Millions of organisms form a protective layer on the surface of our body and within the cavities connected to the outside, like the mucous membranes of the respiratory and digestive systems, vaginal mucosa, etc. This is the microbiota, an organ in its own right. Although we cannot see it, our health depends on its correct functioning.
Composition of the microbiota
The first bacterial colonisation takes place at birth, when the baby comes into contact with the vaginal and skin bacteria of the mother. It has been shown that the sooner this colonisation occurs, the better will the microbiota perform its functions. At a later stage, other factors such as diet, use of antibiotics, living with older siblings, in the countryside or in an urban environment, having pets in the family, among others, will determine the amount and diversity of the bacteria, fungi, viruses and protozoa that constitute the microbiota. Each individual has a microbiota composition of his own, a characteristic pattern. A disturbance of this pattern or dysbiosis can lead to disease.
The microbiota’s immune function
In addition to its digestive, metabolic and neuro-endocrine functions, the microbiota plays a key role in the defence of the organism since it is in direct contact with the outside.
– Commensal bacteria produce mucin and antimicrobial peptides hindering the entry of pathogens and controlling their replication. They also contribute to maintaining the intercellular junctions of the mucosal epithelium to secure a physical barrier and prevent intestinal permeability, i.e. foreign molecules crossing the intestinal lumen.
– Dendritic cells, immune cells specialised in detecting foreign elements, are trained through their interaction with commensal bacteria, triggering cellular and humoral immunity and promoting the secretion of IgA antibodies that detect the entry of pathogens into the mucosa.
– The microbiota regulates the function of lymphoid cells, thereby promoting adaptive immunity and tissue repair and controlling inflammation.
Taking care of your microbiota
Promoting the diversity and balance of your microbiota is key for intestinal tolerance.
– Watch your diet: rather than excluding food of animal origin, increase the variety and amount of vegetables. A varied diet ensures a stable microbiota. Fibre from fruit and vegetables, cereals and dried fruit, is the gut flora’s main source of food. Intestinal bacteria are responsible for digesting it, producing short chain fatty acids beneficial for health.
– Avoid fats and processed foods rich in additives and preservatives, since these are proinflammatory and detrimental to the balance of the intestinal milieu.
– If needed, use prebiotics (resistant starch, inulin, among others), probiotics (yeasts such as Saccharomyces, Lactobacillus or Bifidobacteria) and synbiotics (prebiotics+probiotics with a greater effect than separate intake). Their integration into diet is being studied as a possible treatment for diseases such as antibiotic-associated diarrhoea, baby colics, diabetes, among others. In such cases, treatment should not be initiated without consulting an attending nutritionist.
Would you like to discover more about Micro-immunotherapy?
Discover more about micro-immunotherapy, a treatment to regulate immune function and cellular metabolism towards homeostasis by contacting us at email@example.com
If you are a doctor, a member of a specialist medical group or a therapist take this opportunity to request free and non-binding access to our professional area and enjoy additional content.
- Belkaid Y, Harrison OJ. Homeostatic Immunity and the Microbiota. Immunity. 2017 Apr 18;46(4):562-576. doi: 10.1016/j.immuni.2017.04.008. PMID: 28423337; PMCID: PMC5604871.
- Julia Álvarez, José Manuel Fernández Real, Francisco Guarner, Miguel Gueimonde, Juan Miguel Rodríguez, Miguel Saenz de Pipaon, Yolanda Sanz. Microbiota intestinal y salud.Gastroenterología y Hepatología,Volume 44, Issue 7,2021,Pages 519-535,ISSN 0210-5705. https://doi.org/10.1016/j.gastrohep.2021.01.009.
- Holscher HD. Dietary fiber and prebiotics and the gastrointestinal microbiota. Gut Microbes. 2017 Mar 4;8(2):172-184. doi: 10.1080/19490976.2017.1290756. Epub 2017 Feb 6. PMID: 28165863; PMCID: PMC5390821.
- C. Petersen and J. L. Round, “Defining dysbiosis and its influence on host immunity and disease,” Cell. Microbiol., vol. 16, no. June, pp. 1024–1033, 2014.
- K. Brown, D. DeCoffe, E. Molcan, and D. L. Gibson, “Diet-induced dysbiosis of the
- S. K. Mazmanian and Y. K. Lee, “Interplay between intestinal microbiota and host immune system,” J. Bacteriol. Virol., vol. 44, no. 1, pp. 1–9, 2014.
- N. Cerf-Bensussan and V. Gaboriau-Routhiau, “The immune system and the gut microbiota: friends or foes?,” Nat. Rev. Immunol., vol. 10, no. 10, pp. 735–744, 2010.
- T. Hrncir, et al. “Gut microbiota and lipopolysaccharide content of the diet influence development of regulatory T cells: studies in germ-free mice.,” BMC Immunol., vol. 9, no. 1, p. 65, Jan. 2008.
- M.-A. von Schillde, et al. “Lactocepin secreted by Lactobacillus exerts anti-inflammatory effects by selectively degrading proinflammatory chemokines.,” Cell Host Microbe, vol. 11, no. 4, pp. 387–96, Apr. 2012.
- J. L. Round and S. K. Mazmanian, “The gut microbiota shapes intestinal immune responses during health and disease.,” Nat. Rev. Immunol., vol. 9, no. 5, pp. 313–23, May 2009.