A MICROSCOPIC VIEW OF THIS CHAPTER
• Inside your body is a war between good and bad microbes.
• Probiotics have many mechanisms of action.
• Probiotics prevent bad microbes from growing and causing disease.
• Bad microbes are inhibited by probiotics competing for receptor sites, masking sites and making the environment acidic.
• Probiotics produce enzymes that promote health.
• Probiotics produce antimicrobials that kill bad microbes.
• Probiotics support the health of cells that line the intestines.
• Probiotics work synergistically.
• Probiotics positively affect the immune system.
• Candida, E. coli, H. pylori and Salmonella can all be inhibited by probiotics.
A war is waging. The battles have commenced. Inside your body lie miles of intestines, bunched, curled and crammed into your abdomen. This is the battle ground of a life-long war—a war between good and evil. If only microbes were a more glamorous topic, this epic war would be the next blockbuster hit in Hollywood, but we are not likely to soon see Brad Pitt on the big screen, depicting this bacterial intestinal war.
Despite the lack of glamour and glitz, the war in your intestines between good and bad microbes is perhaps the most important war you’ll ever learn of. Let’s first look at why your intestines are exposed to incoming microbes. The intestines are exposed to almost everything in your environment. Food enters the body and brings along with it tons of chemicals, pollutants, dirt and microbes. As such, your intestines are one of the most important gatekeepers to your body. Entrance will only be granted to those worthy of entry. Like a castle wall in medieval times, your intestinal lining has a dangerous and important job. Invaders can charge the castle at any hour. As such, your intestines need to be armed with valiant, strong knights—and the more, the better.
Who is worthy of being a knight in your intestines? Despite common feelings that bacteria are disgusting and dirty, some bacteria are strong, valiant species that are effective at protecting your body from harmful substances you ingest. Certain bacteria are particularly excellent knights; these bacteria are called lactic acid bacteria, a type of probiotic. There are many types of probiotics worthy of being knights. Lactic acid bacteria such as Lactobacilli and Bifidobacteria are worthy knights, as are some yeast species like Saccharcomyces boulardii.
Probiotics offer a great number of health benefits. Probiotics guard the intestinal lining protecting the gates to your body from harmful substances. Probiotics also strengthen your gates by promoting a healthy intestinal lining; they are involved in a variety of reactions in the body that stimulate the immune system helping you stay healthy. Also, probiotics limit the growth of pathogenic microbes in the intestinal tract, keeping you healthy. In many studies, lactic acid bacteria has flexed its muscle and shown how it helps protect the host against pathogens. By doing so, lactic acid bacteria acts as a shield, protecting you against the negative effects of unfriendly microbes such as E. coli, Salmonella and Candida albicans. In other words, probiotics are like knights that protect the intestines from ransacking invaders.
FORTIFIED BY FOOD
These friendly microbes are consumed orally in breast milk, vegetables, dairy products and other foods. In the days before antibacterial and food processing, humans ate lots of foods that contained microbes. Some of these microbes were unhealthy; modern processing techniques that limit our exposure to these harmful microbes are beneficial to our health. However, some of the bacteria and yeasts we used to eat in our foods were good for us. Sauerkraut, kimchi, kefir, kvass, miso, beer, wine and tamari are all foods that are made with the help of bacteria and yeast. The most common source in your diet of probiotics is likely yogurt and cheese. New probiotic-rich foods have been emerging on the market since 2000, including probiotic chocolate bars, cereals, milks and more. To date, the best way to get high dosages of probiotics into your gastrointestinal tract is through probiotic supplementation. Probiotic supplementation supplies billions of live active cells to the intestines, which is far more than can be added to most food products. We take a more in-depth look into probiotic foods and supplements in Chapter 18.
HOW DO PROBIOTICS WORK?
The exact mechanisms of action by which probiotics elicit their beneficial effects are not fully understood. Researchers are working to better understand the specifics of these proposed mechanisms by which probiotics appear to affect the health of humans. Here are some of the known mechanisms by which probiotics can elicit their beneficial effects in the human gastrointestinal tract.
Probiotics Compete for Receptor Sites
This mechanism can be thought of as drivers fighting for parking spots in a small lot. Once in the intestinal tract, probiotics strive to reach the receptor sites along the epithelial cells that line the intestines. Epithelial cells, which line the intestinal tract, mouth and vagina, are host to millions of receptor sites for various microbes. Some probiotics are very effective at attaching to receptor sites. In other words, some probiotics are like aggressive drivers that are good at finding parking spaces. One of the main selection criteria used by scientists when looking for probiotics to use in foods and supplements is their ability to attach to receptor sites. Good probiotics can find open parking spots in a lot, thus preventing bad microbes from finding space. Probiotics literally “crowd out” the bad microbes. Of note, some probiotics can affect bad microbes’ ability to adhere to a receptor, in the same way you can make it hard for a car to park in the space beside yours if you park on an angle or very close to the line.
Figure 3-1: Mechanisms by which Lactic Acid Bacteria (Probiotics) Inhibit Bad Microbes from Attaching to Your Cells.
Probiotics Mask Receptor Sites
When probiotics bind to a receptor site on an epithelial cell, they elicit a number of effects in the cell. One of the proposed effects is that probiotics communicate with the cell, causing the cell and its neighboring cells to alter their lining. The lining of the intestinal tract is covered in mucus, similar to your nose. This mucus lining of the intestinal tract helps protect the intestinal wall from invading pathogens. When probiotics cause a positive change to the lining, bad microbes are less able to attach.
The cells that line the intestinal tract appear to be able to crosstalk, allowing for a communal exchange. Cells have junctions between them called “tight junctions.” Through these junctions scientists think that cells communicate to each other, which enables them to react as a group. When a probiotic tells one cell to change to prevent bad microbes from attaching, the cell can then tell all of its neighbors to do the same. The result is a large protective change that protects the body from infection and creates immunity. When pathogens cannot adhere to the intestinal receptors, they cannot colonize and cause disease.
Researchers Lu and Walker have suggested that probiotics strengthen tight junctions between intestinal cells, which ultimately improves immunity.
Probiotics Affect the Immune System
Probiotics positively affect the immune system in a number of ways, but we do not yet completely understand how they do what they do. There are two parts to your immune system: innate and acquired. Probiotics enhance both of these. They also increase the production of compounds (certain cytokines) that promote good inflammation. In the intestinal tract, probiotics cause the intestinal lining to be less permeable, which means that harmful microbes and toxins that are not supposed to enter into your bloodstream cannot do so. Let’s take a closer look at this area of research.
The gastrointestinal tract is the main entry for pathogens into your body. Just think about the number of bacteria and chemicals you ingest each day. As such, your gastrointestinal tract is lined with its own set of immune cells to help prevent these harmful substances from gaining entry to your body. These immune cells are called the gut-associated lymphoid tissue (GALT). The GALT is the largest mass of immune tissue (lymphoid tissue) in the human body and as such is an important element of the body’s immune system. You may be familiar with other lymphoid tissues such as the tonsils and spleen. The tonsils are also located in an area where you are commonly exposed to harmful substances (the throat). Your immune tissues are in locations where you need them most, such as your intestinal tract, throat, nose and lungs. They may not physically touch each other, but they stay in close communication with each other by producing protein-messengers, such as antibodies and cytokines. Antibodies are proteins that help the body tag or identify unwanted items, called antigens . When a bad microbe or substance (antiges) interacts with the intestinal lining, the immune cells produce antibodies (e.g., Immunoglobulin A[IgA]).
The ability of the immune tissues to communicate allows an immune response initiated in the GALT to affect other immune tissues, such as the lungs. In other words, a response to an antigen (e.g., peanuts) in the digestive tract could cause an effect in the lungs such as shortness of breath and tightening of the throat, as seen in anaphylactic shock. It is not surprising that researchers are discovering that probiotic supplementation is useful in a wide variety of immune-based ailments including allergies, asthma, eczema and irritable bowel disease.
The gut microflora is an important part of the intestine’s defense barrier. This is known because where there is no microflora more antigens are able to get across the intestinal lining and gain access to the body. In other words, when there are no probiotics present, the defense barrier is weak. To simplify further, without knights out front to protect your castle, it is more susceptible to invading pillagers.
Probiotics appear to reduce the severity of some allergic reactions such as anaphylaxis and asthma. It is not fully understood how this happens, but scientists think that probiotics help balance good and bad messengers of the immune system by keeping the system in check. The result is healthy immune reactions and a healthier you. A careful balance of inflammation is required in the intestinal tract. Too much of an immune reaction can result in inflammation and damage to the intestines reducing their ability to digest and absorb nutrients, and can also lead to the development of diseases such as irritable bowel disease. Too little immune reaction allows pathogens to grow in the intestines, causing infectious diarrhea, which can develop into a chronic illness such as allergies or an autoimmune disease without the anti-inflammatory effect of specific strains of probiotics.
All in all, it appears that probiotics:
• reduce allergic reactions
• improve overall immunity
• promote proper immune reactions against pathogens.
Probiotics are great helpers to the immune system in the intestines and appear to support proper immune reactions throughout the body.
Probiotics Consume Available Nutrients
The intestines are the ideal environment for lactic acid bacteria to grow. There are lots of nutrients available in the digestive tract that support the needs of lactic acid bacteria to grow. By consuming a large portion of the available nutrients suitable for microbes, lactic acid bacteria restrains the growth of bad microbes. With little to eat, pathogens find it hard to grow and colonize in the intestines.
Probiotics Create an Acidic Environment
Lactobacilli and Bifidobacterium are bacteria families that excrete lactic acid and acetic acid into their environment. This excretion of acid is part of their regular daily functions. In the gastrointestinal tract, this causes the pH to lower. Many bad microbes do not like a low pH. As such, lactic acid bacteria are capable of inhibiting the growth and colonization of bad microbes in the gastrointestinal tract.
Probiotics Produce Beneficial Enzymes
Probiotics make a variety of enzymes that offer health benefits to you. These enzymes include lactase, which breaks down lactose, a sugar in milk that many people cannot digest. Some probiotics produce enzymes that are harmful to bad microbes. The enzyme activity of probiotics has been found to help fight infectious disease, lactose intolerance, immune system deficiencies, and urogenital and vaginal diseases.
Probiotics Produce Antimicrobial Effects
Some probiotics have antimicrobial effects. Many of the probiotic strains of bacteria are able to produce substances that kill bacteria, called bacteriocins such as lactocidin, reuterin or acidophilin. These bacteriocins have antimicrobial activities that reduce the growth of disease-causing microbes. To date, only some strains are known to to produce antimicrobial substances. L. reuteri, L. plantarum and L. casei are examples of clinically studied probiotic species that have antimicrobial effects and can produce bacteriocins. Each antimicrobial substance appears to target certain bad microbes. As more antimicrobial substances are discovered, scientists will be able to recommend specific probiotic species for the nasty microbes humans encounter, including E. coli and C. difficile. Perhaps then, if you eat E. coli-contaminated spinach, you could use a probiotic to help fight the E. coli in your system.
Probiotics Support Gut Barrier
Lactobacilli and Bifidobacteria produce fats that encourage the growth of cells that line the intestinal tract. These fats are called short chain fatty acids. These fats also have nutritional effects on the intestinal cells, keeping them well nourished and healthy. Probiotics help with the proper maintance of the gut barrier function by helping keep intestinal cells healthy.
Probiotics Encourage Healthy Microflora
Probiotics may also work synergistically to create an environment that promotes probiotic growth, not growth of bad microbes. Some probiotics excrete substances that enhance the growth of fellow probiotics. Lactobacillus reuteri excretes AGGH, a protein that appears to encourage growth of good bacteria in the small intestine. This is a fascinating area of research. In clinical trials, the use of combinations of probiotic species has been found to offer greater health benefits than any one of the probiotic species alone. As such, it is likely that probiotics work synergistically in the intestines to promote the growth and colonization of fellow friendly microbes.
BYE, BYE BAD BUGS
It’s like the Wild West in your intestines. Probiotics are the sheriff and they’re saying to the bad microbes, “There ain’t enough room in this intest-town for the two of us.” Which bug will reign supreme in your gut? Say goodbye to bad bugs because one of the most unique attributes of probiotics is their selective ability to promote the growth of friendly bacteria in the human digestive tract, while inhibiting the growth of pathogenic ones. There are many mechanisms by which probiotics inhibit the growth of bad bacteria in the human digestive tract:
1. Competitive nutrient consumption
2. Epithelial cell receptor interactions
3. Excretion of antimicrobial substances
4. Interaction with the immune system.
These mechanisms and other actions of probiotics were discussed in detail earlier in this chapter. So let’s move on and investigate how probiotics work against specific bad microbes.
Candida
Everyone’s body is host to Candida (Candida albicans). Candida is a type of yeast. Candida is normally kept under control by good health and probiotics. However, Candida overgrowth can occur when the system is challenged or altered. The use of antibiotics can reduce the ability of probiotics to keep Candida at bay. Also, the overconsumption of yeast-feeding foods such as simple carbohydrates, sugars, peanuts, alcohol and milk products can encourage Candida growth.
Candida overgrowth can elicit a number of symptoms, the worst of which is the burning, itching symptoms associated with a vaginal candida overgrowth, also known as a yeast infection or vulvovaginal candidiasis (VVC). The development of VVC is associated with a lower number of Lactobacilli in the vagina, particularly those which produce hydrogen peroxide. Hydrogen peroxide is a chemical that kills bacteria. The presence of hydrogen peroxide in the vagina would kill bad microbes like Candida.
To date, there is some argument as to the ultimate effect of hydrogen peroxide producing Lactobacilli in the control of Candida in the vagina. In vitro (test tube) studies have shown that Lactobacilli can inhibit the growth of Candida albicans and its adherence on the vaginal lining. Clinical trials (human studies) support the effectiveness of Lactobacilli, especially Lactobacillus acidophilus, Lactobacillus rhamnosus and Lactobacillus fermentum, administered either orally or intravaginally. These probiotics colonize in the vagina and prevent the growth of Candida albicans.
Lactobacillus crispatus and Lactobacillus jensenii are capable of displacing the well-known vaginal pathogens Candida albicans and Gardnerella vaginalis. All of these probiotic species are effective in inhibiting Candida albicans growth, reducing its ability to attach to vaginal cells. There is more research required in this area and it is likely that there are more probiotic species that can effectively inhibit Candida albicans infections in the vagina.
Candida overgrowth in the vagina, also known as a yeast infection, is perhaps the most common Candida problem. Candida also lives in the gastrointestinal system, where it can cause havoc. In the mouth it can cause thrush in infants, and in the intestines it can cause a gamut of problems. Some experts believe that an overgrowth of Candida in the intestines is common and causes what is referred to as the “yeast syndrome.” Physical symptoms include fatigue, headache, mood swings, sinus congestion, depression, poor memory and concentration, and cravings for sweets. The 1980s book The Yeast Connection made the public aware of yeast growth control and catapulted Candida into a mainstream health concern. It is thought that the following factors contribute to Candida overgrowth: use of oral contraceptives, steroids, antacids, ulcer medications, antibiotics, high-sugar diets, pregnancy, smoking, food allergies or intolerances and diabetes. Luckily, Lactobacillus probiotics are capable of keeping Candida albicans under control in all areas of the body.
The mouth is host to a large number of microbes including Candida albicans. As Candida overgrowth is a particular problem in the elderly, a double-blind, placebo-controlled study investigated the effects of eating a probiotic cheese daily for four months. The study included 276 elderly people and found the probiotic was successful in reducing the risk of high yeast counts by 75%. In other words, probiotic bacteria are effective in controlling Candida in the mouth, a problem of particular concern for the elderly.
The exact mechanism by which probiotics inhibit Candida growth is not fully understood to date. Some suggest the ability of probiotics to produce hydrogen peroxide plays a role; however, in vivo studies suggest that probiotics might prevent Candida growth through multiple mechanisms.
E. coli
Escherichia coli O157:H7 (E. coli) is a leading cause of foodborne illness. People can become infected with E. coli in a variety of ways. Though most cases have been associated with eating undercooked, contaminated ground beef, people have also become ill from eating contaminated bean sprouts or fresh leafy vegetables such as lettuce and spinach. Person-to-person contact in families and childcare centers is also a known mode of transmission. In addition, infection can occur after drinking raw milk and after swimming in or drinking sewage-contaminated water.
Based on a 1999 estimate, 73,000 cases of infection and 61 deaths occur in the United States each year. Infection with E. coli often leads to bloody diarrhea and occasionally to kidney failure. Once digested, E. coli attaches to the host epithelial cells and causes detrimental changes to them. Probiotics can positively change the cells that line the intestines so that bad bacteria such as E. coli cannot live there.
Many species of probiotics have traits that might help rid an intestinal tract of E. coli; however, clinical trials have found that L. acidophilus is the superior probiotic for an E. coli-infected intestine. It can effectively inhibit the growth and ability of E. coli to attach to the intestines. Thus, this pathogen cannot thrive in the intestinal tract. L. rhamnosus is also respected as an effective probiotic for infected human intestinal tracts.
H. pylori
Helicobacter pylori (H. pylori) is the most common bacterial infection in developing countries and often results in chronic gastritis (inflammation of the stomach), peptic ulcers and gastric cancer. H. pylori is a bad bacterium that can inhabit the cells that line the stomach. Many who are infected do not show any symptoms of disease. The Helicobacter spp. are the only known microbes that can thrive in the highly acidic environment of the stomach. Treatment of an H. pylori infection typically involves the use of antibiotics, commonly two, and omeprazole, a pharmaceutical used to reduce acid production in the stomach. By completely eliminating H. pylori, the harm of the infection, typically peptic ulcers, can heal. Therefore, getting rid of this bacteria infection is a way to regain health.
Probiotics are able to prevent infection by H. pylori. Research in animal models has shown probiotics prevent infection from this nasty bacterium. Researchers have found that pretreating animals with probiotics reduces the ability of H. pylori to infect them. The probiotics were also able to reduce the inflammation caused by an H. pylori infection. Less inflammation means less pain and damage to the stomach. Based on this and other research, probiotics are thought to be an effective defense against infection from H. pylori.
The ability of probiotics to prevent against an H. pylori infection has yet to be confirmed in humans; however, probiotics are effective in treating people who are already infected. A half-dozen clinical trials investigating the ability of probiotics to treat people with H. pylori infections have showed a positive result.
It is a difficult task to eradicate H. pylori in the stomach. For a probiotic to be a good treatment for H. pylori infections it would have to be tolerant to the low pH of the stomach and have the ability to attach to the unique lining of the stomach. L. acidophilus, L. gasseri and L. rhamnosus show potential as effective probiotics to fight H. pylori infections and invasions. Another successful probiotic is L. reuteri. In Italy, researchers investigated the ability of L. reuteri to eradicate H. pylori in a double-blind, placebo-controlled study of 30 infected people. A dosage of only 800,000 (8 x 105) CFUs was administered twice daily, along with omeprazole to the infected subjects. The study found that L. reuteri was able to stop H. pylori infections by reducing the ability of H. pylori to attach to the stomach lining. As such, there appear to be a number of probiotic species that may be useful in the prevention of H. pylori infections and potentially in the eradication of an infection.
Rotavirus
Rotavirus is the pathogen responsible for infantile diarrhea, winter diarrhea, the stomach flu, acute nonbacterial infectious gastroenteritis and more. Seven major groups of Rotaviruses have been identified, three of which infect humans. Rotaviruses cause vomiting and diarrhea. The virus infects the villi, which are small, finger-like projections on the small intestine. Rotavirus causes a change in the villi structure that results in diarrhea. It is the most common cause of severe diarrhea in children, killing about 600,000 children every year in developing countries. The incubation period ranges from one to three days. Symptoms often start with vomiting followed by four to eight days of diarrhea. Recovery is usually complete; however, severe diarrhea without fluid and electrolyte replacement may result in death.
The probiotic Lactobacillus rhamnosus GG is effective in promoting a rapid recovery of watery diarrhea in children with a Rotavirus infection. The exact way this probiotic helps children get better has not been discovered; however, preliminary research suggests that L. rhamnosus GG may increase cell production in the small intestine which acts to wash out cells that are infected with the virus. Removing the virus from the body shortens the duration of diarrhea.
Diarrhea in children can be life threatening: there is a research study that is worth noting. Children (aged one month to three years) with acute-onset diarrhea were enrolled in a double-blind, placebo-controlled study. The children were randomly divided into two groups, one to receive placebo or Lactobacillus rhamnosus GG. Probiotic dosages were at least ten billion (1010) CFU. Children receiving the probiotics had a significant reduction in the duration of their diarrhea (56 hours versus 77 hours in the placebo group) and hospital stays were significantly shorter in the probiotic group. This study and others support the use of Lactobacillus rhamnosus GG in children with acute diarrhea as a safe way to shorten the duration of their diarrhea and reduce the time they have to be in the hospital.
L. reuteri is another probiotic known to help with diarrhea. Two double-blind, placebo-controlled research trials looked at the effects of L. reuteri in children with acute infectious diarrhea. Daily dosages of one hundred billion (1011) CFU of L. reuteri was well tolerated and effectively prevented diarrhea in the young children. The probiotic significantly reduced diarrhea symptoms to only one and a half days. In another study, newborns were supplemented with L. reuteri. The newborns had no evidence of adverse effects and experienced a significant reduction in the incidence of watery diarrhea. In these trials, many children had confirmed Rotavirus infections causing the diarrhea. A large number of clinical trials support the use of L. reuteri to reduce the severity and duration of diarrhea.
Salmonella
Salmonella is one of the major causes of foodborne illness worldwide. Every year, approximately 40,000 cases of Salmonella infections (poisoning) are reported in the United States. Because many milder cases are not diagnosed or reported, the actual number of infections may be thirty or more times greater. Young children, the elderly and those with weak immune systems are most likely to have severe Salmonella infections. It is estimated that approximately 600 persons die each year with acute Salmonella infections. There are many different kinds of Salmonella bacteria with Salmonella serotype typhimurium and Salmonella serotype enteritidis being the most common in the United States.
Salmonella is a type of bacteria that lives in the intestinal tracts of humans and other animals. As such, Salmonella is usually transmitted to humans by eating foods contaminated with feces. Many raw foods of animal origin are frequently contaminated, but fortunately, cooking kills Salmonella. Improper hand washing by food handlers is another source of contamination. Of note, Salmonella can also exist in animal feces and thus pet owners, including reptile owners, should be careful to wash their hands after handling pets and/or their excrement.
Animal researchers are working with probiotics to see if they can help reduce the presence of Salmonella in the feces of farmed animals to reduce the likelihood of human food contamination. At the University College in Ireland, researchers divided pigs into two groups, one of which received regular milk, while the other received milk containing five probiotic strains. Following six days of treatment, the pigs were exposed orally to Salmonella bacteria and their health was then monitored for 23 days. The pigs that had received the probiotic treatment had fewer incidences, less severe, and shorter durations of diarrhea, as well as significantly lower numbers of Salmonella in their fecal samples. Thus, administration of probiotic bacteria appears to improve the outcome of Salmonella infection in pigs and may help reduce the likelihood of human infection from contaminated food.
In Canada, researchers at the University of Guelph investigated the ability of probiotics to prevent Salmonella infection in broiler chickens. The researchers found that pre-administration with probiotics (Lacobacillus acidophilus, Bifidobacterium bifidum and Streptococcus faecalis) enhanced the chicken’s immune response. The probiotic supplement chickens had superior health. Prebiotics were also investigated in this trial, and they were found only to be of added health benefit when probiotics were given simultaneously. It appears that probiotics can prevent Salmonella’s growth in many animals commonly farmed for human consumption.
These animal studies have shown a number of probiotic species are capable of preventing Salmonella from growing. Two other probiotics, S. cerevisiae and L. reuteri can inhibit the growth of Salmonella, according to laboratory-style research trials. As a result, it appears that the use of probiotics in farmed animals may help reduce their illness and the possibility of food-contaminated cases of Salmonella among the general human population.
To date, there are no clinical trials on probiotic use in the prevention and treatment of Salmonella infections in humans. However, animal studies offer promise that probiotics may play a role in the prevention and treatment of Salmonella infections in humans.
There are many bad microbes that probiotics are known to fight. Appendix 3-1 lists a number of human disease conditions, along with the corresponding microbe that causes each condition, and the probiotic shown in scientific studies to destroy it.
BIFIDOBACTERIA AND BAD BACTERIAL INFECTIONS
Most of the probiotic species mentioned above are of the Lactobacillus family. This is because many bad microbes like to inhabit the small intestine where lactobacilli like to live. However, the large intestine is also a location in which bad microbes try to live. As such, Bifidobacteria also play an important role in preventing infections. Bifidobacteria has been shown in a number of research trials to protect the body from intestinal infections that can cause illnesses such as diarrhea.
We know that infants with high numbers of Bifidobacteria can resist certain infections by bad microbes. The elderly are not as able to withstand infection. Could this be due to the decrease in the number of Bifidobacteria in our colon that occurs as we age? As the number of Bifidobacteria decreases, the number of Clostridium perfringen, a bad microbe, increases. C. perfringen strains produce a variety of toxins and volatile amines. Toxins and volatile amines can cause damage to the colon causing inflammation, constipation and potentially cancer. Luckily, supplementation with Bifidobacteria has been shown in clinical studies to substantially decrease the number of clostridium in the elderly and to promote colon health.
Bifidobacteria are great at reducing the growth of bad microbes in the colon. B. longum is one probiotic known to help fight Salmonella typhimurium infections. There are many bad microbes that can be controlled by Bifidobacteria. Appendix 3-2 lists bad microbes known to be inhibited by species of Bifidobacteria.
SUMMARY
Once probiotics reach their receptor sites, they serve as a protective shield along the intestinal mucosa. They are able to inhibit the ability of bad microbes to attach and grow in the intestines. Some probiotics can produce antimicrobial or synergistic substances that kill bad microbes and promote the growth of friendly microbes respectively. Probiotics also consume nutrients, thus reducing those available for bad microbes and thereby limiting their growth. These many ways that probiotics reduce the ability of bad microbes to live and grow in your intestines promote a healthy intestinal lining.
Bye, bye bad bugs. Probiotics have a unique ability to inhibit pathogenic microbe adhesion, invasion and colonization in the human body. Pathogens such as E. coli, Salmonella and Rotavirus cause serious illness at high frequency among the human population. Candida, a natural inhabitant of the human body, can cause havoc if allowed to grow uncontrolled. Lactobacilli and Bifidobacteria have illustrated the ability to inhibit the invasion and growth of all of these nasty microbes.
As well, probiotics support the immune system and thus enhance the body’s ability to fight these pathogens. Their effect on the immune system goes even farther. Probiotics have positive effects on the immune system, which keeps it functioning properly.
Probiotics can be used as prevention against infection or overgrowth of bad microbes to support overall health, and research indicates they can also be used to effectively treat pathogenic microbe infection.
