Description: Join us for an enlightening presentation on the fascinating world of probiotics. Delve into the microscopic universe of beneficial bacteria that reside within us and discover how they contribute to our overall well-being. From improving digestion and boosting immunity to their potential influence on mood, this presentation will explore the science behind probiotics and their impact on human health. Gain insights into selecting the right probiotics for you, understanding strain diversity, and making informed choices for a balanced and vibrant life. Don’t miss this opportunity to uncover the secrets of a harmonious gut microbiome and its profound effects on your health.

1. Probiotics in Health & Disease
Hawler Medical University
College of Medicine
Microbiology Unit
Twana Omar

2. Outlines
• Introduction
• Definition
• Characteristics of Effective Probiotics
• Roles of Probiotics on health
• Side Effects
• Factors Altering the Gut Microbiota
• Probiotics and disease Prevention/Treatment
• References

3. In the complex world of the human
body, a healthy gut is like a
foundation for good health. Inside
this tiny world, different
microorganisms affect digestion,
immunity, metabolism, and even
how we feel.
Two important parts that help keep
this tiny world in balance are
Prebiotics and Probiotics.
Introduction

4. Definition
• Probiotics are live microorganisms that are intended
to have health benefits when consumed or applied to
the body. They can be found in yogurt and other
fermented foods, dietary supplements, and beauty
products.
• A Dietary Prebiotic is 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. Found in typically high-fibre foods such as
whole grains

5. • Viability: Probiotics must be alive and able to survive the
digestive process.
• Adhesion: They should adhere to the gut lining to exert their
benefits.
• Safety: Probiotics should be safe for consumption and not cause
harm.
• Activity: They should have the ability to influence the gut
environment positively.
• Strain-specific effects: Different strains of probiotics may have
varying benefits.
Characteristics of Effective Probiotics

6. Benefits & Roles of Probiotics
• Probiotics, mostly lactic acid bacteria and their food variants,
provide various important nutritional and remedial health benefits
to the consumers such as anticarcinogenic and antimutagenic
activity.
Probiotics maintain or restore the balance of host-microbial association and
therefore reduce intrusion and colonization of pathogens.
They can change the local environment directly by secreting short-chain fatty
acids (SCFAs), bacteriocins, lactic acid, and reactive oxygen species that
suppress the growth of pathogens.
1- Competition with Pathogens

7. 2- Production of Metabolites
Several species of the gut microbiome impart the production of SCFAs and
various vitamins (nicotinic acid, thiamine biotin, vitamin B12, folate,
pyridoxine, and vitamin K). Moreover, probiotic microorganisms also produce
butyrate which plays a major source of energy for enterocytes and is involved
in the wear and tear of the gastrointestinal wall.
3- Immunomodulatory Effects
Probiotics have diverse positive effects on the immune system such as immune-
stimulatory by inducing IL-12 and also have natural killer (NK) cell immunity.
Others are considered to be immune-regulatory due to their ability to regulate
T cell pathways and stimulation of interleukin IL-10.
Also some strains may performing as pro-inflammatory while others as anti-
inflammatory agents on the immune system.

8. 4- Removal of Contaminants/Heavy Metals
Some probiotics have the ability to lower the risk of ingested heavy metals and
hazardous chemicals. Cell wall of probiotic bacteria plays an important role in
the removal of metals.
The bacterial cell wall binds to the metals by using three main mechanisms:-
• firstly, by ion exchange reactions with teichoic acid and peptidoglycan
• secondly, by nucleation reactions causing precipitation
• and thirdly, by forming complexes with oxygen and nitrogen ligands. For
example, Pediococcus pentosaceus destroy fumonisins, cluster of
mycotoxins produced by fungi.

9. 5- Metabolism of Xenobiotics and Drugs
Several studies showed that pollutants from dietary and environmental
chemicals interfere with gut bacterial function and therefore can induce a pro-
inflammatory response and affect host health. Supplementation of probiotics
can further help gut flora to effectively metabolize various drugs and even
xenobiotics.
E.g Conversion of Sulindac into active compound sulindac sulfide by gut
microbes like E.coli, Enterobacter, Proteus spp …etc

10. 6- Bile Acid Metabolism
Primary bile acids are deconjugated and dehydrated by some
species of the gut microbiota—like Bacteroides intestinalis—and
convert them into secondary bile acids.
Secondary bile acids are responsible for inhibition of spore
germination in Clostridium difficile and, hence, restrain the growth
of vegetative forms of C. difficile.

11. Are There Any Risks Related To Probiotics?
Probiotics are generally considered safe. However, there are some
risks linked to the supplements, especially if you have a medical
condition that weakens your immune system.
Unlikely, but possible, risks can include:
• Developing an infection.
• Developing a resistance to antibiotics.
• Developing harmful byproducts from the probiotic supplement.
• Health risks due to contamination of supplements by other
microorganisms.
Probiotics

12. • A Diet rich in Refined Carbohydrates:
• Bad Sleep Habit:
Factors Affecting Gut Microbiota
E.g White bread, white pasta, white rice, sugars and even artificial
sweeteners.
After consumption of a Western diet, the gut microbiota ferment amino
acids, which result in production of short-chain fatty acids as energy sources,
and harmful compounds can be produced
Chronic disturbance and lack of sleep can alter the gut microbes metabolism
and replacing the good bacteria such as Lactobacilli spp by pathogenic
bacteria such as Baceriodes, Inflammation and endocrine hormones play
important roles in this process.

13. • Antibiotics:
• Stress:
When you use antibiotics inappropriately or overuse them on your
own, You actually kill that good microorganisms and can make an
environment suitable for overgrowth of harmful bacteria.
• High stress levels can also have harmful effects on the body. In the gut,
stress can increase sensitivity, reduce blood flow and alter the gut
bacteria.
• One study in humans looked at the effect of stress on the composition
of gut bacteria in 23 college students.
• The high stress associated with final exams caused a reduction in
friendly bacteria, including Lactobacilli.

14. Probiotics and disease treatment/prevention
• Probiotics can help maintain a balanced gut microbiota, Support digestion,
Boost the immune system & Influence mental health
• They may also aid in managing conditions like :
• Hypertension
• Urogenital Infections
• Cancer
• Irritable Bowel Syndrome (IBS)
• Allergies.
• Antibiotic Associated Diarrhoea
• Hypercholesterolemia and many more…

15. • Probiotics and their products impact cholesterol and blood
pressure by mechanisms like insulin resistance and renin-
angiotensin modulation.
• They've been shown to lower blood pressure and heart rate in
hypertensive patients.
• Tripeptides from probiotics inhibit angiotensin-converting
enzymes, reducing blood pressure.
• Regular probiotic consumption might serve as a preventive
measure against heart disease due to its effects on blood
pressure and cholesterol.
1- Hypertension:

16. 2- Urogenital Infections:
• Urogenital infections result from imbalances in vaginal environment and
can lead to various issues. Lactobacillus species are crucial for
protecting urogenital cells and maintaining vaginal health.
• Probiotic microorganisms like Lactobacillus acidophilus, L. crispatus,
and others are used to eliminate recurrent bacterial vaginosis and treat
urinary tract infections.
• Probiotics stimulate immune responses, lower vaginal pH, and produce
antimicrobial substances.
• They help prevent vaginal infections and recolonize lactobacilli in the
vaginal tract. Lactobacilli play a key role in suppressing pathogenic
bacteria and preventing urogenital infections in women.

17. 3- Cancer:
• Abnormal genes, variations, and exposure to chemicals contribute to
cancer development.
• Probiotics can reduce exposure to chemical carcinogens by
detoxification and altering intestinal conditions.
• Probiotics generate compounds that inhibit tumor cell expansion,
enhance programmed cell death, and activate the immune system.
• Studies suggest probiotics may inhibit colon cancer by deactivating
mutagenic compounds, generating antimutagenic substances, and
improving immune functions.
• Utilization of fermented dairy foods with probiotic cultures like
lactobacilli or bifidobacteria is linked to reduced breast and colon
cancer occurrence.

18. • Bifidobacterium decreases intestinal pH, inhibiting enteropathogens
and displaying antitumor properties.
• Lactobacillus casei strain Shirota and Lactobacillus GG stimulate the
immune system, reducing tumor growth.
• Probiotics like Lactobacillus acidophilus, Bifidobacterium longum,
and L. helveticus show anticancer activity against various tumors.
• Fermented milk with L. delbrueckii ssp. bulgaricus starter culture
exhibits antimutagenic activity.

19. • IBS is a persistent gastrointestinal disorder characterized by symptoms
like abdominal pain, bloating, flatulence, and diarrhea.
• Causes of IBS include factors like food ingestion, abnormal nutrient
absorption, and psychosomatic disorders, affecting the gastrointestinal
tract’s motor function.
• Probiotics have shown promise in alleviating IBS symptoms.
• Clinical trials indicate that various lactic acid bacteria species, such as
Saccharomyces boulardii, can reduce stomach ache, bloating,
flatulence, and constipation.
• Another study found a significant decrease in IBS symptoms in an
experimental group consuming a milk drink with a mixture of probiotic
strains.
4- Irritable Bowel Syndrome

20. • Overall, probiotics offer a potential avenue for managing IBS symptoms,
although their effectiveness may vary based on the specific bacterial
strains used.
5- Allergies
• Microflora Alteration: Probiotics modify the gut’s microenvironment by
changing the local microflora, impacting the immune response.
• Cytokine Regulation: Consumption of probiotics influences cytokine
production. They stimulate Th1 cytokine response, which suppresses Th2
responses, crucial in allergic reactions.
• Toll-Like Receptors (TLRs): Probiotics interact with TLRs and recognition
proteins in the gut lining, triggering dendritic cells and promoting a Th1
response, which counteracts allergic reactions.

21. • Immune System Stimulation: Probiotics stimulate B and T cell responses
specific to allergens, boosting mucosal IgA levels, which helps mitigate the
effects of allergic diseases.
• Anti-Inflammatory Action: Probiotics upregulate anti-inflammatory cytokines
like interleukin-10, aiding in down-regulating inflammation during
hypersensitivity reactions.
• T Regulatory Cells: Probiotic-host interactions stimulate T regulatory cells
and the production of cytokines like IL-10, contributing to immune regulation.
• IgA Production: Consumption of probiotics enhances IgA production in
areas like Peyer’s patches, which helps combat potentially harmful antigens.
• Protein Digestion: Probiotics aid digestion of proteins, including those
responsible for food allergies, reducing the likelihood of allergic reactions.

22. • Eczema Relief: In infants, supplementing with probiotics like Lactobacillus
rhamnosus GG has been shown to decrease the occurrence of eczema,
possibly due to the regulation of immune responses.
6- Antibiotic Associated Diarrhea:
• Antibiotic-associated diarrhea (AAD) is caused by an imbalance in gut
microflora due to antibiotics.
• AAD can lead to osmotic diarrhea due to reduced breakdown of
carbohydrates and short chain fatty acids.
• Probiotics like Lactobacillus strains and Saccharomyces boulardii help
prevent AAD by restoring gut microbiota.
• Probiotics compete with pathogens for binding sites, produce metabolites
to inhibit pathogen growth, and block their attachment.
• Studies show that certain probiotic combinations reduce C. difficile related
diarrhea.

23. • Probiotics like Streptococcus thermophilus, Lactobacillus rhamnosus GG,
and Bifidobacterium bifidum are effective against nosocomial diarrhea in
newborns.
• Various probiotic strains have shown benefits against different types of
diarrhea, including travelers' diarrhea and rotavirus-associated diarrhea.
7- Hypercholesterolemia
• Cholesterol affects cardiovascular disease risk.
• LDL carries cholesterol to arteries, while HDL takes it to the liver.
• Probiotics impact cholesterol through various mechanisms by
increasing:-

24. •Meta-analyses show probiotics lower total and LDL cholesterol.
•Specific strains like Lactobacillus acidophilus, mixtures, and Lactobacillus
plantarum are effective.
• Still more researches needed.
• Bile salt hydrolase activity, which increases the need for new bile acids and
thus reduces serum cholesterol levels.
• Binding of cholesterol in the small intestine, which reduces the amount that
the body absorbs.
• Assimilation and incorporation of cholesterol into bacteria, thus lowering
cholesterol levels in blood;
• Production by lactobacilli and bifidobacteria of short-chain fatty acids, which
lower hepatic cholesterol synthesis and regulate cholesterol metabolism.

25. • Advances in Probiotics for Sustainable Food and Medicine
References
• https://www.nccih.nih.gov/health/probiotics-what-you-need-to-
know#:~:text=Probiotics%20are%20live%20microorganisms%20that,di
etary%20supplements%2C%20and%20beauty%20products.
• https://my.clevelandclinic.org/health/articles/14598-probiotics
• https://ods.od.nih.gov/factsheets/Probiotics-HealthProfessional/#h3
• https://youtu.be/scDmziIwUEY. From a doctor licensed in the US

26. Thank You