The following are microorganisms considered to be human Probiotics:
Lactobacillus species: L. acidophilus, L. amylovorus, L. brevis, L. casei, L. casei subsp. rhamnosus (Lactobacillus GG), L. caucasicus, L. crispatus, L. delbrueckii subsp. bulgaricus (L. bulgaricus), L. fermentum (L. fermenti), L. gasseri, L. helveticus, L. johnsonii, L. lactis, L. leichmannii, L. paracasei, L. plantarum, L. reuteri, L. rhamnosus
Bifidobacterium species: B. adolescentis, B. bifidum, B. breve, B. infantis, B. lactis (B. animalis), B. licheniformis, B. longum
Other lactic acid bacteria: Enterococcus faecium, Lactococcus lactis, Leuconstoc mesenteroides, Pediococcus acidilactici, Streptococcus thermophilus
Nonlactic acid bacteria: Bacillus subtilis, Escherichia coli strain nissle, Saccharomyces boulardii, Saccharomyces cerevisiae
Lactobacillus organisms are normal inhabitants of the human intestine and vagina. They are the main ones that produce lactic acid in the digestive tract, which is important for overall health. Some nutritional benefits gained from lactic acid include an improved nutritional value of food, control of intestinal infections, improved digestion of lactose, control of some types of cancer, and control of serum cholesterol levels.
Lactobacilli are gram-positive facultative anaerobes; non-spore forming; and non-flagellated, rod or coccobacilli. To date, some 56 species of Lactobacillus have been identified.
L. acidophilus is the most commonly known probiotic bacterium. It is found primarily in the small intestine where it produces natural Antibiotics
called “lactocidin” and “acidophilin”. These increase immune resistance against such harmful bacteria and fungi as Candida albicans, Salmonella, E. coli, and Staphylococcus aureus.
L. acidophilus implants itself on the intestinal walls, as well as on the lining of the vagina, cervix, and urethra, thereby preventing other organisms from multiplying to the extent that they can cause infections. For years, it was assumed that it was the most beneficial form of the “good” bacteria; but recent research has revealed that L. rhamnosus may be just as important.
L. acidophilus helps control intestinal infections, thus reducing the potential of diarrhea and other infections or diseases. It also inhibits some types of cancer and helps control serum cholesterol levels. However, reaching the intestines is the problem because the L. acidophilus found in most commercial yogurts cannot live with stomach acids and bile.
L. amylovorus is a bacterium found normally in the intestinal tract of animals and humans, as well as in the mouth and vagina of humans. It can sometimes be found in acidophilus milk, but it is mainly being studied as a potential for a silaging agent and a commercial producer of lactic acid.
L. brevis is a lactic acid-producing organism important in the synthesis of vitamins D and K. Research studies have shown that L. brevis decreases intestinal permeability (leaky gut syndrome), improves intestinal micro flora, and has a positive effect on the intestinal immune system. A recent study showed that this friendly bacterium also has a positive effect in eliminating the ulcer-causing bacteria Heliobacter pylori.
L. bulgaricus is an important bacterium used in fermenting yogurt. It helps produce lactic acid, thereby providing a good environment for other beneficial bacteria to grow, especially Lactobacilli and Bifidobacterium. It was the first organism to be implicated in providing benefits to human health and so named after its discoverer, a Bulgarian scientist, when he isolated it from yoghurt cultures in 1908.
L. bulgaricus is considered to be a transient microorganism. This means that it does not implant itself in the intestinal tract, but roams throughout providing an important protective role. Studies indicate that certain strains of L. bulgaricus improve the digestion of milk, and stimulates the production of “interferon” and “tumor necrosis factor”, regulators of the immune system. L. bulgaricus assists in the metabolism of lipids (fats) and may help control cholesterol levels. It also produces natural Antibiotic
substances and helps reduce the proliferation of less desirable microorganisms.
L. caseii is closely related to L. acidophilus and L. rhamnosus. It secretes a substance called “peptidoglycan”, which supports the natural defences of the body and stimulates immune responses in the intestinal tract. L. casei has demonstrated effectiveness in increasing circulating IgA (immunoglobulin A) in infants infected with rotavirus and has shortened the duration of associated diarrheal episodes.
As with many of the Lactobacillus strains, this one also has some of the same immune-enhancing effects provided through the production of “bacteriocins”, compounds that inhibit the growth of pathogenic bacteria in the small intestine. In a 2003 issue of the Journal of Nutrition Health and Aging, fermented milk containing the probiotic L. caseihad a positive effect on lessening winter infections in the elderly. It is a highly prolific organism and has strong resistance to digestive enzymes.
L. caseii rhamnosus (Lactobacillus GG) is a name given in honor its discoverers, Drs. Sherwood Gorbach and Barry Golden who isolated the bacterium in 1985. Lactobacillus GG does survive and grow in the acidic environment of the digestive tract. Once there, it shows an exceptional ability to adhere to the intestinal mucosa and proliferate.
According to the November 1999 Journal of Pediatrics, when it was given to children who were taking Antibiotics
for minor bacterial infections, Lactobacillus GG reduced the number and severity of the bouts of diarrhea, including those hospitalized with rotavirus. It has also been successful in eradicating Clostridium difficile in patients with relapsing colitis. During research experiments,Lactobacillus GG demonstrated the ability to inhibit chemically induced intestinal tumors, as well as binding to some chemical carcinogens.
Lactobacillus GG and Bifidobacterium lactis were found to produce significant improvement of atopic eczema in children with food allergies
. Lactobacillus GG along with other lactic acid bacteria, including strains of Lactobacillus acidophilus, Lactobacillus bulgaricus, Bifidobaterium longum and Streptococcus thermophilus, have also demonstrated antioxidative ability, especially the chelation of metal ions, particularly iron and copper.
L. caucasicus is commonly found in kefir – a word likely originating from the Turkish word "Keif" which means"good feeling". The scientific name “caucasicus” comes from the area of the Caucasus Mountains where shepherds diets consisted mainly of kefir and who often lived to be over 100 years of age.
L. crispatus is a part of the normal vaginal microflora. Lactobacillus organisms help keep the vagina free from infection by producing hydrogen peroxide, a substance that is highly acidic. When the ecology of the vagina is disrupted through infection, douching, or poor hygiene, for example, Lactobacillican die off, leading to a condition known as bacterial vaginosis. In recent studies, L. acidophilus, L. crispatus, and L. delbrueckii subspecies delbrueckii all inhibited bacterial vaginosis-associated species in vitro, causing researchers to conclude that these probiotics might be useful for vaginal recolonization in women with recurrent symptoms. There are vaginal suppositories available in some countries that promote this bacterium to increase vaginal acidity. These suppositories also hold promise as another protective agent against such diseases as gonorrhea and AIDS.
L. fermenti is one of the “friendly flora” bacteria useful in protecting the vaginal area from vaginitis. It is used in making sourdough bread, yogurt, and kefir.
L. gasseri appears to be the main Lactobacillus species that inhabits the human gastrointestinal tract, havving a good survival rate, even in the elderly. Other probiotic organisms (S. thermophilus and L bulgaricus) did not survive when the elderly were given yogurt or pasteurized yogurt. Tests have revealed that L. gasseri plays a significant role in reducing gastic inflammation and in suppressing H. pylori, the ulcer-causing bacterium.
L. helveticus is often used in making Swiss-type cheeses to enhance flavour. It is also added specifically to certain fermented milks. The surprising thing about this bacterium is in the studies conducted on post-menopausal women by the University of Helsinki (2004), L. helveticus proved to have significant effects on bone density and in preventing trabecular bone loss when compared to other milk products that did not contain the organism. In addition, by adding L. helveticus, the results proved to increase bone formation of osteoblasts (bone cells), as well as serum calcium concentrations. The conclusion was that L. helveticus produces superior active components not found elsewhere. In a separate study by the same university, the bacterium also demonstrated some effect on hypertension by lowering blood pressure somewhat.
L. johnsonii is an important probiotic because it survives passage through the digestive tract. It adheres to intestinal cells, blocking the colonization of potentially pathogenic bacteria. L. johnsonii stimulates important mechanisms of the body's natural immune defences, demonstrating the ability to produce an increase in the phagocytic activity of peripheral blood monocytes and granulocytes.
Studies have shown that when fermented products containing this organism were eaten, colonization of the small intestine by E. coli was reduced significantly. In addition, a single oral dose of L. johnsonii was sufficient to suppress all aspects of colonization and persistence of C. perfringens and may be a valuable tool in controling the endemic disease of necrotic enteritis common in the poultry industry. C. perfringens can cause lesions in chicks and food poisoning in humans. Preliminary studies have shown that L. johnsonii may also have a protective effect against Campylobacter jejuni. L. johnsonii has shown not only to help stimulate the immune system but also to help with lactose intolerance and traveller’s diarrhea.
L. lactis is used in the making of some cheeses, as well as in starter cultures for making fermented milk products. The bacterium appears to inhibit both gram positive (eg. listeria) and gram negative (eg. E. coli) pathogens.
L. leichmannii is another bacterium that helps to produce lactic acid and is often used to determine the concentrations of vitamin B12 in products. Normally present in rye grain, it is one of the bacteria use in making German rye bread.
L. paracasei is both acid and bile resistant, meaning it survives the journey through the gastrointestinal tract to lodge in the intestines. Recent research indicates that it is effective in the prevention and treatment of certain types of diarrhea, as well as irritable bowel syndrome. In addition, it has the ability to alter the activity of the intestinal micro flora, modulate the immune system, and perhaps reduce the risk of some cancers.
Studies have also been done as to its effects on the intestinal microflora of the elderly. When fermented milk products containing L. paracasei were consumed twice daily, dramatic reductions in the occurrences of Clostridium difficile and Helicobacter pylori were noticed in the elderly. In addition, it was also noticed that there was an increase in the numbers of other Lactobacillus strains.
In other studies from the University of Nebraska, it was found that the transport of L. paracasei was reduced significantly with the use of glucose, fructose, and sucrose, but that other mono-, di-, and trisaccharides did not affect it nearly as much.
L. plantarum has been studied for the treatment of recurrent Clostridium difficile-associated diarrhea and for Candida yeast infections. A particular strain called “299v”, derived from sour dough and used to ferment sauerkraut and salami, has demonstrated that it can improve the recovery of patients with enteric bacterial infections. The adherence of this bacterium reinforces the barrier function of the intestinal mucosa, thus preventing the attachment of the pathogenic bacteria.
L. plantarum has many significant uses including:
Preserving key nutrients, vitamins, and antioxidants
Manufacturing vitamins B1, B2, B3, B5, B6, B12, vitamins A and K, and short chain of fatty acids
Helping to produce “lactolin”, a natural antibiotic
Contributing to the destruction of moulds, viruses, and parasites
Eradicating such pathogens as Staphylococcus aureus from fermented food
Helping to maintain healthy cholesterol and triglycerine levels
Increasing the number of immune system cells
Providing protection from such environmental toxins as pesticides and pollutants
Reducing toxic waste at the cellular level
Stimulating the repair mechanism of cells
Synthesizing the anti-viral amino acid, L-lysine
Producing glycolytic enzymes which degrade cyanogenic glycosides
Eliminating toxic components from food including nitrates
L. reuteri is naturally found in the intestinal flora of animals, as well as in humans, including breast milk. This bacterium strengthens the immune system and helps to maintain the equilibrium of other friendly microorganisms because it secretes an antibacterial substance called “reuterin”. According to a 1997 issue of the Journal of Pediatric Gastroenterology and Nutrition, L. reuteri is an effective treatment for rotaviral diarrhea in children.
L. rhamnosus is closely related to L. caseii and L. acidophilus but more transient. It is a healthier species of “good bacteria” and easily colonizes in the lining of the intestines and in the vaginal tract. It is very prolific and has a high tolerance for bile salts and digestive enzymes, meaning it survives the digestive process.
Certain strains of this organism have been shown to stimulate an immune response against foreign intestinal organisms, as well as preventing rotoviral or Clostridium difficile-induced diarrhea. Some of its other abilities include:
Relieves hypersensitivity reactions and intestinal inflamation in individuals with exzema and food allergies
, especially those caused by a "leaky gut" condition
Stabilizes over a wide range of temperatures and pH levels
Inhibits the growth of bad bacteria, especially Streptococci and Clostridia
Enhances the immune system
Demonstrates anti-tumor activity
Assists those with lactose intolerance by releasing the lactase enzyme in the stomach and small intestine that breaks down the lactose molecule
Demonstrates significant health benefits, especially in infants and the elderly
Produces the desirable lactic acid
L. salivarius is most abundant in the mouth and gums (hence its scientific name), but it is also flourishes in the lining of the small intestine. It is important in helping to normalize the flora of the gut, especially in those with chronic bowel conditions. In one study printed in the American Journal of Gastroenterology (1998), only L. salivarius, and not L. casei or L. acidophilus, was able to produce high amounts of lactic acid and completely inhibited the growth of H. pylori in a mixed culture.
L. salivarius appears to help digest protein and may assist in the breakdown of any incompletely digested proteins and their undesirable by-products left in the gut which can cause putrefication. L. salivarius is classified as a facultative bacterium, which means that it can survive and grow in both anaerobic (without oxygen) and aerobic (with oxygen) environments, although its main effects take place in anaerobic conditions. This is a decided advantage over the well-known Lactobacillus acidophilus, which has little or no growth in an aerobic environment. L. salivarius is a very resilient bacterium which doubles its population every twenty minutes.
Bacillus strains are found in soil, manure, and plant matter. Most species are harmless; but others are not only harmful, but can be deadly. Some strains are used to make Antibiotics
while others are used as insecticides. The two that are considered to be probiotics and, therefore, beneficial, are listed below.
B. lichenformis is a soil-based organism that has proven to inactivate such lipid-enveloped viruses as HIV (human immunodeficiency virus), SIV (simian immunodeficiency virus), HHV-6 [A and B] (human herpes virus), EBV (Epstein-Barr virus), and CMV (Cyto-megalo-virus – related to herpes). It also is effective against other organisms including bacteria, mycoplasmas (a type of bacteria), and fungi.
This ability is attributed to its production of “surfactin”, a substance that has an Antibiotic
effect. In one follow-up of the effects of soil-based organisms on 100 people, all but one reported some sort of improvement. While many noticed improvements in the first two weeks, some required up to 2 or 3 months of use before they found benefit.
B. subtilis is a non-pathogenic bacterium that is widespread in soil, water, and air. Certain strains are known to control the growth of, or inhibit, harmful bacteria and fungi.
Bifidobacterium strains are common in the natural flora of human and animal digestive systems. Some strains show a tendency to inhibit the growth of such harmful bacteria as Salmonella. As probiotics, they stimulate the immune system, aid in digestion, and assist in the absorption of food ingredients and nutrients. They are also capable of synthesizing some vitamins.
Bifidobacteria are gram-positive anaerobes; non-motile, non-spore forming and catalase-negative. They have various shapes, including short, curved rods, club-shaped rods, and bifurcated Y-shaped rods. Their name is derived from the way they often exist; that is in a Y-shaped or bifid form. Bifidobacteria are classified as lactic acid bacteria,and, to date, about 30 species have been isolated.
Breastfed newborns begin to colonize bifidobacteria within days of birth. However, populations begin to decline with advancing age unless they are supplemented in the diet. Bifidobacteria are influenced by a number of factors, including diet, antibiotics, and stress.
B. adolescentis inhabits the lower large intestine and appears to have anti-tumor effects. B. adolescentis shares similar characteristics with B. breve. Along with B. infantis and B. longum, B. adolescentis accounts for almost 99% of the cultivatable flora. They have strong effects against gram negative bacteria and prevent the colonization of invading pathogens by competing for nutrients and attachment sites. At the same time, they increase vitamin production and calcium absorption. These beneficial bacteria also help ferment over 20 kinds of carbohydrates into lactic acid.
B. bifidum (also known as Bacillus bifidus, Bacterium bifidum, Lactobacillus bifidus, and Lactobacillus parabifidus) resides mainly in the lining of the large intestine and the vaginal tract.
Strains of this species have been used in the production of certain fermented foods and in therapeutic preparations for the treatment of the following: digestive disorders in infants, enterocolitis, constipation, cirrhosis of the liver, imbalance of intestinal flora following Antibiotic
therapy, and for promotion of intestinal peristalsis.
In hospitalized children, it has been shown that supplementation of infant formula milk with Bifidobacterium bifidum and Streptococcus thermophilus reduced rotavirus shedding and episodes of diarrhea.
B. bifidum is the most beneficial form of lactic acid and acetic acid production. It has the ability to:
Ferment indigestible fibers, thereby producing more energy
Synthesize some vitamins, especially several of the B vitamins
Assist in mineral absorption, especially iron, calcium, magnesium, and zinc
Inhibit the growth of Salmonella, Bacillus cereus, Staphylococcus aureus, Candida albicans, Campylobacter jejuni, Listeria, Shigella, E. coli and Clostridium by crowding them out and eating the nutrients they need
Fight bad bacteria by lowering the intestinal pH through its production of fatty acids, lactic acid, and acetic acid
Absorb large quantities of ferrous ions, thereby inhibiting the growth of bad bacteria that use it for food
Help decompose nitrosamines (cancer-causing substances) and suppress the production of nitrosamines in the intestines
Help lower serum cholesterol
B. breve is probably the most common bifidobacterium in infants but remains in the gut throughout adulthood. It is a lactic acid-producing bacterium found in the small and large intestines. B. breve shares many common characteristics with B. adolescentis. B. breve assists in the production of the natural antibiotic called “lactobrevin”. It appears to have an affinity for absorbing carcinogenics, especially those produced by charred meats. It tolerates bile acid well thereby surviving its trip through the digestive system. It has been shown that B. breve was able to eradicate Campylobacter jejuni from the stools of children with enteritis, although less rapidly than in those treated with erythromycin.
B. infantis is also known as B. lactentis, B. liberorum, and Actinomyces parabifidus. B. infantis is found mainly in the large intestines of infants (and thus its scientific name), but it can also be found in adults and in the vaginal tract of women. This bacterium is important because it has proven to stimulate the production of such immune agents as cytokines. Like other bifidobacteria species, this one can produce acids that may retard the colonization of the colon by certain foreign or harmful bacteria including Clostridia, Salmonella, and Shigella.
B. lactis (Bifidobacterium animalis subsp. lactis) is a strain of friendly bacteria known to stimulate the immune response. According to researchers in New Zealand, B. lactis proved to be an effective means of enhancing cellular immunity in the elderly. Those who consumed fermented products containing this bacterium showed a significant increase in the proportions of total, helper, and activated T lymphocytes, as well as natural killer cells. In addition, their immune cells’ ability to phagocytize (engulf and destroy) invaders and the tumor cell killing ability of their natural killer cells was also increased. The greatest improvements in immunity were found in those subjects who previously had poor immune responses before receiving B. lactis.
This strain appears to resist acid digestion and the action of bile salts, thus surviving intestinal transit to reach the colon in significant numbers. B. lactis also helps to relieve constipation and prevents diarrhea, especially in children. It also has the ability to decrease chronic inflammation of the sigmoid colon. In addition, its anti-microbial properties decrease the effect of negative bacteria, especially Clostridium.
B. longum is found in high concentrations in the large intestine. It helps prevent the colonization of invading pathogenic bacteria by attaching to the intestinal wall and crowding out unfriendly bacteria and yeasts. Along with other microorganisms, it produces lactic and acetic acids that lower the intestinal pH, which further inhibits undesirable bacteria.
In studies, B. longum was found to reduce the frequency of such gastrointestinal disorders as diarrhea and nausea during antibiotic use and can improve the nutritional value of foods. Some strains have the ability to produce B vitamins, as well as digestive, casein phosphatase, and lysozyme enzymes. It also increases calcium absorption. B. longum has a strong antitumor activity by regulating markers and reducing incidence of colon tumors.
Enterococcus strains are found in the intestines of animals and humans. They are gram-positive, facultative anaerobic cocci of the Streptococcaceae family; spherical to ovoid in shape and occur in pairs or short chains. They are also catalase-negative, non-spore forming, and usually nonmotile.
In most cases, they cause no infection. In some people though, enterococci can cause serious infections, especially those found in the urinary tract (UTIs), wounds, and the blood. Vancomycin is often the “last resort” antibiotic used to treat enterococcal infections, but even this is becoming ineffective as new strains are formed.
A new strain called "Enterococcus faecalis TH10” is proving to be highly effective against even the most deadly antibiotic-resistant bacterial strains, including MRSA (methicillin-resistant Staphylococcus aureus). Enterococcus faecium SF68 is another probiotic strain that has been used in the management of diarrheal illnesses.
E. faecium should not be confused with the pathogenic strain called Enterococcus faecalis. Although often uses synonymously, preliminary studies have shown that E. faecalis has virulent factors while E. faecium does not. E. faecalis is found mainly in animals other than humans, but it can be found in humans as a pathogen.
E. faecium is an important nutritional support in the event of diarrheal diseases, especially in cases when such pathogenic microbes,as rotavirus, invade the bowel. It is a transient bacterium so needs to be replaced continually. In several studies, it has proved resistant to a wide variety of antibiotics and proved to be more effective than L. acidophilus in shortening the duration of diarrheal episodes. However, because of the concern over the similarities in the Enterococcus (Staphylococcus) strains, many fermented foods manufacterers have stopped adding E. faecium to their products.
Lactococcus strains are lactic acid producers and commonly used to sour milk. They are gram-positive facultative anaerobes. Several strains are being used or are being developed as protiotics.
L. lactis (formerly known as Streptococcus lactis) has the ability to synthesize both folate and riboflavin, two important B vitamins. It is one of the most important microorganisms used in the dairy industry, particularly in cheese making, since it produces copious amounts of lactic acid. Scientists are now experiementing with it by creating a genetically modified version which secretes “interleukin 10”. This is expected to provide a therapeutic approach for inflammatory bowel disease. However, the release of any genetically modified organism always raises many safety concerns.
Leuconostoc strains may be found in various environments. The genus belongs to the lactic acid-producing family of bacteria used in fermenting foods to increase their nutritive quality. Some strains produce the characteristic flavor in cultured milk products and vegetables (sauerkraut)
L. mesenteroides is the organism most often used in fermenting vegetables, particularly in the making of pickles and sauerkraut where it initiates the desirable lactic acid. It is also used in the fermentation of sour dough bread, sorghum beer, all fermented milks, and cassava. It differs from other lactic acid species in that it can tolerate fairly high concentrations of salt and Sugar
(up to 50% sugar). It also initiates growth in vegetables more rapidly over a range of temperatures and salt concentrations than any other lactic acid bacteria.
L. mesenteroides produces carbon dioxide and acids which rapidly lower the pH and inhibit the development of undesirable micro-organisms. The carbon dioxide produced replaces the oxygen, making the environment anaerobic and suitable for the growth of subsequent species of lactobacillus. Removal of oxygen also helps to preserve the colour of vegetables and stabilizes any ascorbic acid that is present.
Pediococcus strains are found in foods, on plants, and as beer-spoilage agents. They produce inactive lactic acid and are used mainly for making fermented vegetables, mashes, beer, and wort.
P. acidilactici is a specific strain of lactic acid-producing bacteria helping to keep a proper balance of microflora in the digestive system. The organism has been used to control Listeria monocytogenes in temperature-abused vacuum-packaged wieners.
Saccharomyces strains are beneficial yeast organisms used in making beer, bread, and as a nutritional supplement.
S. boulardii is a lactic acid yeast that does not promote the growth of Candida albicans nor is it related to the Candida yeast species which cause infections in the gastrointestinal and urinary tracts. In fact, studies have shown it prevents Candida from spreading. However, prescription antifungals should not be taken at the same time as supplements with S. boulardii since these will kill it as well. Alcohol will also inactivate this organism.
S. boulardii is considered to be a non-pathogenic, non-colonizing baker’s yeast species which is closely related to brewer’s yeast (S. cervesiae). S. boulardii is a unique probiotic in that it is known to survive gastric acidity and is not adversely affected or inhibited by antibiotics or does not alter or adversely affect the normal flora in the bowel. For this reason, other friendly probiotic organisms can be taken at the same time as S. boulardii.
In a study published in a 2003 issue of the European Journal of Gastroenterology and Hepatology, S. boulardii proved to be helpful in ulcerative colitis. Studies suggest that it also protects the gut from amebas and cholera. In addition, it has proven to alleviate the diarrhea caused by Clostridium difficile, Crohn's disease, and that of other causes. S. boulardii has been found to secrete a protease which digests two protein exotoxins, toxin A and toxin B, which appear to mediate diarrhea and colitis caused by Clostridium difficile.
In Europe, S. boulardii is sold in capsules over-the-counter for the treatment of diarrhea and for preventing and treating various other digestive disorders.
S. cerevisiae is commonly known as baker's or budding yeast used in making bread and beer. “Budding” refers to how the yeast multiplies. It is also the strain that makes the nutritional dried supplement known as “Brewer’s Yeast”. Some nutritional yeasts are made from the by-products of breweries, distilleries, or paper mills; but a superior kind should be that which is grown on a base of molasses. This gives it a higher content of vitamins and minerals, as well as other beneficial components. Brewer’s nutritional yeast also does not contribute to Candida yeast infections.
Streptococcus strains are mostly noted pathogens causing illnesses that range from sore throats to rheumatic fever. However, there is one beneficial strain which is found in cultured milk products.
S. thermophilus, in combination with L. bulgaricus, is used commercially to produce yogurt. This organism is known to be efficient in breaking down lactose, a desirable trait for those who are lactose-intolerant. S. thermophilus is found in fermented milk products, especially in the production of yogurt. S. salivarus subspecies thermophilus type 1131 is another probiotic strain.
S. thermophilus is a gram-positive facultative anaerobe; cytochrome-, oxidase- and catalase-negative; nonmotile, non-spore forming and homofermentative; an alpha-hemolytic species of the viridans group; and, classified as a lactic acid bacteria.
S. thermophilus is known to destroy such pathogens as Pseudomonas, E. coli, Staphylococcus aureus, Salmonella, and Shigella. This activity is likely because of its ability to produce “methanol acetone”, a potent anti-pathogenic agent. In addition, it stimulates the production of “cytokine” which are involved with the immune system.
Other research suggests that S. thermophilus can improve the nutritional value of foods by making micronutrients available to the host. In hospitalized children, it has been shown that supplementation of infant formula milk with Bifidobacterium bifidum and Streptococcus thermophilus reduced rotavirus shedding and episodes of diarrhea.
Escherichia coli (E. coli) is a very familiar bacterium. Although found everywhere, including the human body, E. coli strains are usually harmless; but some can cause diarrheal diseases and even death. However, their presence in the human intestine is necessary for normal health and development. Some strains help synthesize B vitamins and vitamin K. Keeping the intestines healthy with probiotics will automatically keep this one in check so that its numbers will not get out of hand to where it becomes a pathogen.
Escherichia coli strain nissle 1917 is the most studied probiotic strain of E. coli. Its name is derived from the fact that it was isolated from a World War I soldier who survived a particularly severe outbreak of diarrhea.
The Nissle strain has been found to reduce significantly allergy incidences in children by the age of ten. The use of this strain in treating Crohn’s disease and ulcerative colitis is generating some attention. In well-controlled, double-blind trials, Nissle was found to be as effective as the drug mesalazine in maintaining periods of remission in these patients. In addition, it was found to inhibit adhesion of the pathogenic strains of E. coli, isolated from patients with Crohn’s disease. These findings validate the long-time belief that probiotics in general, and this strain in particular, play a significant role in preventing and curing many cases of Crohn's disease and ulcerative colitis.