Probiotics are cultured doses of living bacteria that are marketed as “beneficial”, in contrast to the pathological bacteria that cause disease.
A vast population of essential bacteria lives in the gut of a healthy horse. These bacteria are necessary for efficient digestion; they have evolved alongside their hosts as part of the normal healthy function of the mammalian gut.
When this “gut flora” is upset by disease or stress, the animal can suffer. It makes sense to promote healthy gut flora by feeding extra amounts of the good bacteria to restore the balance.
Three Danish scientists have recently reviewed all the available evidence for the efficacy of equine probiotics in a lengthy research paper. They point out that most of the research supporting the benefits of probiotics is in humans, and that the evidence for their usefulness in horses is very limited.
A few facts remain undisputed, however. In horses, the probiotic bacteria do not survive long in the gut, so although they may have a temporary benefit when they are being given, the effect does not last.
It is also clear that no one probiotic strain or product can be beneficial for every bowel problem; specific strains and bacterial species are required for different challenges.
Despite these reservations, the Danish scientists say that probiotics do horses no harm, are relatively cheap and — in some cases — may be of some benefit.
Ref: Horse & Hound; 12 February 2015
