Probiotics Flashcards
Probiotics are defined as ________________________
live microorganisms which when administered in adequate amounts confer a health benefit to the host
Give the definition of abiotics
Typically consist of probiotic strains that have been inactivated by lysis, heat, or UV irradiation and have demonstrated some effectiveness in downregulating the inflammatory response in intestinal epithelial cells.
Give the definition prebiotics
Prebiotics are non-digestible carbohydrates that act as “food” for probiotics. Prebiotics help probiotics grow and remain in your digestive system. Not all non-digestible carbohydrates are prebiotics. All prebiotics must meet specific scientific criteria.
Give the definition of synbiotics
Food ingredients or dietary supplements combining probiotics and prebiotics in a form of synergism
What are the 4 major categories of microbial populations in the gut:
1) Autochthonous microbiota
2) Normal microbiota
3) Pathogens
4) Allochthonous microbiota
What are autochthonous microbiota?
They are populations of microbes that are present in large numbers and permanently colonize the host
What are Normal microbiota?
Microorganisms that are frequently in the gut but can vary in number and be sporadically absent
What are pathogens?
Microorganisms that are periodically acquired can persist and cause infection or disease
What are allochthonous microbiota?
Microbes from another origin that are present temporarily (most probiotics are also allochthonous)
Probiotic preparations generally contain ____ and __________ which are normal constituents of the human gastrointestinal microflora
LAB
Bifidobacteria
Which E.coli strain is considered a probiotic?
E.coli Nissle
Saccharomyces ___________ is used in probiotic formulations
boulardii
What are the criteria for selection of probiotic strain? (6)
1) Origin of strains
2) Biosafety
3) Tolerance to acid and bile salts (in order to reach the GIT specifically the colon)
4) Adhesion to intestinal cells
5) Production of antimicrobial substances (hydrogen peroxide, lactic acid and bacteriocins produced by LAB
6) Utilization of prebiotics (probiotics should be able to use fructo-oligosaccharides)
What are the mechanisms of action of probiotics in the GIT? (3)
1) Interaction with the immune system (shift cytokine production from IL-12 to antinflammatory IL-10)
2) Strengthening the mucosal barrier (produce protective proteins like mucins)
3) Exclusion of pathogens (inhibit the attachment of bacterial pathogens to the GIT epithelial cells by physically blocking the receptor sites)
Name a few proposed health outcomes from using probiotics :
- Lactose digestion
- Weight loss
- Resistance to enteric pathogens
- Reduction of ulcers
- Anti-carcinogenic
