Bifidobacteria bacteriocins

The effects of dietary FOS on the GI microflora of poultry are well documented. Flidaka et ol. (1991) found that consumption of 8 g FOS per day increased numbers of bifidobacteria, improved blood lipid profiles and suppressed putrefactive substances in the intestine. Patterson et d. (1997) found that caecal bifidobacteria concentrations increased 24-fold and lactobacilli populations increased 7-fold in young broilers with FOS. Bifidobacteria may inhibit other microbes because of a high production of volatile fatty acids (VFAs) or the secretion of bacteriocin-like peptides (Burel and Valat, 2007). The improvement in gut health status by dietary FOS supplementation often results in improved growth performance. Ammerman et d. (1988) demonstrated that the addition of dietary FOS at a level of 2.5 or 5.0g/kg diet improved feed efficiency over the period from 1 to 46 days of age. Mortality was reduced with the higher level. However, Waldroup et d. (1993) found that supplementing the diet of broilers with 3.75 g/kg FOS had few consistent effects on production parameters or carcass Sdmonella concentrations. 

Lactic acid bacteria and bifidobacteria are preferred as protective and probiotic cultures, and have been used since the beginning of history as starter cultures. They have a long history of being safely used and consumed. LAB are widely used for fermentation of milk, meat, and vegetable foods. In fermentation of dairy products, lactose is metabolized to lactic acid. Other metabolic products, hydrogen peroxide, diacetyl, and bacteriocins may also play inhibitory roles and contribute to improving the organoleptic attributes of these foods, as well as their preservation (Messens and De Vuyst, 2002). 

Some probiotics produce anti-microbial agents targeting important gastrointestinal pathogens which is a desirable characteristic. Many lactic acid bacteria and bifidobacteria have been shown to produce bacteriocin-like molecules with different spectrums of activity. 

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