Bacillus Subtilis - Safety

Safety

B. subtilis is only known to cause disease in severely immunocompromised patients, and can conversely be used as a probiotic in healthy individuals. It rarely causes food poisoning. Some B. subtilis strains produce the proteolytic enzyme subtilisin. B. subtilis spores can survive the extreme heat during cooking. Some B. subtilis strains are responsible for causing ropiness — a sticky, stringy consistency caused by bacterial production of long-chain polysaccharides — in spoiled bread dough. For a long time, bread ropiness was associated uniquely with B. subtilis species by biochemical tests. Today, molecular assays (randomly amplified polymorphic DNA PCR assay, denaturing gradient gel electrophoresis analysis, and sequencing of the V3 region of 16S ribosomal DNA) revealed greater Bacillus species variety in ropy breads which all seems to have a positive amylase activity and high heat resistance.

The Bacillus subtilis microbial strain and substances derived from this microorganism were subjects of evaluation by different authoritative bodies for their safe and beneficial use in food and has been regarded as not presenting safety concerns. In the United States an opinion letter issued in the early 1960s by the Food and Drug Administration (FDA) recognized some substances derived from microorganisms as GRAS, including carbohydrase and protease enzymes from Bacillus subtilis. The opinions are predicated on the use of non-pathogenic and non-toxicogenic strains of the respective organism and on the use of current good manufacturing practice (FDA partial list of microorganisms, 2002).

The FDA concluded that the enzymes derived from the B. subtilis strain were in common use in food prior to January 1, 1958. The FDA stated that non-toxigenic and non-pathogenic strains of B. subtilis are widely available and have been safely used in a variety of food applications, including the documented consumption of B. subtilis in the Japanese fermented soy bean, natto. Natto, which is commonly consumed in Japan, contains as many as 108 viable B. subtilis per gram. The natto fermented beans are recognized for their contribution to a healthy gut flora and vitamin K₂ intake; during this long history of widespread use natto has not been implicated in any adverse events potentially attributable to the presence of B. subtilis. The unique strain of Bacillus subtilis R0179 which is genetically comparable to that found in natto, received the non-novel status in Canada based on history of consumption meaning that this specific strain can safely be used as a probiotic to conventional foods. The strain R0179 also received the self-affirmed GRAS status in January 2012.

The natto product and the Bacillus subtilis natto as its principal component are FOSHU approved in Japan. The Foods for Specified Health Use (FOSHU) are the foods approved by the Ministry of Health, Labor and Welfare as effective for preservation of health by adding certain active ingredients or removing undesirable ones. They are designed to be safe and effective for the maintenance and improvement of health by incorporating them into one’s diet. The Japanese FOSHU products are products the safety and efficacy of which have been verified scientifically.

The Association of American Feed Control Officials (AAFCO) has listed Bacillus subtilis approved for use as a feed ingredient under Section 36.14 Direct-Fed Microorganisms. This microorganism was reviewed by the Food and Drug administration Center for Veterinary medicine and found to present no safety concerns when used in direct-fed microbial products. The Canadian Food Inspection Agency (CFIA)-Animal health and production Feed Section has classified Bacillus culture dehydrated approved feed ingredients as a silage additive under Schedule IV-Part 2-Class 8.6 and assigned the International Feed Ingredient number IFN 8-19-119.

The Bacillus subtilis species has a long history of safe use. It has been granted Qualified Presumption of Safety (QPS) status by the European Food Safety Authority (EFSA) and is part of the authoritative list of microorganisms with a documented history of safe use in food established by the International Dairy Federation (IDF) in collaboration with the European Food and Feed Cultures Association (EFFCA) in 2002 and updated in 2012.