Probiotics & The Body Natural Defences

Probiotics & The Body’s Natural Defenses : 

Probiotics & The Body’s Natural Defenses By Dr. Deryck D. Pattron, Ph.D. Public Health Specialist & Consultant Chaguanas, Trinidad, West Indies

Background : 

2 Background Pasteur postulated that microorganisms are necessary for human life. Metchnikoff confirmed the importance of microbes and the interactions between host and bacteria for normal life. Use of microbes in the diet could have beneficial effects.

What are probiotics? : 

3 What are probiotics? Living microorganisms which upon digestion in sufficient numbers, exert health benefits beyond basic nutrition (NYA & ILSI, USA).

Characteristics of Probiotics : 

4 Characteristics of Probiotics Safe and bring health benefits to host. Stable and viable under conditions of storage. Present in the form of live cells in high quantities, prior to ingestion. Food grade.

Beneficial effects of Probiotics : 

5 Beneficial effects of Probiotics Depletion and/or competition for limited substrates leads to exclusion of pathogenic microorganisms. Competition for receptor sites. Creation of a restrictive physiological environment. Production of antimicrobial substances. Gut flora exerts a barrier effect.

Probiotics & effects on the composition of intestinal microflora : 

6 Probiotics & effects on the composition of intestinal microflora Eliminates unwanted microorganisms by: Rendering specific nutrients unavailable. Rendering specific binding-sites unavailable. Reduction of luminal pH. Production of broad spectrum antimicrobial substances.

Probiotics modulate the activity of the gut microflora : 

7 Probiotics modulate the activity of the gut microflora Lowering the pH of the medium in the intestinal tract. Altering the pH of the intestinal tract that affects the enzymatic activity of the flora. Reducing activity of procarcinogenic enzymes produced in the intestinal flora.

How does probiotics affect intestinal defense? : 

8 How does probiotics affect intestinal defense? Stimulates mucin production thereby increasing the barrier effect and preventing the attachment of microorganisms. Modify cellular carbohydrate pattern thereby promoting colonization of specific bacteria. Restores disrupted gut epithelium permeability.

Effect of Probiotics on tight junctions : 

9 Effect of Probiotics on tight junctions Tight junctions are highly regulated macromolecular structures that link epithelial cells to one another forming an intracellular barrier. Probiotics reduce the levels of microorganisms such as E.coli, and salmonella that attack tight junctions. Probiotics restore and maintain the patency of tight junctions, thus restricting pathogens into the bloodstream.

Effect of Probiotics on Intestinal Antimicrobial Peptides : 

10 Effect of Probiotics on Intestinal Antimicrobial Peptides Probiotics stimulate goblet cells and Paneth cells into action and provide the necessary medium for enhanced activity. Trefoil peptides are produced by goblet cells. These are a small group of protease-resistant proteins produced in response to bacterial toxins, chemicals and drugs. Lytic peptides are produced by Paneth cells located at the bottom of crypts between intestinal villi. They produce peptides that dissolve the cell membrane of pathogenic bacteria.

Effects of Probiotics on the Immune System : 

11 Effects of Probiotics on the Immune System Stimulates increased cytokine production that facilitates greater communication and activation of immune system cells. Stimulates increased phagocytic activity and the greater engulfment and containment of pathogens, thus minimizing infection. Stimulates increased antibody production and the generation of memory cell thereby increasing the strength and efficiency of the immune defense.

Effects of Probiotics on the Immune System (Cont’d) : 

12 Effects of Probiotics on the Immune System (Cont’d) Stimulates increased natural killer cell production that assist in effectively killing pathogenic microorganisms. Modulate lymphocyte proliferation that increases strength of the immune defense.

Conclusion : 

13 Conclusion Probiotics assist in forming an effective barrier against microorganisms in the intestines. Probiotics work principally by modulating the activity of intestinal cells. Probiotics stimulate the production of antibacterial proteins from goblet and Paneth cells in the intestines. Probiotics stimulates and primes the immune system for effective defense against pathogenic microorganisms.

References : 

14 References Belley A. et al. Intestinal mucins in colonization and host defense against pathogens. Am J Trop Med Hyg. 1999;60(6):1062. Bernasconi P. The Intestinal flora and ecosystems. Ed. Lab. Biocodex, 1984. Benet M.F. et al. Lactobacillus acidophilus LAI binds to cultured human intestinal cell lines and inhibits cell attachment and cell invasion by enterovirulent bacteria. Gut 1994;35:483-489.

References (Cont’d) : 

15 References (Cont’d) Berzirtzoglou E. Normal human microflora Ed. Univ. Ioannina, 1994. Falk P. et al. Creating and maintaining the gastrointestinal ecosystem. Micobiol Molecula Bio Rev 1998;62:1157-1170. Ganz T. Paneth cells-guardians of the gut cells hatchery. Nat Immunol 2000; 1:99-100.

References (Cont’d) : 

16 References (Cont’d) He F Tuomola E et al. Modulation of humoral immune response through probiotic intake. FEMS Immunol Med Microbiol 2000;29:47-52. Meydani S. et al. Immunologic effects of yogurt. Am J Clin Nutr 2000;71:861-872. Ogra et al. Mucosal Immunology. Academic Press, 1999. Ouellette A.J. Paneth cells antimicrobial peptides and the biology of the mucosal barrier. Am J Physiol 1999;277: G257-G261.

Slide 17: 

17 Thank You! Dr. Deryck D. Pattron, Ph.D. Public Health Scientist & Consultant Chaguanas, Trinidad, West Indies