Probiotic therapy in its rudimentary form originated in the Near and Middle East, where ancient physicians prescribed fermented milks for the treatment of various diseases, including tuberculosis and gastrointestinal disorders. Clinical interest in fermented milks and their role in human health was triggered by a Russian physician, E. Metchnikoff, who attributed the longevity of people in the Balkan countries to the regular consumption of fermented milk. The healthful properties of fermented milk are provided by the indigenous lactobacilli, which are also normal inhabitants of the human gastrointestinal tract, skin and vaginal mucosa.
Lactobacillus therapy has been shown to be effective in the treatment of a variety of disorders, including gastrointestinal disorders, vaginal infections, hepatic encephalopathy, hypercholesterolemia and conditions related to deficiency of vitamins B. Lactobacilli have proved to be useful in delaying the induction of tumors and have found use in the prevention of colon cancer. Lactobacilli are thus valuable therapeutically and are often used as adjuvants to antibiotic therapy. They also find use as growth enhancers for domestic animals and poultry.
Lactobacilli through their metabolic processes prevent the growth of putrefactive organisms by competitive inhibition, the generation of a non-conducive acidic environment and the production of bacteriocins. They improve the digestibility of ingested food constituents and the bioavailability of nutrients, possess hypocholesterolemic activity and enhance the immune response.
The therapeutically used species of Lactobacillus include L. acidophilus , L. brevis, L. casei, L. bulgaricus and L. bifidus. However, the evidence for effectiveness of implantation, survival and proliferation of these organisms in the gut are not impressive.
A superior species, which is effectively implanted in the gut, is semi-resident and can survive the gastric acidity and bile is L. sporogenes*. This organism forms spores which are protected by nature’s own microencapsulation system and germinate into viable cells in the intestine, which can then proliferate extensively. Clinical trials with L. sporogenes* have proven successful in the treatment of gastrointestinal disorders, non-specific vaginitis, aphthous stomatitis, hepatic encephalopathy and in growth improvement of farm animals. L. sporogenes* is therefore the probiotic of choice in clinical applications .
* The taxonomical classification was revised in 1939 in the seventh edition of the Bergey’s Manual of Determinative Bacteriology to B. coagulans, although some researchers continued to use the original name.