Till the 1960s, the only microorganisms identified as gut microflora were clostridia, lactobacilli, enterococci, and escherichia coli, but modern research has revealed trillions of other microbes that live in our bodies. Not all of these are probiotic bacteria, but pathogens (bad microbes) are kept in check by those that have probiotic properties.
Probiotic bacteria are identified by their genus, species and strain. The probiotic acidophilus (the ‘acid-loving’ bacterium) is the most well-known, but there are various other beneficial microorganisms that help us maintain better health. In fact, there are over 400 different species, each with thousands of strains, which live in a mutually beneficial symbiotic relationship with our system.
Before we get into the details of how probiotics work, let’s take a look at some of the most common kinds of probiotic bacteria (and some microbes that aren’t really bacteria, but considered in the probiotics group anyway) that inhabit our system and are also found in probiotic foods and probiotic supplements biotic foods:
Lactobacillus is a type of friendly or probiotic bacteria that our bodies use to fight off diseases and effectively digest milk products. There are more than 50 different species of the genus lactobacillus, and they form a major part of the lactic acid bacteria group that helps to break down lactose and sugar in the body, converting them into lactic acid for easier digestion.
Through the production of lactic acid, probiotic lactobacillus bacteria create a friendlier environment for the growth of other probiotic microbes. Modern research suggests that specific species and strains such as L. acidophilus, L. acidophilus DDS-1, L. bulgaricus, L. rhamnosus, L. gasseri, L. rhamnosus GG, L. casei, L. salivarius and L. johnsonii play a huge role in our health.
This ‘super bacteria’ is commonly found in fermented foods and dairy products like soft cheeses and yogurt, but many species of this genus also happen to be naturally present in the genital, urinary and digestive systems of our bodies. Other strains of lactobacilli include L. fermentum, L. caucasicus, L helveticus and L. lactis.
The intake of lactobacillus probiotic sub-species and strains in the form of foods or probiotics supplements offers a wide range of health benefits. These include treatment and prevention of lactose intolerance, high cholesterol, irritable bowel syndrome, digestion problems and yeast infections, antibiotic-related diarrhea, traveler’s diarrhea and infectious diarrheaespiratory, vaginal and urinary tract infections, as well as skin disorders such as acne, blisters, eczema and sores.
Read more about Lactobacillus here
This is actually not bacteria but a type of fungus, more commonly accepted as tropical strain of yeast, which is known for its medicinal qualities that help to treat a wide variety of health conditions. It was first isolated from the fruits of mangosteen and lychee, and is now commonly used as a probiotic supplement.
Saccharomyces boulardii is considered to be transient, as it passes through the system without inhabiting it, which makes it a high-quality probiotic microbe. It is also known for its anti-inflammatory properties, which help to maintain a healthy gut. In addition, it is effective at treating acne, preventing the reoccurrence of Clostridium difficile, reduces the side effects of treatment for Helicobacter pylori and helps to spruce up activity in the small and large intestines too.
Research shows that saccharomyces boulardii protects the host against pathogenic microorganisms such as E. coli and salmonella. It can be used to treat acute or traveler’s diarrhea (as well as diarrhea and other gastrointestinal problems caused by the use of antibiotics), among a whole list of other issues – with such vigor that it is registered as a medicine in over 100 countries!
Read more about Saccharomyces Boulardii here
Bacillus coagulans was referred to as lactobacillus sporogenes until 1974 due to its similar attributes, as it works in a similar manner to the Lactobacillus group. It too helps the body produce lactic acid but is rarely used in industrial applications, and only a few strains are used as probiotics or in the commercial food production.
These bacteria are typically rod-shaped and have the ability to generate endospores, which develop into rapidly multiplying vegetative cells and form tough outer shells when conditions are not ideal. The cell components help to increase the immune system’s ability to fight off pathogens, which is why bacillus coagulans are added to products with unfavorable conditions (like food and beverages), for increased shelf life.
Bacillus coagulans hammer strains are nonpathogenic and considered safe for human nutrition, and these are the most common variants used as dietary probiotics. They aid in preventing respiratory infections, retard the formation of cancer cells, help to ward off diarrhea and alleviate symptoms of gastrointestinal diseases, besides increasing the efficiency of vaccines and improving the immune system too.
Read more about Bacillus Coagulans here
Bifidobacterium is another well-known genus of probiotic bacteria which makes up most of the probiotics in the colon. It is also found in probiotics foods and supplements and is very useful in the food industry. It belongs to a genus of gram-positive microorganisms that are incapable of movement, and is often branched as anaerobic bacteria that don’t tolerate oxygen-rich environments.
Bifidobacteria were originally found in the intestinal flora of breast-fed infants, emphasizing the theory that lactic acid was beneficial for humans and needed to be enriched with age. Besides being lactic acid-producing bacteria, some strains also produce acetic acid, a short chain fatty acid which provides extra energy to the host, aiding in the food digestion process and detoxifying bile.
Over 30 species of bifidobacterium inhabit the oral, gastrointestinal and vaginal tracts of mammals (including humans), and due to their ability to fight off pathogens in the body are especially useful for improving the health of beneficial bacteria that line the intestines. Of these, B. bifidum, B. infantis, B. lactis, B. breve, B. thermophilum, B. longum, B. longum and B. pseudolongum are typically considered powerful probiotics.
When ingested by animals and humans, specific strains of bifidobacteria are effective at preventing and treating an extensive array of gastrointestinal and other disorders. These range from intestinal infections, IBS and certain types of diarrhea, to psoriasis, chronic fatigue syndrome, dental cavities, low blood lipids, glucose intolerance, colonic transit disorders, colonic adenomas and possibly even cancer.
Read more about Bifidobacterium here
Streptococcus thermophilus belongs to the streptococcus genus of gram-positive, spherical-shaped anaerobes that are nonmotile. Other strains of Streptococcus include S. cremoris, S. faecium and S. infantis. While it may sound similar, it is not related to the bacterial strain that causes strep throat (streptococcus pyogenes).
Originally isolated for the production of yogurt in 1974, it is largely used in dairy products manufacturing, especially yogurt and mozzarella cheese. S. thermophilus not only plays a huge role in dairy food production, but also boosts the digestive system, supplements a stable growth rate in children, prevents inflammation of the small intestines and helps in preserving the micro-ecology of the digestive system.
This bacterial species is transiently present in the intestines and works synergistically with lactobacillus strains, so it is also classified as lactic acid bacteria. These bacteria break lactose down to produce large quantities of the enzyme lactase (which digests milk sugars), aiding with the symptoms of lactose intolerance and gastric distress.
Since streptococcus thermophilus works synergistically with L. bulgaricus to process nutrients that promote growth as well as help to lessen the symptoms of intestinal problems and lactose intolerance, it is added to several health supplements, most commonly in probiotic yogurt and soft cheeses. People suffering from organ failure are prime candidates for this particular probiotic, especially those who have acute pancreatitis.
Read more about Streptococcus Thermophilus here
Like bifidobacterium, leuconostoc is a genus of ovoid or rod-shaped gram-positive bacteria that belongs to the family leuconostocaceae, classified as lactic acid bacteria and able to convert sucrose to dextran. While a few species of this genus have been associated with causing infection or disease in humans, exposure to them is uncommon.
Leuconostoc is most commonly used in the food processing industry for the fermentation of kefir and sauerkraut and the production of certain kinds of cheese, working symbiotically with other lactic acid bacteria like lactobacillus. It converts the sucrose present in cabbage into lactic acid, which is what gives fermented cabbage products their distinctive sour flavor and improved ‘keeping’ quality.
Probiotic strains of leuconostoc are ingested through various kinds of probiotics supplements and foods, which contain live and dead bacteria, as well as metabolites of these microorganisms. Other than their ability to promote lactic acid production in the body, specific strains like leuconostoc mesenteroides also seem to offer benefits in treating liver disorders like cirrhosis and fibrosis.
Enterococcus is another genus of gram-positive bacteria that is found in the intestinal tract of humans as well as animals and often used as an indicator of fecal contamination. This organism is very resistant to antibiotics and antimicrobial agents, as well as high heat and high concentrations of bile salts.
Studies have also shown that this strain may help lower LDL or bad cholesterol levels in the body. Although a transient guest, E. faecium is a welcome natural resident in the human body, and specific strains like E. faecium SF68 and E. faecium M-74 are considered to be probiotic.