Hi Peter,

Sorry, I'm rather late on that. Had lots of work.

Peter wrote::
> Sylvia, you seem to know a lot about the many colonies of small critters
> that occupy our guts.

I am by no means a specialist of gastroenterology. I'm a veterinary
microbiologist and currently working on (porcine) E. coli. I'm afraid
my contributions won't exceed general knowledge by far.

> There seems to be a fair amount of controversy over
> what kind of bacterial cultures are the best to ingest.  Claims are made
> for the uniqueness of each product and why each particular one is the only
> that is able to survive our stomach acids thanks to a special proprietary
> process and a special type/blend of rare culture(s) with unique properties.

I consider much of it pure sales promotion. But the point of
stomach acids could hold true.
Ironically, (lactic acid producing) Lactobacilli seem to be sensitive
to low pH (I could look up the precise values). Therefore, many
providers have raised/selected (or genetically engineered?) special
cultures that are more resistant to acids. So they are better able to reach
the colon, perhaps displace pathogenic strains and strengthen the local immune
system of the gut.

>  Just the other day a chiropractor told me that a special culture from
> "Metagenics" that is delivered overnight packaged in ice is the only viable
> culture that will do the job.  I would appreciate to get your opinion on
> this.

I don't know "Metagenics" and can't give a comment on it. But I
always get suspicious when I hear terms like "the only one". A fresh
culture delivered on ice surely can be viable. But still I think that
lyophilized cultures could do the same job.

> Also, I have often wondered that if antibiotics kill off the good flora in
> our intestines, why is it that most people after a treatment of antibiotics
> are able to digest their foods with no problem?
The bacterial flora of the (human) gut has not much to do with
digestion. Roughly speaking, digestion takes place from the mouth to
the Jejunum/Ileum with the help of many enzymes and changing pH
values. The bacterial flora (in the colon) only breaks down what hasn't
been resorbed or what we can't digest (mainly complex plant
carbohydrates like cellulose, lignine etc.). So, for  an
omnivore's  or carnivore's digestion  bacteria are less important.
But, as Roberta has already mentioned, they also produce a lot of
useful substances such as B vitamins and their full impact on the
intestinal health (to my knowledge) still is not fully understood.

Best,  Sylvia