22- Microbiota Flashcards
How does the presence of a dense microbial population on surfaces ensure that the immune system operates optimally on the skin?
Essential for all animals as it helps maintain essential oils and plays ‘guard’ in the first line of immune defense. The normal skin microbiota is necessary for optimal skin function, modulating the innate immune response and preventing colonization
How does the presence of a dense microbial population on surfaces ensure that the immune system operates optimally on the respiratory tract?
The airway microbiota plays a role in resistance to respiratory infections as well as the development of asthma and chronic obstructive pulmonary disease
In the absence of microbiota, the airways are prone to mount exaggerated TH2 responses. The presence of microbiota induced Treg activity that suppresses this. This explains the protective effects of healed antigens on the development of allergies.
How does the presence of a dense microbial population on surfaces ensure that the immune system operates optimally on the genitourinary/reprodutive tracts?
The urinary bladder is free of bacteria. The canine urinary bladder is not a sterile environment and possesses its own unique microbiota.
Protection via lactic-acid producing bacteria and lining of squamous cells rich in glycogen source for lactobacilli.
The microbiome in the repro tract is not fully understood.
How does the presence of a dense microbial population on surfaces ensure that the immune system operates optimally on the GI tract?
For ruminants, the balance of the microbes is important as any disturbances can lead to rumen acidosis. In the case of hind gut fermenters, their biomes need to be monitored in their cecum, disturbances in this balance can lead to acute laminitis
Identify the functional role of the microbiota in nutritional efficiency.
At birth, the digestive tract is sterile. Colonized by microbes within the first days and colonization is dependent on diet. Foals will eat their mothers manure to replenish their digestive flora and promote a healthy life
Identify the functional role of the microbiota in intestinal protection.
Microbiota blocks colonization by pathogenic bacteria by covering the surface and secreting inhibiting substances such as acids
Identify the functional role of the microbiota in the development of lymphoid organs.
Begins in the GI tract before birth and matures after bring born. They bring in B cells that secrete IgA. Leading to an influence on adaptive immunity. Germ-free animals have smaller Peyer’s patches, mesenteric lymph nodes, fewer CD4+T cells therefore, less B cells and IgA production.
Identify the functional role of the microbiota in microbiota signals to the body
Interaction between microbiota and the host’s immune system is essential to the proper functioning of the innate and adaptive immune responses. Imbalances have profound effects on the functions of the immune system.
Butyrate and others: Suppresses macrophages and promote Treg production, influences goblet cell differentiation and mucus production
Describe why the microbiota does not trigger excessive inflammation in the intestinal epithelium.
There is potential to trigger massive acute inflammation, but this must not happen unless necessary. There needs to be balance between pro-inflammatory TH17 cells and anti-inflammatory Treg cells
Describe the hygiene hypothesis
Lack of early childhood exposure to infectious agents, symbiotic microorganisms and parasites increase susceptibility to allergic diseases by suppressing the natural development of the immune system
