Autoimmune diseases are human diseases that manifest themselves as a consequence of the body’s immune system being too active against its own cells. The immune system perceives its own tissues as foreign elements and begins to damage them. Such diseases are also called systemic, as there is a defeat of a certain system of the body as a whole, and sometimes the whole body is affected. For modern physicians, the causes and mechanism of manifestation of such processes remains unclear. Thus, there is an opinion that autoimmune diseases can cause stress, trauma, and infections of various kinds, hypothermia, and disruptions in microbiota. In addition, alterations in the microbiota composition are believed to play a role in the development of autoimmune diseases.
The most common autoimmune diseases
- Type 1 diabetes. The immune system attacks the beta cells of the pancreas. The patient feels intense thirst, lack of strength, sometimes – constant hunger.
- Rheumatoid arthritis – in this case, the immune system destroys the joints. The joints (mainly of the hands and feet) swell, ache, and the fingers unnaturally bend and twist.
- Multiple sclerosis – brain neurons and their myelin sheath are destroyed.
- Ulcerative colitis – lesions of the intestinal mucosa and the bacteria living in it. The mucous membrane becomes inflamed, and the patient is tormented by abdominal pain, nausea and digestive disorders.
- Psoriasis – the immune system attacks the skin, causing it to become dry, red and flaky.
Risk factors for autoimmune diseases
- Genetics. Autoimmune diseases in any of the close relatives significantly increase the risk of developing similar disorders in offspring.
- Gender. Women suffer from autoimmune diseases more often than men.
- Age. Autoimmune diseases occur more often in the young than in the elderly.
- Infectious diseases. Certain infections can contribute to the development of autoimmune diseases.
In addition, the influence of the microbiota on immunity and on the development of autoimmune diseases is being actively studied.
Linking autoimmune diseases to the gut microbiota
The human gut is home to about 100 trillion bacteria that play an important role in our health. In healthy individuals, the gut microflora consists of six major types of bacteria, with Firmicutes and Bacteroidetes being the most common. Normally, in healthy people, the number of Firmicutes is slightly higher than Bacteroidetes.
People with autoimmune diseases such as diabetes, rheumatoid arthritis or multiple sclerosis have a different microbiota composition than healthy people.
Bacteria in the gut produce various substances (metabolites) that can both promote autoimmune reactions and protect the body. For example, some species of gut bacteria can influence the development of immune cells such as T helper 17 cells, which are associated with autoimmune diseases such as multiple sclerosis, psoriasis, and rheumatoid arthritis.
Some species of staphylococci can secrete toxins that activate T-lymphocytes, which can also contribute to autoimmune processes.
However, there are also beneficial bacteria, such as the genera Clostridia and Bacteroides (e.g., Bacteroides fragilis), that can suppress inflammatory autoimmune diseases. They do this by stimulating regulatory T lymphocytes that help control inflammation and protect against autoimmune reactions.
Thus, the composition of the gut microbiota has a significant impact on the development of autoimmune diseases and may be an important factor in their prevention or treatment.
How to maintain a healthy microbiota
Maintaining your gut microbiota, and thus protecting yourself from many diseases, can be done with a few healthy habits.
- Eat more fiber
Fiber is a prebiotic and food for bacteria. It is fiber that allows bacteria to synthesize short-chain fatty acids. The main sources of fiber are vegetables, fruits, berries, legumes, grains, and nuts. The less processed a food is, the more dietary fiber it contains. This means that it is healthier to eat vegetables and fruits raw, choose uncooked cereals and whole-grain pasta.
A diet rich in fiber will reduce the risk of diabetes while increasing the diversity of the microbiota and decreasing the Firmicutes/Bacteroidetes ratio.
- Sugar in moderation
Eating too much sugar reduces microbial diversity and SCFAs. As a result, the risk of ulcerative colitis and other autoimmune diseases increases.
The amount of sugar should not exceed 10% of all calories consumed, or better yet, 5%. On average, this is no more than 50 grams of sugar per day. Approximately so much is contained in one two-hundred-gram piece of cake.
But do not forget that many unsweetened products also contain sugar. This does not mean that you should always go with a calculator and count the amount you eat – 22 grams from a bag of juice, another 10 grams from a jar of yogurt. Just pay attention to how much sweet stuff you eat (and drink).
- Move more
Exercise has a beneficial effect on the microbiota, increasing its diversity, decreasing the Firmicutes/Bacteroidetes ratio and limiting T-lymphocyte activity. This reduces the risk of developing diseases, including autoimmune diseases.
The role of stress and sleep in maintaining a healthy microbiota
Stress and sleep quality are equally important factors in maintaining a healthy microbiota. Chronic stress can negatively affect the balance of gut bacteria, reducing their diversity and promoting the growth of harmful microorganisms. This, in turn, can increase inflammation and increase the risk of developing autoimmune diseases. Quality and adequate sleep, on the other hand, helps normalize the microbiota, improving immune response and reducing inflammation. Regular rest and stress management, such as practicing meditation or breathing exercises, can help maintain a healthy balance of the microbiota and reduce the risk of developing autoimmune disorders.
Conclusion
The gut microbiota plays a key role in maintaining the overall health of the body and has a direct impact on the development of autoimmune diseases. The composition of the microbiota in people with these diseases differs from that of healthy individuals, and certain bacteria can both promote inflammation and autoimmune reactions and protect the body from them. Understanding the relationship between the microbiota and autoimmune diseases opens new horizons for the prevention and treatment of these disorders.
Maintaining a healthy balance of the microbiota through proper nutrition, physical activity, stress management, and adequate sleep can be an important step in the prevention and control of autoimmune diseases. Research in this area is ongoing, and every day we are becoming more aware of how the microbiota affects our health. Taking care of your gut and practicing healthy habits can help strengthen your immune system and reduce your risk of developing many diseases, including autoimmune diseases.
