I found this quote from the following article, which discusses a research project in which probiotics were given to some long-distance runners, to be rather interesting:
http://news.bbc.co.uk/2/hi/health/7243006.stmBlood tests taken from the athletes found doubled levels of interferon gamma, a chemical involved in the body's immune system, suggesting that the probiotics might somehow be helping the body to protect itself.
The remark below, also caught my eye. Since no justification is mentioned, I can't help but wonder if it's simply a matter of biased opinion, or if there's a logical reason for the statement.
TexHowever, a British specialist said the same effect was less likely for people who were less active.
