What are the links between Candida and bad breath from stomach?

Posted in: Gut Health

IBS Specialists as featured in the Guardian

By Victoria Tyler 29.04.23

Table of Contents

  • Can a Yeast infection and Candida cause bad breath?
  • What is candida and what causes candida to overgrow?
  • What is the cause of a candida infection?
  • What are the symptoms of oral candida?
  • Should I get a candida test?
  • Dietary recommendations for Bad breath and Candida
  • Natural treatments for bad breath and candida
  • Candida and Biofilms
  • Is there a connection between candida die-off and bad breath?
  • SIBO and Bad breath
  • Are there any other causes of bad breath?

Can a Yeast infection and Candida cause bad breath?

Are you experiencing bad breath? Perhaps you weren’t even aware of the issue until it was brought up by a family member? If so, you’re not alone!

Studies indicate that bad breath, also known as halitosis, can affect a significant portion of the population—ranging from 2.4% to a staggering 78%. [Source: PubMed]

Halitosis, commonly referred to as bad breath is a condition that can lead to considerable embarrassment, whether it’s a subtle hint from a partner or the fear of colleagues noticing the issue.

Perhaps you have already made several proactive visits to dentists, hygienists, and periodontists, and been told that your teeth are in perfect condition.

Did you know that bad breath may be due to a condition known as candida overgrowth?

Please read on to learn more about what candida is, the causes of Candida and how to get rid of it.

What is candida and what causes candida to overgrow?

Candida is a naturally occurring fungus (not bacteria) in your oral cavity, gastrointestinal tract, and on your skin and is benign in small amounts. In some cases however, Candida can overgrow.

In fact medical studies do indicate [Source PubMed ] that a high level of Candida colonization may be associated with a number of gut health conditions as well as inflammation.

So firstly let’s discuss the factors that may have contributed to candida overgrowing and causing your bad breath.


Have you taken any broad-spectrum antibiotics? If so you may have noticed a white coating on your tongue once you have completed the course. Unfortunately, because antibiotics disrupt your gut microbiome and your levels of friendly gut flora, this may lead to infection in your oral cavity – the scientific name is oral candidiasis or, more simply, oral thrush. [Source: PubMed]

Candida, the fungus that causes oral thrush, usually stays under control when you have plenty of good bacteria, like Lactobacillus and Bifidobacterium, in your gut. These friendly bacteria help protect you from infections.

2. Other medications such as Steroids/ Pill

Have you had to take any steroids or even the contraceptive pill? Both of these medications may also have caused a proliferation of yeast and fungal strains.

3. Refined foods

Do you consume many refined foods including chocolates, cakes, biscuits sugars or foods containing yeast?

All of these delicious foods may have contributed to an overgrowth of candida and other species of yeast. Candida will simply feed off of sugars, this includes unrefined sugars such as fruit juice.

Clinically we have seen an increasing number of patients who have developed bad breath linked to candida due to a poor diet and consumption of refined, over processed foods including sugar, cakes, biscuits, white bread and alcohol.

4. Nutritional deficiencies and low immune system

Nutritional deficiencies have also been linked to an overgrowth of candida- this includes deficiencies in important mineral and vitamins such as iron, zinc, magnesium, selenium, folic acid, vitamins A, B6, B12, and  vitamin C. [Source PubMed]

What are the Symptoms of Oral Candida?

Oral candida may be characterized by the appearance of a furry tongue with a coating or white, creamy patches. Source: PubMed

Sometimes there can yellow-white plaques. [Source: PubMed]

In severe cases there may be lesions on the tongue, inner cheeks, gums, or tonsils and these patches may be sore.

Other symptoms of Candida include:

  • Digestive symptoms such as bloating, constipation and diarrhoea are also common. This is probably the most common complaint we see as well as bad-breath. Many of our patients are constipated as well as experiencing bad-breath.
  • Genital yeast infections: Itching, burning, and discharge in the genital area.
  • Skin infections: Redness, itching, and rash in warm, moist areas like the armpits and groin.
  • Fatigue: Feeling tired or lethargic despite adequate rest.
  • Joint pain: Pain and stiffness in the joints.
  • Brain fog: Difficulty concentrating or remembering things.

Should I Get a Candida Test?

Getting a test for Candida may be a good idea if you’re experiencing persistent symptoms that could be related to Candida overgrowth, such as oral thrush, recurring yeast infections, or digestive issues.

Candida tests may include swabs, blood tests, stool tests, urine tests, or cultures from affected areas. Please read more about the tests that may be of benefit to you on our candida test page.

Dietary recommendations for Bad breath and Candida

If you have bad breath and suspect it is due to Candida, the first step will be to address your diet. A balanced diet can help manage bad breath and Candida overgrowth. Here’s a general guide:

  1. Limit Sugars and Carbs: Candida thrives on sugars, so reducing your intake of sugary foods and refined carbohydrates can help control its growth. This includes chocolates, cakes, biscuits, and dried fruit.
  2. Many patients also react to yeast, so you may need to avoid bread, soy sauce, marmite, and balsamic vinegar.
  3. Probiotics: If you have recently taken antibiotics, probiotics may help combat Candida. Foods rich in probiotics, include yoghurt, kefir, sauerkraut, and kimchi, can help restore the balance of healthy bacteria in your gut and mouth, potentially reducing Candida overgrowth.
  4. Avoid fermented cheeses such as blue cheese and cheddar cheese as these may also cause the yeast to grow,
  5. Eat Fibre-Rich Foods: Fibre promotes digestion and helps maintain a healthy gut microbiome. Include plenty of fruits, vegetables, whole grains, and legumes in your diet.
  6. Stay Hydrated: Drinking enough water can help flush out toxins and keep your mouth moist, reducing the risk of bad breath.
  7. Include Antifungal Foods: Some foods have natural antifungal properties that can help combat Candida overgrowth. Examples include garlic, coconut oil, ginger, and turmeric.
  8. Limit Alcohol and Caffeine: Both alcohol and caffeine can contribute to dry mouth, which can worsen bad breath. Limit your intake of alcoholic and caffeinated beverages.
  9. Practice Good Oral Hygiene: Alongside dietary changes, maintaining good oral hygiene is crucial. Brush your teeth twice a day, floss daily, and use an alcohol-free mouthwash.

If you need tailored dietary advice we recommend you book an appointment with a registered nutritional therapist.

Natural anti-fungal treatments for bad breath and candida

Treatment for Candida-related bad breath typically involves taking some form of anti-fungal, herbal or pharmaceutical.

Here are some natural anti-fungal options:

  1. Garlic: Garlic has natural antifungal properties that can help combat Candida overgrowth. Incorporate fresh garlic into your meals or take garlic supplements every day.
  1. Coconut Oil: Coconut oil contains caprylic acid, which has been shown to have antifungal properties. You can swish coconut oil in your mouth for a few minutes each day (oil pulling) to help reduce Candida levels and freshen your breath.
  1. Caprylic acid is also a strong anti-fungal that may be helpful to combat the overgrowth. You should take this every day for two weeks.
  1. Tree Oil: Tea tree oil has antifungal properties and can be diluted and used as a mouthwash to help reduce Candida levels in the mouth.
  1. Apple Cider Vinegar: Some people find relief from bad breath by gargling with diluted apple cider vinegar, which has antimicrobial properties. Be sure to dilute it with water before use.
  1. Grapefruit seed extract (GSE) is often promoted for its potential antimicrobial properties, including its ability to combat bacteria, viruses, and fungi, including Candida.
  1. Mouthwash or Oral Rinses: Antifungal mouthwashes or oral rinses containing neem may also be helpful to reduce Candida population in the oral cavity.

Candida and Biofilms

Did you know that candida has the ability to shield itself from treatment? It does this by forming a protective shield called a biofilm. A biofilm is a slimy, sticky layer formed by the fungi to make it difficult for anti-fungals to reach and kill the microorganisms inside. However there have been studies on a supplement called N-acetylcysteine (NAC), that can stop fungi from growing in biofilms, especially at high doses, and it helps other drugs work better against some types of fungi. Source PubMed

Is There a Connection Between Candida Die-Off and Bad Breath?

So you have changed your diet, you have taken anti-fungals and biofilm disruptors but yet you are still experiencing bad breath! What exactly is going on? You might be experiencing ‘ candida die-off’.

The scientific term for die-off, especially in the context of microbial populations, is “Herxheimer reaction” or “Jarisch-Herxheimer reaction.” It refers to the temporary worsening of symptoms that can occur when the body is eliminating toxins produced by bacteria or other pathogens during treatment.

There’s evidence suggesting a possible link between Candida die-off and bad breath. When treating Candida overgrowth in the mouth, whether through medication or dietary changes, toxins will be released as Candida fungi die off. This could contribute to temporary bad breath during the process of elimination of yeast.

Die off is a sign that strains of yeast and candida are literally ‘dying off’ in your body. This is a good sign. When yeast die, they release some chemicals called endotoxins. These toxins can cause bad breath and may cause other die-off symptoms including:

Other Signs of Die-off

In addition to bad breath you may experience other symptoms but rest assured these should improve within a week. Some of these symptoms include:


Skin issues such as rashes

Digestive issues including diarrhoea



If you experience very strong die-off symptoms it may be a sign that your liver is overloaded and you probably should reduce the strength and amount of anti-fungal supplements you are taking. It is best to receive advice from a qualified Nutritional Therapist who can guide you on dosage as side-effects are common.

SIBO and Bad Breath

If you follow the above guidelines you should be able to see some improvements in your bad breath.

However if for any reason you do not see any improvement, you should consider investigating other areas such as small intestinal bacterial overgrowth.

SIBO occurs when there is an overgrowth of bacteria in the small intestine, leading to symptoms such as bloating, abdominal pain, diarrhoea, and malabsorption of nutrients.

The excess bacteria in the small intestine can produce gases and other by-products during digestion, some of which can contribute to bad breath.

Additionally, SIBO can disrupt normal digestive processes and lead to changes in metabolism, which may also contribute to halitosis.

Addressing SIBO through dietary modifications, antimicrobial therapy, and other treatments aimed at reducing bacterial overgrowth can help alleviate symptoms of bad breath associated with this condition.

Please do get in touch if you need help with SIBO tests and SIBO treatments.

Are there any other causes of bad breath?

There a number of other gastrointestinal conditions can be linked to bad breath, including:

  1. Gastroesophageal Reflux Disease (GERD): GERD occurs when stomach acid flows back into the oesophagus, leading to symptoms like heartburn and regurgitation. The acidic contents can also contribute to bad breath.
  2. Oesophageal Reflux: Similar to GERD, oesophageal reflux involves the backward flow of stomach contents into the oesophagus, potentially leading to bad breath.
  3. Achalasia: Achalasia is a condition where the lower oesophageal sphincter fails to relax properly, causing difficulty swallowing and regurgitation of food. Residual food in the oesophagus can contribute to bad breath.
  4. Pyloric Stenosis: Pyloric stenosis is a narrowing of the opening between the stomach and the small intestine. This can cause food to remain in the stomach for longer periods, leading to bad breath.
  5. Hiatal Hernia: A hiatal hernia occurs when a portion of the stomach protrudes through the diaphragm into the chest cavity. This can affect the function of the lower oesophageal sphincter, contributing to GERD symptoms and bad breath.

These areas are medical conditions that we recommend  you see a Doctor to discuss further.

Key Takeaways

In conclusion, if your bad breath is caused by candida overgrowth you can modify your diet take anti-fungals and probiotics and possibly Biofilm disruptors to effectively manage symptoms such as bad breath and promote overall health and well-being. Identifying and addressing the root causes of candida overgrowth can lead to long-term relief and improved quality of life.

About the Author

Victoria Tyler a UK registered Nutritional Therapist and member of the British Association of Nutritional therapy. She was awarded UK BSc Honours Degree in Nutritional Therapy and has trained in GI Functional Medicine. Victoria has been working with Gut disorders since 2004 after first experiencing digestive problems herself. She felt that the NHS was unable to provide the support individuals needed and went on to specialise in this area before offering a bespoke IBS service.

Booking an appointment

If you need help with digestive symptoms please contact us and we would be pleased to book you in for a consultation at our IBS clinic

If you are experiencing any of these symptoms our team of Nutritional Therapists   can help you choose the herbal anti-fungal, test for Candida and provide you tailored dietary advice to reduce oral thrush linked to bad breath.