Probiotics

Question 1

What are probiotics?

Answer 1

live microorganisms which when administered in adequate amounts confer a health benefit to the host

Question 2

What is abiotics

Answer 2

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.

Question 3

What is prebiotics

Answer 3

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.

Question 4

What is synbiotics

Answer 4

Food ingredients or dietary supplements combining probiotics and prebiotics in a form of synergism

Question 5

There are four major categories of microbial populations in the gut

Answer 5

1. Autochthonous microbiota are populations of microbes that are present in large numbers and permanently colonize the host
2. Normal microbiota are microorganisms that are frequently in the gut, but can vary in number and be sporadically absent
3. Pathogens are microorganisms that are periodically acquired can persist and cause infection or disease
4. Allochthonous microbiota are microbes from another origin that are present temporarily (most probiotics are also allochthonous)

Question 6

Is e.coli always pathgenic?

Answer 6

•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

Question 7

Most probiotic formulations

Answer 7

• 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

Question 8

6 criteria for selection of probiotic strains

Answer 8

1. Origin of strains
2. Biosafety
3. Tolerance to Acid and Bile salts
4. Adhesion to intestinal cells
5. production of antimicrobial subtances
6. utilization of prebiotics

Question 9

Expand on origin of strains criteria selection

Answer 9

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.

Question 10

Expand on biosafety criteria fro selection of prebiotics

Answer 10

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).

Question 11

Expand on criteria: tolerance to acid and bile salts for probiotics

Answer 11

1. 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.

Question 12

Expand on adhesion to intestinal cells criteria for probiotics

Answer 12

Strains should be able to adhere to intestinal cells and colonize the GIT, at least temporarily

Question 13

Expand on the production of antimicrobial substances for probiotics

Answer 13

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.

Question 14

Expand on utilization of prebiotics for probiotics selection

Answer 14

4.The relationship between prebiotics and probiotics is also important. Probiotics should be able to use fructo-oligosaccharides (FOS).

Question 15

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:

Answer 15

1. 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
2. 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
3. Exclusion of Pathogens: Probiotics appear to inhibit the attachment of bacterial pathogens to the GIT epithelial cells by physically blocking the receptor sites.

Question 16

How probiotics can be beneficial to lactose digestion

Answer 16

Question 17

How probiotics can be effective for weight loss

Answer 17

Microbiota with less efficient energy use mechanisms

Question 18

How probiotics is effective against enteric pathogens

Answer 18

Colonization resistance, unfavorable conditions for pathogens (lower pH, bacteriocins, short-chain fatty acids)

Question 19

How probiotics are essential for anti-carcinogenic properties?

Answer 19

Antimutagenic activity (bind mutagens), lower pre-carcinogenic enzyme activities (nitroreductase, azoreductase) of colonic bacteria, influence on secondary bile salt concentrations

Question 20

How probiotics can be antihypertensive

Answer 20

Peptidase activity on milk produces a peptide that acts on angiotensin-1 converting enzyme inhibitor to lower blood pressure in hypertensive animals

Question 21

How antibiotics can be helpful against ulcers

Answer 21

LAB produce bacteriocins that are effective against H. pylori

Question 22

How probiotics can be effective against urogenital infections?

Answer 22

Adhesion to urinary and vaginal cells, competitive exclusion, production of inhibitors (biosurfactants, hydrogen peroxide)

Question 23

What probiotic mix was able to expand fruit fly life almost by two and potential outcomes

Answer 23

• A probiotic formulation that included L. plantarum,L. fermentum, and Bifidobacteria longum along with a prebiotic (Triphala) was able to almost double the lifespan of fruit flies
• The mechanism was through the gut-brain-axis of communication
• This means that it could potentially be a therapeutic tool in neurodegeneration, diabetes, obesity, cardiovascular disease and other age-related chronic diseases

Question 24

What is Ulcerative colitis and what bacteria is thought to play a role in it?

Answer 24

• Ulcerative colitis (UC) is a chronic inflammatory bowel disease, the underlying causes are unknown
• It is thought that pathogenic E. coli play a role in the establishment and in “flair-ups” of this disease (ANSC350)

Question 25

What is used right now to maintain remission of UC

Answer 25

•At the moment mesalazine is used to maintain remission in UC patients

Question 26

What is the proposed new solution for UC

Answer 26

* 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: 1. Direct antimicrobial effect (bacteriocins) 2. Bacterial-epithelial crosstalk 3. Immune-modulatory properties

Question 27

Are *S. thermophilus* and *L. bulgaricus* in yogurt probiotics?

Answer 27

Question 28

A bacteria that is able to colonize vagina following oral intake

Answer 28

* *L. rhamnosus* has been shown to colonize the vagina following oral intake * In a placebo-controlled trial of 64 healthy women given oral capsules of *L. rhamnosus* for 60 consecutive days: * Women who had the probiotic had a depletion of yeast at day 28 * Women who had the probiotic had a decrease in the coliforms present at day 28, 60, and **_90_**

Question 29

Who is Gregor Reid?

Answer 29

* Received 1.4 million dollars from Global Affairs Canada to start a company/ project called **_Fermented Food For Life_** * The project distributes one-gram sachets that contain probiotic *Lactobacillus rhamnosus* GR-1 bacteria and a unique *Streptococcus thermophilus* strain for approximately $0.50 each * Each sachet can produce 100 Litres of yogurt These sachets are distributed to “producers” who are “poor” women in ***Uganda, Kenya and Tanzania.*** The sachets provide an opportunity to begin businesses and earn a steady income, as the yogurt is very easy to produce.

Question 30

How probiotics are used in animal nutrition (give concrete examples with chickens and cattle)

Answer 30

* The primary health targets for agricultural animal probiotics are enhancement of animal growth, weight gain, and reduction in the carriage of human enteric pathogens * Reduced pathogen carriage is of significant interest because a reduction of pathogens at the farm level would result in a reduction in the risk of foodborne illness * Newly hatched chicks are generally inoculated with bacteria (a 29 species mixture) and this provides resistance to ***Salmonella*** * Cattle given a probiotic cocktail are also more resistant to ***E. coli*** **O157:H7** colonization

Question 31

Why probiotic studies are very limited and should be done better?

Answer 31

1. The effect of probiotics is likely small (smaller than with conventional drugs) and is likely confounded by age, diet, and lifestyle 2. Study results vary with the strains used, the population level of the probiotic cells delivered, the health marker targeted, and the number, age, and condition of the subject evaluated (we don’t know what the minimal dosage is, and we don’t know how frequently you would have to consume the organism to get the desired effect) 3. What are the biomarkers for a healthy GIT? No one can agree on this.

Question 32

Describe Seuz et al., 2018 study and what they found, what was bad and good

Answer 32

•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**

Question 33

What is probiotic regulation status in Europe

Answer 33

* Probiotics are not governed under specific regulatory frameworks * The Novel Foods Regulation act governs the introduction of newly discovered or genetically modified LAB * The EU parliament did adopt a new regulation that the health claims of foods must be accompanied by relevant scientific justification

Question 34

How probiotic are regulated in Canada?

Answer 34