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Title: Topics in nutrition and food science.


1
Topics in nutrition and food science.
  • Dr M. Altamimi

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Characteristics of Modern life
  • Urbanisation
  • Ready to eat food, fast food and processed food.
  • High calories (fat and carbohydrate) low fibre.
  • Low in vitamins and minerals.
  • Packaging. Not natural preservation.
  • Refrigeration and freezing.
  • Less physical activity.

4
  • Office based jobs.
  • Chronic diseases, obesity etc.
  • Aging, people live longer.

5
  • Diet together with physical exercise plays a
    major role when we try to prevent or postpone the
    onset of chronic conditions such as the metabolic
    syndrome.
  • The food industry has already reacted to this
    challenge and a large number of products have
    been either reformulated or re-positioned to meet
    the current need for healthier foods.

6
WHO
  • Chronic diseases are diseases of long duration
    and generally slow progression. Chronic diseases
    are by far the leading cause of mortality in the
    world, representing 63 of all deaths. 36 million
    people died from chronic disease in 2008.

7
Noncommunicable diseases
  • Cardiovascular diseases account for most NCD
    deaths, or 17 million people annually, followed
    by cancer (7.6 million), respiratory disease (4.2
    million), and diabetes (1.3 million). These four
    groups of diseases account for around 80 of all
    NCD deaths, and share four common risk factors
  • tobacco use
  • physical inactivity
  • the harmful use of alcohol and
  • poor diets.

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Bad habits
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Stages of life and R F
  • In the uterus
  • intrauterine growth retardation (IUGR)
  • premature delivery of a normal growth for
    gestational age fetus
  • over nutrition in utero
  • Intergenerational factors.

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  • Infancy
  • Retarded growth in infancy can be a reflected in
    a failure to gain weight and a failure to gain
    height. Both retarded growth and excessive weight
    or height gain can be factors in later incidence
    of chronic disease. Such as CVD
  • There is increasing evidence that among term and
    pre-term infants, breastfeeding is associated
    with significantly lower blood pressure levels in
    childhood.
  • Consumption of formula instead of breast milk in
    infancy has also been shown to increase diastolic
    and mean arterial blood pressure in later life.
    Obesity

(type 1 diabetes, coeliac disease, some childhood
cancers, inflammatory bowel disease) have also
been associated with infant feeding on
breast-milk substitutes and short-term
breastfeeding
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  • Childhood
  • low growth in childhood and an increased risk of
    CHD has been described, irrespective of size at
    birth.
  • Relative weight in adulthood and weight gain have
    been found to be associated with increased risk
    of cancer of the breast, colon, rectum, prostate
    and other sites.
  • Higher blood pressure in childhood (in
    combination with other risk factors) causes
    target organ and anatomical changes that are
    associated with cardiovascular risk, including
    reduction in artery elasticity.
  • High blood pressure in children is strongly
    associated with obesity,

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  • Most chronic diseases are present at later period
    of life - the result of interactions between
    multiple disease processes as well as more
    general losses in physiological functions (due to
    risk factors)
  • lack of oxygen and adapted metabolism.

13
Angiogenesis
  • Angiogenesis is a process of new blood vessel
    growth that occurs in the human body at specific
    times in development and growth.
  • Although crucial for embryonic development and
    wound healing, angiogenesis also contributes to
    disease, such as in the growth of solid tumors,
    chronic inflammation, atherosclerosis, ischemia,
    and diabetic retinopathy.

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Inducers
  • A number of inducers of angiogenesis have been
    identified, there is an emerging concept that
    reactive oxygen species (ROS such as )

superoxide anion O2- hydroxyl radical (OH-),
lipid radical (LOO-), peroxy radicals (XOO-)
and singlet oxygen (O-).
Free radicals
ROS are products of mitochondrial respiration
(energy production).
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Dietary sources of ROS
  • High fat diet and deep fries
  • High sucrose (or refined carbohydrates )diet
  • Protein sugar in high temperature (glycation)
  • Low fruit and veg. diet
  • Low vitamin and mineral diet (antioxidant).

Life style stress, pollution, smoking and low
activity.
18
Golden rule
  • More free radicals chronic diseases faster
    aging.
  • Less free radicals healthier body.

19
How to slow down generation of Free radicals?
  • Homework.

20
Comparison
B
A
Distance 10,000 km Fuel consumption 50,000
liter
Distance 200, 000 km Fuel consumption 1000,000
liter
Waste? Maintenance? Type of fuel?
21
The challenges for nutrition in the twenty-first
century
  • 1. Application of new scientific knowledge in
    nutrition.
  • 2. Improved scientific knowledge on dietdisease
    relationships.
  • 3. Exponential increase of health-care costs.
  • 4. Increase in life expectancy.
  • 5. Consumer awareness of nutrition and health
    relationships.
  • 6. Progress in food technology.

22
Functional foods
History
Japan 1940-1950 economical food with minimal
nutrients. 1950-1970 safe and hygienic food with
better taste. 1970- 1980 convenient food. Easy
or precooked food. 1980- Food for specific
health use (foshu). 1990 - Functional food.
(project)
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  • The project also proposed for the first time the
    new concept of functional food and defined food
    functions as primary (nutritional), secondary
    (sensory) and tertiary (physiological). Food with
    physiological functions was of particular
    interest, because such food would be useful for
    improving the health of the general public

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Definition
  • no simple, universally accepted definition of
    functional food exists. Examples
  • food and drink products derived from naturally
    occurring substances consumed as part of the
    daily diet and possessing particular
    physiological benefits when ingested.
  • food derived from naturally occurring substances
    that can and should be consumed as part of the
    daily diet and that serve to regulate or
    otherwise affect a particular body process when
    ingested.
  • food similar in appearance to conventional food,
    which is consumed as part of a usual diet and has
    demonstrated physiological benefit and/or reduces
    the risk of chronic disease beyond basic
    nutritional functions.

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The main aspects of this working definition are
  • the food nature of functional food that is not a
    pill, a capsule or any form of dietary
    supplement
  • the demonstration of the effects to the
    satisfaction of the scientific community
  • the beneficial effects on body functions, beyond
    adequate nutritional effects, that are relevant
    to improved state of health and well-being and/or
    reduction of risk (not prevention) of disease
  • the consumption as part of a normal food pattern.

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F F Science
  • By reference to the new concepts in nutrition
    outlined above, it is the role of functional food
    science to stimulate research and development of
    functional foods

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Claim promise of improvement
  • Disease reduction claims meaning
  • consumers have difficulties to differentiate
    between the terms disease risk reduction and
    prevention of diseases.

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How to write a claim
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EFFECT OF FOOD PROCESSING ON FUNCTIONALITY OF
FOODS
In foods containing vastly different
phytochemicals, the physiological activity due to
food processing may be a result of more than one
mechanism. Consequently, there may be a
decrease, increase, or a slight change in the
content and functionality of phytochemicals.
No/slight effect carotenoids comprising of
b-carotene and lycopene are generally stable to
heat treatments encountered in blanching,
cooking, and pasteurization/sterilization.
Interactions between polyphenols and ascorbic
acid may slow the degradation of the latter
during storage.
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Decrease in content and activity of
phytochemicals a classic example is that of the
technological indicator, ascorbic acid, which
is by far the most sensitive nutrient, and can be
damaged during most treatments. Chemical and/or
enzymatic oxidations are reported to decrease the
antioxidant efficacy of polyphenolics, while
leaching into the cooking water is mainly
responsible for loss of folates.
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Heat processing of Brassica vegetables of the
Cruciferae family greatly reduces their
functionality . Manufacture of black tea causes
a higher degree of enzymatic aerobic oxidation of
flavonoids, resulting in lower antioxidant
activity. Some processing operations such as
peeling and juice clarification can remove the
polyphenolics .
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Increase in content and activity of
phytochemicals partially oxidized
polyphenolics that result during food processing,
have been recently shown to exhibit higher
antioxidant activity than the corresponding
non-oxidized forms, due to increased ability to
donate a hydrogen atom
A moderate increase in carotenoid bioavailability
and enhanced phytochemical nutrient function in
cereal processing
36
Examples of functional ingredients
Vitamin antioxidant mineral premixes tomato
powder, garlic powder, onion powder, spice mixes
amino acids, chitosan Omega-3-fatty acids (fish
and flax seed) whey protein powder Guarana
extract, G. biloba extract, ginseng extract,
rosemary probiotics natural antioxidants (from
tea) shield liquid antioxidants vegetable
peptones
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essential fatty acids concentrates performance
proteins natural fruit based flowering
compounds natural colours total extracts of
medicinal plants antioxidants soy ingredient,
soy proteins, soy protein hydrolysate soya
protein isolate concentrate super critical
extracts of spices and herbs glutamine
peptides lactoferrin, milk calcium lycopene,
garcinia, raw herbs whey protein concentrate
wheat fiber, b-carotene A. vera gel powder.
38
Risk factor or state Design a Functional Food
CVD
osteoporosis
diabetes
Irritable bowl syndrome (IBD)
Pregnant woman
39
OXIDATIVE STRESS AND ROS
  • Oxidative stress rusting of tissues.
  • Oxidative stress is imposed on the body s cells
    when the level of ROS outweighs the reducing
    capacity of antioxidant and antioxidative stress
    mechanisms

ROS
40
Sources of ROS
  • Endogenous sources of ROS
  • tissue injury
  • via auto - oxidation reactions in the presence of
    transition metal ions. Fe 2 or Cu
  • during cytochrome P450 cycling.
  • at inflammatory sites by activated and
    phagocytes.

41
  • Exogenous sources of ROS
  • Exposure to ultraviolet (UV) radiation.
  • Overexercise.
  • Extrinsic xenobiotics found in tobacco smoke.
  • Heavy metals.
  • Organic pesticides.
  • Lipid hydroperoxides in particular are
    potentially toxic products of peroxidized
    polyunsaturated fatty acids (PUFAs) derived from
    dietary fats.
  • Compounds present in foods such as transition
    metal ions, heme from meats, isoprostanes,
    additives, lipids,

42
DEFENSE SYSTEMS
Endogenous antioxidants and antioxidative defenses
  • Glutathione ( GSH )
  • tripeptide of ? glutamylcysteinylglycine.
  • directly scavenge free radicals or act as a
    substrate.
  • GSH present in foods and secreted in the bile can
    contribute to GSH concentrations in the
    intestinal lumen.

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  • Antioxidative stress enzymes
  • glutathione peroxidase (GPx).
  • glutathione S -transferase ( GST ).
  • Catalase
  • Additional antioxidants
  • uric acid.
  • bilirubin - bound albumin, and albumin itself.
  • Histidine - containing peptides such as
    carnosine.
  • Melatonin.
  • Amino acids, peptides, and even proteins.
  • Se, Zn, Cu, Mn and riboflavin can all have
    co-factor functions for one of the above enzymes.

44
Phytochemicals with antioxidant activities
  • Polyphenols
  • 5000 polyphenols and over 2000 flavonoids having
    been identified.
  • Phenolic acids, Flavonoids, Lignans

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  • Amides
  • strong antioxidants capsaicinoids in chili
    peppers.
  • Carotenoids
  • Lycopene, ß carotene, xanthophylls such as
    zeaxanthin.

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Mechanism of action
  • direct radical scavenging
  • (2) downregulation of radical production
  • (3) elimination of radical precursors
  • (4) metal chelation
  • (5) Inhibition of xanthine oxidase
  • (6) elevation of endogenous antioxidants.

Curcumin and flavonoids have been shown to
upregulate intracellular GSH synthesis and
increase antioxidant enzyme activities
50
METABOLISM AND BIOAVAILABILITY OF FLAVONOIDS
  • The extent of absorption of dietary polyphenols
    in the small intestine is relatively small.
  • Bacterial enzymes may catalyze several reactions.
  • Anthocyanins were found in the cerebellum,
    cortex, hippocampus. important for learning and
    memory.

51
Antioxidant and C D
  • CVD
  • Antioxidant prevent LL oxidation.
  • Cancer
  • Block activation to carcinogens.
  • DNA repair.
  • Inhibit the formation and growth of tumors.

52
Dietary Fiber
  • Dietary fiber (DF) has been consumed for
    centuries and most food labels in the supermarket
    now list dietary fiber.
  • Even though fiber is not considered a nutrient,
    health professionals and nutritionists agree that
    fiber is required in sufficient amounts for the
    proper functioning of the gastrointestinal tract.

53
Definition
  • DF is the edible parts of plants or analogous
    carbohydrates that are resistant to digestion and
    absorption in the human small intestine with
    complete or partial fermentation in the large
    intestine.

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Why ?
  • DF consumption has established the basis for
    associating high-fiber diets in epidemiological
    studies with reduced risk of most of the major
    dietary problems in the U.S.A. namely, obesity,
    coronary disease, diabetes, gastrointestinal
    disorders, including constipation, inflammatory
    bowel diseases.

Chronic diseases
55
Classification Of Dietary Fiber
  • dietary fiber has been to differentiate dietary
    components on their solubility in a buffer at a
    defined pH, and/or their fermentability in an in
    vitro system using an aqueous enzyme solution
    representative of human alimentary enzymes.

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Solubility
  • Soluble fiber dissolves in water
  • This includes gums, mucilages, pectin and some
    hemicelluloses.
  • found in all types of peas and beans like
    lentils, split peas, pinto beans, black beans,
    kidney beans, garbanzo beans, and lima beans, as
    well as oats, barley, and some fruits and
    vegetables like apples, oranges, and carrots.

57
Benefits
  • For people with diabetes, eating foods that
    contain soluble fiber can help control or lower
    the level of sugar in their blood and decrease
    insulin needs
  • It may also help lower blood cholesterol levels,
    especially LDL-cholesterol or the bad
    cholesterol.

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  • Insoluble fiber does not dissolve in water.
  • Whole grains, wheat and corn fiber, and many
    vegetables like cauliflower, green beans, and
    whole potatoes are good sources of insoluble
    fiber.
  • aids digestion by trapping water in the colon.
  • helps prevent two kinds of intestinal diseases,
    diverticulosis and hemorrhoids.

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Fermentability
  • Fibers that are well fermented include pectin,
    guar gum, acacia (gum arabic), inulin,
    polydextrose, and oligosaccharides.
  • Generally, well fermented fibers are soluble in
    water, while partially or poorly fermented fibers
    are insoluble.

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Physiological Effects of D fiber
  • major physiological effects of dietary fiber
    originate from the interactions with colonic
    content throughout its fermentation.
  • It influences several metabolic processes,
    including the absorption of nutrients,
    carbohydrate and fat metabolism, and cholesterol
    metabolism.

63
  • influences the colonic structure and barrier
    function, and as the large intestine encompasses
    a significant body of the human immune system.
  • Some form gels (pectins), while others have a
    high water holding capacity (WHC).
  • its ability to adsorb or bind bile acids and its
    fermentability by microorganisms in the gut.

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Colonic Fermentation And Its Consequences
  • The large intestine is the most heavily colonized
    region of the digestive tract, with up to 1011
    -1012 anaerobic bacteria /gram.
  • end products produced from the fermentation,
    including gases (methane, hydrogen, carbon
    dioxide), short chain fatty acids (SCFA).
  • Increases in microbial mass from fiber
    fermentation contribute directly to stool bulk

65
  • Gas production from colonic fermentation can also
    have some influence on stool bulk.
  • Poorly fermented cellulose produces very little
    acid during its fermentation, most of which is
    only acetic acid by contrast, in the case of
    more fermentable fibers, large quantities of SCFA
    are formed.
  • The metabolic end products of fermentation
    including the gases, SCFA, and increased
    microbiota, play a pivotal role in the
    physiological effects of fiber and implications
    for local effects in the colon and systemic
    effects

66
PHYSIOLOGICAL FUNCTIONS OF DIETARY FIBER
  • Dietary Fiber And Cancer
  • Colon cancer is one of the leading causes of
    cancer morbidity and mortality among both men and
    women in the Western countries, including the
    U.S.A.
  • Dietary Fiber And Carbohydrate Metabolism
  • An association between insufficient dietary fiber
    intake and increased risk of diabetes has been
    postulated since 1970s.

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  • Dietary Fiber, Lipid Metabolism, And
    Cardiovascular Disease
  • bind bile acids increasing their excretion and
    decrease cholesterol in the liver.
  • SCFA are absorbed from the colon to the liver.
  • Dietary Fiber, Mineral Bioavailability And Bone
    Health.
  • certain highly fermentable fibers have resulted
    in improved metabolic absorption of certain
    minerals, such as calcium, magnesium, and iron,

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  • Dietary Fiber, Role In Gut Barrier Function And
    Gastrointestinal Disorders.
  • SCFA stimulating repair in a damaged colon.
  • barrier to prevent foreign materials from dietary
    or microbial origin from crossing into the
    internal body cavity. Prevent Intestinal
    permeability or leaky gut syndrome.

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Probiotics
  • Intestinal tract is home to one hundred trillion
    (1014) microorganisms.
  • called the intestinal microflora.
  • over 400 different species of microbes.
  • The 400 species of microbes living in your body
    are fighting for space. They want to live, thrive
    and reproduce in your intestinal tract, an
    environment that offers the ideal temperature,
    humidity and food sources.

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  • Depending on the type of bacteria, there is a
    different effect on the body bacteria can have
    healthy, e.g.,
  • immune-boosting benefits or cause harm to the
    body.
  • A careful balance is necessary for health.

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  • Bad microbes live in your intestines and normally
    do not cause any disease-like symptoms.
  • Bad microbes flourish in an alkaline environment.
  • Opportunistic and neutral the majority.
  • Good microbes found in the body, called
    probiotics.
  • Probiotics have a positive impact on the bodys
    health. They prefer a more acidic intestinal
    environment. Many of the probiotics are called
    lactic acid bacteria.

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They define the term probiotic as live
microorganisms which when administered in
adequate amounts confer a health benefit on the
host.
How do they work? What are these health
benefits? How can we get them? What species can
provide them? Whats the relationship with
Chronic diseases? How can we maintain them?
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Some history
  • Pasture 1880,
  • Eli Metchnikoff 1908,
  • Tisser 1900,
  • W W I Nissil
  • Southeast Asia, Boulardi. Cholera.
  • 1950, group of scientists, found out that mice
    that were given oral antibiotics, which kill all
    bacteria, including probiotics, were more
    susceptible to infection.

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  • Yakult Company of Japan in the 1930s. Yakult
    Company introduced a fermented milk product that
    contained a probiotic culture.
  • The term probiotic was not actually coined until
    the 1960s.
  • In 1978, Dr. Tomotari Mitsuoka, illustrated how
    the composition of intestinal flora changes
    during a lifetime.
  • Probiotics decrease with aging.
  • WHY?

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How Do Probiotics Work?
  • The intestinal microflora has the metabolic
    activity potential equal to that of the liver,
    the most active organ in the body!
  • The exact mechanisms of action by which
    probiotics elicit their beneficial effects are
    not fully understood.

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Suggested mechanisms
  • Probiotics Compete for Receptor Sites

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  • Change secretion to mask receptors

mucus
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  • Probiotics Affect the Immune System
  • Gastrointestinal tract is equipped with effective
    immune system, the most number of lymphoid is
    around the gut.
  • Immune system is the key element of what to enter
    your body or not to.
  • By producing antibodies these are messengers for
    all tissues connected with immune system.
  • Probiotics supplementation is useful in a wide
    variety of immune-based ailments including
    allergies, asthma, eczema and irritable bowel
    disease.

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  • probiotics help balance good and bad messengers
    of the immune system by keeping the system in
    check.
  • The result is healthy immune reactions and a
    healthier you. A careful balance of inflammation
    is required in the intestinal tract.
  • Too much of an immune reaction can result in
    inflammation and damage to the intestines
    reducing their ability to digest and absorb
    nutrients I B D.

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  • Too little immune reaction allows pathogens to
    grow in the intestines, causing infectious
    diarrhea, which can develop into a chronic
    illness such as allergies.
  • All in all, it appears that probiotics
  • reduce allergic reactions
  • improve overall immunity
  • promote proper immune reactions against pathogens.

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  • Probiotics Consume Available Nutrients
  • There are lots of nutrients available in the
    digestive tract that support the needs of lactic
    acid bacteria to grow. By consuming a large
    portion of the available nutrients suitable for
    microbes, lactic acid bacteria restrains the
    growth of bad microbes.
  • Probiotics Create an Acidic Environment
  • Many bad microbes do not like a low pH.

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  • Probiotics Produce Beneficial Enzymes
  • The enzyme activity of probiotics has been found
    to help fight infectious disease, lactose
    intolerance, immune system deficiencies, and
    urogenital and vaginal diseases.
  • Probiotics Produce Antimicrobial Effects
  • Many of the probiotic strains of bacteria are
    able to produce substances that kill bacteria,
    called bacteriocins

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  • Probiotics Support Gut Barrier
  • Lactobacilli and Bifidobacteria produce fats that
    encourage the growth of cells that line the
    intestinal tract. These fats are called short
    chain fatty acids. These fats also have
    nutritional effects on the intestinal cells,
    keeping them well nourished and healthy.
  • Gut integrity.

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  • Probiotics Encourage Healthy Microflora
  • In clinical trials, the use of combinations of
    probiotic species has been found to offer greater
    health benefits than any one of the probiotic
    species alone.
  • Example
  • Lactobacillus reuteri produces protein to enhance
    the growth of other lactobacilli.
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