Probiotics were defined by a group of experts convened by the Food and Agriculture Organization of the United Nations (FAO) as “live microorganisms administered in adequate amounts which confer a beneficial health effect on the host”. Most probiotics are bacteria, which are small, single-celled organisms. Bacteria are categorized by scientists with genus, species and strain names.
Probiotics are live microorganisms (in most cases, bacteria) that are similar to beneficial microorganisms found in the human gut. They are also called “friendly bacteria” or “good bacteria.” Probiotics are available to consumers mainly in the form of dietary supplements and foods. They can be used as complementary and alternative medicine (CAM).
Probiotics are bacteria that help maintain the natural balance of organisms (microflora) in the intestines. The normal human digestive tract contains about 400 types of probiotic bacteria that reduce the growth of harmful bacteria and promote a healthy digestive system. The largest group of probiotic bacteria in the intestine is lactic acid bacteria, of which Lactobacillus acidophilus, found in yogurt with live cultures, is the best known. Yeast is also a probiotic substance. Probiotics are also available as dietary supplements.
It has been suggested that probiotics be used to treat problems in the stomach and intestines. But only certain types of bacteria or yeast (called strains) have been shown to work in the digestive tract. It still needs to be proved which probiotics (alone or in combination) work to treat diseases. At this point, even the strains of probiotics that have been proved to work for a specific disease are not widely available.
People use probiotic products as CAM to prevent and treat certain illnesses and support general wellness. There is limited evidence supporting some uses of probiotics. Much more scientific knowledge is needed about probiotics, including about their safety and appropriate use. Effects found from one species or strain of probiotics do not necessarily hold true for others, or even for different preparations of the same species or strain.
To understand how probiotics work, it is important to understand a little about the microbiology and physiology of the human gastrointestinal tract.
Human beings, like all animals, play host to many types and high numbers of microbes on our skin, in our mouths, in women's vaginal tracts, and all the way through our gastrointestinal tract. In fact, it has been estimated that there are more microbes associated with the human body (about 1014, or 100,000,000,000,000 bacterial cells) than there are human cells in it (about 1013). In addition to this very large number of bacteria, there also is a very large diversity of bacteria. It has been estimated that more than 1000 different species, or types, of bacteria make their homes on humans.
Taking this into consideration, it is not surprising that microbes have been found to play an important role in human health. Most of these bacteria are not harmful, and in fact contribute positively to normal human growth and development. But some of these bacteria can have negative influences. It is therefore important that the balance of microbes be maintained to favor the beneficial bacteria over the potentially harmful ones.
Many people use probiotics to prevent diarrhea, gas, and cramping caused by antibiotics. Antibiotics kill “good” (beneficial) bacteria along with the bacteria that cause illness. A decrease in beneficial bacteria may lead to digestive problems. Taking probiotics may help replace the lost beneficial bacteria. This can help prevent diarrhea.
A decrease in beneficial bacteria may also lead to other infections, such as vaginal yeast and urinary tract infections, and symptoms such as diarrhea from intestinal illnesses.
Probiotics may also be used to:
Help with other causes of diarrhea.
Help prevent infections in the digestive tract.
Help control immune response (inflammation), as in inflammatory bowel disease (IBD).
Probiotics are being studied for benefits in colon cancer, skin infections, and irritable bowel syndrome (IBS).
First, the world is full of microorganisms (including bacteria), and so are people's bodies -- in and on the skin, in the gut, and in other orifices. Friendly bacteria are vital to proper development of the immune system, to protection against microorganisms that could cause disease, and to the digestion and absorption of food and nutrients. Each person's mix of bacteria varies. Interactions between a person and the microorganisms in his body, and among the microorganisms themselves, can be crucial to the person's health and well-being.
This bacterial “balancing act” can be thrown off in two major ways:
By antibiotics, when they kill friendly bacteria in the gut along with unfriendly bacteria. Some people use probiotics to try to offset side effects from antibiotics like gas, cramping, or diarrhea. Similarly, some use them to ease symptoms of lactose intolerance -- a condition in which the gut lacks the enzyme needed to digest significant amounts of the major sugar in milk, and which also causes gastrointestinal symptoms.
“Unfriendly” microorganisms such as disease-causing bacteria, yeasts, fungi, and parasites can also upset the balance. Researchers are exploring whether probiotics could halt these unfriendly agents in the first place and/or suppress their growth and activity in conditions like:
Infectious diarrhea
Irritable bowel syndrome
Inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease)
Infection with Helicobacter pylori (H. pylori), a bacterium that causes most ulcers and many types of chronic stomach inflammation
Tooth decay and periodontal disease
Vaginal infections
Stomach and respiratory infections that children acquire in daycare
Skin infections
Another part of the interest in probiotics stems from the fact there are cells in the digestive tract connected with the immune system. One theory is that if you alter the microorganisms in a person's intestinal tract (as by introducing probiotic bacteria), you can affect the immune system's defenses.
Some probiotics have been shown in preliminary research to possibly treat various forms of gastroenteritis. They might reduce both the duration of illness and the frequency of stools. Fermented milk products (such as yogurt) also reduce the duration of symptoms.
Antibiotic-associated diarrhea (AAD) results from an imbalance in the colonic microbiota caused by antibiotic therapy. Microbiota alteration changes carbohydrate metabolism with decreased short-chain fatty acid absorption and an osmotic diarrhea as a result. Another consequence of antibiotic therapy leading to diarrhea is overgrowth of potentially pathogenic organisms such as Clostridium difficile.
Probiotic treatment might reduce the incidence and severity of AAD as indicated in several meta-analyses. For example, treatment with probiotic formulations including Lactobacillus rhamnosus may reduce the risk of antibiotic-associated diarrhea, improve stool consistency during antibiotic therapy, and enhance the immune response after vaccination. However, further documentation of these findings through randomized, double blind, placebo-controlled trials are required to confirm specific effects and attain regulatory approval, which currently does not exist.
Potential efficacy of probiotic AAD prevention is dependent on the probiotic strain(s) used and on the dosage. Up to a 50% reduction of AAD occurrence has been found in preliminary studies. No side-effects have been reported in any of these studies. Caution should, however, be exercised when administering probiotic supplements to immunocompromised individuals or patients who have a compromised intestinal barrier.
As lactic acid bacteria actively convert lactose into lactic acid, ingestion of certain active strains may help lactose intolerant individuals tolerate more lactose than they would have otherwise.
In general, cancer is caused by mutation or activation of abnormal genes that control cell growth and division. (A substance that causes a mistake in genes is known as a mutagen). Most of these abnormal cells do not result in cancer since normal cells usually out-compete abnormal ones. Also, the immune system recognizes and destroys most abnormal cells.
Many processes or exposures can increase the occurrence of abnormal cells. Precautions that minimize these exposures decrease the risk of cancer. Among the many potentially risky exposures are chemical exposures. Cancer-causing chemicals (carcinogens) can be ingested or generated by metabolic activity of microbes that live in the gastrointestinal tract. It has been hypothesized that probiotic cultures might decrease the exposure to chemical carcinogens by (1) detoxifying ingested carcinogens, (2) altering the environment of the intestine and thereby decreasing populations or metabolic activities of bacteria that may generate carcinogenic compounds, (3) producing metabolic products (e.g., butyrate) which improve a cell's ability to die when it should die (a process known as apoptosis or programmed cell death), (4) producing compounds that inhibit the growth of tumor cells, or (5) stimulating the immune system to better defend against cancer cell proliferation.
Research suggests that the consumption of probiotic cultures may decrease cancer risk. Researchers testing the effect of the consumption of fermented milks, probiotic bacteria, components of bacteria or extracts of bacteria have found:
A reduction in the incidence of chemically induced tumors in rats.
A reduction of the activity of fecal enzymes (β-glucuronidase, azoreductase, nitroreductase, and 7-α-dehydrogenase) postulated to play a role in colon cancer in human and animal subjects.
Degradation of nitrosamines.
A weakening of mutagenic activity of substances tested in the laboratory.
Prevention of damage to DNA in certain colonic cells.
In vitro binding of mutagens by cell wall components of probiotic bacteria.
Enhancement of immune system functioning.
Taken together, these results suggest that probiotic cultures may positively influence the gastrointestinal environment to decrease the risk of cancer. However, cancer reduction must be demonstrated in humans to confirm the significance of these observations. The impact of consumption of milk fermented by Lactobacillus casei Shirota on recurrence of superficial bladder cancer was tested. The recurrence-free period for the Lactobacillus-consuming group was found to be almost twice as long as the control group. In another study, this same strain was found to decrease atypical recurrent polyps in subjects with previous history of colonic polyp (Ishikawa et al. 2005). The European Union (EU)-sponsored Synbiotics and Cancer Prevention in Humans project tested a synbiotic (oligofructose plus L. rhamnosus GG and Bifidobacterium lactis Bb12) in patients at risk for colonic polyps and looked at intermediate end points that can be used as biomarkers of colon cancer risk. This study found that the synbiotic decreased uncontrolled growth of intestinal cells. These results must still be considered preliminary, but are encouraging that impacting the colonic environment may improve cancer occurrence.
Cholesterol is essential for many functions in the human body. It acts as a precursor to certain hormones and vitamins and it is a component of cell membranes and nerve cells. However, elevated levels of total blood cholesterol or other blood lipids are considered risk factors for developing coronary heart disease. Although humans synthesize cholesterol to maintain minimum levels for biological functioning, diet also is known to play a role in serum cholesterol levels. The extent of influence varies significantly from person to person. Probiotic cultures have been evaluated for their effect on serum cholesterol levels. Clinical studies on the effect of lowering cholesterol or low-density lipid levels in humans have not been conclusive. There have been some human studies that suggest that blood cholesterol levels can be reduced by consumption of probiotic-containing dairy foods by people with elevated blood cholesterol, but in general the evidence is not overwhelming. It is likely that some strains may demonstrate this property while others do not, or that only subsets of people with elevated cholesterol respond.
Helicobacter pylori is a bacterium which colonizes the stomach and can cause gastric ulcers and gastric cancer. The effect of probiotics on H. pylori has been studied. Mechanistic studies in laboratory assays or in animal models have shown that antibacterial substances including (but not limited to) organic acids produced by some lactobacilli inhibit the growth and survival of this pathogen. When tested in humans, results are mixed. Results in humans suggest that some probiotic strains or milk fermented with a probiotic strain can reduce metabolic activity or colonization by H. pylori but eradication has not been achieved. Probiotics have also been used to manage side effects of triple antibiotic therapy used to treat H. pylori infections. In these studies, the use of probiotics decreases the side effects of antibiotics, improves patient compliance with taking the prescribed therapy, and increases the rate at which H. pylori is eradicated.
The immune system defends against microbial pathogens that have entered our bodies. The immune system is extremely complex, involving both cell-based and antibody-based responses to potential infectious agents. Immunodeficiency can result from certain diseases (e.g., cancer, AIDS, leukemia) or, to a lesser extent, from more normal conditions such as old age, pregnancy, or stress. Autoimmune diseases (e.g., allergies, rheumatoid arthritis, inflammatory bowel diseases) also can occur due to misdirected immune system activity.
Probiotic cultures have been shown in a variety of test systems to stimulate certain cellular, biochemical and antibody functions of the immune system. Animal and some human studies have shown an effect of yogurt or lactic acid bacteria on enhancing levels of certain immunoreactive cells (e.g. macrophages, lymphocytes) or on regulation of immune factors (cytokines, immunoglobulins, interferon). In addition, some studies have shown improved survival of pathogen-infected laboratory animals consuming probiotic cultures as compared to animals consuming a control diet. Results accumulated so far suggest that probiotics may provide an additional tool to help your body protect itself.
An exciting area of research has been documenting the ability of certain probiotic bacteria to modulate immune dysregulation. Studies have shown that probiotics are effective in decreasing the development of allergy and relapse of inflammatory bowel disease.
High levels of oxalate in the urine is a risk factor for the development of kidney stones. Utilization of oxalate by intestinal microbes limits its absorption. A probiotic preparation that contained bacteria that were able to degrade oxalate in vitro was shown to reduce oxalate fecal excretion in six patients. These results suggest that manipulation of the gut flora with the right probiotic bacteria may have a positive impact on gastrointestinal tract oxalate levels and may decrease oxalate absorption. These results are intriguing, but preliminary.
Under certain conditions (production of low stomach acid, kidney dialysis and others), microbial populations in the small intestine can increase beyond normal levels. This is termed small bowel bacterial overgrowth. The misplaced microbes can produce byproducts from their growth that can be toxic. Researchers have found that feeding high levels of certain probiotic strains can control the toxic effects of these microbes. This is another example of the ability of probiotic strains fed in high numbers to modulate the activity of other intestinal bacteria.
Some live microorganisms have a long history of use as probiotics without causing illness in people. Probiotics' safety has not been thoroughly studied scientifically, however. More information is especially needed on how safe they are for young children, elderly people, and people with compromised immune systems.
Probiotics' side effects, if they occur, tend to be mild and digestive (such as gas or bloating). More serious effects have been seen in some people. Probiotics might theoretically cause infections that need to be treated with antibiotics, especially in people with underlying health conditions. They could also cause unhealthy metabolic activities, too much stimulation of the immune system, or gene transfer (insertion of genetic material into a cell).
Probiotic products taken by mouth as a dietary supplement are manufactured and regulated as foods, not drugs.
Some other points to consider:
If you are thinking about using a probiotic product as CAM (complementary and alternative medicine), consult your health care provider first. No CAM therapy should be used in place of conventional medical care or to delay seeking that care.
Effects from one species or strain of probiotics do not necessarily hold true for others, or even for different preparations of the same species or strain.
If you use a probiotic product and experience an effect that concerns you, contact your health care provider.
While probiotics have the potential to help the body they also can harm the body as well. There are some probiotics side effects that anyone taking probiotics should understand before they take this supplement. Keep in mind that probiotics are considered supplements and not medical treatment. As such they are not subject to the same scrutiny and testing that medicines are. Supplements aren’t regulated by government so it’s important that you read the label and understand what you’re taking before taking it. Learn to recognize some of the symptoms of probiotics side effects and immediately stop taking them if you experience any of them.
One of the most commonly reported of the probiotics side effects is abdominal discomfort. Bloating is a common problem that occurs when excess gas is produced in the digestive process. This can sometimes be caused by taking probiotics. One of the symptoms of bloating is a distended stomach or having a very full feeling. Another of the probiotics side effects is that can occur from taking probiotics is abdominal pain. Stomach pain may mean that you need to adjust your probiotics intake or it may indicate that you should stop taking probiotics.
Headaches are frequently reported probitotics side effects. If you suffer from headaches after taking probiotics it may be that you need to adjust your dosage. Some people report that the headaches subside after the body becomes more used to taking the supplement. However, if headaches persist or become severe you should discontinue taking probiotics and consult your doctor.
While for most people taking probiotics is helpful a small number of people should not take probiotics. Probiotics side effects may include being more prone to infections, particularly fungal infections. These infections may occur more frequently because the immune system has been compromised. Other probiotics side effects may include intestinal infections. If you have any underlying medical condition that affects your digestive system you should not take probiotics unless your doctor recommends them. Infections can become severe so if you have any symptoms of infection such as fever and skin rash you should discontinue taking probiotics and see a doctor.
Probiotics are becoming more popular. However, people need to understand the probiotics side effects that could occur when taking them. If you experience any probiotics side effects you may want to adjust your intake or simply stop taking them for the time being. If you have a compromised immune system you should not take probiotics unless you first consult your physician. In some people with suppressed immune systems taking probiotics can actually do more harm than good. Talk to your doctor before starting any new supplement.
Great taste August 31, 2010, From California
... but cant say that I noticed any benefits in taking it.
It works. July 16, 2010
I have IBS, and this really snaps me out of it faster. ...
Great Stuff! January 20, 2011, From California
... and it has cured my heartburn/acid reflux/upset stomach. I'm hooked.
Delicious April 06, 2011, From Florida
... and helps with digestive distress. Two teaspoons two or three times a day soothes the stomach.
Good Product October 21, 2010, From New York
This works better for me than the pills or tablets. I feel it to be much more effective.
no effects June 13, 2011, From Singapore
I've gastric,this product shows no effects....
Thank you! November 22, 2009, From Indiana
I received my order ... today and began taking 3 a day. Within two days my nausea and heartburn which I had suffered with everyday for the last three years had subsided. My energy has increased drastically, I am sleeping better, and the depressed feeling I had from feeling so lousy all the time has lifted. I will never stop using this probiotic.
awesome!!!! March 20, 2009, From Pennsylvania
These are a God sent i was always irrugular and have lots of gas and these keep all that under control. I was not always so bloated all the time. Thanks again. ...
... April 08, 2008, From Texas
My daughter, who is 8 years old, has been taking these for a few weeks now. She used to frequently complain of stomach problems, she has not complained once since beginning these!
Awesome for IBS! April 30, 2011, From North Dakota
These little pearls really work! I have IBS and they really help make me feel better and more regular. If you suffer from any gastrointestinal disorders or just looking to boost your immune system, definitely consider using these!
Didn't seem to do much for me October 19, 2010, From Switzerland
Didn't seem to do much for me
No difference April 17, 2010, By Wendy Savino From Texas
I have not seen any noticeable difference since taking this daily.
Been taking this because I know probiotics is beneficial to the body March 22, 2011, From Georgia
Nothing extraordinary
... May 24, 2009, By Michael Counts From Arkansas
I'm a Paraplegic and use these to help with digestion. Couldn't go without them. Helps in more ways than one! Thanks.
... October 14, 2009
Really keeps my IBS in check. Missed one day recently and had much more gas/bloating.
great product March 22, 2007, From California
... It has stopped my husand's nightly heartburn.
Amazing Probiotics March 03, 2011, From Massachusetts
This product not only helps with being "regular" but since I have been using it, greatly reduces "brain fog" and helps me to think more clearly. I also give it to my son who is on the Autism Spectrum Disorder as part of his daily regimen to address constipation and his immune system. We love it!