Most people take one probiotic capsule a day and call it a day.
I take 25.
A single capsule of Lactobacillus rhamnosus GG (L. Rhamnosus GG) usually contains 10-15 billion CFU—but for my latest megadosing experiment, I took 375 billion CFU in one day to test its effects on cardiovascular health and brain function.
I do these experiments because standard doses don’t always give clear effects—but when you take 20-30x the normal amount, you quickly find out what a supplement can really do.
I chose L. Rhamnosus because it showed up in my SelfDecode recommendations, meaning my genes indicate that this probiotic would be particularly beneficial for me.
On top of that, it’s one of the most well-researched probiotic strains.
Here’s what I discovered:
- It lowered glutamate levels, which helped me feel calmer and more mentally clear.
- It helps reduce TMAO, a metabolite linked to cardiovascular risk.
In this email, I want to highlight the science behind L. Rhamnosus, why it had a positive impact on my health, and which genes you should check to find out if this probiotic is right for you.
What is L. Rhamnosus?
L. Rhamnosus is one of the most well-studied probiotic strains, and it’s been on my radar for a while.
There are a bunch of different strains of L. Rhamnosus, but the one I’ve been experimenting with is L. Rhamnosus GG—which is by far the most researched. It’s naturally found in the human gut, unlike some strains that come from dairy sources.
What makes it interesting is how wide-ranging its benefits are.
On SelfDecode, It’s ranked high up on my personalized recommendations list due to its impact on these health topics:
So, how did it tackle my low mood?
GABA-A, Glutamate & L. Rhamnosus
One of the most shocking things I noticed when megadosing L. Rhamnosus GG was just how much it affected my brain and mood.
Glutamate is the brain’s excitatory neurotransmitter—too much of it, and you feel wired, anxious, and overstimulated.
GABA is the opposite, keeping you calm, collected, and stress-resistant.
L. Rhamnosus affects both glutamate and GABA in a way that makes it one of the most interesting probiotics for mood.
How?
First, it increases GABA, by stimulating GABA production and influencing GABA receptors in the brain.
More GABA means a greater sense of calm, better stress resilience, and improved mood stability.
And my genes predispose me to lower GABA activity, which is why I felt a massive impact when I took L. Rhamnosus.
Second, it lowers glutamate.
L. Rhamnosus helps shift the balance by reducing excess glutamate, which may be why I felt clearer, calmer, and more focused when megadosing.
TMAO, Cardiovascular Health & L. Rhamnosus
I have a lot of genetic predispositions for cardiovascular issues, so it’s always been a goal of mine to reduce lab markers that are linked to heart health.
TMAO is produced when gut bacteria break down choline, carnitine, and other nutrients found in animal products like red meat, eggs, and fish.
Once formed, TMAO can contribute to arterial plaque buildup, increasing heart disease risk.
I’ve tested my TMAO levels multiple times, and they’ve consistently been on the higher side, which makes sense with my genetic predispositions.
This is where L. Rhamnosus GG stands out. Research shows that it can help lower TMAO levels by breaking down choline before it gets converted into TMAO.
I haven’t done a lab test since I incorporated L. Rhamnosus in my daily regimen, but I feel like it’ll definitely be decreased.
Should You Take L. Rhamnosus?
Genetics plays a massive role in how your body responds to supplements, and the only way to know for sure is to check your unique genetic profile.
For me, the effects were clear—lower glutamate, higher GABA, improved mood, and potential cardiovascular benefits.
Given my genes, it makes sense why this probiotic was ranked high on my SelfDecode recommendations.
If you want to know whether L. Rhamnosus (or any other supplement) is a good fit for your body, that’s where genetic analysis comes in.
With SelfDecode, you don’t have to guess—you can see exactly which supplements match your genetics and optimize your health accordingly.
