Probiotics are defined by the World Health Organization as "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host." (1) Worldwide, there are numerous strains of probiotics used in dietary supplements and foods, but most are unstable at room temperature and need to be freeze dried or encapsulated via special processes to remain viable during manufacturing, storage, and exposure to stomach acid and bile. (2) Consequently, for most probiotics, only a very small percentage of the starting material is actually viable at the end of shelf life. Bacillus coagulans is a notable exception which, due to its sporulated form, survives without special handling and proliferates in the gastrointestinal environment.
Bacillus coagulans is a gram-positive, spore-forming, microaerophilic, lactic-acid producing bacillus. It was originally isolated and described in 1932 by Horowitz and Wlassowa and named Lactobacillus sporogenes (L. sporogenes). (3) In 1957, the organism was reclassified in Bergey's Manual of Determinative Bacteriology based on its biochemical properties, and the current correct nomenclature is Bacillus coagulans (B. coagulans). (4) However, the organism is still sometimes referred to as L. sporogenes; for the purposes of this monograph, the correct nomenclature--B. coagulans--will be used. B. coagulans is unique among probiotics in that it possesses a protective, spore-like protein coating, which allows it to survive stomach acid, reach the small intestine, germinate, and multiply. The organism requires a complex mixture of organic substrates for growth, including fermentable carbohydrates and peptides. (4)
Subsequent to oral administration, B. coagulans arrives in the stomach in its spore form, where it is exposed to the stomach's churning action and acidic pH that causes the spore coating to absorb water, swell, and begin the germination process. Upon arrival in the duodenum, the spores germinate and multiply rapidly. Estimates suggest the average duration of time between oral dosing and germination is 4-6 hours, (5) with approximately 85 percent of the starting material reaching the intestinal tract. After germination, B. coagulans is metabolically active in the intestines, producing levorotatory L(+)lactic acid, the form most readily metabolized in glycogen synthesis by the body (i.e., the isomeric form that would not be expected to contribute to metabolic acidosis). (4) B. coagulans is considered a transient colonizing probiotic, indicating it takes up only temporary residence in the human intestines. (3) Spores of B. coagulans are excreted slowly via the feces for approximately seven clays after discontinuation of administration. (3)
Mechanisms of Action
Despite the transient nature of this organism in the digestive tract, it is thought to produce a shift in the intestinal environment in support of a complex gastrointestinal flora. (6-8) This is presumed to be a result of improving gastrointestinal ecology by replenishing the quantity of desirable obligate microorganisms and antagonizing pathogenic microbes. (3,6)
B. coagulans has also been shown in vitro to produce bacteriocins, (3) bacteriocin-like substances, (9) and short-chain fatty acids that nourish the colonic mucosa. (10) Bacteriocins are peptides produced by some strains of bacteria that inhibit the growth of other bacteria. Coagulin,...