The Cause of Bad Breath

When I first started researching bad breath for my mission to develop a breath mint that actually works, I thought I understood the problem. Pop a mint, feel that sensation, and voila—fresh breath. But the deeper I dug into the science, the more I realised I’d been thinking about this completely backwards. In our previous post, I discussed my realisation that cooling sensation is just menthol tricking our nerve receptors into sensing cold when there isn’t any. Meanwhile, the real culprits behind bad breath were slipping by stealth-mode (or not so stealth? they still smell).

The Real Villains

What I’ve learned is that bad breath is less about what we eat or drink and, fundamentally, more about what happens after. The primary cause of halitosis is the production of volatile sulphur compounds (VSCs) by anaerobic bacteria (bacteria that thrive in places where there’s no oxygen) living in our mouths. And these bacteria are super efficient at what they do. They break down proteins from food particles, dead cells, and other organic matter, converting sulphur-containing amino acids into hydrogen sulfide, methyl mercaptan, and dimethyl sulfide.

Sound confusing? Yeah.. And they make the distinctive foul-smelling gases that make up what we recognise as bad breath. And these tie in with what I’m about to share next.

The tongue, I discovered, is particularly important in this process. The textured nature of the tongue creates an ideal environment for odour-producing bacteria to thrive.

Beyond the Mouth: When Bad Breath Signals Something More

While most bad breath originates from the mouth, my deep dive revealed a number of conditions that can contribute to halitosis.

Dry mouth, or xerostomia, creates perfect dry conditions for bacteria to build their societies by reducing the cleansing purpose of saliva. This can occur from medications (e.g. hayfever tablets), medical conditions, or simply breathing through the mouth.

Gastroesophageal reflux disease (GERD) presents another fascinating connection for my research. When stomach acid and partially digested food reflux into the oesophagus and throat, they can create distinctive odours and provide a base for bacteria to grow.

What also intrigues me is how certain medical conditions can produce characteristic breath odours. Diabetes can cause breath that smells fruity (not in a nice way), while a liver that isn’t functioning properly would lead to the production of musty odours.

Gum disease, particularly when it progresses, tends to create deeper pockets in the mouth where bacteria can thrive. And this relationship is unfortunately bidirectional. VSCs not only cause bad breath, but is also toxic to human cells, potentially contributing to tissue damage and disease progression. Which makes everything even worse.

There are a lot of things that can arise from bad breath. And I’m sharing this not to scare you, I’m doing this to help you understand that bad breath isn’t a moral failing or something to lose hope on, it can any mix of things that interplay with each other.

A New Understanding

What strikes me most about this research is how interconnected everything is. Bad breath isn't just about oral hygiene—it's a complex interplay of bacterial ecosystems, systemic health, saliva production, and protein breakdown. The cooling sensation from traditional mints provides psychological comfort but does nothing to address the underlying bacterial processes that create VSCs.

This understanding has really got me thinking on my approach to developing a truly effective breath mint.

The Path Forward

If you're dealing with persistent bad breath, consider starting with tongue scraping (gently, so you don’t create more pits for bacteria to reside in), research shows this can immediately reduce VSC levels. Stay hydrated to support saliva production, and don't ignore potential underlying conditions like GERD or dry mouth.

As I continue developing this new approach to breath freshening, I'm committed to creating a product that addresses the root causes rather than just the symptoms. Because true freshness shouldn't be about temporary masking while tricking our nerve receptors—it should be about supporting systems so that odour-producing bacteria simply can't thrive.