactobacillus.
The bacteria seemed to balance out the mice’s behavior. "A single strain of Lactobacillus is able to influence mood," Gaultier said in a press release.
To support their findings, researchers identified biochemical mechanism that may potentially link gut bacteria and behavior.
Kynurenine is a metabolite found in the bloodstream of mice. This metabolite has been long associated with depression in previous studies.
The research found that the more Lactobacillus a mouse had in their gut, the less kynurenine. When Lactobacillus levels were lower in their gut, levels of kynurenine went up, and the symptoms of depression would set in.
Gaultier, one of the lead researchers, was careful to point out that the symptoms the mice displayed were “depressive-like behavior” as mice have no way of communicating how they feel when depressed.
Those symptoms are widely accepted as best available model for looking at depression in creatures that are not humans.
Testing In Humans
Gaultier's intentions are to study effects that Lactobacillus has on depressed patients diagnosed with multiple sclerosis who are likely to experience depression more at some point in their lifetime.
In addition to looking at effects in people, researchers are still exploring the important role of kynurenine.
There have been experiments carried out on humans, however, there is still much research to be done.
How is metabolite, kynurenine, able to influence behavior? How does this molecule affect a human brain? What are the processes?
These are just some of the question these researchers are hoping to answer before continuing with human research.