Changes

The collection of living microorganisms (bacteria, fungi, protozoa and viruses) that inhabit a specific environment are referred as the '''microbiota or microbiome''', (the latter referring to the microorganisms and their genes) and are terms which now supersede the outdated ‘microflora’.

The collection of living microorganisms (bacteria, fungi, protozoa and viruses) that inhabit a specific environment are referred as the '''microbiota or microbiome''', (the latter referring to the microorganisms and their genes) and are terms which now supersede the outdated ‘microflora’.

These microbes form complex and dynamic associations with humans, animals and plants that range from mutually beneficial to commensal or pathogenic.

These microbes form complex and dynamic associations with humans, animals and plants that range from mutually beneficial to commensal or pathogenic.

Mutually beneficial organisms are organisms from two different species that exist together and each provides the other with some benefit from their individual activity. An example of this would be ''Ruminococcus'', a cellulose-digesting bacteria present in herbivores: the host provides these bacteria with a constant supply of nutrients (from fibre), and in return the bacterial products of digestion (primarily glucose) supply the host with energy and nutrition from a food source they would otherwise be unable to utilise.

Mutually beneficial organisms are organisms from two different species that exist together and each provides the other with some benefit from their individual activity. An example of this would be ''Ruminococcus'', a cellulose-digesting bacteria present in herbivores: the host provides these bacteria with a constant supply of nutrients (from fibre), and in return the bacterial products of digestion (primarily glucose) supply the host with energy and nutrition from a food source they would otherwise be unable to utilise.

Commensal organisms are those that benefit from the host without affecting the host in any way (positively or negatively). This term is, however, controversial amongst many biologists who do not truly believe that an organism can ‘take’ from another organism without exerting any change at all; this theory promotes the idea that all commensal organisms must have some mutualistic or parasitic effect on the host, no matter how subtle or small that effect may be.

Commensal organisms are those that benefit from the host without affecting the host in any way (positively or negatively). This term is, however, controversial amongst many biologists who do not truly believe that an organism can ‘take’ from another organism without exerting any change at all; this theory promotes the idea that all commensal organisms must have some mutualistic or parasitic effect on the host, no matter how subtle or small that effect may be.

This imbalance to the normal, diverse equilibrium of micro-organisms is termed a dysbiosis.<ref>Older CE, Rodrigues Hoffmann A, Hoover K, Banovic F. Characterization of Cutaneous Bacterial Microbiota from Superficial Pyoderma Forms in Atopic Dogs. Pathogens 2020; 9(8):638 </ref><ref>Hata TR, Gallo, RL. Antimicrobial peptides, skin infections, and atopic dermatitis. Semin Cutan Med Surg 2008; 27(2):144–150</ref>

This imbalance to the normal, diverse equilibrium of micro-organisms is termed a dysbiosis.<ref>Older CE, Rodrigues Hoffmann A, Hoover K, Banovic F. Characterization of Cutaneous Bacterial Microbiota from Superficial Pyoderma Forms in Atopic Dogs. Pathogens 2020; 9(8):638 </ref><ref>Hata TR, Gallo, RL. Antimicrobial peptides, skin infections, and atopic dermatitis. Semin Cutan Med Surg 2008; 27(2):144–150</ref>

Pathogenic or parasitic organisms are those that will gain some benefit from the host but simultaneously cause some degree of harm in the process. The microbiota provides protection against colonisation by these pathogenic microorganisms through a number of complex mechanisms, however occasionally organisms can override this microbial barrier, out-competing the commensal community resulting in infection or disease.<ref>Rolhion N, Chassaing B. When pathogenic bacteria meet the intestinal microbiota. Phil. Trans. R. Soc. B 2016; 371 (1707): 20150504</ref> Factors such as antibiotic administration can reduce colonisation resistance against pathogens<ref>Kennedy EA, King KY, Baldridge MT. Mouse Microbiota Models: Comparing Germ-Free Mice and Antibiotics Treatment as Tools for Modifying Gut Bacteria. Front Physiol 2018; 31(9):1534</ref>, and germ- free mice have shown a greater susceptibility to epithelial injury in induced colitis.<ref>Hernández-Chirlaque C, Aranda CJ, Ocón B et al. Germ-free and Antibiotic-treated Mice are Highly Susceptible to Epithelial Injury in DSS Colitis. Journal of Crohn's and Colitis 2016; 10(1):1324–1335</ref> Thus, the importance of a harmonious and diverse microbiota in preventing the proliferation of pathogenic species and driving normal gut development is widely accepted.

Pathogenic or parasitic organisms are those that will gain some benefit from the host but simultaneously cause some degree of harm in the process. The microbiota provides protection against colonisation by these pathogenic microorganisms through a number of complex mechanisms, however occasionally organisms can override this microbial barrier, out-competing the commensal community resulting in infection or disease.<ref>Rolhion N, Chassaing B. When pathogenic bacteria meet the intestinal microbiota. Phil. Trans. R. Soc. B 2016; 371 (1707): 20150504</ref> Factors such as antibiotic administration can reduce colonisation resistance against pathogens<ref>Kennedy EA, King KY, Baldridge MT. Mouse Microbiota Models: Comparing Germ-Free Mice and Antibiotics Treatment as Tools for Modifying Gut Bacteria. Front Physiol 2018; 31(9):1534</ref>, and germ- free mice have shown a greater susceptibility to epithelial injury in induced colitis.<ref>Hernández-Chirlaque C, Aranda CJ, Ocón B et al. Germ-free and Antibiotic-treated Mice are Highly Susceptible to Epithelial Injury in DSS Colitis. Journal of Crohn's and Colitis 2016; 10(1):1324–1335</ref> Thus, the importance of a harmonious and diverse microbiota in preventing the proliferation of pathogenic species and driving normal gut development is widely accepted.

The mammalian microbiota is comprised of 10-100 trillion microbial cells, outnumbering host cells by 10 to 1 and in humans adding over 8 million genes to our set of 22,000. Our understanding of the microbiota it still in its infancy, however its huge impact on host physiology is clear and the symbiotic relationship that exists between the host and microbiota has led to a new paradigm in our consideration of this system; is the microbiota actually a ‘virtual organ’ in its own right?

The mammalian microbiota is comprised of 10-100 trillion microbial cells, outnumbering host cells by 10 to 1 and in humans adding over 8 million genes to our set of 22,000. Our understanding of the microbiota it still in its infancy, however its huge impact on host physiology is clear and the symbiotic relationship that exists between the host and microbiota has led to a new paradigm in our consideration of this system; is the microbiota actually a ‘virtual organ’ in its own right?

[[File:ProtexinVeterinary.jpg|thumb|201x201px|In Partnership With Protexin Veterinary]]

[[File:ProtexinVeterinary.jpg|thumb|201x201px|In Partnership With Protexin Veterinary]]