Aspects of In Vitro and In Vivo Research Approaches Directed Toward Identifying Probiotics and Prebiotics for Human Use

Abstract

The microbiota of the human gastrointestinal tract plays a key role in nutrition and health. Through the process of fermentation, gut bacteria metabolize various substrates (principally dietary components) to end products such as short-chain fatty acids and gases. This anaerobic metabolism is thought to contribute positively toward host daily energy requirements. However, under certain circumstances, the fermentative process may produce undesirable metabolites. This may cause the onset of gut disorders that can be manifest through both acute and chronic conditions. Moreover, the gut flora may become contaminated by transient pathogens that serve further to upset the normal community structure. There has been a recent increase in the use of dietary components that help to maintain, or even improve, the gut microflora "balance." Probiotics are live microbial feed supplements added to appropriate food vehicles (usually fermented milks), whereas prebiotics are dietary carbohydrates that have a selective metabolism in the colon and serve to increase numbers of bacteria seen as desirable. Because of their purported health-promoting properties, lactic acid-producing bacteria, including bifidobacteria, are the usual target organisms. The market value and biological potential of both approaches are enormous. This article will summarize how efficacious types can be identified.

In vitro assessment of gastrointestinal tract (GIT) fermentation in pigs: Fermentable substrates and microbial activity

“…According to Gibson and Fuller [10], continuous culture systems can be used to simulate intestinal conditions more closely than for batch cultures. Dilution rates and other parameters can be varied, so that optimum conditions can be maintained.…”

Influence of different prebiotics and mode of their administration on broiler chicken performance

“…By definition, prebiotics contain fermentable oligosaccharides that selectively stimulate growth of beneficial bacteria in the guts. In general, they share common properties, including resistance to acidity, hydrolysis and absorption in the gastrointestinal tract; fermentability by the intestinal microflora and expression of the positive effect on the growth and activity of beneficial intestinal microorganisms (Gibson and Fuller, 2000;Roberfroid, 2007).…”

Effect ofBacillus SubtilisSpore (GalliPro®) Nutrients Equivalency Value on Broiler Chicken Performance

“…A probiotic, which means for life in Greek (Gibson and Fuller, 2000), has been most commonly defined as viable micro-organism which, after sufficient oral intake, causes beneficial effects for the host by modifying the intestinal microbiota (FAO, 2002). Most commonly used probiotic bacteria in poultry are Lactobacillus, Bifidobacterium, Bacillus, Streptococcus, Pediococcus, Enterococcus, and yeast such as Saccharomyces cerevisiae.…”