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2006 Experimental Biology
Annual Conference

Probiotics and The Hygiene Hypothesis:
A Case for Protective Nutrients

April 3, 2006

San Francisco, CA


The “hygiene hypothesis” helps to explain the fact that immune disorders are increasing while improved hygiene and anitibiotics have caused infectious diseases to decrease during the last half century. Now you can learn more about this problem and how probiotic administration can help, at this symposium, “Probiotics and the Hygiene Hypothesis: A Case for Protective Nutrients”.

With the evidence mounting that immune disorders are increasing – especially in North America and Europe – this symposium explores how decreased microbial exposure – even from vaccinations and improved sanitation – can lead to abnormal responses to allergens and autoantigens in the mucosal immune system.

It also offers encouraging scientific evidence that probiotic administration may prevent and reduce the immune-mediated disease trend. Probiotics are living organisms, which when administered in adequate amounts, confer a health benefit on the host. Regular consumption of certain probiotics can help regulate the balance of bacteria in the digestive tract and reinforce mucosal defenses that helps limit the propagation of immune mediated disease bacteria. Probiotics have been used historically by many societies worldwide to promote health.


  • Explain the hygiene hypothesis.
  • Define the term probiotics and explain the key benefits of probiotic administration.
  • Define the hygiene hypothesis from a regulatory T-cell perspective.
  • Understand the role of pathogen TLR agonists in protection against autoimmune disease.
  • Explain how a TH1/TH2 imbalance contributes to the development of allergy.


Welcome and Introduction W. Allan Walker, MD
Director, Division of Nutrition,
Harvard Medical School;
Director of Mucosal Immunology Laboratory, Massachusetts General Hospital; Conrad Taff Professor of Nutrition, Harvard Medical School
“The Effect of Infections on Susceptibility to Allergic and Autoimmune Diseases” Discussion of the Bach NEJM article in 2002 and recent work on the role of pathogen TLR antagonists in protection against autoimmune disease. Nathalie Thieblemont, PhD
Senior Scientist, CNRS, Hôpital Necker, Paris, France
“Counter-Regulation and the Hygiene Hypothesis” Will update thesis of regulatory T-cells in the hygiene hypothesis published in Nature Immunology, 2000. Christopher Karp, MD
Esiason Professor of Pediatrics, Children’s Hospital, University of Cincinnati, Ohio
“Postnatal maturation of immune competence and risk for atopic disease” Recent clinical data on TH1/TH2 imbalance and development of allergy Patrick Holt, DSc, FRCpath, FAA Head, Division of Cell Biology Telethon Institute for Child Health Research, West Perth, Australia
“Mechanism(s) of the probiotic affect in atopic

Review mechanisms from a basic perspective of work that has been done in the Massachusetts General Hospital laboratory as well as clinical work.
W. Allan Walker, MD
Panel Discussion / Adjournment

Sponsored by
Harvard Medical School Division of Nutrition
American Society for Nutrition
American Association of Immunologists

Made possible through an unrestricted educational grant from
The Dannon Company, Inc. and Yakult Honsha Co., Ltd

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