The Oral Microbiome and your health

Your mouth is the gateway to your gut, and gum disease (that currently affects 40% of adults) plus other oral pathogens are now linked to multiple diseases such as IBS, type-2 diabetes, liver cirrhosis, chronic kidney disease and several cancers. It’s time to pay attention to oral hygiene.

It probably won’t surprise you to know that your mouth (your ‘oral cavity’) contains a host of microorganisms both good and bad. These microorganisms have been referred to as the oral microbiome, the oral microbiota or the oral microflora, depending on which scientist is explaining the issues. What is consistent, however, is the science that an imbalance in these microorganisms contributes to oral diseases such as dental cavities and gum disease.

However, over the last five years more and more research has linked an imbalance in the oral microbiome to issues such as Liver cancer (1), Pancreatic cancer (2) and even to the accurate prediction of a risk of Parkinson’s Disease (3).

The oral cavity microbiome is inconsistent

In a study reviewing the oral microbiome and its links to chronic kidney disease, researchers took swabs from several different locations – the saliva, left and right molars and the tongue. Each microbiome was slightly different.

In the patients tested, the saliva and tongue microbiomes were the most similar with higher levels of Neisseria, and lower levels of Veillonelia. There was also lower levels of Streptococcus in both samples. Again there was talk of predictive tests.

Professor Paul O’Toole of the Cork Microbiome Institute was part of a team looking at the oral microbiome and Colorectal Cancer. Much is already known about the links of gut bacteria such as Fusobacterium and E Coli with CRC tumours. In the research (5) using oral swabs, they found several oral microorganisms such as Streptococcus and Prevotellas in higher volumes in the CRC patients.

O’Toole in one interview we covered on CANCERactive said that he was convinced gut bacteria played a role in cancer. He also felt it was not surprising that the oral microbiome was involved, as the vast majority of bacteria enter the gut through the mouth.

A single Gastrointestinal Tract (GI)

There can be now little doubt that the gut microbiome is central to human health. The Human Microbiome Study concluded that your gut became ill first and then you became ill. A chap called Hippocrates said it 2,500 years ago too, without the benefit of RNA analysis. In 2000, the US Surgeon General called the oral cavity “the mirror of health and disease in the body”.

It seems increasingly clear that there is but one gastrointestinal tract and what takes place in the mouth cann also take place in the gut. With 800 species (families) and approximately 25 strains (family members) each, clearly these bacteria are important. When you realise they haven 75,000 genes to your 25,000 genes and that they are making three times more micro-RNA than you make, you realise how easy it is for them to enhance your physical and mental biochemistry, or weaken it.

Go to: Heal your gut; Heal your Body

They would also affect your immune system positively or negatively since 85% of your immune memory is produced as a reaction to the volume and diversity of the bacteria in your gut. The same would hold for your mouth and throat – the strength of the immune system there will be a reflection of the microbiome in that area,

A 2012 study (7) showed that 45% of the faecal microbiome was identical to the oral microbiome and a 2019 study (6) showed that oral microorganisms definitely did move into the gut changing the gut microbiome balance.

Gum disease – a major health problem

The bacterium, Porphyromonas gingivalis, is associated with periodontitis, commonly called gum disease, where inflammation and even bleeding occurs. There are links between this pathogen and several chronic illnesses such as cirrhosis of the liver, and there is also a two-way connection with type-2 diabetes (8).

Here, researchers found a clear relationship between the severity of the gum disease and the degree of hypoglycaemia and, although not fully understood, certain aspects of immune system, neutrophil and cytokine activity are involved.

When pathogens (bad bacteria) from the mouth enter the GI tract, a fight occurs with the Commensal bacteria already there. Depending on numbers and strength, the good or the bad can end up winning. This is not rocket science. However, IBS has now been associated (9) with higher levels of oral pathogens such as Streptococcus, Neisseria, Veillonella, Prevotella, Gemella and even yeasts which can be linked to both IBS and mouth ulcers. Once you have IBS, it can all turn really nasty if your gut gains the oral pathogen Klebsiella (10), which causes severe inflammation, a boost of T-cells and is resistant to antibiotics.

A leaky gut is associated with IBS. Thanks to gum disease, you can also have leaky gums and pathogens can enter the rest of the body via the blood system too.

Visit the dentist more often

If the pathogens are entering the mouth and colonising certain areas, clean this up! A whopping 40% of adults have bad breath and/or gum disease. When I ask the spouse of someone with pancreatic cancer, if their partner has gum problems they invariably jump and say ‘yes’. I have even had patients sent to the dentist by their oncologist. Then there is research (11) showing people with cirrhosis of the liver had reduced symptoms if they clean up problems in their mouths.

But, cleaning the mouth is not straightforward. In the healthy mouth, the good keep the bad under control. Using an astringent mouth wash kills all; my Dentist has considered this and does not offer alcohol-based mouthwash in their surgery.

Eat a good diet

We know that eating processed, refined and empty calorie foods – added sugar, high-fructose corn syrup, alcohol, lactose, refined wheat and refined grains etc. etc., encourages pathogens and yeasts to thrive, while eating whole, soluble fibre – nuts and seeds, pulses (like lentils and broad beans), vegetables (broccoli, Brussels sprouts, avocado) and whole oats and psyllium increase levels of commensal bacteria and help them win the war. These foods are at the heart of the Rainbow Diet.

Go to: Foods that boost your commensal bacteria

* * * * * * * * * * * *

References

1. Liver cancer and oral health
2. Oral bacteria linked to pancreatic cancer
3. Oral microbiome can predict Parkinson’s Disease
4. https://www.sciencedirect.com/science/article/pii/S2468024917303790
5. https://www.ncbi.nlm.nih.gov/pubmed/28988196
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427756/
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3446314/?report=reader
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3228943/
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3925391/
10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5682622/
11. https://journals.physiology.org/doi/full/10.1152/ajpgi.00230.2018