Probiotics Shown to Alleviate Anxiety

In a new meta-analysis of ten studies, probiotics are proving useful in decreasing symptoms of anxiety. 

Probiotics Shown to Alleviate Anxiety
A worker checks inventory of yogurt containers on a supermarket shelf July 30, 2007 in Berlin, Germany. German milk producers have announced they will raise prices on milk and dairy products starting July 31 nationwide by as much as 50%. (Photo by Sean Ga


Our stomach is a fascinating place. With all the advancements being made in neuroscience, the complexities of digestion have not been well understood, the dark matter of our body’s galaxy. That is changing, quickly. 

Part of the challenge is complexity: there are 100,000 times more microbes in your gut than humans on this planet, writes Emeran Mayer in The Mind-Gut Connection. There are also more immune cells inside of our stomachs than in blood and bone marrow, which makes what we put into our mouths so important. Our diets might affect our brains more than the other way around. As Mayer puts it,

Your gut microbes are in a prime position to influence your emotions, by generating and modulating signals the gut sends back to the brain. 

Humans are collectively experiencing increased rates of anxiety, which is now the planet’s most pervasive psychological disorder. Increased stress has numerous destructive tendencies in our guts, including the alteration of contractions, transit rates between our stomach and large intestine, and blood flow. When that blood is transporting extra cortisol due to an increase in our corticotropin-releasing factor (CRF), the result is increased storage of visceral fat, decreased function of our immune system, and, of course, anxiety. 

While there are a number of means for altering your gut environment—a healthier diet with less sugar; stress-reducing techniques like meditation; regular exercise; therapy—one of the most prominent is the intake of probiotics, as new research published in Neuropsychiatry (London) shows.

Our guts are filled with microbes. I remember my high school biology teacher trying to gross us out by informing us that if she were to zap us so that only living microorganisms would remain, a few pounds would end up next to each of our desks. Turns our these critters are necessary for survival; how we treat them affects how they treat us. 

Probiotics are, in the words of the World Health Organization, “live micro-organisms which, when administered in adequate amounts, confer a health benefit on the host.” In 2010 the organization began developing guidelines for probiotics in food, which is tricky for a number of reasons. First off, each host has a different gut environment; what works for you might not work for me. Second, dosage amounts are also relative for each host. Constructing widespread guidelines on what needs to be individualized prescriptions is challenging. 

Thirdly, the FDA is notoriously inefficient when screening health claims. There’s a world of difference between refrigerated and room temperature probiotics, one that extends well beyond price. Yet this barely-regulated industry is difficult to navigate. Stated benefits exceed actual benefits, as often happens with medicine masquerading as nutritional supplements. 

The research team above, led by Ruixue Huang at the Xiangya School of Public Health in Hunan, China, searched seven academic databases and chose ten studies that showed probiotics’ efficacy in reducing anxiety. Importantly, the team recognizes crosstalk between gut and brain:

The gut-brain relationship is bidirectional, meaning that changes in microbial flora can affect behaviour, and behavioural changes can affect the gut flora.

The team had been searching for a meta-analysis on probiotics and anxiety disorders, which they were unable to find. Their requirements included studies on human subjects with anxiety disorders, a variety of probiotic sources (fermented yogurt; powders; oil suspensions; capsules), and studies from unique test groups, to avoid overlap. They did not include studies on mice and rats, case reports, or incomplete data. 

Huang’s team collected research from Japan, Spain, Ireland, Iran, the UK, Sweden, France, and Canada, all of which showed beneficial effects from a variety of probiotics, including popular and readily available strains such as Lactobacillus acidophilus and Lactobacillus casei. A total of 660 human subjects were included in their final results: 

Meta-analysis results indicated that probiotics significantly decreased anxiety compared to controls. These results are consistent with some previous studies showing that probiotics on anxiety are effective.

As Mayer concludes in his book, however, there is no “one-size fits all recommendation” for probiotics. He continues, 

We cannot expect that any simple intervention by itself, such as a particular diet, will optimize your gut microbiome, while not paying attention to all the other factors that influence gut microbial function, like the influence of unhealthy gut reactions associated with stress, anger, and anxiety at the same time. 

So while probiotics might not cure your anxiety in one shot, they can play an important role in the process. Understanding strains and dosage is an exciting field of research that is certain to yield critical advancements in the near future. 

--

Derek is the author of Whole Motion: Training Your Brain and Body For Optimal Health. Based in Los Angeles, he is working on a new book about spiritual consumerism. Stay in touch on Facebook and Twitter.

‘Designer baby’ book trilogy explores the moral dilemmas humans may soon create

How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.

Surprising Science
  • A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
  • It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
  • While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Keep reading Show less

Octopus-like creatures inhabit Jupiter’s moon, claims space scientist

A leading British space scientist thinks there is life under the ice sheets of Europa.

Jupiter's moon Europa has a huge ocean beneath its sheets of ice.

Credit: NASA/JPL-Caltech/SETI Institute
Surprising Science
  • A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
  • Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
  • The moon is one of Jupiter's 79.
Keep reading Show less

Lair of giant predator worms from 20 million years ago found

Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.

Bobbit worm (Eunice aphroditois).

Credit: Jenny – Flickr
Surprising Science
  • Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
  • The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
  • The creatures can reach several meters in length and famously ambush their pray.
Keep reading Show less

FOSTA-SESTA: Have controversial sex trafficking acts done more harm than good?

The idea behind the law was simple: make it more difficult for online sex traffickers to find victims.

Has FOSTA-SESTA really lived up to it's promise of protecting sex trafficking victims - or has it made them easier to target?

Credit: troyanphoto on Adobe Stock
Politics & Current Affairs
  • SESTA (Stop Enabling Sex Traffickers Act) and FOSTA (Allow States and Victims to Fight Online Sex Trafficking Act) started as two separate bills that were both created with a singular goal: curb online sex trafficking. They were signed into law by former President Trump in 2018.
  • The implementation of this law in America has left an international impact, as websites attempt to protect themselves from liability by closing down the sections of their sites that sex workers use to arrange safe meetings with clientele.
  • While supporters of this bill have framed FOSTA-SESTA as a vital tool that could prevent sex trafficking and allow sex trafficking survivors to sue those websites for facilitating their victimization, many other people are strictly against the bill and hope it will be reversed.
Keep reading Show less
Videos

What is the ‘self’? The 3 layers of your identity.

Answering the question of who you are is not an easy task. Let's unpack what culture, philosophy, and neuroscience have to say.

Scroll down to load more…
Quantcast