Probiotics

Question 1

Abiotics

Answer 1

Consist of probiotic strains that have been inactivated by lysis, heat or UV irradiation and have demonstrated some effectiveness in downregulation the inflammatory response in intestinal epithelial cells.

Question 2

Prebiotics

Answer 2

non digestible carbohydrates that act as food for probiotics. Prebiotics help probiotics grow and remain in your digestive system. Not all carbs are prebiotics. all prebiotics must meet specific scientific criteria

Question 3

synbiotics

Answer 3

food ingredeints or dietary supplements combining probiotics and prebiotics in a form of synergism.

Question 4

strictly name the 4 major categories of microbial populations in the gut

Answer 4

1. autocthonous microbiota
2. normal microbiota
3. pathogens
4. allochtonous

Question 5

autochthononous microbiota

Answer 5

populations of microbes that are present in large number and permantly colonize the host.

Question 6

normal microbiota

Answer 6

commonly found in the gut, they can vary in number and be sporadically absent

Question 7

pathogens

Answer 7

periodically aquired can persist and cause infection or disease

Question 8

allochtonous microbiota

Answer 8

microbes from another origin that are present temporarily (probiotics)

Question 9

probiotic preperations typically contain

Answer 9

LAB and bifidobacteria which are normal constituents of the human GI microflora.

Question 10

name the 6 criterias for selection of probiotic strains.

Answer 10

1. origin of strains
2. biosafety
3. tolerance to acid and bile salts.
4. adhesion to intestinal cells
5. production of antimicrobial susbtances
6. utilization of prebiotics

Question 11

name the mechanism of action of probiotic cultures

Answer 11

3 major avenues through which probiotics cultures have beneficial activities in the GIT.

1. interaction with the immune system, 2.strengthening of the mucosal barrier
2. exclusion of pathogens

Question 12

how do probiotics interact with the immune system?

Answer 12

some probiotics appear to shift the production of cytokines from the inflammation-including interleukin-12 pathways to the anti inflammatory IL-10 pathway.

Question 13

how do probiotics strenghten the muscosal barrier?

Answer 13

dysfunction of the GIT barrier can lead to inflammatory bowel disease and some probiotics enhance this barrier by encouraging production of protective proteins such as mucins

Question 14

how to probiotics exclude pathogens in the GIT?

Answer 14

inhibit attachment of bacterial pathogens to the GIT epithelial cells by physically blocking the receptor sites.

Question 15

Name 4 proposed health outcomes and suspected mechanisms due to probiotics

Answer 15

lactose digestion = lactase activity by probiotic cultures

weight loss = microbiota with less efficient energy use

resistance to enteric pathogens = colonization resistance, unfav conditions

reduction of ulcers = LAB produce bacteriocins that are effective against H.pylori

Question 16

what types of antimicrobial substances are produced by probiotic strains?

Answer 16

• lactic acid, hydrogen peroxide and bacteriocins. lactic acid also lowers pH of the colon and this low pH affects ability of pathogenic bacteria to grow in the colon and vagina.
• hydrogen production is also particularly good at discouraging urogenital infections

Question 17

The relationship between prebiotics and probiotics is important. probiotics should be able to use _____.

Answer 17

FOS

Question 18

what probiotic formulation was used to double the lifespan of fruit flies?

Answer 18

Lplantarum, L fermentum and Bifidobacteria longum along with prebiotic (Triphala)

Question 19

Explain how Ecoli nissle could be used to treat Ulcerative colitis

Answer 19

Ulcerative colitis is a chronic inflammatory bowel disease. It is thought that pathogenic Ecoli play a role in flair ups. Mesalazine is currently used to treat patients however Ecoli nissile is proposed to be as effective in maintaining remission of UC through 3 mechanism

1. direct antimicrobial effect
2. bacterial-epithelial crosstalk
3. immmune-modulatory properties

Question 20

Are S thermophillus and L bulgaricus in Yogurt Probiotics

Answer 20

Yes; both species have beta glycosidase activities and eating yogurt improves lactoses digestions and eliminates symptoms of lactose intolerance.

No; 2 species are not usually considered probiotics since they are not known to proliferate in the intestines. They are called transient, they do not colonize the GIT, they may have beneficial activities in the GIT, although they do not remain there long enough to be considered probiotics.

Question 21

What are L rhamonosus

Answer 21

colonize vagina following oral intake. depletion of yeasts.

Question 22

Who is George Reid and what did he start?

Answer 22

professor. He found that oral probiotics improve vaginal health and prevent UTIs. Started fermented food for life which distributes 1 grams sachets that contain probiotic Lactobacillus rhamnosus GR-1 bacteria and S. thermophillus.

Question 23

example the use of probiotics in animal nutrition

Answer 23

used in agricultural production and companion aimals to enhance growth, weight gain, reduce carriage of human enteric pathogens

Question 24

what are the limitations of probiotic studies?

Answer 24

the effetcs are likely small and is likely confounded by age, diet, and lifestyle

• study results vary with the strain used and the pop level of probiotic cells delivered, the health marker targeted and the age etc.
  3. limited biomarkers

Question 25

what are the regulations with respect to probiotics in europe

Answer 25

not governed under specific regulatory frameworks

Question 26

what are the regulations with respect to probiotics in Canada?

Answer 26

they can be added to food products, list of marketing statements you can make for the organisms. they are classified as food. health benefit must be supplied evidence to health canada.