If our hypothesis is correct then spores, by germinating, could function as a probiotic in the same way as the conventional probiotic or CE bacteria. By analyzing spore counts in the feces of mice administered spore suspensions, we have also shown that it is possible that spores could germinate in the gastrointestinal tract ( 15).

subtilis do appear to have the potential to suppress all aspects of Escherichia coli 078:K80 infection in a 1-day-old-chick model ( 16). In recent work we have shown that spores of B. There are three basic ways ( 8, 9, 26) in which this might be achieved: (i) immune exclusion of a pathogenic bacterium, (ii) exclusion of a pathogen by competitive adhesion, and (iii) synthesis of antimicrobial substances which impair colonization of the gastrointestinal tract by a pathogen. Probiotics and CE agents are thought to enhance the gut microflora by preventing the colonization of the gastrointestinal tract by pathogenic bacteria.

If there is no common mechanism shared between conventional Lactobacillus-type bacteria and the spore probiotics, then the question must be asked as to whether there is any credibility to some of the claims made about the positive benefits of probiotic bacteria ( 2, 12). If probiotic bacteria are to be taken seriously then we would assume that they would share a common mechanism for enhancing the normal well-being of the gut microflora or for CE of potential pathogens. The best-known examples of these probiotic bacteria are the lactobacilli and bifidobacteria ( 2, 8, 9). This question must be addressed, because the majority of probiotics currently available are bacteria which are non-spore formers: i.e., they are given as vegetative cells (usually as lyophilized preparations). While spores are being sold as probiotics, an important question is that of how spores act to enhance the normal microbial flora of the gastrointestinal tract. The use of probiotics and/or CE agents seems likely to increase as public awareness of their potential benefits increases. In the agricultural industry spores are also receiving increasing attention as potential alternatives to antibiotics as growth promoters. In some countries though (e.g., Vietnam), bacterial spores are being used for oral bacteriotherapy of gastrointestinal disorders often under clinical supervision. For humans they are available either as over-the-counter prophylactics for mild gastrointestinal disorders such as diarrhea or as health foods or nutritional supplements. Intriguingly though, spores of Bacillus subtilis are being used as probiotics and competitive exclusion (CE) agents for both human and animal consumption ( 18). The process of spore formation has been extensively studied as a simple model for understanding cellular differentiation and is one of the primary reasons for the interest in spores and spore formation ( 7).

Bacterial spores are dormant life forms which can exist in a desiccated and dehydrated state indefinitely.

Probiotic spore based