Probiotics

[Sarah Ralston <ralston@AESOP.RUTGERS.EDU>]

Got the following Comments on my caution about probiotics-will address all at
once to avoid clutter:
Lif wrote to ridecamp:

>could you just briefly provide the reasoning for that?  I do believe that
too much 
>of a good thing isn't necessarily best, but I know there are people who
take probiotics 
>daily and of course for those who drink milk & eat yougurt, they're
getting probiotics 
>this way too.  So I'm curious as to what/how they may be messing
themselves up.  
>Personally, I think milk is for baby cows....  Lif

The next two posted privately, so I will keep their comments anonymous- you
know who you are!

>Does that mean products like Acculytes with pro-bi's already in them are not
>recommended?  Have been using Acculytes for horses that do daily training
>rides in the heat.  Also have added a little pro-bi's to all horses rations
>when we transition from feeding hay to turnout to prevent "good bacteria"
>kill off problems (by a little I mean 1/4 tsp per horse per day, the
>recommended dose).

>just saw  your note on pro-bi...so do you think it's really not
>necessary to use them unless the horse is exhibiting problems like diarrhea?

Lif-all mammalian offspring drink milk, by definition! ;-) Also milk should 
not contain bacteria and the bugs that make yogurt (Lactobacilli) are
mostly killed in the
acidic environment of the equine (or human) stomach. (I happen to like
yogurt and frequently
will recommend trying it in cases of chronic diarrhea in foals).

The human study reported diarrhea and cramping when probiotics were taken
IN EXCESS
of the recommended doses by people that really had no reason to take them.
As I said, I can see a place for them, but was warning against their overuse. 
Again, there are more than two "beneficial" species of bacteria in the
horse's gut, 
all of which, (if the horse's fermentation is similar to that of better
studied animal, such as the cow) 
occupy a specific "niche" in a complex "assembly line"! One type will break
the fiber or carbohydrate 
components into smaller pieces that are then metabolized by another type
that produces 
a by product that is utilized by a third, and so on down the line until you
get the final
fermentative by-products that the horse can absorb and utilize (Volatile
fatty acids:
acetate, butyrate, propionate and even lactic acid to a certain extent,
though under normal 
circumstances this is usually metabolized to the other three). An abnormal
build up 
especially of lactic acid  in the hind gut of horses has been associated
with colic and laminitis). 
There are, however, many "scavengers" which neutralize potentially harmful
by products and 
keep the "bad bugs" in checked by maintaining the proper pH etc. If you
dump a large 
number of only two types of bacteria in (assuming they get past the stomach
and small 
intestine), their metabolic by-products, what ever they may be in the chain
of events 
(Which, by the way, have NOT been well defined in horses), will accumulate
due to 
insufficient numbers of the next bug on the assembly line-remember the
classic I Love Lucy 
segment when she and Ethel were working in the chocolate factory
packing line?).

 If the environment is already abnormal, probiotics might fill an empty
niche and 
help stem the overflow. For example, Lactobacilli utilize lactate, so, yes,
if there is a 
build up of it they might help. But if there isn't, they will either starve
or switch to 
different energy sources, perhaps altering the normal sequence.
This is all conjecture since, to my knowledge, there have been no
controlled studies of either 
the actual effect or efficacy of such products in horses. There have been a
few studies on 
live yeast cultures (Yea-Sacc, for example) that demonstrated SLIGHT
increases in digestibility 
of SOME nutrients but the effects were relatively small and the actual
changes that occurred in the gut 
to cause the increase in digestion were not documented.In the recommended
single doses probiotics 
probably won't hurt   The amounts given in the Acculytes are so miniscule
relative to the total 
gut flora as to not pose a problem unless you are giving huge amounts of
the stuff daily-and 
even then, with the daily use their systems will adapt.

Once again, as with previous discussion of single amino acid or fatty acid
supplements
 you are trying to micromanage a system in which even the macros are not
well understood!! 

If you focus on the best quality macro feeds you can get (forage, pasture,
concentrates and, 
to a certain extent electrolytes), the rest should fall in place. How many
horses are successfully 
turned out on pasture without probiotics? My budget is such that if it
ain't broke, I don't 
buy supplements to fix it!

Sarah the parsimonious, Fling the unsupplemented