Probiotics Flashcards
What are probiotics?
live microorganisms which when administered in adequate amounts confer a health benefit to the host
What is 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.
What is 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.
What is synbiotics
Food ingredients or dietary supplements combining probiotics and prebiotics in a form of synergism
There are four major categories of microbial populations in the gut
- Autochthonous microbiota are populations of microbes that are present in large numbers and permanently colonize the host
- Normal microbiota are microorganisms that are frequently in the gut, but can vary in number and be sporadically absent
- Pathogens are microorganisms that are periodically acquired can persist and cause infection or disease
- Allochthonous microbiota are microbes from another origin that are present temporarily (most probiotics are also allochthonous)
Is e.coli always pathgenic?
•Although E. coli is sometimes considered a foodborne pathogen one specific strain E. coli Nissle (sold under the trade name Mutaflor) is considered a probiotic
Most probiotic formulations
- Probiotic preparations generally contain LAB and Bifidobacteria which are normal constituents of the human gastrointestinal microflora
- Lactobacillus and Bifidobacterium species are generally considered to be beneficial to the health of their human hosts
- However, the use of other microorganisms is also possible: Sometimes the yeast Saccharomyces boulardii is used
6 criteria for selection of probiotic strains
- Origin of strains
- Biosafety
- Tolerance to Acid and Bile salts
- Adhesion to intestinal cells
- production of antimicrobial subtances
- utilization of prebiotics
Expand on origin of strains criteria selection
One criteria originally proposed was that all strains should be from human origin. However, LAB exist in diverse environments, and now it’s the biochemical activity that’s considered, not the origin.
Expand on biosafety criteria fro selection of prebiotics
Lactobacillus and Bifidobacteria have low pathogenic potential. Enterococcus can contain opportunistic pathogens. The use of intestinal isolates raised the concern of biosafety. The organism must be generally recognized as safe (GRAS).
Expand on criteria: tolerance to acid and bile salts for probiotics
- Tolerance to Acid and Bile Salts: Probiotic strains must be tolerant to acid and bile salts in order to reach the GIT (specifically the colon)
An exception to this situation is when probiotics are sold in enteric-coated capsules designed to reach the colon (Escherichia coli strain Nissle)
*** There is also evidence that milk and yogurt provide some protection to probiotic microorganisms.
Expand on adhesion to intestinal cells criteria for probiotics
Strains should be able to adhere to intestinal cells and colonize the GIT, at least temporarily
Expand on the production of antimicrobial substances for probiotics
4.LAB produce a number of substances that are inhibitory to other bacteria including: lactic acid, hydrogen peroxide, and bacteriocins. Lactic acid also lowers the pH of the colon, and this low pH affects the ability of pathogenic bacteria to grow in the colon and vagina. Hydrogen production is also particularly good at discouraging urogenital infections.
Expand on utilization of prebiotics for probiotics selection
4.The relationship between prebiotics and probiotics is also important. Probiotics should be able to use fructo-oligosaccharides (FOS).
The mechanism of action is not fully understood, but studies indicate that there are three major avenues through which probiotic cultures have beneficial activities on the GIT:
- Interaction with the Immune System: Some probiotics appear to shift the production of cytokines from the inflammation-inducing interleukin-12 pathway to the anti-inflammatory IL-10 pathway
- Strengthening the Mucosal Barrier: Dysfunction of the GIT barrier can lead to inflammatory bowel disease, some probiotics enhance this barrier by encouraging production of protective proteins such as mucins
- Exclusion of Pathogens: Probiotics appear to inhibit the attachment of bacterial pathogens to the GIT epithelial cells by physically blocking the receptor sites.
How probiotics can be beneficial to lactose digestion
What is the proposed new solution for UC
- There are several peer-reviewed studies indicating that E. coli Nissle is almost as effective as mesalazine in maintaining remission of UC
- There are three proposed mechanisms:
- Direct antimicrobial effect (bacteriocins)
- Bacterial-epithelial crosstalk
- Immune-modulatory properties
Are S. thermophilus and L. bulgaricus in yogurt probiotics?
Describe Seuz et al., 2018 study and what they found, what was bad and good
•Examined, in both mice and humans, the effects of an 11-species probiotic or an FMT, administered after antibiotic consumption, on the GIT community structure.•Used an invasive endoscopic technique•The probiotic better colonizes after antibiotic treatment in both humans and mice•The probiotic delays the return of the indigenous microbiome•The probiotic delays the return to a homeostatic mucosal transcriptome
What if other combination was used?little participants
How probiotic are regulated in Canada?
