Probiotics Flashcards
Probiotics definition?
Live microorganisms which when
administered in adequate amounts confer
a health benefit on the host
preparations that contain viable, microbial agents that
have been demonstrated to improve health
typically, these products will contain freeze-dried
(lyophilized) or live bacteria or yeasts;
most commonly from the genera Lactobacillus and
Bifidobacterium
powders, capsules, tablets, lozenges, oils, medicinal
yoghurts, drinks
Food Sources of Live
and Active Cultures?
Includes
◦ fermented foods, such as non-medicinal yoghurts,
kombucha, sauerkraut, kim chi, kumis and kefir
these foods may contain a diverse community of microbes that
are not well-defined in terms of strain composition or stability;
both of which can also differ from batch to batch
strains contained in these foods may also lack specific
therapeutic qualities
e.g., they may not confer any health benefit on the host, beyond the
enhanced nutritional profile of the fermented food
wild ferments can’t be relied upon for therapeutic effects in
the same way as products containing standardized , wellcharacterised and well-researched probiotic strains
What 2 bacterial species are responsible for
the taste, consistency and smell that we associate with
yoghurt?
(Lactobacillus delbrueckii ssp.
bulgaricus and Streptococcus thermophilus)
What strains are routinely added to yogurt to enhance therapeutic effects?
Lactobacillus spp. and Bifidobacterium spp.
Uses of Probiotics
Traditional…?
◦ With/post antibiotics
◦ Irritable bowel syndrome
◦ Inflammatory Bowel Disease
◦ Gut infections
◦ Constipation
◦ Dysbiosis
◦ Lactose intolerance
◦ Intestinal permeability
◦ Vaginal thrush
Uses of Probiotics
Novel…?
◦ Cervical dysplasia
◦ Mastitis
◦ Endometriosis
◦ Prevention of
gestational diabetes
◦ Prevention of
postpartum obesity
◦ Prevention and
treatment of atopic
eczema
◦ Non-Alcoholic Fatty
Liver Disease
◦ Anxiety
◦ Depression
◦ Low immunity/
recurrent infections
◦ High cholesterol
◦ Gastrooesophageal
reflux
◦ Prevention of urinary
tract infections
◦ Treatment of bacterial
vaginosis
◦ Small intestinal bacterial
overgrowth (SIBO)
prevention & treatment
◦ Metabolic syndrome &
type 2 diabetes
◦ Obesity
◦ Food allergies
◦ Hayfever
Desirable Characteristics of probiotics?
- human origin
- Gastric acid and bile salt stability
- Adherence to intestinal mucosa
- Colonisation of intestinal tract
- Safety in food and documented clinical
safety - Production of anti-microbial compounds
- Antagonism against pathogenic organisms
- Clinically documented and validated health effects
- Increased shelf life and stability during processing
- Clinically documented and validated
health effects
Strains of bacteria within the same species
may vary in regards to:
◦ shelf stability
◦ resistance to gastric acid and bile salts
◦ adherence capacity & method of adherence
◦ colonisation capacity
◦ ability to produce anti-microbial compounds
- AND clinical efficacy
The most important facet in probiotic
prescribing is…..
administering the right
strain for the job
applications for lactobacillus plantarum PS128?
Anxiety
Insomnia
Autism
Gut motility
visceral hypersensitivity
How do probiotics work/help?
- Compete with potentially pathogenic bacteria and fungi along the GIT for the limited space that is available
◦ car park theory - Antagonism against potentially pathogenic microorganisms
◦ inhibit the effects of bacterial toxins
◦ produce anti-microbial substances that can selectively kill off
potentially pathogenic bugs and fungi
bacteriocins
hydrogen peroxide
other anti-microbial compounds
◦ bind to viruses (e.g., rotavirus)
preventing & shortening gut viral infections (Salminen et
al., 2010)
◦ reduce the expression of pathogen virulence factors via
inhibition of gene encoding - Interact with immune cells
◦ trains & balances the immune system
dampen allergy & hypersensitivity reactions and
intestinal inflammation
induces oral tolerance
may help prevent development of allergic diseases
◦ increase gut sIgA production
key protective antibody in the gut
◦ may modify allergens to less allergenic forms
induces & maintains oral tolerance - Produce beneficial compounds in the gut
◦ Short Chain Fatty Acids
help create a healthier colonic environment by
decreasing the pH (i.e., making it more acidic) and
some (e.g., butyrate) are used as energy sources by
colon cells
◦ Polyamines
help restore normal small intestinal architecture and
upregulate digestive enzyme function - Anti-inflammatory activity
◦ can secrete compounds with anti-inflammatory
properties (e.g., anti-TNF-α effects) (Ménard et al, 2004)
◦ they can interact with toll-like receptors (Rachmilewitz et al,
2004)
◦ down-regulate the transcription of a number of genes
encoding pro-inflammatory effectors (Tien et al, 2006)
◦ up-regulate production of anti-inflammatory
chemicals (cytokines) - Modify gut transit time
◦ two strains of bifidobacteria have been found to
significantly speed colonic transit time (Waller et al., 2011,
Meance, 2001)
◦ a strain of propionbacteria has been shown to slow
descending colon transit - Decrease visceral hypersensitivity
◦ some probiotic strains are capable of decreasing
visceral hypersensitivity (McKernan et al, 2010, Johnson et
al, 2011, AitBelgnaoui et al, 2006)
believed to be one of the main contributing factors to
IBS and other functional gastrointestinal disorders
◦ possibly via inducing cannabinoid and opioid
receptor expression in the colon cells - Strengthen the intestinal barrier
◦ can increase mucin (mucous) production in the gut
via increases in mucin gene expression
which provides a protective coating between the lumen
and intestinal epithelial cells - Alter Brain Chemistry
- Beneficially alter metabolism
◦ Decrease body-wide inflammation
◦ Improve intestinal permeability
◦ Improve blood sugar control
◦ Enhance sense of satiety
◦ Lower oxidative stress
What Defines a “Good” Probiotic
Supplement?
◦ 1) the characteristics of the strains contained in
the supplement
bacterial strains used should demonstrate all the desirable
characteristics
at a minimum all the essential characteristics
probiotic strains should demonstrate the action that is
required for the condition being treated
◦ 2) adequate viability
so that sufficient numbers of bacteria are viable at the point
of consumption
Probiotic Supplement Red Flags
Not listing the strain names on the label
Refuse to tell you the strain names or uses “secret” strains
Contains non-existent species
Research results are extrapolated from other strains onto the
ones contained in the product
◦ either from a different species or from strains within the
same species
◦ may show up in the product’s promotional material, where
the strain designations may be deleted from the clinical
trials being discussed/highlighted
note: this will sometimes require follow-up
investigation of references
Strain(s) provided in insufficient dosages
What are the probiotic myths?
- Myth # 1 – Research conducted on one
probiotic strain can be accurately
extrapolated to other strains within the
same species - FALSE due to evidence of strain specificity - Myth # 2 - Don’t use probiotics during
antibiotic treatment because the antibiotics
will kill all the probiotic bacteria - FALSE
Reality – research clearly shows that
concurrent administration not only
significantly decreases AB-related side
effects, but also attenuates AB-associated
damage to the gut microbiota
- Myth # 3 – Probiotic supplements are best
taken on an empty stomach - FALSE - Myth # 4 – Bacterial strains in your typical
probiotic supplement will permanently
colonise the gut after oral ingestion
Reality – research clearly shows that few
exogenously supplied probiotic strains
permanently colonise the human GIT
◦ in general you cannot “recolonise” with probiotic
supplements
◦ unless there is evidence for a specific strain
permanently colonising, it is very unlikely to!
- Myth # 5 – After a course of antibiotics (or
other gut insult) you can reinoculate or “reseed” your gut by eating fermented foods like kefir and kombucha - FALSE - Myth # 6 – Giving probiotics in supplement form (e.g., capsule, powder or tablet) is superior to food forms (i.e., yoghurt)
◦ False assumption 1 - supplements contain better strains of probiotic bacteria than yoghurts
False assumption 2 - supplements contain greater numbers of viable bacteria
- Myth # 7 – Taking probiotics with antibiotics slows the normalization/ restoration of the ecosystem - FALSE
