Published on September 23, 2021

Video Friday: Research shows how the microbes in our gut can affect the way we think, feel, and act through the microbiome-gut-brain axis

Key Points

  • The gut microbiome has the ability to affect physical and mental health
  • Research shows that changes in the microbiome can influence depression, influence social interactions, anxiety, autism, memory issues, and more
  • The composition of the microbiome and its metabolites can be affected by lifestyle and diet, and can benefit from prebiotic nutrients (such as fiber and omega-3s), vitamin D, and even sunshine or UVB


The gut microbiome is known to have several effects on both mental and physical health. A disruption of a healthy microbiome, called dysbiosis, can contribute to obesity, chronic diseases such as diabetes and heart disease, and even influence your mental-emotional health, as explained in the video below, created by the Neural Academy.

Watch the Video: The Gut Microbiome and The Brain

After watching the video, be sure to make note of our added details below!

Here is a quick summary of what this video discusses, along with additional information and details from GrassrootsHealth:

  • The microbiome consists of a community of bacteria, viruses, fungi, protozoa, bacteriophages, and archaea, which plays a major role in health and can affect the progression of various diseases
  • It produces metabolites that influence all cells.  Changes in gut flora composition can also lead to increased intestinal permeability that allows neuroactive compounds into the blood, some of which can activate the inflammatory response or affect gene expression or affect the way we think and feel.
  • The gut, sometimes called the “second brain,” can communicate with the brain and central nervous system; in fact, there are 5 times as many neurons in the gastrointestinal tract as there are in the spinal cord
  • The bi-directional interaction between the microbiome and the central nervous system, where one can influence the other, is called the microbiome-gut-brain axis
  • A healthy microbiome is essential for normal cognitive and emotional processing. One study in particular showed a link between supplementation with probiotics (which positively affects the gut microbiome), C-reactive protein (hsCRP) levels (markers of inflammation in the body), and Alzheimer’s Disease.
  • Research shows that changes in the microbiome can influence depression, influence social interactions, anxiety, autism, memory issues, and more
  • The microbiome changes throughout the lifetime, and is affected by our diet and lifestyle – what we eat, stress levels, medications, hormones, and more
  • Sunshine can affect the microbiome; in fact, certain diseases, such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD), have a demonstrated link between disease risk and sun or UVB exposure, vitamin D levels, and the microbiome

What Can You Do to Create Positive Changes in Your Microbiome?

This video ends promoting a healthy diet and lifestyle, however, what is considered healthy for the microbiome?

Prebiotics for the Microbiome

Prebiotics are nutritional compounds that are known to benefit health through their effects on the microbiome and its metabolites. In our last post, we reviewed a study showing how supplementing with omega-3 fatty acids resulted in similarly positive and significant changes within the microbiome and its byproducts when compared to supplementing with inulin fiber, a well-known prebiotic supplement. This study demonstrated the prebiotic effects of omega-3s, indicating a new way they can impact our overall health.

Vitamin D Affects the Microbiome as Well

Another study found that vitamin D supplementation over 12 weeks resulted in positive changes in the microbiome in healthy women. Vitamin D supplementation was found to beneficially increase the overall diversity of the gut microbiota, and in particular increased the relative abundance of Bacteroidetes while decreasing the relative abundance of Firmicutes. A high ratio of Firmicutes to Bacteroidetes has been correlated with obesity and other diseases whereas a decreased ratio has resulted in improvements to gut permeability and inflammation. In other words, vitamin D supplementation altered the relative levels of the healthy type bacteria (Bacteriodetes) that are especially associated with improved gut health. These authors suggest that the differences in microbiome may contribute to the large variation seen in blood vitamin D levels in response to vitamin D supplementation.

Similar Shifts in the Microbiome Seen with Sun Exposure

A study conducted by Bosman et al. demonstrated that UVB light from the sun increased serum vitamin D levels and also had a beneficial impact on diversity and abundance of the bacteria species of the microbiome. Another study looked at the differences in microbiome diversity among women who took vitamin D supplements compared to women who did not. They found that the diversity and richness of the microbiota was much lower in those who did not supplement with vitamin D compared to those who did supplement. Exposure to UVB resulted in a significant increase in microbiota diversity and richness among those who did not supplement, but interestingly, no change was observed among those who were supplementing with vitamin D and already had a healthier microbiome. The end result was a similar diversity of microbiota between both groups post UVB. This suggests that individuals with lower vitamin D serum levels have a less diverse microbiota, and that UVB exposure alone is sufficient to increase that diversity.

Make Sure You Are Getting Enough Vitamin D, Omega-3s and Other Important Nutrients

Having and maintaining healthy vitamin D, omega-3, and other nutrient levels can help improve your health now and for your future. Choose which to measure, such as your vitamin D, omega-3s, and essential minerals including magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. You can also track your own intakes, symptoms and results to see what works best for YOU.

Enroll and test your levels today, learn what steps to take to improve your status of vitamin D (see below) and other nutrients and blood markers, and take action! By enrolling in the GrassrootsHealth projects, you are not only contributing valuable information to everyone, you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it.

Help everyone Move Research into Practice with vitamin D and other nutrients! As a special birthday gift to everyone, in honor of the science, we have created a special scholarship fund for anyone to donate to that will go towards helping others participate. Your donation will allow anyone to get help with funding their participation when they need it.

Text-to-give: Text Daction to 44321 to add to our Scholarship Fund.

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!