Nutraceuticals Immune Modulators

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NutraceuticalsImmune Modulators
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Immune System

• Function
• To protect the body from foreign antigens
• Identify potential foreign antigen
• Eliminate or isolate them from the body
• Antigen
• Substance that causes an immune response
• E.g. Bacteria, virus, allergen, toxin

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Components of the Immune System

• Immune system is a complex array of
• Cells
• Tissues
• Compounds

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Components of the Immune System

• Immune System
• Innate Immunity Adaptive Immunity

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Innate Immunity

• Physical barriers
• Skin
• GIT
• Nonspecific phagocytic cells
• Neutrophils, macrophages, natural killer cells
• Blood Proteins
• Complement system
• Inflammation mediators
• Regulatory cytokines

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Characteristics of Innate Immunity

• Rapidly reacts to general structures that are
  common to groups of microbes
• Cannot distinguish between closely related
  foreign substances
• Damage caused by an antigen is related to its
  ability to resist innate immunity

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Adaptive Immunity

• B lymphocytes
• Produce antibodies
• T lymphocytes
• Act on intracellular microbes that are
  inaccessible to circulating antibodies

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Characteristics of Adaptive Immunity

• Highly specific
• Increases in magnitude with successive exposures
  to a particular antigen
• Distinguishes subtle differences among antigens
  (foreign bodies)
• Reacts to a large, diverse group of antigens

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Interaction between Innate and Adaptive Immunity

• Innate and adaptive immunity do not act
  independently
• Must act together for protection from foreign
  antigen
• Critical links between innate and adaptive
  immunity
• Innate immune cells can stimulate an adaptive
  immune response
• Compounds produced during an adaptive immune
  response can augment innate immunity

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Gut Associated Lymphoid Tissue (GALT)

• Mucosal epithelia is a barrier between the
  internal and external environments
• GALT spans the entire intestine
• Largest immune organ of the body
• Specialized to produce large quantities of
  immunoglobulin A (IgA)

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Interaction of Nutrition and Immunity

• Many nutrients can enhance or suppress the immune
  system
• Early studies focused on the effects of protein
  and energy on the immune system
• These are not typically lacking in todays
  companion animal diets
• Currently, nutrient supplements are being used to
  enhance the immune system

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Goals in Nutritional Enhancement of the Immune
System

• 1. Increase response to an antigen
• Eliminate antigen faster
• Return to normal faster
• Prevent/minimize symptoms

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Goals in Nutritional Enhancement of the Immune
System

• 2. Prevention of infection by strengthening
  the immune system
• Focus on times of high susceptibility
• e.g. weaning

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Goals in Nutritional Enhancement of the Immune
System

• 3. Maintain the capability of the immune system
• Immune capacity declines with age

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Examples of Nutritional Enhancement of the Immune
System

• Fatty Acids
• n-6n-3 ratios affect skin inflammation
• Proteins
• Peptides have immune stimulatory effects
• Carbohydrates
• Affect both gut and systemic immunity

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Examples of Nutritional Enhancement of the Immune
System

• Vitamins and minerals
• Many are required for immune cell production
• Novel ingredients
• Unique food ingredients identified that affect
  immune system

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Enhancement of Immune System with Dietary
Antioxidants

• Cells of the immune system are particularly
  sensitive to oxidant/antioxidant balance due to
• High of PUFA in plasma membrane
• Frequent exposure to high levels of reactive
  oxygen species produced as byproducts of
  metabolism
• High concentration of Vitamin E
• Lymphocytes, erythrocytes

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Effects of Antioxidant Mixtures on the Immune
System

• Feeding puppies and kittens antioxidant mixtures
  can increase adaptive immunity response to a
  vaccination (Devon, 2000 Devon, 2001)
• Fed diets contain antioxidants (Vitamin E)
• Vaccinations given at 8-12 weeks of age
• Puppies distemper, parvovirus, adenovirus
• Kittens herpesvirus, panleukopeniavirus,
  calicivirus

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Effects of Antioxidant Mixtures on the Immune
System

• Feeding puppies and kittens antioxidant mixtures
  can increase adaptive immunity response to a
  vaccination (Devon, 2000 Devon, 2001)
• Results
• Puppies and kittens developed stronger humoral
  responses (immunity to disease) than controls

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Effects of Dietary Fiber on the Immune System

• Dietary fibers can effect the immune system by
• Alteration in microbial populations
• Local effect on GALT (increase IgA production)
• Systemic effect on the immune system
• In reality, these effects do not occurs
  exclusively, but interact to cause an overall
  effect

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Nondigestible Oligosaccharides

• Nondigestible OS effect GIT health by
• Promotion of beneficial bacterial population
  (prebiotic effect)
• Enhancing the immune system

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Nondigestible Oligosaccharides

• Fructans
• Fructooligosaccharides (short chain fructans)
• Oligofructose
• Inulin
• All are prebiotic
• All aid in pathogenic bacteria resistance by
  promoting beneficial bacterial growth that
• Competes for nutrients
• Competes for binding sites
• Produces antimicrobial compounds

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Oligofructose and the Cat

• Sparkes et al. (1998) investigated the effects of
  OF on the intestinal bacterial populations of
  healthy cats
• 0 or 7.5 g/kg BW OF for 12 weeks
• Results
• Cats fed OF had
• Reduced pathogenic bacteria (E. coli and C.
  perfringens)
• Increased beneficial bacteria (lactobacilli and
  bacteroides)

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Effect of Mannanoligosaccharides on the Immune
System

• MOS can affect the immune system by
• Bacterial exclusion
• Neutralizing mycotoxins
• Immunostimulation

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Bacterial Exclusion

• MOS contains a mannose sugar
• Most pathogenic bacteria bind a mannose unit on
  the intestinal wall
• Once bind infection
• Bacteria bind mannose of MOS instead and get
  carried out of the GIT without causing infection

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Effect of FOS and MOS fed to Dogs

• MOS and FOS act via different mechanisms
• MOSbacterial exclusion
• FOSprebiotic/competitive exclusion
• Additive effect??
• Swanson et al. (2000)
• Dogs supplemented with MOS, FOS or both
• Evaluated effects on immune system

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Effect of FOS and MOS fed to Dogs
systemic response to MOSincreased amount of
lymphocytes in circulation
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Effect of FOS and MOS fed to Dogs

increased Ileal IgA affecting the GALT and
improving immune response
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Effect of FOS and MOS fed to Dogs
Increase seen in ileum not so at fecal level
because bacteria in colon are digesting IgA
(protein)
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Conclusions

• New interactions between nutrients and the immune
  system are found daily
• Current research is investigating the potential
  for enhancement of the immune response through
  nutrient supplementation
• Future research needs will focus on determining
  the role of specific nutrients on the immune
  system and their potential to improve the health
  of companion animals