Lecture 1: Probiotics

Question 1

What is a probiotic?

Answer 1

“Live microorganisms which when administered in adequete amounts, confer beneficial health effect on the host” - UN and WHO (2002)

Question 2

who promoted the use of probiotics?

Answer 2

Elie Metchinkoff

Question 3

How many microbes are there in a healthy gut?

Answer 3

10^14

Question 4

Explain how bacteria can fit on spectrum of opportunistic and beneficial

Answer 4

Bacteria can often be either opportunisitc (harmful), beneficial, or both.

Question 5

How can you isolate probiotics?

Answer 5

Isolate them using a selective media. For example, some are anaerobic (Bifidobacteria), some are microaerophilic (Lactobacilli), some are aerobic (Bacillus)

Question 6

How are bacteria often identified? Why in this way?

Answer 6

using 16s ribosomal RNA gene. It is present in all life forms, with conserved and variable regions of DNA.

Question 7

Give two examples of commercial probiotic products. What probiotics do they claim to contain?

Answer 7

Yakult (Lactobacillus casei Shirota)

Actimel (Lactobacillus casei Immunitas)

Question 8

What are 4 key categories of probiotics. Include 2 examples within each.

Answer 8

Lactobacilli - Lactobacillus acidophilus & casei
Bifidobacteria - Bifidobacterium bifidum & longum
Yeast - Saccharomyces cerevisiae & bouardiii
Others - Streptococcus thermophilus & Bacillus subtilis

Question 9

What are the requirements of probiotics?

Answer 9

1. contain sufficient live good bacteria
2. stable and viable to survive from manufacturing to consumption
3. survive stomach acids
4. survive bile acids
5. provide health benefits
6. safe for human consumption

Question 10

What are 4 case studies where probiotics show an improvement in health

Answer 10

1. Eczema (reduction compared to placebo in eczema cases of children with eczema mothers)
2. Inflammatory bowel disease (100% of control suffered Pouchitis relapse, only 15% relapsed in probiotic group)
3. Neonatal necrotic enterocolitis (NEC) (cases and severity of NEC far reduced)
4. COVID 19 (w/in 72hours, remission of diarrhoea and other symptoms)

Question 11

How can probiotics improve immune response to illness (such as SARS-CoV-2)?

Answer 11

maintain the immune homeostatic balance by preventing cytokine storms

Question 12

What are prebiotics?

Answer 12

“a selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health”

Question 13

What are three requirements of prebiotics?

Answer 13

1. resist gastric acidity, hydrolysis by mammalian enzymes and absorption
2. fermented by intestinal microbiota
3. stimulated selectively the growth and/or activity of intestinal bacteria associated with health

Question 14

What are some examples of prebiotics

Answer 14

Fructo-oligosaccharides: insulin and oligofructose (FOS)
Galacto-oligosaccharides (GOS)
Soybean oligosaccharides
Lactulose, Lactosucrose
Xylo-oligosaccharides
Isomalto-oligosaccharides

Question 15

What do prebiotics claim to do?

Answer 15

• stimulate growth of good gut bacteria
• increase calcium absorption = bone density
• improve immune system
• etc

Question 16

Give one key example of a prebiotic being studied

Answer 16

Bergamot (Citrus bergamia Risso)

Question 17

What are synbiotics?

Answer 17

Probiotics + prebiotics

Question 18

Give an example of a studies into synbiotics

Answer 18

Prevention of sepsis in infants of rural India.

Reduction of: death and sepsis, diarrhoea, and local infections

Question 19

What is the future of probiotics.

Answer 19

• Stricter regulation of probiotic claims
• Evidence based market product
• Specific design of probiotic for specific benefit (SMART probiotics)
• Understanding of probiotic function

Question 20

What is the commercial issue with probiotics

Answer 20

False claims about how they can help and inappropriate use such as in mattresses