Can You Use Probiotics for Brain Health Benefits? - Dr. Michael Ruscio, DC

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Can You Use Probiotics for Brain Health Benefits?

The Benefits of Probiotics May Extend to Improving Mood, Brain Fog, and Stress

Key Takeaways:

  • The evidence supports an important link between gut health and brain health, and that support is continuously growing.
  • Research suggests probiotics can lower brain inflammation, which may be the avenue through which they benefit brain health.
  • Probiotic supplementation may benefit people with depression and those with cognitive issues.
  • Having the basics in place (healthy diet, probiotics, stress management, and exercise) may increase the chance that nootropics (cognition boosters) will show brain health benefits. 
  • In some cases, probiotics may improve how people cope with stress.
  • It’s unclear which are the best probiotics for brain health, but any high-quality probiotic is probably useful.
  • Anecdotally, people seem to do better when they take a few different probiotic strains together.

If you have been using probiotics for digestive benefits but have found that you also have clearer thinking and a better mood, it’s probably not a coincidence. 

In fact, research shows a significant link between the gut and brain function. So, while you might not have started out taking probiotics for brain health improvements, they could be a beneficial side effect.



If you’re looking for brain health support but don’t quite understand where probiotics fit in, you’re not alone. The gut-brain connection, though well-established in the literature, isn’t widely understood.

So, let’s take a closer look at how probiotics taken for your intestinal health might have secondary benefits for your mental well-being.

Your Gut “Talks” to Your Brain

Though your gut and your brain may not be physical neighbors, they have a surprisingly close relationship and are in constant communication. 

The so-called gut-brain axis connects your central nervous system to your gut’s nervous system (also known as the enteric nervous system) via the vagus nerve [1, 2].

You feel the effects of this gut-brain connection any time you experience anxiety diarrhea, have “butterflies” in your stomach, or feel sluggish after consuming too many foods you don’t tolerate well. 

To be more specific, the gut microbiome — the massive collection of bacteria, yeasts, and other microorganisms living throughout your gastrointestinal tract — is an active communicator between your digestive system and your brain. 

How does it do this? The gut microbiome produces neurotransmitters like serotonin and dopamine, which regulate your mood [3]. Your gut microbiota also plays a vital role in regulating the immune system [3].

When your gut microbes become out of balance (dysbiosis), it creates an inflammatory gut environment and sends signals to the central nervous system that can trigger undesirable mood and cognitive changes.

This gut-to-brain chatter could explain why a higher-than-average percentage of people with irritable bowel syndrome (IBS), celiac disease, and inflammatory bowel disease develop depression and anxiety [4, 5, 6, 7, 8, 9].

Given that an unhealthy gut microbiota is linked with conditions like anxiety and depression, it seems logical that supporting gut health with “good bacteria” (aka probiotic supplementation) may help turn some of these mental health issues around. 

We still have much to learn about the benefits of probiotics on psychological health and cognitive function because there aren’t yet enough good studies on the subject. That said, the research on probiotics for brain health is definitely starting to stack up, so let’s look at what the evidence tells us to date.

Probiotics Help Tamp Down Inflammation

Neuroinflammation, like fire in the brain, appears to be a primary cause of low mood, reduced cognition, and brain fog. Persuasive evidence from many meta-analyses suggests that probiotics can help reduce neuroinflammation [10, 11].

The main inflammatory markers that decrease when people take probiotics include [10, 12, 13, 14]:

  • C-reactive protein
  • Interleukin (IL)-6
  • Tumor necrosis factor (TNF)-alpha 

Probiotic consumption has been shown to reduce these inflammatory markers in people of all ages with a range of health conditions. Given that inflammation is behind many mood, cognitive, and stress issues, probiotics may therefore help these conditions via their anti-inflammatory action.

Probiotics and Mood Disorders

Research on how probiotic bacteria affect mood is still fairly limited, but we have enough information to say that probiotic supplements might help, particularly with more severe cases of depression.

  • One meta-analysis showed that probiotics didn’t do much for healthy people with mild symptoms of depression, but they did lift depression in clinically depressed people with or without other conditions [15, 16].
  • Similarly, another meta-analysis showed probiotics had a medium to large positive effect on the moods of mildly to moderately depressed adults, but no impact on those of healthy people [17].

When it comes to probiotics dialing down anxiety, the jury’s still out. One recent study, a placebo-controlled trial, found that probiotics helped alleviate anxiety, depression, and insomnia in anxious college students [16]. However, four meta-analytic reviews of such studies found that probiotics had little, uncertain, or no effect on anxiety in a variety of different patient groups [15, 18, 19, 20].

As for general mood states, another study found that nurses who took a heat-killed probiotic (Lactobacillus helveticus) scored higher on “friendliness” and “relaxed” mood metrics, suggesting an overall increase in positive mood [21].

Probiotics May Improve Hippocampus Function

One seminal study found that giving probiotics to people with major depressive disorder also changed activity levels in their hippocampi. The hippocampus is a center of the limbic system that largely affects memory, learning, and emotional health [22]. Probiotics seem to dampen overactivity in this part of the brain, which is something you want if you are looking for balanced emotions.

Probiotics and Cognition

The evidence on probiotics and cognition is again mixed, with potentially bigger benefits for some adults. 

For example, a meta-analysis showed that probiotics had no effect on cognition in healthy people [23]. In contrast, a systematic review found that probiotics were more likely to boost cognitive function or slow down cognitive decline in adults with pre-existing conditions (like chronic fatigue and fibromyalgia) that impact cognitive function. 

The same review also concluded that, although kids do not seem to show cognitive benefits from probiotic use, older people may get some memory improvements from taking probiotics [24].

In two other meta-analyses, probiotics had either a beneficial effect or no impact on cognition in elderly people with Alzheimer’s disease or mild cognitive impairment [25, 26]. 

So, it seems that probiotics may help adults with existing conditions affecting their cognition.

Can Probiotics Help Other Supplements Boost My Brain Power?

Later, when your brain health is back on track, you can, by all means, start experimenting with nootropics, or vitamins and other natural supplements that might slightly sharpen your cognitive function.

However, it is unlikely that these supplements will work without having the basics of good brain health in place. In addition to probiotics, these building blocks for brain health include a healthy diet, stress management, and exercise. 

Focusing on these fundamentals is the first, and by far the most important step you can make toward better brain health.

Probiotics and Stress

Overall, the evidence for how probiotics affect stress is also mixed. One meta-analysis suggested that probiotics could modestly reduce perceived stress in healthy people [27], yet another found no effect on stress perception in those with depression and anxiety [18]. 

However, when it comes to Bifidobacteria specifically, the stress-bolstering benefit may be notable. For example:

  • One large trial [28] with a secondary analysis [29] found that Bifidobacterium bifidum reduced the number of viral infections and stress-related diarrhea in stressed-out university students.
  • Another, smaller clinical trial showed that Bifidobacterium longum helped reduce perceived stress in healthy people with mild-to-moderate stress [30].
  • A third, small randomized controlled trial found that B.longum calmed brain activity, possibly helping people cope with social stress [31].

Perhaps when it comes to reducing perceived stress, the type or strain of probiotics matters.

Probiotics Are Just One Piece of the Brain Health Puzzle

While it’s important to highlight the potential role of probiotics in brain health, I don’t want to give the impression that they can supercharge your cognitive abilities. Instead, probiotics are an important step in normalizing gut health imbalances, which can help turn fuzzy cognitive function into clearer thinking and performance. 

My patient Adrian was a classic example of someone for whom a gut health overhaul resolved 10 years of brain fog, fatigue, and joint pain symptoms.

In Adrian’s case, as with most patients, probiotics were only part of the picture. For him, using an elemental diet while finding the right whole-foods diet for his food sensitivities came together with probiotics to change his brain health symptoms relatively quickly. 

The exact regimen for dealing with brain and gut symptoms will be different for each individual, but the basic healing framework Adrian used was my Great-In-8 protocol, as outlined in Healthy Gut, Healthy You. This protocol can easily be adapted to fit your own needs.

Fine Tuning Your Probiotics

One thing many of my patients with gut and cognitive issues find is that supplements containing several different beneficial microbes tend to be more successful than single-strain probiotics. This might not be what you’d expect if you’ve seen highly specific (and often expensive) proprietary strains touted for specific conditions, like IBS, brain fog, or a C. diff infection. 

The three categories that work best for our patients at the clinic are:

Depending on how sensitive your gut is, you might want to start with the Lactobacillus-Bifidobacterium blend first and add the others one at a time when you know you’re tolerating the first probiotic well. If taking all three turns out to be optimal for you, as it does for many people, you can simplify things with this triple formula,  which contains all three together in one handy stick. Most patients need two to three months of probiotic supplementation before they can make a realistic assessment of the benefits. 

The main thing to know is that current research doesn’t strongly favor any particular probiotic strain or combination of strains for brain health. In fact, a wide variety of different probiotics seem to be beneficial, so you can generally choose at least one that fits with your budget. 

The latest research shows that even heat-killed probiotics may be useful, so keep an open mind when trying different probiotics. What works for one person may not be what works for you, so don’t be afraid to experiment. Just make sure the probiotics you try are independently tested for potency and purity.

Probiotics Work for the Brain and the Gut

When you choose the right probiotics and combine them with a healthy diet and lifestyle, their anti-inflammatory benefits can extend beyond the gut and improve brain symptoms like brain fog, low mood, and impaired cognition.

Choosing probiotics for brain health doesn’t have to be complicated, and the most expensive or “cutting-edge” product isn’t necessary. However, our experience with patients suggests that a combination of different probiotics is probably the most effective route.

Mood and cognition problems can be hard to deal with, so if self-help isn’t enough for you to turn things around, you could also set up an appointment with one of the Ruscio Institute’s experienced functional health practitioners. We’ll always guarantee you a personalized and empathetic approach.

The Ruscio Institute has also developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.

➕ References
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