The use of different strains of probiotics has been a subject of much discussion. I do not pretend to know the answers for most of them and have told the list that spending one year doing library research convinced me that there is more ambiguity than black and white answers.
To further the confusion, very smart people are advising some very dumb things. Companies have jumped on the band wagon proposing oral administration of various types of Lactobacillus strains along with things like bifidis and have given absolutely no attention to the fact that these bacteria will mutate depending upon what is in the colon for them "to eat."
Seth on healing crow referenced a wonderful article which was a chapter in a book written by his former professor of bacteriology at the University of Wisconsin. (copyright 2000 Kenneth Todar. Bacteriology pg 303. I have it in front of me.
"The normal flora of humans is exceedingly complex and consists of more than 200 species of bacteria. The makeup of the normal flora depends upon various factors including genetics, age, sex, stress, nutrition and diet of the individual......The distribution of the bacterial flora of humans is shown in the following table. This table lists only a fraction of the total bacterial species that occur as normal flora of humans and does not express the total number or concentration of bacteria at any site."
It then goes on to list many species including Bacteroides sp and Bifidobacterium bifidum. I understand that these two are closely related. Others include Enterobacteriaceae (E. coli) and Lactobacillus, etc.
Then comes the confusing part:
"Intestinal Floras of Populations That Have a High Risk of Colon Cancer
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Sept. 1995, p. 3202-3207 Vol. 61, No. 9
The study finds that populations with the highest colon cancer risk have a higher number of bifido bacteria than populations with the lowest risk. The authors were very surprised at this result since bifido bacteria is a "good" bacteria. Of course this is an epidemiology study (which always have flaws) but combined with Elaine's knowledge on the subject sends a powerful warning in my mind.
L. Acidophilus is about as community-minded a bacterial strain as you will find, with S.Thermophilus and L.Bulgaricus running a close second. The others are either less friendly, or are unknown quantities. It gets even more complicated if you consider soil based strains.
So we stick with Acidophilus in our supplements, and Acidophilus, Thermophilus and Bulgaricus in our yoghurt, because they are good neighbours.
the LI listserve
The book should be required reading for anyone with Crohn's disease and we wish gastroenterologists would read it as well. The diet is a real alternative to the drug based therapy from the medical community.
- Bruce Senn