Probiotic isolates used in farm animals
The direct fed microbial (DFM) supplementation concept
involves microorganisms mixed with feed to benefit
the animals. It is mainly used in the US. In European
countries, probiotics have been developed for use mainly
in animal production. This supplementation is also
based on the administration of one or several live microorganisms,
usually yeast or bacteria. In the last two decades,
most Lactobacillus strains used in humans have
also been used as probiotics in animals, but Bifidobacterium
strains isolated from a human origin were used as
probiotics only in humans. Over the past 20 years, the
probiotic strains widely used in animals, especially those
used in Europe and Japan, are spore forming bacteria of
the genus Bacillus [22]. Currently, most of the probiotics
used in animal farming are lactic acid bacteria (LAB).
Sources of probiotics for use in various animal species,
including poultry [62], pigs [63] and ruminants [64], are
mainly the gastrointestinal (GI) tracts of the same animal
species. These probiotics can also be isolated from
the feces of different animal species, including chickens
[65], pigs [66] and ruminants [67]. Probiotics isolated
from an animal species have also been used in another
animal species. They may also come from other sources,
including fermentation products of plants and animal
origin. B. pumilus WIT 588 isolated from sea water has
been tested in animals and exhibits an ability to inhibit
the growth of Escherichia coli [68]. Propionibacterium
freudenreichii isolated from dairy products has been
used to reduce enteritis and to improve health in pigs
[69]. Several researchers have isolated probiotics from
different sources and used in animals as summarized in