Microbiota, importance and impact

The human body is populated by a vast array of micro-organisms, mainly bacteria, that we refer to as the microbiota. They are found on all areas of the body that are in contact with the outside world, such as our skin, mouth, nose, ears, throat, gut and reproductive organs. The composition of the microbiota is strongly linked to the area they populate, where they fulfil a significant role in protecting our health.

Bacteria as a human

The development of the microbiota starts right after birth, when a baby makes its first contact with bacteria in the birth canal1. The microbiota in the mother’s vagina plays an important part in this. Immediately after that, there is contact via the mother’s skin and eventually via her breast milk, which also contains a number of bacteria species. These bacteria are important for the development of the immune system2. Under normal circumstances, the micro-organisms that settle on and around our body are harmless and protect us from infections by bacteria that do not belong there. Bacteria in our gut also assist in the breakdown of food content that humans are unable to digest into absorbable components. These mainly concern short-chain fatty acids, the most important of which is butyrate. As an important food source for cells in the intestinal wall, butyrate contributes to a healthy gut and the effectiveness of the intestinal barrier. The microbiota is also needed for producing essential nutrients the body is unable to produce itself, such as certain vitamins (K, B12 folic acid) and amino acids3. The microbiota also produce neurotransmitters that influence a range of physiological and psychological aspects4.

In recent years, there has been a boom in research into the microbiota and their role in health and disease. The development of culture-independent analytics in particular, and especially DNA analytics, has greatly simplified microbiota research, thereby enabling large-scale research5.  This has led to significant new insights3. For instance, we now know that bacterial diversity in particular is one of the main indicators of a healthy microbiota6 7 8.

An unbalanced microbiota is also referred to as dysbiosis. Prolonged dysbiosis is associated with a range of diseases, including inflammations and throat, nose and ear infections, vaginal complaints, chronic bowel disease, obesity, cancer, asthma, diabetes and allergies9. Dysbiosis can have a number of causes. It can be the result of a not yet fully developed microbiota in young children. This gives pathogenic bacteria an opportunity to cause an infection, which can manifest as tonsillitis, otitis media or laryngitis. Other possible causes of dysbiosis are a weakened immune system, an inadequate or monotonous diet, persistent stressful situations, lack of exercise, or a combination of these factors. This can cause micro-organisms that would be harmless in a balanced microbiota to suddenly develop pathogenic properties. Examples are stomach ulcers caused by infections of the normally harmless bacterium Helicobacter pylori, or bacterial vaginosis, which is caused by bacteria also present in a healthy vaginal microbiota10. In addition, the use of antibiotics has a strong influence on the composition of the microbiota. A different form of dysbiosis can occur in the event of exposure to external pathogenic micro-organisms capable of crowding out the bacteria typical of a healthy microbiota (food poisoning, forms of eczema).

Microbiota management

Microbiota management involves measures aimed at maintaining a healthy, balanced microbiota,  and enables the control or prevention of microbiota-related conditions and diseases. A rigorous method for rebalancing the gut flora is faecal microbiota transplantation (FMT)11, in which the microbiota is largely replaced by the microbiota of a healthy donor.  The method has proved extremely effective in the treatment of antibiotic-related conditions12. And promising results have also been achieved in other conditions, demonstrating that microbiota management can in fact influence disease progression.

However, FMT does have its fair share of disadvantages. Apart from the treatment itself being fairly unpleasant, it is not entirely devoid of risks either. Each donor needs to be thoroughly screened to prevent the potential transmission of any pathogens or viruses present in the microbiota. In addition, there has not been sufficient research into the long‑term effects of FTM13. Microbiota management offers a promising perspective for many conditions but FTM, as it stands, does not seem to be the most suitable method.

Probiotics

7 different bacteria, multi species
Image of different bacteria

The microbiota is a complex ecosystem made up of many different bacteria, each fulfilling its own purpose. This suggests that effective microbiota management is only possible using a multibacterial approach, as is the case with FMT in which multiple bacterial species have different purposes. A number of probiotic strains are known to be capable of influencing the immune system. Other strains have been found to be beneficial for the intestinal barrier.  For that reason, it would be an obvious choice to use a combination of carefully selected strains for effective microbiota management using probiotics. This is also referred to as multispecies probiotics. Winclove has developed a number of multispecies probiotics with an indication-specific composition. They can be used as a food supplement, medical device and/or food for special medical purposes.

 

Please find enclosed some nice independent videos explaining the importance and possibilities of the human microbiota:

 

References

  • 1. Houghteling, P. D. & Walker, W. A. Why is initial bacterial colonization of the intestine important to infants' and children's health? Journal of pediatric gastroenterology and nutrition 60, 294-307 (2015).
  • 2. Gensollen, T., Iyer, S. S., Kasper, D. L. & Blumberg, R. S. How colonization by microbiota in early life shapes the immune system. Science 352, 539-544, doi:10.1126/science.aad9378 (2016).
  • 3. a. b. Ottman, N., Smidt H Fau - de Vos, W. M., de Vos Wm Fau - Belzer, C. & Belzer, C. The function of our microbiota: who is out there and what do they do? Front Cell Infect Microbiol 2, 104 (2012).
  • 4. Dinan, T. G. & Cryan, J. F. Microbes, Immunity, and Behavior: Psychoneuroimmunology Meets the Microbiome. Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, doi:10.1038/npp.2016.103 (2016).
  • 5. McCartney, A. L. Application of molecular biological methods for studying probiotics and the gut flora. Br J Nutr 88 Suppl 1, S29-37, doi:10.1079/bjn2002627 (2002).
  • 6. Muhleisen, A. L. & Herbst-Kralovetz, M. M. Menopause and the vaginal microbiome. maturitas 91, 42-50 (2016).
  • 7. Heiman, M. L. & Greenway, F. L. A healthy gastrointestinal microbiome is dependent on dietary diversity. Mol Metab 5, 317-320 (2016).
  • 8. Dreno, B. et al. Microbiome in healthy skin, update for dermatologists. . J Eur Acad Dermatol Venereol (2016).
  • 9. Shreiner, A. B., Kao Jy Fau - Young, V. B. & Young, V. B. The gut microbiome in health and in disease. Curr Opin Gastroenterol 31, 69-75 (2015).
  • 10. Nasioudis, D., Linhares, I. M., Ledger, W. J. & Witkin, S. S. Bacterial vaginosis: a critical analysis of current knowledge. LID - 10.1111/1471-0528.14209 [doi]. BJOG (2016).
  • 11. Fuentes, S. & de Vos, W. M. How to Manipulate the Microbiota: Fecal Microbiota Transplantation. Advances in experimental medicine and biology 902, 143-153 (2016).
  • 12. Rao, K. & Safdar, N. Fecal microbiota transplantation for the treatment of Clostridium difficile infection. J Hosp Med 11, 56-61 (2016).
  • 13. Koenigsknecht, M. J. & Young, V. B. Faecal microbiota transplantation for the treatment of recurrent Clostridium difficile infection: current promise and future needs. Curr Opin Gastroenterol 29, 628-632 (2013).