Anette Wind

This review presents selected data on the probiotic strain Bifidobacterium animalis subsp. lactis BB-12(®) (BB-12(®)), which is the world's most documented probiotic Bifidobacterium. It is described in more than 300 scientific publications out of which more than 130 are publications of human clinical studies. The complete genome sequence of BB-12(®) has been determined and published. BB-12(®) originates from Chr. Hansen's collection of dairy cultures and has high stability in foods and as freeze dried powders. Strain characteristics and mechanisms of BB-12(®) have been established through extensive in vitro testing. BB-12(®) exhibits excellent gastric acid and bile tolerance; it contains bile salt hydrolase, and has strong mucus adherence properties, all valuable probiotic characteristics. Pathogen inhibition, barrier function enhancement, and immune interactions are mechanisms that all have been demonstrated for BB-12(®). BB-12(®) has proven its beneficial health effect in numerous clinical studies within gastrointestinal health and immune function. Clinical studies have demonstrated survival of BB-12(®) through the gastrointestinal tract and BB-12(®) has been shown to support a healthy gastrointestinal microbiota. Furthermore, BB-12(®) has been shown to improve bowel function, to have a protective effect against diarrhea, and to reduce side effects of antibiotic treatment, such as antibiotic-associated diarrhea. In terms of immune function, clinical studies have shown that BB-12(®) increases the body's resistance to common respiratory infections as well as reduces the incidence of acute respiratory tract infections.

The increased use of food cultures to ferment perishable raw materials has potentiated the need for regulations to assess and assure the safety of food cultures and their uses. These regulations differ from country to country, all aimed at assuring the safe use of food cultures which has to be guaranteed by the food culture supplier. Here we highlight national differences in regulations and review a list of methods and methodologies to assess the safety of food cultures at strain level, at production, and in the final product.

Classified as a distinct species in 1980, Lactobacillus reuteri strains have been used in probiotic formulations for intestinal and urogenital applications. In the former, the primary mechanism of action of L. reuteri SD2112 (ATCC 55730) has been purported to be its ability to produce the antibiotic 3-hydroxypropionaldehyde (3-HPA), also known as reuterin. In the vagina, it has been postulated that probiotic Lactobacillus reuteri RC-14 does not require reuterin production but mediates a restoration of the normal microbiota via hydrogen peroxide, biosurfactant, lactic acid production, and immune modulation. The aim of the present study was to determine whether strain RC-14 produced reuterin. Using PCR and DNA dot blot analyses, numerous Lactobacillus species, including RC-14, were screened for the presence of the gene encoding the large subunit of glycerol dehydratase (gldC), the enzyme responsible for reuterin production. In addition, lactobacilli were grown in glycerol-based media and both high-performance liquid chromatography and a colorimetric assay were used to test for the presence of reuterin. L. reuteri RC-14 was determined to be negative for gldC sequences, as well as for the production of reuterin when cultured in the presence of glycerol. These findings support that the probiotic effects of L. reuteri RC-14, repeatedly demonstrated during numerous studies of the intestine and vagina, are independent of reuterin production.