Understanding probiotics and health Gemma Laws MSc Student Microbiology and Immunology Department The gut microbiota The name given to the total microbial population living in our intestine Bacteria, fungi, viruses Gut microbiota plays an important role in food absorption and may contribute to obesity It is important in the development of the immune system The gut microbiome has a role in health and disease 1
The gut microbiota The good bacteria: Break down food (complex sugars into simple sugars) Proteins into amino acids Allows us to absorb these nutrients Outcompete and suppress bad bacteria or pathogens The bad bacteria: Damage the gut walls Cause infection Cause inflammation The gut microbiome and health Disruptions in the gut microbiota underlies many gastrointestinal diseases Individuals with IBS and IBD may have a disruption in their gut microbiome Changing or manipulating our microbiome may influence our health Growing interest into probiotic research 2
Probiotics -What are they? An ingredient in yoghurt or kombucha A dietary supplement Live bacteria that are good or helpful Live microorganisms that when administered in adequate amounts confer a health benefit to the host - WHO Current marketing often portrays probiotics as one ingredient, However, there is a wide range of bacteria and yeasts that are probiotics Each will affect our bodies in different ways Types of probiotics Gut probiotics: Most common probiotic bacteria: Lactobacillus species (yogurt and fermented foods) Bifidobacterium species (dairy products) Yeasts Saccharomyces boulardii Oral probiotics Streptococcus salivarius BLIS K12 Format Pill, chewable tablet, drink, powder, lozenge, yoghurt 3
Why take probiotics? Reported health benefits: Contributes to a healthy gut, increases nutrient absorption Prevents diarrhoea Immune support prevent or reduce the severity of colds and flu Reduce irritable bowel syndrome symptoms Restore a healthy microflora after taking antibiotics Probiotics after antibiotics We destroy both good and bad bacteria Normal microflora will eventually re-establish, however this takes time So sometimes we can take good bacteria or probiotics after a course of antibiotics Bad bacteria examples: E. coli, Salmonella, Clostridia Often present in peoples bowel but are usually kept under control If allowed to grow unrestricted, they can cause disease (diarrhea, gastroenteritis) 4
How do they work? Increasing the integrity of the gut Promotes the secretion of mucus Prevents pathogenic adhesion and colonisation Outcompete pathogens Takes up available space and nutrients (competitive exclusion) Reduce bad bacteria getting through the gut wall and causing infection Probiotic bacteria How do they work? Lactic acid bacteria which are common probiotics can lower the ph in the gut due to the section of lactic acid Can inhibit pathogenic bacteria and prevent infection Produce bacteriocins X Molecules that kill bad bacteria 5
How do they work? Interact with the gut epithelial cells and beneficially stimulate the immune system Probiotics consumption reduced the incidence of cold and flu in school children Enhanced the immune system in elderly people Immune modulation Probiotic research Trials investigating probiotics usually involve: Administration of a probiotic / placebo Collecting faecal and or blood samples pre and post consumption Measuring a health outcome, e.g. changes in abdominal pain or incidence of sickness (colds and flu) t= 0 Pre sample (baseline) t= 2 weeks 3 months 6
Probiotic research and marketing Not all probiotic bacteria have been researched thoroughly Probiotics have varying effects Results can vary due to: Number of participants, differences in trial design, treatment duration, patient characteristics, dosage, the use of different bacterial strains Conflicting research raises doubts for consumers and health care professionals Global health supplement industry Recognize probiotic bacteria are different and will have different effects Guidelines vary between countries In NZ, it s sold as as functional food/ dietary supplement USA: dietary supplement or probiotic drug The category determines the required evidence for health claims Generalised statements improves digestive health Attractive for consumers, encourages sales 7
How to choose? Look at a companies website for research Clinical trials Peer reviewed articles Streptococcus salivarius (Blis) K12 Gram positive cocci Commensal bacteria of the oral cavity Secretes bacteriocin molecules that can kill pathogenic bacteria Protects against strep throat infections S. salivarius also colonizes the intestinal tract It is not known if K12 can stimulate a systemic immune response Scanning electron microscope image of S. salivarius K12 Blis Technologies Aim: Investigate if S. salivarius K12 stimulates an acute systemic immune response 8
Conclusions Probiotics may have health benefits in a range of gastrointestinal diseases Probiotics may also have benefits in healthy individuals Probiotic bacteria will affect us in individual ways Not all probiotics have been researched to the same extent Acknowledgements Roslyn Kemp Kemp lab Blis technologies Kirman lab Trial participants 9
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