Lactobacillus Bacteria May Guard Against Anxiety and Depression

Summary: Researchers have discovered the significant role of Lactobacillus, a bacterium in fermented foods and yogurt, in managing stress and potentially preventing depression and anxiety.

This research is crucial for its specific focus on Lactobacillus, distinguishing it from other microbiota. The study found that Lactobacillus maintains interferon gamma levels, crucial for stress response and mental well-being.

These insights offer a new avenue for developing treatments for mental health conditions.

Key Facts:

  1. Lactobacillus, found in fermented foods, plays a crucial role in regulating the immune system and influencing mood disorders.
  2. The study successfully isolated the effects of Lactobacillus, showing its specific role in maintaining interferon gamma levels, important for stress management.
  3. This groundbreaking research opens the door to new probiotic treatments for mental health conditions like anxiety and depression.

Source: University of Virginia

University of Virginia School of Medicine researchers have discovered how Lactobacillus, a bacterium found in fermented foods and yogurt, helps the body manage stress and may help prevent depression and anxiety.

The findings open the door to new therapies to treat anxiety, depression and other mental-health conditions.

The new research from UVA’s Alban Gaultier, Ph.D., and collaborators is notable because it pinpoints the role of Lactobacillus, separating it out from all the other microorganisms that naturally live in and on our bodies.

This shows AI representations of bacterria.
Our guts are naturally home to countless bacteria, fungi, and viruses. Credit: Neuroscience News

These organisms are collectively known as the microbiota, and scientists have increasingly sought to target them to battle disease and improve our health. UVA’s new research represents a major step forward in that effort, providing scientists an innovative new approach to understand the role of individual microbes that could facilitate the development of new treatments and cures for a wide variety of diseases, both mental and physical.

“Our discovery illuminates how gut-resident Lactobacillus influences mood disorders, by tuning the immune system,” said Gaultier, of UVA’s Department of Neuroscience, the Center for Brain Immunology and Glia (BIG Center) and the TransUniversity Microbiome Initiative. “Our research could pave the way towards discovering much-needed therapeutics for anxiety and depression.”

The Microbiota and Depression

Our guts are naturally home to countless bacteria, fungi, and viruses. There are more microorganisms living in and on us than there are cells in our bodies. That may sound disgusting, even alarming, but scientists have increasingly realized that these tiny organisms and their endless interactions are critical to our immune systems’ health, our mental health, and many other facets of our well-being.

Disruptions of the microbiota, whether from illness, poor diet, or other causes, are known to contribute to many diseases and even help cancer spread. So, researchers have been hugely excited in recent years about the potential to battle diseases by targeting the microbiota.

Early attempts to manipulate the gut flora with beneficial bacteria, called probiotics, have produced mixed results. A big part of the problem has been the sheer complexity of the microbiome.

It’s estimated that there are 39 trillion microorganisms inside each of us, so trying to understand what specific bacteria or fungi do – much less how they interact with all the other microorganisms and their host – can be like trying to count grains of sand on the beach.

Gaultier and his team took an innovative approach to hone in on Lactobacilli in specific. Prior research from Gaultier’s lab suggested that the bacteria could reverse depression in lab mice – a hugely promising finding. But the researchers needed to understand how.

“We were aware from our prior research that Lactobacillus was beneficial in improving mood disorders and was lost following psychological stress, but the underlying reasons remained unclear, primarily due to the technical challenges associated with studying the microbiome.”

Gaultier and his team decided to continue their depression research using a collection of bacteria, known as Altered Schaedler Flora, which includes two strains of Lactobacillus and six other bacterial strains.

With this rarely used bacterial community, the team was able to create mice both with and without Lactobacillus,circumventing the need for antibiotics.  

Sure enough, the Altered Schaedler Flora produced exciting results. Gaultier and his colleagues were able to explain exactly how Lactobacilli influence behavior, and how a lack of the bacteria can worsen depression and anxiety. Lactobacilli in the family Lactobaccillacea, they found, maintain the levels of an immune mediator called interferon gamma that regulates the body’s response to stress and helps stave off depression.  

Armed with this information, researchers are poised to develop new ways to prevent and treat depression and other mental-health conditions in which Lactobacillus plays an important role. For example, patients struggling with (or at risk for) depression might one day take specially formulated probiotic supplements that will optimize their levels of helpful Lactobacillus.

“With these results in hand, we have new tools to optimize the development of probiotics, which should speed up discoveries for novel therapies,” said researcher Andrea R. Merchak, Ph.D.

“Most importantly, we can now explore how maintaining a healthy level of Lactobacillus and/or interferon gamma could be investigated to prevent and treat anxiety and depression.” 

Findings Published

The UVA scientists have published their findings in the journal Brain Behavior and Immunity. The research team consisted of Merchak, Samuel Wachamo, Lucille C. Brown, Alisha Thakur, Brett Moreau, Ryan M. Brown, Courtney Rivet-Noor, Tula Raghavan and Gaultier. The researchers have no financial interest in the work.

Funding: The work was supported by the National Institutes of Health, grants T32 NS115657, T32 GM008136, F31 AI174782, T32 GM007267 and T32 GM148379; the Owens Family Foundation; the Miller Family; the UVA TransUniversity Microbiome Initiative; and the UVA Presidential Fellowship in Neuroscience.

About this psychology research news

Author: Josh Barney
Source: University of Virginia
Contact: Josh Barney – University of Virginia
Image: The image is credited to Neuroscience News

Original Research: Open access.
Lactobacillus from the Altered Schaedler Flora maintain IFNγ homeostasis to promote behavioral stress resilience” by Alban Gaultier et al. Brain Behavior and Immunity


Lactobacillus from the Altered Schaedler Flora maintain IFNγ homeostasis to promote behavioral stress resilience

The gut microbiome consists of trillions of bacteria, fungi, and viruses that inhabit the digestive tract. These communities are sensitive to disruption from environmental exposures ranging from diet changes to illness.

Disruption of the community of lactic acid producing bacteria, Lactobaccillacea, has been well documented in mood disorders and stress exposure. In fact, oral supplement with many Lactobacillus species can ameliorate these effects, preventing depression- and anxiety-like behavior.

Here, we utilize a gnotobiotic mouse colonized with the Altered Schaedler Flora to remove the two native species of LactobaccillaceaL. intestinalis and L. murinus. 

Using this microbial community, we found that the Lactobacillus species themselves, and not the disrupted microbial communities are protective from environmental stressors.

Further, we determine that Lactobaccillacea are maintaining homeostatic IFNγ levels which are mediating these behavioral and circuit level responses.

By utilizing the Altered Schaedler Flora, we have gained new insight into how probiotics influence behavior and provide novel methods to study potential therapies to treat mood disorders.

Join our Newsletter
I agree to have my personal information transferred to AWeber for Neuroscience Newsletter ( more information )
Sign up to receive our recent neuroscience headlines and summaries sent to your email once a day, totally free.
We hate spam and only use your email to contact you about newsletters. You can cancel your subscription any time.
  1. If our stomachs are out of sorts it makes us feel YUK. So it seems like common sense to make sure our stomach bacteria is in balance.

  2. Want some advice from a wise grandmother? Drink homegrown live kefir that you have fermented in a jar on your kitchen counter. Live kefir is lactose free and contains dozens of strains of beneficial bacteria and yeasts, all living and working together cooperatively and collaboratively to heal your gut and straighten out your brain chemistry.

    Per longstanding global tradition, people can acquire live kefir grains (colonies) generally for free from anyone who is already growing a colony. Colonies are nurtured, protected, and greatly appreciated in many, many kitchens in many countries; they live forever and are passed down through grateful generations of smart families. The grains grow quickly and therefore are easy to gift to new growers.

    Each colony will personalize itself to the conditions of its household, adjusting its strain balance to fill in gaps or to rein in overzealous strains.

    A live kefir colony’s innate wisdom in balancing its complexity is what you scientists think of as your problem to solve. Fun research, I’m sure, but if you really want to help people, simply give them a cup of live kefir to drink. And don’t monetize it. Just thank your wise grandmother.

Comments are closed.