Fri Jan 20 15:55:01 EST 1995

Ted Farnworth writes:

"I would like to know if it is common practice for medical doctors to perscribe
yogurt to patients that have undergone surgery or antibiotic treatment in order
to assist in the restoration of GI microflora. It would be really helpful to get
a reference (article or textbook) where this practice is recommended."

Eating yoghurt is probably good nutrition whether or not you have taken  
antibiotics but the bacteria in yoghurt are not those commonly found in the GI 
tract nor would they expect to colonize the GI tract long term.  It has 
certainly not been demonstrated that eating yoghurt leads to a more rapid 
recolonization by the normal intestinal microflora.  This is despite the claims 
of a Finnish group: see Ann Med 1990 Vol: 22:57-9  There are probably several 
foods you could eat that would be better than others in helping restore the gut 

Yoghurt cultures usually consist of  a mixture of Lactobacillus bulgaricus and 
Streptococcus thermophilus (I think this is now called Lactococcus 
thermophilus).  Other LAB (lactic acid bacteria) can also be used.  Yoghurt and 
other fermented milk products contain such bacteria as Lactococcus lactis, 
Lactococcus cremoris, Bacillus kefir and Leuconostoc dextranicum.  None these 
will readily colonizes the gut.  We don't use E. coli (and other coliforms) to 
make yoghurt but they are what we find in the gut.  

I have heard it suggested that women each yoghurt so that they may restore 
Lactobacilli to the vaginal cavity where they provide a protective effect 
(probably by keeping the pH low) but I am not sure how the dietary Lactobacilli 
are supposed to migrate from the colon to the vagina.  There was an Israeli 
group that claimed positive results by direct vaginal application of yoghurt see 
Acta Obstet Gynecol Scand  1993 Vol:72:17-9.

I know this is an oft repeated repeated remedy for diarrhoae related to 
antibiotic use but the science is not there to back it up. 

Steve Projan
Lederle Labs

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