Bad breath? Experts reveal how to tell if it’s a sign of a GUT problem

If you are struggling with bad breath that smells a bit like rotten eggs, you should probably take a closer look at your gut health.

That is according to experts, who say you shouldn’t necessarily blame acid reflux, gum disease or tonsillitis. 

Smelly breath can be caused by hydrogen sulphide, which has an egg-like smell.

The colourless gas can be released if there is too much of a bacteria in the gut or bacteria growing in the small intestine, dietitians say.

Dr Zoe Williams, This Morning’s resident doctor, says bad ‘gut breath’ usually smells like something rotten and can vary in severity. 

It may also be accompanied by burping and gas.

Eating fermented foods like yoghurts, kimchi and sauerkraut could help reduce your bad breath, says Dr Zoe Williams

‘Your microbiome is made up of trillions of microorganisms that live in your gut and communicate with the brain via the vagus nerve and by sending chemical signals,’ Dr Williams says.

‘When there is overgrowth of bacteria, or too much of the wrong kind of bacteria, it can lead to bad breath.’

Helicobacter pylori, a bacteria present in the stomachs of 40 per cent of people in the UK, raises the risk of stomach ulcers and can cause bad breath, she says.

That’s because the bacteria produces hydrogen sulphide.

While having some hydrogen sulphide in breath is normal, high levels of it have been associated with several serious digestive diseases.

An overproduction of bacteria in your gut could be the reason you have bad breath. But it could also be caused by tooth or gum problems and from eating spicy or strong smelling food

Anna Pettit, gut specialist dietitian at The Gut Health Clinic, claims small intestinal bacterial overgrowth (SIBO) can also be to blame.

Huge numbers of bacteria live in the large intestine and are vital for digestion and boosting health.

In SIBO, sufferers experience an uncontrolled growth of these bacteria that can invade the small intestine and trigger gut problems.

Here, they can produce high amounts of hydrogen sulphide gas as a byproduct, causing bad breath as well as diarrhoea, loose stools and excess wind, she says.

‘Generally, hydrogen sulphide is involved in managing inflammation and repair of the mucosal layer in the gastrointestinal tract, so is good for us,’ according to Ms Pettit.

However, too much has been linked to ulcerative colitis, she warns.

The long-term condition is caused by inflammation in the large intestine and rectum, which can cause small ulcers to develop. 

Those who suspect their gut is the root cause of their bad breath can make lifestyle and diet changes.

Eating a wide variety of plants and consuming plenty of fermented foods, such as yoghurts, kimchi and sauerkraut, can boost the gut microbiome, according to Dr Williams, who is working with yogurt brand Activia.

She also recommends getting enough sleep, regular exercise and reducing stress levels to support the gut. 

Ms Pettit suggests eating parsley to ‘combat the taste and the smell of volatile odour-causing sulphur compounds in the mouth’. 

‘Try chewing some fresh leaves after a meal,’ she says.

Probiotics containing the bacterial strains lactobacillus and bifidobacteria are also thought to be helpful at reducing bad breath within weeks, according to Ms Pettit.