Safety & Efficacy

The Safety and Efficacy of Bacillus sp. as Probiotics:
A Brief Review By:
Professor Lee B. Dexter / Summer 2010

Introduction: Probiotics or "friendly bacteria" are now being recognized in the United States for their ability to improve the health of consumers. Americans are now finding out, what has long been known in Europe, that specific species and strains of bacteria can improve resistance to pathogenic bacteria, aid in lactose digestion, modulate the immune system, prevent overgrowth of bacteria in the small intestine, reduce blood lipids, reduce blood pressure, and help to alleviate allergies, urogenital infections, Helicobacter pylori infections, and hepatic encephalopathy20. Acceptance of these phenomena by scientists in the U.S. has been slow in coming. But the evidence has been mounting; so much so, that the mainstream, Institute of Food Technologists has issued an Expert Panel Report on the most common of these organisms and has sponsored a symposium on their use at a recent annual meeting.21 *

Clearly, there is much more to learn about how these organisms interact with the body, and with each other to produce these effects. The most advanced formulators of probiotic products have recognized the fact that each person carries about three to four and a half pounds of active bacteria in their colon, and that the products of these bacteria can have a profound effect on the body's health and metabolism.2 It is for that reason that researchers around the world have been investigating the safety and efficacy of potential probiotic species, including those in the genus Bacillus.16 *

Bacillus spp. as Probiotics Several strains of Bacillus sp. are in use as probiotics today in both the U.S., Europe, and Southeast Asia.9, 10, 11 These probiotics include strains of the species subtilis and licheniformis.12 Strains of these organisms have been included in the group of probiotic organisms for several reasons. First viable spores of both species have been found to enhance the growth of various species of Lactobacillus, suppress the growth of pathogenic organisms, such as E. coli 078:K80 and Helicobacter pylori, and produce antibiotic substances, which retard the growth of harmful organisms, and help the body restore its natural flora. 12, 9, 10, 18 For example, both Bacillus subtilis and Bacillus licheniformis are widely used in probiotic formulas in the livestock and poultry industries, especially in Europe, where the feeding of antibiotic growth promoters has been banned. In this instance, the spores of these organisms act as competitive exclusion agents. One study showed that 1-day old chicks, who consumed 2.5 X 108 (250,000,000) Bacillus subtilis spores, were able to completely resist infection by the pathogenic E. coli strain mentioned above.9, 10 As to Bacillus licheniformis, any reader who has ever had skinned knees will recognize one of the antibacterial substances produced by this organism. Bacitracin has been incorporated into antiseptic ointments for several decades.*

Both Bacillus subtilis and Bacillus licheniformis are spore-forming bacteria found in the soil, and particularly in the case of Bacillus subtilis may also be a frequent resident on human skin.1, 3, 9 Since these organisms are not as familiar to the consumer as Lactobacillus, the natural question that arises is, "Are these organisms safe to take as probiotics"? *

When the U.S. Food and Drug Administration review the safety of a food ingredient, the agency considers whether or not the food substance has a history of safe consumption. That is, was there significant consumption of the food ingredient either within the U.S. or other countries prior to January 1, 1958? If not, does the preponderance of scientific evidence indicate that there is a consensus among scientists that the particular material is safe? *

In food safety questions, the identity of the material to be considered is extremely important. This principle is even more important, where the safety of bacteria is concerned. Bacteria are identified according to a taxonomic system. This means that all characterized bacteria are classified by genus, species, and a strain within a species. Each species may have hundreds or even thousands of strains. *

An example may illustrate this point. The media has made nearly everyone familiar with E. coli. However, E. coli is a normal resident of the human body. It occurs in numbers of 10 8.6/ gram of feces (860,000,000/gram) in the human colon.2 The vast majority of the thousands of strains of the species coli are not disease producing. Further, recent peer-reviewed published research has shown that non-pathogenic non-toxigenic E. coli can be used as a probiotic to promote the health of the gastrointestinal tract, and can be taken orally to treat various diseases. 5, 7, 13, 14, 20 One paper showed that the immune system was stimulated in a positive direction, when humans consumed the bacteria at levels of 1.0 X 108 (100,000,000) cells daily for 14 days.13 Non-pathogenic wild-type E. coli strains have been used as probiotics in Europe for at least two decades. Yet, most individuals remember only the most well known pathogenic strain of E. coli O157:H7. This strain is a true pathogen, in that it is capable of crossing a barrier in a healthy individual.17 While many microorganisms, including widely used industrial species like those responsible for the production of bread and beer, can be associated with incidental infections in immune-compromised people, they do not fit the definition of a pathogen, as described above. *

Regulatory agencies around the world have considered these distinctions, when they recognized the safety of wild-type strains of both Bacillus subtilis and Bacillus licheniformis. 4,9 Wild type strains, (of both organisms or their metabolic products,) have a long history of being consumed by humans. Bacillus subtilis is the organism responsible for the Japanese soybean-based condiment, natto, which has been consumed for more than 1,000 years.11 In the U.S. various species of Bacillus have been approved to produce familiar food-grade enzymes.4 These enzyme preparations (many of which may contain all or portions of the entire culture medium, including the cells) have been approved as generally recognized as safe (GRAS), or as food additives. A partial list of these enzyme preparations and their Code of Federal Regulations citation appears below. *

Traditional strains of Bacillus sp. are considered non-pathogenic and harmless by researchers on several continents. 8, 9, 11, 12 However, it is the responsibility of each probiotic formulator to chose appropriate strains with respect to safety and functionality from among the many considered food-grade. *

The Bacillus Genetic Stock Center, which is supported by the National Science Foundation maintains nearly 1,000 strains of Bacillus subtilis and tens of strains of other Bacillus species. According to an international group of researchers publishing in Applied and Environmental Microbiology, the real frontier in probiotic research seems to be directed towards choosing the right strain for the job and attempting to understand how Bacillus spores achieve their beneficial effect on the colonic microflora.10 *

This new area, called spore probiotics, may have certain advantages when used in combination with non-spore forming probiotics, like Lactobacillus sp. In nature Bacillus sp. are often found in conjunction with other probiotics as part of stable groups of bacteria called "consortia." Consortia are assemblages of microorganisms, in which each organism benefits from the metabolic activities of others in the group. Such naturally occurring consortia are known to be quite stable during transfer from one culture to another, and to retain their functional integrity better than single organisms alone or combinations of single species 24 , 25. During growth these naturally occurring consortia produce their own matrix that surrounds the living cells, and they reach an ideal balance between species. This means that some organisms die back and others multiply within a culture, so that the functionality of the group is maintained. *

As an example, spores are able to survive transit through the gut more easily than non-spore-formers, and some evidence suggests that they may exert an influence on lymph nodes, promoting local immunity. As mentioned above there is also evidence that members of consortia protect each other along their journey down the gastrointestinal tract, possibly by secreting hydrogen peroxide in tiny amounts along with specific antimicrobials. 12, 9, 10, 18 Thus spore formers may serve as part of an "advance guard" for members of their consortia. Researchers have also shown that the spores, although not fully capable of growth and reproduction in the colon due to its anaerobic environment, may produce their effects through biochemical signaling mechanisms. *

While this area remains the subject of active research, it is likely that humans consuming probiotics would receive the most benefit if the product they were consuming contained naturally occurring consortia. Bacteria within these consortia are already "team players", who function together to produce desirable health benefits, often multitasking to fight off bad bacteria or fungi on one hand, while interacting with the immune system, and the lining of the colon on the other. Products containing consortia allow consumers to take advantage of a system that has already been honed by nature. As an example one product which contains a natural consortium of soil-based probiotics is Body Biotics™ by Life Science Products, Inc. This 35 year old formula may well be the only probiotic product that is based on a natural consortium on the market today. *

Summary Bacterial strains of the genus Bacillus are currently being marketed in probiotic formulations for both humans and livestock. International teams of scientists have been actively investigating their use to provide bacteriotherapy for gastrointestinal disorders. In combination with other probiotics the spore-forming Bacilli enhance the growth of Lactobacillus sp., and suppress the growth of harmful microorganisms. Various Bacillus species have a long history of safe use in human nutrition, and are widely recognized as non-pathogenic by regulatory authorities. Bacilli are often found in symbiotic groups of naturally occurring probiotics called consortia. Consortia represent stable cultures of bacteria that produce desired heath effects in the gastrointestinal tracts of consumers who consume them on a regular basis. One source of a natural consortium of soil-based probiotics is Body Biotics™ by Life Science Products, Inc. This product may be the only probiotic product providing a natural consortium of probiotics on the market today. *

* Note: These customer statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
Food-Grade Enzymes Derived from Various Bacillus Species

Enzyme/Source Chemical Abstracts Registry # 21 Code of Federal Regulations #

Alpha-Acetolactate 977164-02-5 173.115
Decarboxylase Enzyme Preparation from Bacillus sp.
Alpha-Amylase 098002-53-0 184.1012
Enzyme Preparation from Bacillus stearothermophilus
Carbohydrase from 977184-71-6 184.1148
Bacillus amyloliquefaciens
Carbohydrase from 977031-70-1 184.1148
Bacillus subtilis
Carbohydrase/ 977083-17-2 184.1027
Proteinase Preparation from Bacillus licheniformis
Glucose Isomerase 977042-63-9 184.1372 from Bacillus coagulans
Milk Clotting Enzyme 977017-74-5 173.150
from Bacillus cereus
Protease from 977031-93-8 184.1150
Bacillus amyloliquefaciens
Protease from 051931-23-8 184.1150
Bacillus subtilis