What is the human body? Internal and external organs, water - we all studied on school lessons anatomy. Another half of the body is a plurality of microorganisms that make up microbiota - "alien" bacteria throughout our body, which, while they remain in the balance sheet, help us be healthy. The human body contains trillions of specialized cells - tiny building blocks that are collected together to maintain the development and functioning of the body. But human cells are not the only "materials", of which our bodies consist. In fact, we live in symbiosis with trillion microorganisms. It is about them that we will tell you today.
Opinion of scientists on this account
The researchers have long discussed the proportion of the ratio of human cells and microorganisms in the body on average. Evaluations ranged, but the last study dedicated to the study of this issue, which appeared in PLOS Biology in 2016, suggests that we have in the body and on the body about as many microorganisms as human cells. In addition to bacteria and viruses, these microorganisms include archaeys, primitive organisms without core, and eukaria, type with a core that protects its chromosomes. All of them together make up various microbiotes: communities of microorganisms present in different places on the human body or in its body.
The imbalance of bacteria in the body causes violations
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Why bacteria are important to health
Various microbiotes are microbis of a person: the combination of microorganisms communities extends throughout the human body. The accumulations of microorganisms in different parts of the body play a crucial role in maintaining our health - although it is necessary that this is necessary that the number of different types of bacteria, fungi and other microorganisms remained in the balance sheet. When this balance is violated and, for example, one type of bacteria is over-selected, it can lead to infections and other health problems. This feature describes various organisms living in the intestines, mouth, vagina and the uterus, penis, skin, eyes and lungs.
Intestinal environment
The most discussed medium for colonization of microorganisms, especially bacteria, is the intestine of a person. Studies show that the gastrointestinal tract of a person contains an extensive "collection of bacteria, archey and eukaryot", which play an important role in the intestine homeostasis, helping to support the health of the gastrointestinal tract. Studies also showed that intestinal bacteria soften the relationship between the intestines and the brain by interacting with the intestinal nervous system and other mechanisms that can be hormonal or immunological. The main bacterial types in the intestines are Firmicutes and Bacteroidetes, which make up 90% intestinal microbiotes. Other are actinobacteria, proteobacteria, Fusobacterua and VerruComicrobia. These include some familiar bacterial groups or childbirth from the genus Firmicutes, such as Lactobacillus, which is known for its positive effect on health. This list, however, is not exhaustive. According to compiled data, there are about 2172 species of bacteria in the gastrointestinal tract.
Other microorganisms present in the intestines are viruses, but not those that usually cause disease. This type, called "bacteriophages" - literally, Bacteria Eaters - which help maintain a microbial balance by capturing the internal activities of bacteria. Bacteriophages "constitute the overwhelming majority of the virus component of intestinal microbioma," and researchers argue that part of their role is to infect certain bacteria to preserve the healthy balance of microorganisms in the intestine. Nevertheless, much of them remains badly understood.
Microorganisms in the mouth
As in the intestines, the mouth also contains numerous bacteria necessary for homeostasis. "A wide range of microorganisms is present in the oral cavity. It is in constant contact and, as shown, vulnerable to environmental impacts, "explain the authors of the review published in Journal of Oral and Maxillofacial Pathology in 2019. They continue, noting that "the various surfaces in the mouth are colonized mainly by the bacteria of the oral cavity," depending on the type of surface, to which they stick, for example, cheeks, tongue or teeth. The microbiota of the oral cavity contains 12 bacterial types - Firmicutes, Fusobacteria, Proteobacteria, Actinobacteria, Bacteroidetes, Chlamydiae, Chloroflexi, Spirochaetes, Sr1, Synergistetes, Saccharibacteria and Gracilibacteria - with several species named or not named. But the mouth is also located other microorganisms, namely the simplest, most common of which are entamoeba gingivalis and Trichomonas Tenax, as well as mushrooms and viruses. In the oral cavity there are 85 generics of mushrooms, including Candida, Cladosporium, Aureobasidium, Saccharomycetales, Aspergillus, Fusarium and Cryptococcus. "[Microbiota of the oral cavity] plays a decisive role in maintaining the homeostasis of the oral cavity, the protection of the oral cavity and the prevention of disease development," write the authors of the 2019 review.
Women's urogenital zones
Genitals and urinary pathways also contain a large number of microorganisms. Studies show that in the vagina "bacteria dominate", although which bacteria and in what quantities are not so simple to answer. Recent studies show that the number of bacterial populations into the vagina can not only fluctuate at different stages of the menstrual cycle, but may also differ in people of different races and ethnic groups. Some types of bacteria identified in the vaginal canal include Lactobacilli, Prevotella, Dialister, Gardnerella, Megasphara, Eggerthella and Aerococcus. "The microbiota human vagina plays a key role in the prevention of a number of urogenital diseases, such as bacterial vaginosis, yeast infections, sexually transmitted infections, urinary tract infections and HIV infection," says PNAS review. That is why experts advise to show extreme caution when it comes to intimate hygiene: many products can destroy a thin bacterial balance in this area. Doctors recommend rinse the outdoor genitals with water without soap several times a day, or use the means with a slightly acidified medium.
About bacteria in the genitals still much is unknown
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In addition, little is known about the microbiota of the uterus. Scientists began to learn this issue only recently. One study showed that Lactobacillus and Flavobacterium turned out to be the most common bacteria in the uterus, regardless of whether the woman is pregnant. Little is also known about the microbiety of the female bladder and the urethra. In a study published in the Current Opinion in Urology in 2017, it is noted that "the overwhelming majority of urine health studies were carried out without a knowledge or metering of urine microbiota." After recent studies, it turned out that the most common types of bacteria in the female urethra are Lactobacillus, followed by Gardnerella, Corynebacterium, Streptococcus and Staphylococcus. The authors of one experience put forward a hypothesis that bacterial populations of female lower urinary tract may vary depending on the age, the level of sexual activity and whether a person has entered the menopause or not.
Men's urogenital zones
If the researchers still have little a little about the microbiota of women's urogenital regions, they seem to know even less about those bacteria that are present in the men's urogenital region. One study conducted in 2010 revealed differences in microbial communities during circumcision compared with uncircumcised penises in an independent culture of the study. More specifically, the Bacteria of the Clostridiales family and PrevoteLaceae turned out to be more common on non-cut genital members. The authors of the newspaper noted that such differences can play a role in inflammation and exposure to infections. "In men who are not cropped, significantly more bacteria on the sexual dick, and the types of bacteria are also very different," said Dr. Cindy Liu's collapse in an interview.
On the skin
As in the intestines, the human skin contains many bacteria and mushrooms. In a review published in the journal Nature Reviews MicrobioLogy in 2018, it is explained that the populations of bacteria differ greatly in the regions of the skin, as well as depend on a number of factors, such as skin moisture and the amount of natural oil or sebum. According to the review, "PropioniBacterium prevailed areas prevailed, while bacteria that thrive in a wet environment, such as Staphylococcus and Corynebacterium, were mainly numerous in wet areas, including bends of elbows and feet."
The most common microorganisms on human skin are bacteria, and the least common are mushrooms. According to researchers, throughout the body and on the skin of the hands, Mushrooms genus Malassezia are the most common. On the contrary, the combination of Malassezia, Aspergillus, Cryptococcus, Rhodotorula and Epicoccum, among others, is most common on the skin of the legs.
Bacteria on the skin can serve to prevent the penetration of pathogenic microorganisms and the development of diseases, depending on which colonies are dominated. As the authors of the study are written: "Interactions between members of microbiota, both form a resident microbial community, and prevent colonization with pathogenic bacteria in the process, called" colonization resistance ". Under certain conditions, they continue, - bacteria that are usually useful for their owners can become pathogenic. Many common skin diseases are associated with changes in microbiota, which are called dysbiosis.
In the lungs
We often think about bacteria in the lungs only in the context of respiratory diseases. However, bacteria are present in healthy lungs. Some of the most common bacterial types in healthy lungs - Firmicutes, Bacteriodetes, Proteobacteria, Fusobacteria and Actinobacteria, according to the review from 2017. When the thin balance of bacterial populations in the lungs is broken, it can lead to the development of diseases such as asthma and chronic obstructive pulmonary disease. For example, with asthma, the number of bacteria Haemophilus and Neisseria increases, and the amount of Prevotella and Veillonella decreases. This confirms the hypothesis that the lung microbioma dysbioma can be the main cause of asthma. The team that submitted a review of 2017 emphasizes the need to further study the microbiota-related mechanisms that can affect the health of the lungs, noting that "future studies should take into account possible complex interactions between bacteria, viruses and mushrooms."
Man's microbis is a complex system, and researchers continue to learn more about his important role in human health and its diseases. In the future, scientists seek to dive deeper into the riddles of this microcosm.