Scientists discovered that two types of helpful bacteria in your gut—Lactobacillus rhamnosus GG and Bifidobacterium longum 1714—may help your brain work better. Using advanced lab techniques, researchers found that these bacteria produce special chemicals that can improve brain cell health, reduce brain inflammation, and help your brain make important mood-regulating chemicals. The study combined genetic analysis, brain cell studies, and lab experiments to show how these bacteria communicate with your brain. While these results are promising, they’re from lab studies, so more research in humans is needed before we know if probiotics can truly help people’s brain health.

The Quick Take

  • What they studied: How two specific probiotic bacteria (good bacteria) might help brain cells work better and reduce brain inflammation by studying their genes and how they affect brain cells in the lab.
  • Who participated: This was a laboratory study using brain cells grown in dishes (not human volunteers). Researchers used 3 samples per test group to study how the bacteria affected these cells.
  • Key finding: The two bacteria increased brain-protective chemicals by 50-70% (GABA increased 1.7-fold and serotonin increased 1.5-fold) and reduced harmful inflammation markers in brain cells by 18-22%.
  • What it means for you: These results suggest that specific probiotics might someday help support brain health, but this is early-stage research. Don’t expect probiotics to treat brain conditions yet—scientists need to test this in actual people first.

The Research Details

This was a laboratory research study that combined three different approaches. First, scientists examined the genetic blueprints of the two bacteria to identify which genes might help the brain. Second, they studied how brain cells respond when exposed to these bacteria by measuring changes in thousands of genes at once. Third, they grew human brain cells in dishes and tested whether the bacteria actually produced the helpful effects they predicted. This multi-layered approach allowed researchers to connect the dots from bacterial genes to actual brain cell improvements.

By combining genetic analysis with brain cell studies, researchers could prove that the bacteria don’t just theoretically have brain-helping potential—they actually produce real effects on brain cells. This approach is important because it moves beyond simple observation to show the actual mechanism of how gut bacteria might influence brain health.

This study used advanced scientific techniques and was published in a respected scientific journal. However, it’s important to know that all testing was done in laboratory dishes with human brain cells, not in living people. The sample size was small (3 replicates per test), which is typical for this type of detailed laboratory work but means results need confirmation in larger studies. This is foundational research that opens doors for future human studies.

What the Results Show

The researchers identified two different ways these bacteria help brain cells. Lactobacillus rhamnosus GG primarily works by producing GABA (a calming brain chemical) and short-chain fatty acids that support brain cell connections and reduce inflammation. Bifidobacterium longum 1714 works differently by producing tryptophan-related compounds that boost serotonin (the mood-regulating chemical) and also reduce inflammation. When brain cells were exposed to these bacteria, important brain-protective genes (like BDNF and SYN1) became more active, while harmful inflammatory chemicals (IL-6 and TNF-α) decreased. The bacteria also released special packages called extracellular vesicles that carried anti-inflammatory and brain-protective messages to the cells.

Beyond the main findings, the study showed that the bacteria reduced oxidative stress (harmful chemical damage) in brain cells by 18-22%. The bacteria also increased the activity of serotonin transporters, which are important for mood regulation. The two bacteria appeared to work through complementary pathways, meaning they help the brain in different but compatible ways, suggesting they might work better together than separately.

This research builds on earlier observations that probiotics might affect mood and brain health. Previous studies suggested these bacteria could help, but didn’t explain how. This study goes deeper by showing the specific genetic and molecular mechanisms. It confirms what smaller studies hinted at while providing much more detailed evidence of the biological pathways involved.

This study has important limitations to understand. All experiments were performed in laboratory dishes using human brain cells, not in living organisms or people. The sample size was small (3 replicates), which is standard for this type of detailed lab work but means results need larger-scale confirmation. The study doesn’t tell us whether these effects would actually happen in a real human gut and brain. Additionally, the study only tested two specific bacterial strains, so results may not apply to other probiotics. Finally, we don’t know the right dose, duration, or whether these effects would persist over time in people.

The Bottom Line

Based on this research alone, we cannot recommend probiotics as a brain health treatment. This is early-stage laboratory evidence that suggests potential, but human studies are needed first. If you’re interested in gut health and brain health, focus on proven strategies: eat fiber-rich foods, manage stress, exercise regularly, and sleep well. Talk to your doctor before taking probiotics, especially if you have health conditions or take medications.

This research is most relevant to neuroscientists, microbiologists, and pharmaceutical researchers developing new treatments. People interested in preventive health and the gut-brain connection may find it interesting. However, people with neurological conditions should not change their treatment based on this study—consult your healthcare provider instead. This is not yet ready for general health recommendations.

This is fundamental research, not a clinical treatment. If these findings lead to human studies, it would typically take 5-10 years of additional research before any probiotic treatment could be available and recommended. Don’t expect immediate practical applications from this work.

Want to Apply This Research?

  • Track daily probiotic intake (if you choose to take them) alongside mood and digestive health using a simple daily log. Note: This is for personal tracking only, not as a treatment, since human evidence is still limited.
  • Users could log their current diet quality, fiber intake, and stress levels—all factors that naturally support a healthy gut microbiome. This creates a baseline before any future probiotic recommendations become available based on human research.
  • Establish a long-term tracking system for general wellness markers (mood, energy, digestion, sleep quality) that could be compared if and when human probiotic studies produce actionable recommendations. This allows users to have baseline data for future personalized health decisions.

This research is laboratory-based and has not been tested in humans. It should not be used to diagnose, treat, cure, or prevent any disease. Probiotics are not regulated the same way as medications. Before taking any probiotic supplement, especially if you have a medical condition, take medications, or have a weakened immune system, consult with your healthcare provider. This article is for educational purposes only and does not replace professional medical advice.