Probiotics and Prebiotics: Concepts, Definitions and History - Aquaculture Nutrition: Gut Health, Probiotics and Prebiotics - page 171

Lactobacillus reuteri , Lactobacillus helveticus and Lactobacillus rhamnosus . Also, members
of the genus Bifidobacterium (especially Biidobacteriumlactis ) were added to probiotic prod-
ucts (Tannock 2003). Lactobacillus and Bifidobacterium became the main probiotic groups,
but the probiotic potential of Pediococcus , Lactococcus , Bacillus and yeasts have also been
demonstrated (Soccol et al . 2010). Today, a wide range of probiotic products is available for
human consumption.
Interest in the probiotic concept also reached the field of animal husbandry in the 1960s.
Dietary supplements became available for farm animals with the inclusion of LAB as
health-promoting agents (Tannock 2003). The benefits claimed included improved weight
gain, reduced mortality and feed costs, alleviation of stress and decreased incidence of
infections (Parker 1974). The first study to apply the concept of competitive exclusion in
poultry using caecal contents from adult chickens was conducted by Nurmi and Rantala
(1973) who sought to protect chicks against Salmonella infection. In the 1980s, the most
common probiotics for animal feeds belonged to three bacterial and one yeast genera:
Lactobacillus , Streptococcus , Bacillus and Saccharomyces spp. At that time, at least 20
different probiotic preparations were available on the European market, with Enterococcus
faecium (formerly Streptococcus faecium ), Lb. acidophilus and Bacillus cereus var. toyoi
being the most widely applied (Vila et al . 2010). In livestock, probiotics are mainly used
during difficult physiological and technological periods to treat various digestive disorders.
Fuller (1999) reviewed the use of probiotic products in animal husbandry and concluded that
several claims were mentioned, but not always supported by good scientific data. Similarly,
the outcome of basic studies on the effect of probiotic bacteria in health maintenance of
farm animals, such as swine, poultry, cattle and sheep, is summarized by Corcionivoschi
et al . (2010). They concluded that the lack of clinical trials impedes the creation of specific
recommendations on the application of probiotics to treat various digestive disorders in farm
animals. A review on the role of probiotics in the poultry industry conducted by Kabir (2009)
indicates that probiotics could be applied as nutritional tools in poultry feeds for promotion of
growth and meat quality, modulation of intestinal microbiota and inhibition of pathogens, as
well as immunomodulation. Over the last decade, the use of probiotics in animal agriculture
has increased, but their commercial success in poultry production has been limited (Flint
and Garner 2009). Following the 2006 EU ban on antimicrobial growth promoters, to reduce
the use of antibiotics in agri-business productions, new opportunities for the development of
probiotic products have arisen.
Research on the application of probiotic microorganisms in aquaculture started over two
decades ago (for review see Gatesoupe 1999). The main reason for this was the need for
alternative prophylactic methods to remedy the survival problems encountered at different
stages of intensive rearing. The success and availability of human and livestock probiotics
have influenced the selection of microorganisms tested in aquatic rearing systems, particularly
the early research in this field. These solutions may prove safe for human consumption, but
their efficiency has been variable in aquatic animals (Azad and Al-Marzouk 2008). This has
led to the search for tailor-made solutions from the autochthonous microbiota of aquatic
animals. Given the differences in natural GI microbiota of aquatic and terrestrial animals,
the main probiotics researched and studied for aquaculture practices include a wide range
of microorganisms, such as Aeromonas , Alteromonas , Enterobacter , Flavobacterium , Pseu-
domonas , Pseudoalteromonas , Phaeobacter , Roseobacter , Shewanella , Vibrio , Arthrobacter ,
Bacillus , Clostridium , Micrococcus ,LAB, Debaryomyces and Saccharomyces species