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Psychobiotics: can probiotics make our brains work better?

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Nootropics (supplements that increase cognitive ability) are all the rage these days. I’ve already written on this blog about my experiences with the popular nootropic theanine, however, I’ve read studies lately that make me believe that the best path to cognitive enhancement may just travel through the microbiome.

Probiotics for cognitive enhancement

It turns out that certain strains of bacteria can actually enhance cognitive ability while lowering the stress hormone cortisol. Dubbed “psychobiotics,” these probiotic strains could be part of the way we treat anxiety and depression in the future, as well as chronic conditions like IBS, which are tied to imbalances in the gut-brain axis.

Our regular readers know that we’ve been writing a good bit about the microbiome lately. I wrote recently about how exercise can increase microbial diversity, while Jennifer put together a compelling piece on how gut bacteria can influence tumor growth.

Jennifer’s post looked at two commercially available strains of probiotic, B. Longum and B. Breve, and how administration helped slow tumor growth in mice who had previously grown tumors at an accelerated pace.

One of those strains, Bifidobacterium longum (B. Longum), is the focus of my post today. It seems B. Longum is one of the leading probiotic strains associated with cognitive enhancement, although as we will see, its benefits don’t stop with the brain.

As Jennifer notes in her tumor post, the science surrounding the microbiome is new and emerging, and as such, many of the studies have been performed on mice.

However, one of the studies I want to share today looked at the impact of a specific strain of B. Longum (1714) on brain activity patterns, cognition, and the stress response in humans. The study, which appeared in the Journal of Translational Psychiatry, was double blind and placebo controlled, and the authors are quick to point out they weren’t messing with a probiotic cocktail. They only evaluated the impact of B. Longum 1714.

It’s also worth noting that the authors used male subjects, as menstrual cycle can impact cortisol levels, and prior use of probiotics excluded subjects, most of whom ended up being medical students. This was also a small study at just 22 participants.

With that said, let’s dive into the findings.

B. Longum impact on stress

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The findings on stress were interesting.

Study subjects taking B. Longum had a lower amount of stress in response to a stressful event as well as lower levels of daily reported stress. Cortisol levels dropped after administration of B. Longum 1714.

The psychobiotic effect on the acute stress response is complemented by a reduction in daily perceived stress that is consistent with previous findings that a probiotic intervention can affect subjective everyday stress.

B. Longum impact on cognitive performance

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Subjects administered B. Longum 1714 showed subtle improvements in visuospatial memory as well as enhanced prefrontal cortex activity (the part of the brain linked to willpower) based on an electroencephalogram (EEG) test, which I believe are normally used to monitor electrical activity in the brain for seizure risk. To give a visual, this means that the subjects had the metal disks you see in the movies attached to their scalps and the corresponding brain waves recorded.

So, bottom line, B. Longum, or at least B. Longum 1714, was shown to reduce stress and modestly improve beneficial brain activity. I was especially interested to read these results because I’ve had similar experiences with isolated strains of B. Longum recently.

My Experience with B. Longum

Many people would be surprised to learn that a probiotic can alter mood and reduce stress. However, that has been my experience with B. Longum as well, although the results depend heavily on which strain I use.

Some form of B. Longum is found in a ton of commercially available probiotic blends, usually alongside a number of Lactobacillus strains.

As such, I have taken B. Longum in numerous courses of probiotics, and to be honest, never noticed much of a cognitive impact, that is until I took B. Longum Moringa BB536 strain.

When I isolated B. Longum and took it alone, I noticed almost immediate pyschobiotoc benefits, such as enhanced mood and an overall sense of calm and well being. The results were subtle, but undeniable.

The authors of the study Jennifer cites to in her tumor post use B. Longum alongside B. Breve. There are commercially available formulas of Bifidobacterium probiotocs that use both these strains alongside B. lactis and B. bifidum, and I’ve tried them, but I found greatest efficacy with the Moringa BB536 strain.

Possible Explanations

Why do I notice such tangible benefits from supplementing with B. Longum Moringa BB536?

In addition to the Translational Psychiatry study, I am interested in three primary purported benefits associated with B. Longum, all of which impact on mental health, and all of which tie into my genetics or epigentics.

  1. Histamine clearance
  2. Ammonia clearance
  3. Butyrate and short chain fatty acid production

B. Longum helps clear histamine

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I’ve written previously about issues I had with histamine intolerance, and I carry one SNP in the AOC1 gene associated with lower levels of diamine oxidase. Lifestyle factors, such as antibiotic and NSAID use (as the result of getting my wisdom teeth out) presumably aggravated the situation, and of course it doesn’t help that, like most people, I am allergic to Austin, where I now live.

As a neurotransmitter, histamine levels do affect the central nervous system, and all the functional medicine blogs seem to agree that B. Longum is one of the probiotic strains that helps break down histamine. When I started to feel a sense of calm after taking B. Longum, I thought back to my histamine research. But my follow up reading has been stubborn. Just as the consensus view on L. casei as a histamine producing strain of bacteria seems to be overblown, the case for B. Longum as a histamine degrader may be over reported as well.

For example, Dave Asprey’s blog on the different strains of bacteria in yogurt lists B. Longum as a histamine degrader. However, his cites are less than convincing, actually they’re completely absent. Dave cites to a few studies on Amasai, a type of fermented milk, but I didn’t see anything that shows B. Longum breaks down histamine.

My intention here isn’t to “be right,” it’s to learn and spread knowledge, so if you have good studies on B. Longum and histamine please share in the comments.

I was able to dig up a study performed in rats that seems to indicate B. Longum as a strain capable of degrading histamine, and lessening allergic response. However, the study paired B. Longum with B. infantis. This is not to say that B. Longum does not break down histamine. Like I said earlier, I’ve seen good results, the question for me is mechanism.

B. Longum clears ammonia

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Another big one for our readers, especially those with their genetic information, is the issue of ammonia. I’ve written previously about up-regulated CBS gene activity and how that can contribute to elevated ammonia levels, as can mutations in the urea cycle genes like CPS1

See also: Can you handle a high protein diet? The answer may be genetic

Pathogenic bacteria and fungus (Candida) can also release ammonia into the body.

Interestingly, the exact strain of B. Longum I use, BB536, has been shown to degrade ammonia. (R) This is interesting to our conversation about psychobiotics because ammonia is a neurotoxin that readily crosses the blood brain barrier. (R) Whether ammonia levels are elevated due to gut dysbiosis or genetics, or a combination of both, a strain of probiotic that can lighten this load is tremendously valuable. Having said that, the best study I found showed BB536 to be effective at reducing ammonia focused on lowering levels of ammonia released from pathogenic bacteria, such as E. Coli. It’s not clear what BB536 does to ammonia produced from too much animal protein for example.

But consider this: due to widespread antibiotic use, as well as the prevalence of glyphosate in food, gut dysbiosis is a major issue for millions of people in America. Even if the digestive problem isn’t acute, a concert of factors, including genetic mutations in regions associated with higher ammonia levels such as CPS1 or CBS, could act together to equal ammonia levels that are too high. In those cases, BB536 could be just what the doctor ordered to bring levels within a healthier range, benefiting mental performance as a result.

B. Longum increases short chain fatty acid production

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This is the big prize. I wrote two posts recently about butyrate production, one of which focused on how moderate exercise increases levels of butyrate, which is a short chain fatty acid our bodies use to line and protect the “epithelial” wall of the gut. Greater levels of butyrate prevent conditions like leaky gut.

Studies in mice show BB536 as an effective agent for increasing production of butyrate. (R) And guess what? Scientists are starting to recognize that short chain fatty acids, like butyrate, protect the brain and impact on mental health. (R)

Key takeway: the strain matters

I offer this post as a tour of just some of the data behind the popular probiotic strain B. Longum, especially as it pertains to its use in cognitive enhancement.

I haven’t tried 1714, but the BB536 strain is a great supplement for me.

After reading this blog, you may want to experiment with B. Longum, but will it do any good?

The strains used in the studies were very specific. B. Longum 1714 is a different strain of bacteria than is B. Longum BB536, but almost none of the commercially available products on the market differentiate which strain they use.

This is a problem for consumers as it’s likely that you need to narrowly target the strain to the individual for the best results.

John O'Connor

John O'Connor is the founder of Gene Food. Read his full bio here.

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