Wednesday, June 04, 2008

'Good' Bacteria May Ease Hay Fever

'Good' Bacteria May Ease Hay Fever

Study Shows Probiotics Can Change Immune Response to Grass Pollen

By Kelli Miller Stacy

WebMD Health News
Reviewed by Louise Chang, MD

June 4, 2008 -- If springtime's splendor leaves you sniffling, "good" bacteria may one day provide relief. New research suggests probiotics can alter the body's immune response to grass pollen -- a common cause of seasonal allergic rhinitis, or hay fever.

The landmark study published in Clinical and Experimental Allergy suggests that in the future, "good" bacteria, or probiotics, may potentially offer a treatment option to the estimated 35.9 million people in the U.S. who have seasonal hay fever.


Probiotics are beneficial bacteria similar to those that naturally occur in the human gut and help promote a healthy digestive system. Changes in the delicate balance of intestinal bacteria have been linked to certain allergic disorders, leading scientists to theorize that probiotics may affect the body's immune system.

For the current study, researchers with the Institute of Food Researchers randomly assigned 10 volunteers to drink a daily glass of regular milk or milk containing the probiotic Lactobacillus casei Shirota. Lactobacillus casei has been widely studied for its health benefits. The volunteers drank the milk each day and were followed for five months.

The research team took blood samples from each volunteer before, during, and after grass pollen season, checking for antibody levels of immunoglobulin E (IgE). If you have hay fever or other allergies, your immune system produces IgE in response to exposure to pollen. IgE is a key player in allergic reactions.

The blood tests revealed similar levels of IgE between both groups of volunteers at the start of the study. However, those who drank the probiotic drink had significantly lower levels of IgE specific for grass pollens and other allergy-related immune substances at peak season and afterward.

"The probiotic strain we tested changed the way the body's immune cells respond to grass pollen, restoring a more balanced immune response," Kamal Ivory of the division of Gastrointestinal Biology and Health at the Institute of Food Research says in a news release.

"This was a pilot study based on small numbers of patients, but we were fascinated to discover a response," research leader Claudio Nicoletti says. "The probiotic significantly reduced the production of molecules associated with allergy."

However, the researchers admit further studies are needed to determine if probiotic supplementation results in fewer hay fever symptoms. Phase II of the study will address that question.

Aerobic High-Intensity Intervals Improve VO2max More Than Moderate Training

Aerobic High-Intensity Intervals Improve VO2max More Than Moderate Training.

Medicine & Science in Sports & Exercise. 39(4):665-671, April 2007.

JAN HELGERUD; KJETILL HØYDAL; EIVIND WANG; TRINE KARLSEN; PÅLR BERG; MARIUS BJERKAAS; THOMAS SIMONSEN; CECILIES HELGESEN; NINAL HJORTH; RAGNHILD BACH; JAN HOFF

Abstract:

Purpose:

The present study compared the effects of aerobic endurance training at different intensities and with different methods matched for total work and frequency. Responses in maximal oxygen uptake (VO2max), stroke volume of the heart (SV), blood volume, lactate threshold (LT), and running economy (CR) were examined.

Methods:

Forty healthy, nonsmoking, moderately trained male subjects were randomly assigned to one of four groups:

1) long slow distance (70% maximal heart rate; HRmax);

2) lactate threshold (85% HRmax);

3) 15/15 interval running (15 s of running at 90-95% HRmax followed by 15 s of active resting at 70% HRmax);

4) 4 x 4 min of interval running (4 min of running at 90-95% HRmax followed by 3 min of active resting at 70%HRmax).

All four training protocols resulted in similar total oxygen consumption and were performed 3 dwk-1 for 8 wk.

Results:

High-intensity aerobic interval training resulted in significantly increased VO2max compared with long slow distance and lactate-threshold training intensities (P <>

The percentage increases for the 15/15 and 4 x 4 min groups were 5.5 and 7.2%, respectively, reflecting increases in VO2max from 60.5 to 64.4 mLkg-1min-1 and 55.5 to 60.4 mLkg-1min-1.

SV increased significantly by approximately 10% after interval training (P < 0.05).

Conclusions:

High-aerobic intensity endurance interval training is significantly more effective than performing the same total work at either lactate threshold or at 70% HRmax, in improving VO2max. The changes in VO2max correspond with changes in SV, indicating a close link between the two.

(C) 2007 The American College of Sports Medicine