sport science at nottingham trent university
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Getting to the guts of the matter - how changing the gut microbial population using diet may improve quality of life in a care home setting Dr Kirsty Hunter. Sport Science at Nottingham Trent University. 2. 01 August 2014. What causes ageing?. The two main theories of ageing are: - PowerPoint PPT PresentationTRANSCRIPT
Getting to the guts of the matter - how changing the gut microbial population using diet may improve quality of life in a care home setting
Dr Kirsty Hunter
22 April 2023 222 April 2023 2
Sport Science at Nottingham Trent University
22 April 2023 3
What causes ageing?
• The two main theories of ageing are:1. Programmed cell death – cell death is a genetically programmed
event2. Cellular wear and tear – ageing caused by an accumulation of
cellular damage• Cell death is probably caused by a combination of both• Rate of ageing determined by genetics, environment, and lifestyle• Generally accepted that genes only account for 25% of the
determinants of life length
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What is ageing?• Ageing results from impaired immune, genetic, neurological,
hormonal or antioxidant functions• These changes accumulate over time and are responsible for
increased susceptibility to disease and death
Ability of organs to perform
physiological functions decreases
Increased risk of malnutrition e.g.
PEM
Increase in disease
Number of cells and cellular
function decreases
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So, can we influence the rate at which we age?
• Yes, the ageing process is malleable – it may be possible to enhance the body’s natural mechanisms for protection and repair
• Human lifespan may be extended by decreasing exposure to damage, or by enhancing repair, perhaps through improved nutrition, improved lifestyle and modified environment
• Goals of successful ageing are:1. To increase life expectancy2. To increase the number of healthy years i.e. delay the onset
of age-related diseases/disorders• Nutrition is an important factor in achieving both of these goals
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How do physiological changes impact on nutritional status?
Influence of ageing on nutritional status
Appeal of food - reduction in sight, smell,
taste
Digestion and absorption
Nutritional requirements
Ability to obtain food
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The causes and consequences of malnutrition are interlinked
Decreased nutrient intakeIncreased nutrient need
Increased illness
Increased use of medications
Decreased immune function
MALNUTRITION
Decreased accessibility and safety of
food
Decreased muscle mass
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Nutrition has a significant impact on ageing
• Poor nutrition can contribute to a number of health problems including:
• Constipation and other digestive disorders
• Anaemia• Diabetes mellitus• Muscle and bone disorders
including osteoporosis, osteomalacia and osteoarthritis
• Overweight and obesity• Cardiovascular diseases • Declining mental health• Changes to the nervous system
and the immune system• Cataract • Some cancers e.g. breast,
prostate
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Another component of the body which changes are the microorganisms which live in the gut
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The Gastrointestinal Tract
• In our bodies there are 20 x more bacteria than human cells
•We carry around 1kg of bacteria•Gut problems take up significant GP time
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Gut microfloral profile
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Caecum
Ascendingcolon
Transverse colon
Descendingcolon
Rectum
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Distribution of bacteria on the gut wall
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Factors affecting colonisation and growth of bacteria in the gut
Physicochemical•Amount and type of
substrate•pH of gut contents•Redox potential
Microbial•Competition • Inhibition through end
products•Specific inhibitor
substances•Bile salts• Immunity
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F erm en ta tion b y C o lon ic B ac teria
O rg an ic A c id s(ac e ta te , p rop ion a te ,
b u tyra te , lac ta te , su cc in a te )A lcoh o ls
G as es(e .g . h yd rog en , m eth an e,ca rb on d ioxid e , s u lp h id es )
N itrog en ou s m etab o lites(e .g . p h en o lic c om p ou n d s ,
am m on ia , am in es )
S ta rch , N S P ,O lig os acc h arid es , P ro te in s
A m in o ac id s
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Metabolic Fate of Principal Carbohydrate End Products
•Acetate: metabolised in muscle, kidney, heart, brain•Propionate: cleared by the liver•Butyrate: metabolised by the colonic epithelium,
regulates cell growth•Lactate, ethanol, pyruvate: absorbed, electron sink
products•Hydrogen: partially excreted in breath, metabolised by
bacteria
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Metabolic Fate of Principal Protein End Products
Ammonia: formed by deamination of amino acids, detoxified by urea formation in the liver, induces quick cell turnover
•Phenols/indoles: produced from aromatic amino acids, may act as co-carcinogens
•Amines: formed by decarboxylation of amino acids, linked to migraine, cancer, schizophrenia
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Different bacteria use different substances as food and generate different end products
Different bacteria have different effects on body functions
Different bacteria have different effects on disease
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Enterococci
BifidobacteriaBacteroides
StreptococciLactobacilli
E. coli
ClostridiaSulphate reducers
Candida sp.Proteus sp.
Ps. aeruginosa2
11 No./g faeces (log scale)
Inhibition of growthof exogenous and harmful bacteria
Stimulate immune function
Digestion/ absorption of food ingredients &
minerals
Vitamin synthesis
Diarrhoea, constipation,infections, liver damage, cancer, toxigenesis,encephalopathy
Production ofcarcinogens
Intestinalputrefaction
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Gut Disorders
•Acute inflammation•Diverticulitis• Inflammatory bowel disease•Bowel cancer•Constipation•Food poisoning• IBS•Systemic????
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Balanced gut flora Dysbiosis
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Age related changes in gut microflora are caused by:
•Greater permeability of the gut wall•Reduced transit times•Secretion of acids by the stomach lining
•Reduced numbers of beneficial bacteria–Bifidobacteria, Eubacterium
•Increased numbers of putrefactive bacteria–Clostridia, Enterobacteria
What kind of changes occur?
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Could the microbial organisms that live in the gut impact on quality of life and disease in the elderly?
Can we beneficially change the types of gut microorganisms using food and drink?
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Influencing the ‘Balance’
PROBIOTICSA live microbial feed supplement which beneficially affects
the host
Examples: lactobacilli, bifidobacteria
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Commercially available probiotics
• Bio yoghurts• Fermented milks• Fortified fruit juice
Fairly short shelf life
Need refrigeration
Debate on numbers of live organisms
• Powders• Capsules• Tablets• Sprays
Longer shelf life
Storage easy
Labels often misleading
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The Alternative Approach
PREBIOTICS‘Non digestible food ingredients that selectively stimulate a
limited number of bacteria in the colon, to improve host health’
• (after Gibson and Roberfroid, 1995)
•Market leaders are the fructo-oligosacharides, galacto-oligosaccharides & the polysaccharide inulin
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Prebiotics
1. Must be stable under acidic conditionsand small gut secretions
2. Must get tothe colon intact
3. Must beselectivelymetabolised
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Vehicles for Prebiotics
•Beverages and fermented milks•Health drinks, spreads•Cereals•Biscuits*•Confectionery, cakes•Food supplements
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Issues with probiotics
•Species variability•Viability in the product•Contradictory results
Why prebiotics may be better
•Heat stable•Increases the host’s own gut microbial population•Not a living product so no issues of viability
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22 elderly subjects fed prebiotic powder for 10 weeks
Vulevic, 2008
• Increased numbers of Bifidobacterium spp., Lactobacillus spp, Enterococcus spp in faeces
•Lower numbers of Bacteroides spp, Clostridium spp, E. coli, Desulfovibrio spp.
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Effects on markers of immune status
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Synbiotics
Müller® Vitality® Apple & Prune 150g
Nutritional Values per 100g
Energy 415Kj (98kcal)
Protein 4.7g
Carbs 15.6g
Fat 1.9g
Calcium 150mg, 28% RDA per 150g serving
IngredientsYogurt, Sugar, Fruit (Apples (6%), Water, Prune Puree (4%), Inulin, Modified Maize Starch, Flavourings, Omega 3 from Refined Fish Oil, Acidity Regulators: Citric Acid, Sodium Citrates; Cultures: Sugar, Bifidobacterium sp., Lactobacillus acidophilus
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Enterococci
BifidobacteriaBacteroides
StreptococciLactobacilli
E. coli
ClostridiaSulphate reducers
Candida sp.Proteus sp.
Ps. aeruginosa2
11 No./g faeces (log scale)
Inhibition of growthof exogenous and harmful bacteria
Stimulate immune function
Digestion/ absorption of food ingredients &
minerals
Vitamin synthesis
Diarrhoea, constipation,infections, liver damage, cancer, toxigenesis,encephalopathy
Production ofcarcinogens
Intestinalputrefaction
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Potential uses of pro- & prebiotics in the elderly
Probiotics PrebioticsNutritionMalnutrition Possibly, based on results
from childrenCalcium absorption from the diet
GOS shown to be effective in PM women
Bowel problemsConstipation Helpful Lactulose well
established. Other substances show promise
Antiobiotic associated diarrhoea
Helpful Helpful
Immune system Some markers of immune function improved
Some markers of immune function improved
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Why are pro- and prebiotics an attractive proposal for use in residential care?
•Can be incorporated into food (commercially available or cooked on site)
•Virtually tasteless •Prebiotics are heat stable•Food ingredients not drugs•Few side effects•Many potential beneficial effects
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What do we need to do?
• Free-living versus residential care • Measure absence/presence of disease and functional markers• Quality of life markers• Nutritional status
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Thank you for listening