Published on Feb 10, 2017

Researchers at the University of Virginia School of Medicine have reversed depression symptoms in mice by feeding them Lactobacillus, a probiotic bacteria found in some yogurts. Further, the researchers have determined exactly how the bacteria affect mood, providing a concrete link between the health of the gut microbiome and mental health.

Based on their findings, they suspect their discovery will hold true in people and are planning to confirm theirs findings in depressed patients.

“The big hope of this kind of research is that we won’t need to bother with complex drugs and side effects when we can just play with the microbiome,” explained researcher Alban Gaultier, PhD. “It would be magical just to change your diet, to change the bacteria you take, to fix your health – and your mood.”

Lyme/MSIDS patients often have depression and are required to take many medications to effectively deal with numerous Tick Born Infections.  Adding anti-depressants and other medications can yield nasty side-effects.  This mouse study is promising in that taking probiotics do not have the downsides of prescription anti-depressants.  Not only that, these good-guy bacteria help line the gut to prevent or lessen leaky gut syndrome.

https://news.virginia.edu/content/uva-reverses-depression-symptoms-mice-using-probiotics  Evidently, the researchers found that the lower the level of Lactobacillus in the gut, the higher the level of kynurenine, a blood metabolite, which drives depression symptoms.  Mouse behavior was directly correlated to Lactobacillus levels.

Study here:  http://www.nature.com/articles/srep43859

Microbiota alteration is associated with the development of stress-induced despair behavior
Ioana A. Marin, Jennifer E. Goertz, Tiantian Ren, Stephen S. Rich, Suna Onengut-Gumuscu, Emily Farber, Martin Wu, Christopher C. Overall, Jonathan Kipnis & Alban Gaultier

Abstract
Depressive disorders often run in families, which, in addition to the genetic component, may point to the microbiome as a causative agent. Here, we employed a combination of behavioral, molecular and computational techniques to test the role of the microbiota in mediating despair behavior. In chronically stressed mice displaying despair behavior, we found that the microbiota composition and the metabolic signature dramatically change. Specifically, we observed reduced Lactobacillus and increased circulating kynurenine levels as the most prominent changes in stressed mice. Restoring intestinal Lactobacillus levels was sufficient to improve the metabolic alterations and behavioral abnormalities. Mechanistically, we identified that Lactobacillus-derived reactive oxygen species may suppress host kynurenine metabolism, by inhibiting the expression of the metabolizing enzyme, IDO1, in the intestine. Moreover, maintaining elevated kynurenine levels during Lactobacillus supplementation diminished the treatment benefits. Collectively, our data provide a mechanistic scenario for how a microbiota player (Lactobacillus) may contribute to regulating metabolism and resilience during stress.