This article appeared on the website of Nebraska Cultures
For centuries the lactic acid bacteria have been used for the preservation of food for human consumption. It has been well documented that certain types of lactobacilli and bifidobacteria are essential or desirable for optimal health. Metchnikoff (1) was perhaps the first researcher, who in 1908 suggested that the long life span of the Balkans be perhaps due to the ingestion of large quantities of lactobacilli and other lactic organisms through fermented foods, which inhibit pathogens and detoxify their system. At the University of Nebraska research on Lactobacillus acidophilus was started as early as 1925 over 74 years ago. For the past 40 years, scientists headed by Dr. Khem M. Shahani have worked on L. acidophilus, L. bifidus (now renamed as Bifidobacterium bifidum) and other lactic cultures and have published more than 60 scientific papers.
Health promoting or prophylactic properties of lactic acid bacteria were found to be dependent on the inherent properties of each strain rather than on the common characteristics of the bacterial species. It has also been demonstrated conclusively by Dr. Shahani's group that there exist considerable differences among different strains of L. acidophilus. In fact, the same strain grown under different conditions would show different property (26). They observed that a specially isolated and cultured strain of L. acidophilus DDS-1 grown and produced under specific conditions has properties of great significance for digestion and nutrition and in other physiological conditions like health and prophylaxis.
These beneficial properties of L. acidophilus, particularly L. acidophilus DDS-1, based on research documented in internationally reputable, refereed journals are as follows:
Nutritional, Prophylactic and Antibiotic Properties of L. Acidophilus DDS-1
It is probable that the observed variations in the anticarcinogenic, hypocholesterolytic and antibiotic effects of lactobacilli may be related to the extent of the production and/or activation of immune factors in the system. In general, lactobacilli lack any antifungal activity. However, the observed beneficial effect of certain lactobacilli on candidiasis under certain conditions may be, in part at least, related to the immunological augmentation or activation in the host.
- Enzyme production - such as proteases which help digest proteins and lipases to digest fat (2,3).
- Production of B vitamins which are biocatalysts in food digestion, particularly folic acid and B12 (4,5).
- They improve the digestibility of food for animals(6).
- They produce natural antibiotics - like Acidophilin from L. acidophilus DDS-1 (which has been patented) and Bulgarican from L. bulgaricus (7,8,9).
- They inhibit the growth of 23 toxic producing microorganisms (9,10).
- L. acidophilus DDS-1 and certain yogurt cultures (L. bulgaricus and S. thermophilus) appear to possess great potential as anticarcinogenic and antitumor properties (11,12).
- They may help in the alleviation of lactose intolerance caused by the deficiency of the enzyme lactase. Such L. acidophilus cultures produce significant quantities of lactase, which may help digest lactose more fully and thereby reduce the possibility of bad breath, bloating, gas development and stomach cramps (13,14).
- Additional research with Lactobacilli from this laboratory as well as by other scientists has revealed that:
- L. acidophilus, by virtue of their inhibiting gastrointestinal and uropathogens, may help reduce the occurrence of diarrhea and urinary & vaginal infection (15,16, 17).
- L. acidophilus helps enhance calcium metabolism, which may be related to their hypocholesteremic and anticarcinogenic effect as well as prevention and/or cure of osteoporosis (18,19).
- Helps reduce serum cholesterol levels (18,10).
- Helps alleviate dermatitis and other skin disorders by modifying and improving gastrointestinal microbial balance (21).
- Aids in the production and/or augmentation of immune bodies and their functions (22,23,24,25).
ANTICARCINOGENIC AND IMMUNOMODULATING ROLE OF L. ACIDOPHILUS DDS-1
Further, in a recent study (30), L. acidophilus DDS-1 was demonstrated to prevent tumor formation in rats challenged with a chemical carcinogen. The mechanism of cancer prevention/prophylaxis may involve (a) inhibiting the growth of putrefactive bacteria and in turn reducing the production of N-nitrosocompounds. (b) Direct reduction of secondary nitrites and bile salts, etc, since our earlier studies indicated that DDS-1 lowered the rate of conversion of primary bile salts into its secondary derivatives(31). (c) Stimulation of intraperitoneal macrophages and their enzymes may play a role in the antitumor effect of DDS-1. Our other studies with DDS-1 confirmed the immunostimulatory role of this bacterium in stimulating macrophages and inducing the cytokines Interleukin-1-alpha and tumor necrosis factor-alpha (32), which are known to exert cytostatic and cytocidal effects on tumor cells.
ADDITIONAL CRITERIA OF FACTUALLY BENEFICIAL ACIDOPHILUS
To assure that L. acidophilus possesses these nutritional and therapeutic properties, it must implant and multiply rapidly in the gut to avoid its being expunged entirely. Hence for gut inhabitation L. acidophilus must not only be able to tolerate and pass through the high stomach activity (low pH), but also be able to grow and proliferate at physiological levels of bile salts and adhere to the intestinal epithelial cells.
L. acidophilus strains are known to differ tremendously in their ability to grow in the presence of bile salts. Bile salts, produced by the gall bladder, are essential in helping to emulsify fat before it can be digested in the intestine (16). L. acidophilus DDS-1 has been reported to be highly resistant to several commonly known antibiotics like penicillin, streptomycin, aureomycin, etc. Such antibiotic resistance of L. acidophilus DDS-1 is a paramount importance because it can be taken simultaneously or soon after an individual has been on antibiotic therapy. Common antibiotic therapy not only kills the pathogenic bacteria but also kills "friendly bacteria" like lactobacilli and streptococci and may upset gastrointestinal microbial balance. L. acidophilus DDS-1 may thus help in restoring the optimal microbial balance in the gut.
MANUFACTURE OF FREEZE DRIED L. ACIDOPHILUS DDS-1
An exclusive, unique process involving growth in a well-defined and highly nourishing medium for this special strain is used for manufacturing L. acidophilus DDS-1. In the manufacturing process the microorganisms are concentrated first by removing unspent liquid medium by sedimentation, ultrafiltration, reverse osmosis, and/or centrifugation. As far as is known, the viability of the cells is not damaged at all during sedimentation, ultrafiltration, reverse osmosis or centrifugation. To the intact cell concentrate is then added a definite cryoprotectant before freezing to prevent "freezer damage" to the bacteria (29).
Following freezing, the mass is freeze-dried in a specially designed unit. The final product is then subjected to fine screening and quality control involving at least 20 to 15 tests. When the product passes all the rigorous tests, it is then mixed with a natural stabilizer to prevent the loss of its viability during packaging, shipping, storage, marketing and consumption.
Stability: L. acidophilus DDS-1 is highly stable even under adverse conditions of manufacture and storage. Normally, microorganisms such as L. acidophilus are affected adversely by heat, humidity (moisture), light and oxygen (air). The unique process of manufacturing DDS-1 coupled with the addition of a suitable cryoprotectant and specially designed natural stabilizer, protect the microorganisms against heat, humidity, light and oxygen (from air), providing stability unsurpassed as far as is known.
During the past 20 years or so, as a part of our ongoing research program on probiotics at the University of Nebraska, more than 155 acidophilus products collected from U.S.A. and abroad were examined and enumerated. Almost 70 to 80% of the samples did not measure up to numerical claims. In fact, nearly 50% of the samples did not have even 10% of the claimed number of live microorganisms. For example, if the product was supposed to have 5 billion/gm, it did not have even 500 million/gm. More than 40 to 50% of the product had more than one species (acidophilus). Several products had even microorganisms belonging to genus other than Lactobacillus - e.g. In addition to L. acidophilus they had Streptococcus lactis. Several of the samples even had undesirable or pathogenic organisms present. These are not only our observations but also at least two or three papers in scientific journals authored by very renowned microbiologists have reported essentially similar results (27,28).
- Metchnikoff, Eli. 1908. The Prolongation of Life. Ed. P. Chalmers Mitchell, G. P. Putnam's Sons, The Knickerbocker Press, New York & London.
- Lee, H., B. A. Friend, and K. M. Shahani. 1988. Factors affecting the protein quality of yogurt and acidophilus milk. J. Dairy Sci. 71:3203-3214.
- Fernandes, C. F., K. M. Shahani, and M. A. Amer. 1987. Therapeutic role of dietary lactobacilli and lactobacillic fermented dairy products. FEMS Microbiol. Rev., 46:343-356.
- Shahani, K. M. and A. D. Ayebo. 1980. Role of dietary lactobacilli in gastrointestinal microecology. Proc. VI Intern'l Symp. Intestinal Microecol. Am. J. Clin. Nutr. 33:2448-2457.
- Rao, D. R. and K. M. Shahani. 1987. Vitamin content of culture dairy products. Cultured Dairy Prod. 22(1): 6-10.
- Pollman, D. S., D. M. Danielson, W. B. Wren, E. R. Peo, and K. M. Shahani. 1980. Influence of Lactobacillus acidophilus inoculum on gnotobiotic and conventional pigs. J. Ani. Sci., 51:629-637.
- Shahani, K. M., J. R. Vakil, and A. Kilara. 1976. Natural antibiotic activity of L. acidophilus and bulgaricus. I. Cultural conditions for the production of antibiosis. Cultured Dairy Prod. J., 11(4): 14-17.
- Shahani, K. M., J. R. Vakil, and A. Kilara. 1977. Natural antibiotic activity of L. acidophilus and bulgaricus. II. Isolation of acidophilin from L. acidophilus Cultured Dairy Prod. J. 12(2): 8-11.
- Shahani, K. M., J. R. Vakil, and R. C. Chandan. 1972. Antibiotic acidophilus and the process for preparing the same. U. S. Patent 3,689,640. Sept. 5.
- Reddy, G. V., K. M. Shahani, B. A. Friend, and R. C. Chandan, 1983. Natural antibiotic activity of L. acidophilus and bulgaricus. III. Production and partial purification of bulgarican from L. bulgaricus. Cultured Dairy Pro. J., 18(2): 15-19.
- Fernandes, C. F., K. M. Shahani, W. L. Staudinger and M. A. Amer. 1991. Mode of tumor suppression by Lactobacillus acidophilus. J. Nutr. Medicine, 2:25-34.
- Bottazzi, V., B. A. Friend, and K. M. Shahani. 1985. Properta antitumorali dei batteri lattici e degl. alimenti fermentati con batteri lacttici. II Latte, 10:873-879.
- Fernandes, C. F., and K. M. Shahani. 1989. Lactose intolerance and its modulation with Lactobacilli and other microbial supplements. J. Appl. Nutr., 41:50-64.
- Gilliland, S. E. 1990. Health and Nutritional benefits from lactic acid bacteria. FEMS Microbiol. Rev. 87:175-188.
- Fernandes, C. F., K. M. Shahani, and M. A. Amer. 1988. Control of diarrhea by lactobacilli. J. Appl. Nutr. 40:32-43.
- Fernandes, C. F., K. M. Shahani, and M. A. Amer. 1988. Effect of nutrient media and bile salts on growth and antimicrobial activity of L. acidophilus. J. Dairy Sci., 71:3222-3228.
- Chandhan, R. C. Y., G. Reid, R. T. Irvin, A. W. Bruce, and I. W. Costerton. 1985. Competitive exclusion of uropathogens from human uroepithelial cells by Lactobacillus. Infect. Immun., 47: 84-89.
- Kaup, S. M., K. M. Shahani, and M. A. Amer. 1987. Bioavailability of calcium in yogurt. Milchweissenschaft, 42:513-516.
- Lipkin, M., and H. Newmark. 1985. Effect of added dietary calcium on colonic epithelial cell proliferation in subjects with high risk for familiar colonic cancer. N. Engl. J. Med., 313:1381-1384.
- Danielson, A. D., E. R. Peo, Jr., K. M. Shahani, A. J. Lewis, P. J. Whalen, and M. A. Amer. 1989. Anticholesteremic property of L. acidophilus yogurt fed to mature boars. J. Ani. Sci. 67: 966-974.
- Ionescu, G., E. W. Jeaht, R. Linebeck, and K. M. Shahani. 1988. Orale Lactobazillen bei atopischem ekzem. Ortho Suppl. 2:1-4.
- DeSimone, C. et al., 1986. The adjuvant effect of yogurt on gamma interferon by Con-A stimulated human lymphocytes. Nutr. Repts. Intern'l., 33:419-333.
- Perdigon, G. et al., 1986. Effect of perorally administered lactobacilli on microphage. Infect. Immun. 53:404-410.
- Shahani, K. M., C. F. Fernandes and M. A. Amer. 1987. Effect of yogurt on intestinal flora and immune responses. Proc. Symp. on Yogurt-Union of Belgian Dairy Industry, pp. 57-67.
- Fernandes, C. F. and K. M. Shahani. 1990. Anticarcinogenic and immunological properties of dietary lactobacilli. J. Food Prot., 53:704-710.
- Bhatia, V. 1991. Growth optimization of Lactobacillus acidophilus in whey, M.S. Thesis, Univ. of Nebraska, Lincoln.
- Gilliland, S. E. and M. L. Speck. 1977. Enumeration and identity of lactobacilli in dietary products. J. Food Prot. 40:760-762.
- Brennan, M., B. Wanismail, and B. Ray. 1983. Prevalence of viable Lactobacillus acidophilus in dried commercial products. J. Food Prot. 46:887-892.
- Kilara, A., K. M. Shahani, and N. K. Das. 1976. Effect of cryoprotective agents on freeze- drying and storage of lactic cultures. Cultured Dairy Prod. J., 11:8-12.
- Lee, H., N. Rangavajhyala, C. Grandjean, K.M. Shahani. 1996. Anticarcinogenic effect of Lactobacillus acidophilus on N-nitrosobis (2-oxopropyl)amine induced colon tumor in rats. J. Appl. Nutr., 48:59-66.
- Ho Lee, N. Rangavajhyala, C.J. Grandjean and K.M. Shahani (1995). Inhibitory effect of Lactobacillus acidophilus on transformation of bile acid by human fecal microflora. Microbiologie Aliments Nutrition, 13, 241-247.
- Rangavajhyala, N., S. Srikumaran, G. Sridevi, and K. M. Shahani. 1997. Non- lipopolysaccharide component(s) of Lactobacillus acidophilus stimulate(s) the production of IL-1-alpha and TNF-alpha by murine macrophages. Nutrition and Cancer 28:130-134.