8 ways your digestion could be contributing to bad breath

What could your bad breath mean?

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Nutritional Practitioner, BA (Hons), DN, DNT (Distinction)
@AvogelUKHealth
Ask Ali


29 May 2018

How is bad breath connected to the digestive system?

In some cases bad breath is linked to the very first part of the digestive system, the mouth, which is fairly obvious, but in other cases, something may be going on deeper within your digestive system, and could be giving rise to that pongy breath of yours.

In Traditional Chinese Medicine (TCM) bad breath, or halitosis, is considered to be a sign that there is excess ‘fire’ or ‘heat’ in the body. This heat supposedly comes from the body being exposed to something in excess – be it food, alcohol, or medication, which in turn is putting pressure on your liver and your other key digestive organs.

How to tell?

Worried you have bad breath but not quite sure how to check? Well, if you feel comfortable enough, you could ask a close friend or family member for their opinion, but if you feel more comfortable doing this one solo, the simple lick test can work.

Lick the bad of your hand, leave it to dry then have a smell. If it doesn’t smell too fresh, then this is an indication that you may have bad breath.

Checking out your tongue can also be helpful. A thin, white layer is quite normal, but if you have a thicker white or yellow layer on your tongue it could suggest an imbalance of bacteria is at play, which won’t be working in your favour.

Other signs that could also suggest your digestion is under pressure

If you suspect you have bad breath then it could indicate that your digestive system is struggling a little. Other symptoms to look out for which are also characteristic of this ‘excess heat’ in the body, include the following:

What could be contributing to bad breath?

So, if you suspect you have bad breath, what exactly could be going on? Let’s explore 8 common causes and what can be done to help.

1 - Oral hygiene

With bad breath, the mouth is the obvious place to investigate first. Just like the rest of your digestive system, your mouth is a haven for bacteria. This is all quite normal, but if the balance is off, bad breath can soon take hold. Eating the wrong foods or drinks, lazy hygiene habits or avoiding the dentists’ chair could all be upsetting your oral hygiene.

Lifestyle tip

Keeping on top of oral hygiene is a must to help protect against bad breath. Brush your teeth (and tongue!) for at least two mintues, twice a day and don’t skip on the flossing either. Then, if anything seems a miss, get it checked with your dentist before it potentially progresses into a bigger problem. Your dentist will also most likely recommend annual trips to the dental hygienist which you should take them up on to help keep plaque levels down which can act as feeding grounds for bad bacteria. 

Product tip

Mouthwash may be the obvious choice for helping to keep your mouth minty fresh, but the long list of chemical-looking ingredients on the back of some of those conventional products may be off-putting. Stick to a more natural version such as Dentaforce instead to help refresh your breath. 

2 - Dehydration 

We recommend sufficient water intake for almost every ailment here at A.Vogel and bad breath isn’t an exception. Saliva is super important for helping to keep the mouth moist and it helps to neutralise plaque and bad bacteria in the mouth. If bacteria have the chance to thrive, then you could be left with a more pungent breath. This is often what contributes to morning breath, and it can be particularly bad if you tend to sleep with your mouth open which dries the mouth out further. 

Lifestyle tip

Nice and easy – drink enough water! Aim to drink 1.5l of plain, still water daily and avoid sweetened versions which have all sorts of unhelpful ingredients added to them.

Product tip

Not much in the way of products here, some fruit slices can help jazz up your water if you struggle with the ‘plain’ side of things, or Molkosan fruit can be a nice addition to a large glass of water.

3 - Nasal problems

If you have nasal issues, such as a persistent blocked nose, post nasal drip or excess mucous, then you could find that you have more of a problem with bad breath. As a result of these issues, you could be sleeping with your mouth open more often, or mucous can disrupt the internal environment by upsetting the delicate balance of bacteria. Sorting the root of the problem can often be most helpful. 

Lifestyle tip

Start by trying to reduce dairy. Especially if you have a dairy-laden breakfast, you could be starting the day with some questionable breath. Dairy is mucous producing and heavy mucous can not only make issues such as post nasal drip worse, but it also creates more of an anaerobic environment in the mouth, in which bad bacteria can thrive. Aim to lighten the load and opt for some dairy-free milks or yoghurts instead to see if things improve.

Product tip

Rather than a product from us, a trip to your local health food store to browse some of their dairy-free foods would be my best advice. However, if a blocked nose is getting you down, our Sinuforce Nasal Spray may be useful.  

4 - Extreme low-carb diets

I’m not generally a fan of extreme diets anyway, but did you know that your diet could also be contributing to bad breath? Diets very low in carbs, in particular, could be contributing. If you embark on a low-carb diet your body switches to a state called ketosis, where it primarily uses fat for energy. As you burn ketone bodies, certain chemicals are released which can contribute to bad breath. 

Lifestyle tip 

My advice is to stick to a healthy, balanced diet wherever possible. Anything too extreme isn’t sustainable, for one, but it can also give rise to a number of undesirable symptoms such as bad breath. Healthy fats shouldn’t be feared and options such as coconut oil may actually be a fantastic addition to your diet if you have bad breath! When taken internally, coconut oil can help support the balance of bacteria throughout the digestive tract, but it can also be used for a practice called oil pulling which is very helpful for supporting your oral hygiene – check it out!

Product tip

The key is to stick to good quality wholefoods. Aim to get a good balance of complex carbohydrates (limit white varieties which are sugar and carb-heavy and will only risk upsetting your gut bacteria), protein and healthy fats are a must too. Biosnacky Broccoli Sprouts are nice options to add to your regime – they are super nutritious and contain good proportions of protein and fibre too! 

5 - Bad bacteria 

An imbalance of bacteria throughout your digestive tract may be one of the main contributors to bad breath. H. pylori overgrowth in the stomach, small intestinal bacterial overgrowth (SIBO), questionable symptoms elsewhere (such as bloating), together with particularly pungent bad breath, could all suggest that the balance of bacteria is off throughout your digestive tract. 

Lifestyle tip

 If you eat lots of processed foods high in refined sugars, then you risk feeding the bad strains of bacteria throughout your digestive tract which gives them the opportunity to thrive. Aim to eat fresh, and avoid excess alcohol to help support your good bacteria. Repeat doses of antibiotics can also upset your gut so be sure to take a course of probiotics alongside these.

Product tip

Try Molkosan original

6 - Heartburn

If you experience recurrent acid reflux or heartburn then it could contribute to bad breath as well as suggest that your tum isn’t too happy. Did you know that in many cases of persistent reflux, low levels of stomach acid could be at the root of the cause rather than excess levels? This is certainly often the case in many instances of chronic stress or as we get older for example. Stomach secretions are not only vital for breaking down the food we eat properly, but also for keeping levels of bad bacteria such as H. pylori under control. 

Lifestyle tip

 Especially if you are on heartburn medication, my advice is to consider if they are working for you. If they aren’t,speak to your doctor.

Product tip

Employ some bitter herbs to help support your stomach secretions. 

7 - IBS 

IBS is a long-term, chronic condition affecting the digestive system but, more helpfully, it is a set of conditions that can vary from person to person. In some cases of IBS, diarrhoea is more dominant, whereas for others, constipation is more of an issue – both of which can potentially contribute to bad breath. Constipation we’ll discuss next in more detail. However, in terms of diarrhoea, if your gut is moving too quickly, malabsorption of the food you eat can occur, which may contribute to bad breath. Food malabsorption may also occur if there are problems with your liver, gallbladder or in conditions such as Crohn’s disease too, so if your symptoms are unexplained, it’s time to visit your doctor to have them investigate this further.  

Lifestyle tip

 For IBS it’s important to listen to your symptoms. This means firstly, keeping a food diary to help identify any trigger foods. Some people find they can’t tolerate gluten, dairy or meat, for example, whereas for others, certain vegetables may be problematic. There is no ‘one diet fits’ all when it comes to IBS so it’s important to listen to your symptoms.

Product tip

Probiotics can also be a good option for managing the symptoms of IBS.  

8 – Constipation

A slow moving gut could also be contributing to a nasty taste in your mouth. As waste material moves more slowly through your gut, bacteria is more likely to attack it and kick up a stink. Additionally, as waste sits in your system for longer, more toxins are reabsorbed and get pumped back to your liver. Both a slow moving gut and a liver under pressure (which often go hand in hand), could be contributing to bad breath. 

Lifestyle tip

To help keep your gut moving, and keep your liver happy for that matter, it’s important to drink plenty of water and eat a nice range of fresh fruit, vegetables and wholegrains rich in fibre. Garlic, grapefruit and beetroot, for example, are particularly liver-friendly and tasty too!


My Top Tip:


Linoforce Granules 12 years plus: A traditional herbal medicinal product for use in the short term relief of occasional constipation exclusively based upon long-standing use as traditional remedy. Always read the leaflet.

  • Registered herbal constipation remedy
  • Contains whole Linseed, Senna leaf and Frangula bark

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A.Vogel Digestisan Oral Drops

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A.Vogel Molkosan Original | Contains Concentrated Whey | L+ Lactic Acid | Suitable for Vegetarians

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Digestisan Oral Drops: A traditional herbal medicinal product used for indigestion, sensation of fullness and flatulence associated with over-indulgence in food or drink, or both, exclusively based upon long-standing use as a traditional remedy.
Always read the leaflet.

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