Bad Breath (Halitosis): The Real Cause Isn’t What You Think
Brushing, flossing, mouthwash… and it’s still there? Here’s why.
Bad breath is one of the most frustrating — and often embarrassing — symptoms people deal with.
And the usual advice?
Brush more
Use mouthwash
Chew gum
But here’s the truth:
Bad breath is rarely just a hygiene issue
What Causes Bad Breath?
In most cases, bad breath (halitosis) is caused by:
Volatile sulphur compounds (VSCs)
These are gases produced by certain bacteria in the mouth.
Common culprits include:
Porphyromonas gingivalis
Fusobacterium nucleatum
Treponema denticola
These bacteria break down proteins and release sulphur-containing gases
→ which create that unpleasant smell
Why Mouthwash Often Makes It Worse
Most conventional mouthwashes:
Kill bacteria indiscriminately
Disrupt the oral microbiome
Reduce saliva (especially alcohol-based ones)
This can actually:
Worsen imbalance
Allow odour-causing bacteria to return stronger
The Root Cause: Oral Microbiome Imbalance
Bad breath is usually a sign of:
Oral dysbiosis (microbial imbalance)
This can be driven by:
Diet (high sugar / processed foods)
Poor gut health
Dry mouth
Stress
Overuse of antibacterial products
The Gut–Bad Breath Connection
If you’ve tried everything and nothing works…
It may not just be your mouth
Gut imbalances can contribute to:
Increased sulphur-producing bacteria
Poor digestion
Reflux
Bacterial overgrowth
Which can all influence breath odour
Signs Your Bad Breath Has a Deeper Cause
Persistent despite brushing
Worse in the morning
Coated tongue
Gum issues
Bloating or digestive symptoms
How to Fix Bad Breath Naturally
1. Support Your Oral Microbiome
Avoid harsh mouthwashes
Use microbiome-friendly products
Stay hydrated
2. Improve Your Diet
Reduce sugar + ultra-processed foods
Increase fibre + whole foods
Support gut health
3. Support Saliva Production
Saliva is critical for:
Neutralising bacteria
Washing away debris
Dry mouth = higher risk of bad breath
4. Address the Root Cause (This is key)
If bad breath persists:
You need to understand which bacteria are present
This Is Where Testing Changes Everything
Oral microbiome testing can identify:
Odour-causing bacteria
Microbial imbalances
Underlying oral health risks
This allows for targeted, personalised solutions
Explore Oral Microbiome Testing: Oral Microbiome Testing (Regenerus)
The FIT Takeaway
Bad breath isn’t just cosmetic. It’s a signal
And often…
It’s your microbiome asking for support
Also Read: The Oral Microbiome Explained
To understand the bigger picture behind oral health: The Oral Microbiome: Why Your Mouth Could Be the Missing Link to Better Health
Ready to Get Answers?
If you’re:
Dealing with persistent bad breath
Not getting results from standard approaches
Wanting a root-cause solution
Explore Testing & Consultation Packages
If anything in this article sounds familiar, your body may be trying to tell you something. The good news is, you don't have to figure it out alone.
Take the free Find Your FIT Quiz to discover which test or programme suits your symptoms, or book a free 15-minute Personalised FIT Health Review with Becki for a direct, no-obligation conversation about where to start.
About Becki Hawkins
Becki Hawkins, BSc (Hons), mBANT, CNHC, is the founder of FIT Nutrition & Testing Clinic and a Registered Nutritional Therapist with over 20 years of experience. She specialises in evidence-based personalised nutrition and functional testing, helping clients uncover the root causes of digestive issues, hormonal imbalances, and unexplained symptoms. Becki combines clinical expertise with culinary creativity, translating complex test results into practical, delicious nutrition plans that work in real life. Her approach is simple: test, don't guess. Because guessing doesn't heal. Knowing does.