Re: What the heck Are "Probiotics"?

[Susan Evans Garlinghouse <suendavid@worldnet.att.net>]

avpinc@bellsouth.net wrote:
> 
> Hello to all the Ridecampers who have been asking me for
> info. about probiotics:  I am not a qualified nutritionist or
> expert in the scientific world, and I would still refer you
> all to the experts, like Susan Garlinghouse, for  information
> based on professional experience, however, I found what
> is a pretty good description of what Probiotics are and
> thought I would paraphrase the article:
> 
> "Probiotics are living beneficial micro-organisms which ensure
> the most beneficial populations in the microflora throughout
> the digestive tract.  Unlike antibiotics which can destroy
> large numbers of naturally beneficial bacteria while controlling
> potentially harmful strains, active probiotics maintain and
> enhance the populations and aid colonization of the gut
> with the correct microflora."
> 
> I hope this helps, and I look forward to hearing from you
> all after you try our sample Anidophilus.  Take care.
>                                        Linda (AVP)






Well, in the interest of getting some more productive exchanges going
on, I'll add a bit more to Linda's definition of probiotics and how they
relate to horses.

Horses obviously eat alot of foods that contain what are called
structural or insoluble carbohydrates---the fiberous part of plants, as
opposed to the soluble carbos like sugar.  Both soluble and insoluble
carbohydrates are made up of long strings of glucose molecules, but the
bonding in soluble vs. insoluble carbos is different.  Animals possess
the enzymes to break the bonds between *soluble* sugars, but do NOT
possess the enzymes to break the different bonding between the glucose
molecules in structural carbos.

So as animals have evolved, they developed a symbiotic relationship with
hundreds of different species of microorganisms that DO produce the
enzymes capable of breaking this particular bond, thereby making the
food available to both the "bug" and the host animal.  Even better, the
bugs excrete different vitamins such as B vitamins, which is why you
normally don't have to supplement a healthy horse with extra B.  This
concept occurs to one extent or another in any animal that eats foods of
plant origin, including humans.  The species of herbivores that depend
largely or entirely on fibrous plant materials enlarged the parts of the
gastrointestinal tract where all this fermentation and microbial
breakdown occurs---the rumen in cattle, sheeps, goats, etc and the cecum
and large colon in the horse, rabbit, hippo, elephant and many other
species.  Omnivores like bears, raccoons, people, etc still have some of
the equipment for fiber digestion but don't rely on it as heavily. 
(BTW, in humans, the appendix is the vestiges of a cecum, but microbial
fiber breakdown still occurs to a small extent in the large colon). 
Strict carnivores don't have a need for it and at best only have
vestiges, which is why when your dog eats grass and then does the
Technicolor Yawn on the rug, the grass reappears at one end or the other
undigested).  

So, here's the deal---to maintain efficiency of fiber digestion in the
cecum and large colon, the horse has to maintain a reasonably stable
microbial population.  For most horses that don't undergo alot of
stress, this isn't a problem.  It's more of a problem for horses under
stress---like endurance horses, race horses, horses making a drastic
change from one ration to another, nervous horses, etc.  This is because
changes in the internal temperature, antibiotics, dehydration, deworming
medications, changes in pH, etc etc all can temporarily make the cecal
environment less than ideal for the bugs and they start to die off. 
Sometimes the die-off is equal among species, sometimes it can affect
some species much more than others.

Here's an example of how a chain reaction can cause major
problems---let's say you have a horse that normally never gets more than
a pound or so of grain, and his microbial population has adapted and
stabilized itself to a mostly-hay diet.  The horse gets loose one night
and evil creature, tears open a bag of grain and gobbles up a great big
feast of it.  The grain hits the small intestine, some of the soluble
carbohydrates are absorbed directly, but alot of the grain keeps going
and lands in the cecum.  Some species of bug, primarily the
Lactobacillus species, like this kind of food better than anything else
and they go nuts.  As they digest the grain, they excrete lactic acid
into the cecal and large colon.  Being bacteria, they multiply like mad
(and very quickly) to take advantage of this largesse.  The population
of this type of bug explodes, which in turn release more and more lactic
acid, so the pH of the environment begins to drop (become more acidic). 
The pH drops below what some of the OTHER species of bug can tolerate
and so they begin to die.

So now you have several effects going on---one, you have an unbalanced
microbial population, so overall efficiency is upset.  Two, as some
species of bug die, they release a substance called an endotoxin
("poison from inside").  The intestinal mucosa attempts to absorb and
metabolize this toxin, but is damaged itself by the toxin.  The toxin
that is absorbed into the bloodstream can then cause all sorts of very
nasty problems, including laminitis.  All from just upsetting the
microbial population.  All sorts of stress can also create microbial
upset to one extent or another, though usually not to this extreme.

This is where the whole concept of probiotics comes in (didn't think I
was ever gonna get to this part, did you?).  Probiotics are either a
live or freeze-dried culture (which later reactivate) of some of the
species that normally exist in the GI tract and are likely to be
disturbed by stress.  The concept is that even everyday stresses can
affect the microbial population, and that to maintain maximum digestive
efficiency, you should try to keep the bug population on as an even keel
as possible.  So by regularly adding small additional populations to the
existing population, you hopefully fill in the gaps left by small daily
upsets, and avoid major shifts in the population that can decrease
efficiency and cause associated problems.

Here are some of the things that have been reported in the empirical
research (which you should be aware, were done by only one research
company on their own proprietary strain and may not necessarily apply to
ALL brands and types of probios)---when fed to young, growing horses,
the incidence of osteopathic disease was significantly reduced, they
think because the bugs release enzymes that increase phosphorus
utilization, which in turn affects growing bone quality.  Two, they
found that in broodmares fed probios culture, the *amount* of milk
produced did not increase, but the butter fat content did (this is also
why probios are commonly fed to dairy cows), and so foals nursing these
supplemented mares grew faster and were bigger and heavier at 12 and 18
months.  This may not be especially important to an endurance horse
breeder, but is a big deal to say, racehorse breeders that want to sell
nice, big, growthy youngsters at the sales.  Three, when probios were
fed to a large group of horses all undergoing a steady workload (they
were lesson horses at a riding school), supplemented horses maintained
or gained weight better without additional food than did horses not
getting the probios.  Which is of obvious benefit to endurance horses,
especially since the research demonstrates that thin horses have a
higher incidence of metabolic failure.

OK,this is why I *personally* happen to prefer some probios over another
(and this is my OPINION only and Anyone Else Can Do Whatever They
Like).  Alot of the probios brands out there contain only Lactobacillus
species of bugs in them.  Having Lactobacillus species is very good,
because to get a horse to gain weight, you have to maintain the bugs
that digest grains.  But, in my opinion, endurance horses especially
undergo a wide variety of different kinds of stress, and Lactobacillus
species are not the only ones affected in the GI tract.  Also, if a
horse has an upset because of grain overload (as described above) then
adding in yet more Lactobacillus is the LAST thing you want to do, since
it's the *other* species that are going to be adversely affected.  So, I
*personally* prefer feeding a probios that provides more than just
Lactobacillus species if at all possible---no brand is going to provide
everyone of the species found in the gut (or even close), but I still
like having a little variety if at all possible.  But that's just me.

Probiotics are an incredibly complex and fascinating field, as new
research is indicating that probios also positively affect the immune
system and may in the future be increasingly utilized to manipulate the
microbial population to "crowd out" the bad bugs with good bugs (this is
already being done in poultry flocks to eliminate Salmonella bacteria),
to fine-tune digestive efficiency (important to food animal producers)
and even control diseases and the spread of pathogens during
food-processing for human consumption.  Human baby formulas containing
probiotics to boost the immune system are currently being successfully
tested in Europe by Nestle Carnation Company and there is a virtual
explosion of research grant money being available for further work,
which is GREAT.

So, I hope this help explain a bit more about what probiotics are and
what they do.

Susan G