Natural FlorA

Micro biome: collection of all different genomes of microorganisms in an environment Microbiota: collection of all different microorganisms in an environment Normal flora: all microorganisms associated with a healthy individual commensals Pathobionts: disease causing organisms that are non-harming under normal conditions Biofilms: aggregates of microorganisms Micro biome the bacterial populations that form our micro biome differs between different anatomical sites Biofilms: Microorganisms in the human body exists as both planktonic cells and biofilms, self-produced and from host material aggregates of bacteria surrounded by extra cellular materials, bacteria can communicate with each other by quorum sensing Natural flora: Important for protection from invading microbes, present in large numbers and can block competitors and produce anti microbial substances Immune stimulation- production of surface antibody IgA in mucous membranes Human nutrition & metabolism- gut flora i.e. E-coli synthesise vitamin K which produce enzymes which can break down bile salts & sex hormones to allow re absorption Micro biome is linked to a. Number of diseases gut micro biome linked to ibs, obesity, diabetes, dementia, Alzheimer’s Opportunistic infections changes in the host environment can be caused by antibiotics, viral infection etc, bacteria which are a natural part of our flora cause infection pathobionts due to these changes Many things can influence this flora including: Antibiotics- once administered for infections they may kill natural flora which in infants can effect healthy development of micro biome Smoking- significant changes to respiratory and gut microbiota maybe the result of deficient immune responses Breast feeding- mothers milk consumption may effect development as formulas do not contain the same constituents Environment- immediate environment can influence i.e. air pollution Viral infections, vaccines, diets etc Upper respiratory tract: Bacteria continuously enter through breathing Most bacteria trapped in the mucus of nasal & oral passages and expelled by ciliary beating Some bacteria colonise the host mucosa in URT i.e. staphylococci, streptococci, diptheroic bacilli, gram -ve cocci Adenoids First line of defence against bacteria and viruses, important in childhood immunity, harbour healthy microbiota but plays a role in various URT infections, shrink as we age Lower respiratory tract: Sterile environment however, it has a micro biome and microorganisms in LRT thought to originate from URT. Ciliary bating pushed bacteria towards URT where they are expelled or swallowed Skin: Average 2m2 has numerous different micro environments which have different conditions such as temperature, pH, moisture, sebum content. Approximately 1 million bacteria per cm2 skin, different habitats harbour different environments. Other factors such as personal hygiene, age, weather, pet contact may influence micro biome of skin too Children have more varied skin microbiota than adults -ve bacteria potentially Skin supports ammonia-oxidising bacteria, ammonia on skin produces nitric oxide which controls harmful bacteria. Fungi is also found on the skin Oral cavity: Heterogenous complex microbial habitat, saliva as a source of nutrients present in low concentrations and also containing antibacterial enzymes such as lysozyme and lacteoperoxididase. Food and cell debris provide high conc of nutrients near gum and teeth and create a favourable environment for microorganisms 1st year of life, predominantly by aero tolerant anaerobes i.e.e streptococci, when teeth appear there is a shift to anaerobes. Bacteria attach to the teeth as individual bacteria and form micro colonies, thick layers form biofilms or dental plaque and the thicker, the more species can grow Gastrointestinal: 400m2 surface area 1013 microbial cells with stomach, small and large intestine GI tract- host and microorganisms share nutrients & diet and oral antibiotics scan effect gut flora Small intestines have species adapted to rapid changes in nutrient availability Micro environments with large intestine = numerous largely anoxic environment promoting obligate anaerobes growth Bacteria = 1/3 faeces weight ' Urogenital tract: Upper regions of UI in booth male and females are sterile in healthy individuals however, there are some regions where microorganisms can grow Epithelial cells lining urethra are colonised by gram -ve rods and cocci Opportunistic pathogens i.e.e E-coli present in small numbers can multiply ion the urethra and become pathogenic Lactobacillus acidophilus= resident organism of vagina Others include years i.e.e Candida and streptococci