We are not alone in our bodies — approximately 100 trillion bacteria accompany us throughout our lives. The entirety of these microorganisms is called the human microbiome. Its largest part is found in the intestines and is known as the gut flora. But not only the digestive tract — the oral cavity, skin, scalp, and vagina also contain a rich collection of bacteria.
Probiotherapy is based on the assumption that the microbiome is a central element, and the human organism is treated as a holobiont — a complex organism formed by the coexistence of eukaryotic cells and microorganisms. All these organisms work closely together and mutually support one another. Although most studies focus on the digestive system, we must not forget the microbiome present in other areas — on the skin, in the vagina, and in the oral cavity. By the way, did you know that the composition of the microbiome varies significantly depending on its location?
Until recently scientists did little research on the human microbiome. The influence of the microbiome on human development, physiology, immunity and food was largely unknown. In 2008 the National Institutes of Health (USA) launched the Human Microbiome Project (HMP). Their mission is to identify the human microbial communities and to analyse their role in relation to health and disease.
Studies have shown that the microbiome begins developing even before birth — small amounts of bacteria are present in the uterus, placenta, and amniotic fluid. Although the fetus is exposed to bacteria already in the womb, the most important colonizing bacteria reach it during natural childbirth — through the mother’s birth canal. These bacteria are crucial for building a strong microbiome and a well-functioning immune system.
Human cells make up only 43% of the total number of cells in the body — the remaining 57% are bacteria, fungi, and unicellular eukaryotes living in our intestines, oral cavity, on the skin, and in the female reproductive system. Altogether, we have more than 1.5 trillion bacteria!
The composition of the microbiome varies greatly depending on its location in the body. Around 400 species of bacteria can be found in the digestive tract, while the vagina contains “only” about 300. Many factors influence microbiome diversity — environment, diet, and genetics. Someone living in the desert will have a different microbiome than someone living by the sea. Interestingly, microbiomes tend to be similar among relatives or people living in the same household.
The proportions and types of bacteria differ from person to person — the microbiome is as individual as a fingerprint.
Interest in the microbiome — especially probiotics — is growing at a rapid pace. This is driven by increasing scientific research and growing public awareness. The market for pharmabiotics and probiotics is developing dynamically, especially in products supporting the digestive system and healthy digestion. At the same time, the demand for safe OTC (over-the-counter) products is rising, which translates into greater investment in companies involved in genomic research.
Interesting scientific source:
Mitchell CM, Haick A, Nkwopara E, et al. Colonization of the upper genital tract by vaginal bacterial species in nonpregnant women. Am J Obstet Gynecol. 2015 May;212(5):611.e1–9. doi:10.1016/j.ajog.2014.11.043. Epub 2014 Dec 16. PubMed PMID: 25524398; PubMed Central PMCID: PMC4754962.
