Organic acids kill probiotics – or not?

Animal Nutrition Views

Ioannis Mavromichalis, Ph.D., gives his views on poultry, pig and dairy nutrition based on his experience as a nutrition consultant with clients around the world.

We all know that organic acids are quite effective against
pathogenic bacteria in the stomach and small intestine, of both pigs and poultry.
Indeed, certain organic acids have been proven excellent replacements for
growth-promoting antibiotics.

Surprisingly, many nutritionists consider probiotics (live or
sporulated beneficial bacteria) equally effective as organic acids, as
evidenced by a recent nutrition survey by WATT Global Media. 

Indeed, a successful colonization program using a suitable
probiotic product has the potential of creating an unfavorable environment for
pathogens, depriving them of (a) nutrients and (b) colonization sites, and (c)
by the natural ‘antibiotic’ compounds certain bacteria excrete (for example,
lactic acid by lactobacilii).

Now, as we know, organic acids will kill any kind of bacteria,
good or bad, that is sensitive to acidic pH. So, the question in the mind of
many feed formulation experts is what happens when we use organic acids and
probiotics at the same time. Is this OK, or should we start with organic acids
to kill everything (or as much as possible) and then follow up with a probiotic
(as suggested in certain human antibiotic therapy programs).

Here is where probiotic manufacturers should supply us with
in-vitro and in-vivo data proving that the strains they use are acid-resistant,
at least at pH levels found in the stomach of pigs and poultry. Unfortunately,
such data is often missing, and this is indeed a good topic for a full-length