The article “Probing the Oral-Brain Connection” explores the relationship between the oral microbiome and depression in a large community cohort.
Why is this study interesting?
Because depression/anxiety is the leading cause of disability globally, with 582 million suffering (half a BILLION!!!) and more since COVID…
We’re all at risk because of our exposure to high stress, processed foods, antibiotic overuse, increased pollutants, and other “stresses” on our bodies and minds.
The Gut-Brain-Axis has been linked to mental wellness for more than a decade – and now the Oral-Brain-Axis is showing similar (but different) associations.
Let’s take a closer look:
How Could Dental Health be Linked to Mental Wellness?
Some of the same underlying biochemical mechanisms that link the gut to the brain could also be working in the relationship between the mouth and the brain.
For example, oral bacteria can produce cytokines that modulate immune function and regulate inflammatory balance (a hallmark underlying depression and anxiety).
These cytokines can also stimulate the HPA Axis (“fight or flight system), leading to elevated stress responses, changes in stress hormone secretion (cortisol), and alterations in sleep patterns.
Additionally, many species of oral bacteria are involved in tryptophan metabolism (the amino acid precursor to serotonin), so changes in the ratio of tryptophan to serotonin (Trp/5-HT) may alter mental wellness symptoms such as depression, anxiety, and PTSD.
Also, having a “leaky gut” is known to allow passage of bacteria (LPS - lipopolysaccharide) from the gut into the blood, setting off an immune/inflammatory reaction.
This leads to neuroinflammation in the brain (“leaky brain”).
So, the same idea of “leaky mouth” could be at play here.
Now, I bet you’re wondering about this study and what they found.
Check it out:
Let’s Dive Into the Research: What Did the Study Reveal?
The study had 306 subjects with mental health symptoms and 164 healthy controls.
Using 16S rRNA sequencing, researchers analyzed salivary microbiome patterns in individuals with anxiety, depression, and PTSD symptoms compared to healthy controls.
They did not find a relationship between “overall diversity” of the oral microbiome and mental health symptoms – but they did find relationships between mental health and specific types of bacteria in the oral cavity.
The study found distinct microbial compositions linked to mental health conditions, with PTSD symptoms associated with higher levels of Prevotella histicola and lower Haemophilus sputorum. At the same time, anxiety correlated with reduced Neisseria elongata and increased Oribacterium asaccharolyticum.
Additionally, functional analyses suggested that tryptophan metabolism may play a role in the oral-brain axis, supported by lower plasma serotonin levels in symptomatic individuals.
Key Takeaways: How Oral Health Impacts Mental Well-Being
The findings highlight the intricate interplay between oral and mental health and suggest potential for new therapeutic interventions targeting the oral microbiome.
Improving your oral health could have a surprising impact on your mental health and wellness. Just as we modulate the gut microbiome for better mental health, there’s growing potential for targeting the oral microbiome for therapeutic interventions.
Fascinating, right?
Now, I bet you have some questions.
Let’s take a look.
Even “bad breath” can be a sign of an oral environment that may contribute to mental health issues. The mouth bacteria that lead to bad breath do so by producing “volatile sulfur compounds” that both smell bad and lead to inflammation and gingivitis (inflammation of the gums). When prolonged, this elevated inflammation in the mouth can lead to “peripheral” inflammation (in the body) and “neuro” inflammation (in the brain), as well as chronic immune system activation across the entire gut-brain-axis - leading to depression and anxiety.
Final Thoughts: Your Mouth Matters More Than You Think
The connection between oral health and mental wellness is becoming clearer (and resembles a giant “Biochemical Dominoes Game” where the mouth, gut, and brain are all connected) - so this new research highlights just how influential your oral microbiome can be.
While we’ve long understood the gut-brain connection, it’s now evident that the oral-brain axis plays a role in mood regulation, inflammation, and even neurotransmitter production.
The good news?
You have control over your oral health.
Simple habits like maintaining good dental hygiene, reducing sugar intake, and supporting a balanced microbiome through diet and probiotics may not just protect your teeth – they could also help support your mental well-being.
As research continues to uncover more about this fascinating connection, one thing is certain: taking care of your mouth might be a small but powerful step toward a healthier mind.
