The idea that the microbial communities within the GI tract have a
profound influence on general human health actually originated with
Russian scientist Elie Metchnikov at the turn ofthe last century. Also
known as the "fatherofimmunol- ogy", Metchnikovbelievedthat
putrefactivebacteriain the gut were responsible for enhancing the aging
process. He theorized that ingestion ofhealthy bacteria found in
fermented foods could counteract toxic bacteria and was the key to good
health. His theories concerning good bacteria and health can be found in
his treatise "The ProlongationofLife: Optimistic Studies".Thesewritings
promptedJapanesescientist Minoru Shirotatobegin investigationofhow
fermentative bacteriaimprove health. He succeededin isolating
astrainofLactobacillusthat could survive passage through the intestine,
while promoting a healthy balance ofmicrobes. The "Shirota strain" is
still used today in the fermented beverage Yakult.It is clear from a
commercial standpoint that these ideas have inspired the development of
a probiotic industry, which has expanded greatly in the U.S. over the
past 5-10 years.