Is there any scientific basis for the saying “diseases come from the mouth”?

"Diseases come from the mouth" is something we have been taught to pay attention to since we were young. However, with the development of science, many people will tell us that we have strong immunity and a strong acid stomach. Does the saying "diseases come from the mouth" still hold true? Won't immunity and stomach acid kill the virus?

In fact, diseases entering the body through the mouth do not only refer to viruses, but are also related to our nutritional intake. Today, let me tell you what “diseases entering the body through the mouth” is all about.

01. From the perspective of digestive problems, diseases are caused by what you eat.

In fact, no matter how strong the immune system is, it cannot defend against everything, not to mention, there is something that is easily overlooked: diseases that enter the body through the mouth are not only diseases, but also have an impact on our nutritional intake. If we do not pay attention, it may cause disease.

For example, digestive problems. Good food is worth enjoying, but if digestion is not good, not only will the good food be wasted, but the body will also feel uncomfortable. As people age, the incidence of digestive system diseases also begins to increase. For example, the following is the incidence of gastric ulcers and duodenal ulcers (DU) in Tianjin. It can be seen that the number of gastrointestinal diseases in middle-aged and elderly people is significantly higher [1].

Many people attribute digestive problems to age. Indeed, as we age, digestive problems become more and more serious, so many people lament that they are getting old.

But it's not just age that affects digestion; it's also your gut microbes that matter.

02. Briefly talk about intestinal microorganisms

In our intestines, there is a very large group of microorganisms, which is the intestinal flora, also known as intestinal microorganisms, which is the general term for microorganisms living in the intestines. However, don't underestimate intestinal microorganisms, their existence can be said to have far exceeded people's expectations.

To make a simple comparison, the number of cells in our human body is about 40-60 trillion, while the number of intestinal microorganisms is as high as millions to trillions; there are only dozens of types of cells in our human body, while the number of intestinal flora is as high as thousands.

The intestinal flora is very important for our digestion. On the one hand, they can help our body's digestive process and promote digestion. On the other hand, they can also deal with some substances that our body cannot directly metabolize or digest, such as some cellulose, which can be digested by the intestinal flora.

Once the intestinal flora is out of balance, it may cause indigestion or various diseases such as diarrhea at the mildest, or a series of digestive system diseases at the worst.

How do intestinal flora come from? The answer is: ingestion. Microorganisms are everywhere in our daily environment, and some microorganisms enter the body through food and water. After a difficult journey, some of them survive and colonize in the intestines, forming our intestinal flora.

If the flora we ingest is unhealthy, then the intestinal flora will be damaged, and then the disease will come. It can be seen that "diseases come from the mouth" also has another way of thinking. Because of this, if beneficial microorganisms can be supplemented in time after gastrointestinal problems occur, then gastrointestinal problems can be saved to a certain extent, and this is probiotics. Probiotics, as the name suggests, are microorganisms that are beneficial to health.

03. What probiotics do we have?

So what are our probiotics? The following is a picture of intestinal microorganisms from the Institute of Microbiology, Chinese Academy of Sciences

How about it? Do they look familiar? Bifidobacterium? Lactobacillus? In fact, aren’t these two the probiotics we are familiar with?

Yes, it is true. The probiotics commonly added to probiotic products on the market are originally the dominant flora in the intestinal flora. It is precisely because we have studied intestinal microorganisms and found that they can coexist with humans for a long time, so researchers separated these flora and further studied them and found that these fungi are indeed beneficial to humans. With the development of the market and industry, probiotics are increasingly used in the market, such as some of our common yogurts and probiotic preparations.

04. In addition to microorganisms, calcium is also related to intake

It’s not just microbes that are related. Calcium is also related to our intake. Osteoporosis is a very common but easily overlooked bone disease, which is typically characterized by decreased bone mass, destruction of bone microstructure, increased bone brittleness, and decreased bone strength, resulting in a greater susceptibility to fractures [2].

Osteoporosis is also a disease that is closely related to age. Basically, after the age of 30, the body's bone density begins to decline, and osteoporosis begins to appear. For example, this is a bone density survey of different age groups. It can be seen that with increasing age, bone density generally shows a downward trend [3].

And the factor that is closely related to osteoporosis is: calcium.

When we talk about calcium, we often think of bones and growth. This is undoubtedly the most familiar role of calcium for the public, because calcium itself is a component of bones. For middle-aged and elderly people, due to digestive problems and insufficient nutrition intake, calcium ions are actually lacking. When the body lacks calcium, it will separate calcium from the bones to complete more important physiological processes. The result is that the bones lack calcium and become loose.

As you can see, digestion and nutrition are also another type of "disease from the mouth". Of course, it's not just calcium, there are other aspects, such as our three highs, which are also diseases from the mouth.

Therefore, for middle-aged and elderly people, normal diet is not a big problem, but what is worth paying attention to is the health problems caused by insufficient or excessive nutrition. Because of this, for middle-aged and elderly people, nutritional supplementation is also very important.

[1] Guo Qingjie, Cao Zewei. Epidemiological analysis of peptic ulcer in Tianjin[J]. New Medicine, 2010, 41(02):104-106.

[2]Rozenberg, Serge, Olivier Bruyère, Pierre Bergmann, Etienne Cavalier, Evelien Gielen, Stefan Goemaere, Jean Marc Kaufman et al. "How to manage osteoporosis before the age of 50." Maturitas 138 (2020): 14-25.

[3] Liu Siyao, Xiong Lijun. Analysis of bone density in the health examination population in Fengcheng City[J]. Journal of Yichun University, 2022, 44(12): 64-66+99.