Probiotics Revisited, Part 1
Let's face it; probiotics are hot. Yes, it's true that for many years they were confined to the outer fringes of the alternative health market -- restricted to yogurt, sauerkraut, and the small dedicated market that regularly purchased probiotic supplements on faith. In fact, when I first started writing my alternative health newsletter about the benefits of probiotics and their importance 20 years ago, you could count on one hand the mainstream authorities who promoted them. But oh my! How things have changed over just the last 18 months. Suddenly, probiotic benefits are the second coming -- frequently pitched by those in the functional food industry as the next Omega-3.
- Probiotics the New Trend for Children
- Dannon Activa with Bifidus Regularis
- Probiotic Food Bars
- Breakfast Cereals with Added Probiotics
- Probiotics Added to Meat -- No Really, I'm Not Kidding
In this two part series, we'll take a look at the truth behind the hype. We'll discuss what probiotics are and explore the positives and the negatives (yes, there are "potentially" some negatives) behind supplementation. And we'll discuss how to choose an effective probiotic supplement for your own personal health program. In Part 1 of the series, we'll explore exactly what they are and what benefits from probiotics you can expect from supplementation.
What are probiotics?
The simple definition of probiotics is that they are live, naturally-occurring microorganisms (usually bacteria) that function internally to promote healthy digestion and beneficial bacteria, boost the immune system, and contribute to general health. But the more complete definition is far more interesting.
Before you were born, your intestines were free of microorganisms. They were virtually sterile. From the moment you passed through the birth canal, however, bacteria, both beneficial and harmful, entered through your mouth and began a fight for dominance destined to continue until the day you die. If you were breast fed, somewhere between days four and seven after you were born, the "good guys" decisively turned the tide of battle and staked their claim to virtually every square inch of your digestive tract -- from your mouth to your anus. (Note: the same battle is fought in the vaginal tract, the nasal cavities, and in the mouth.) The formal battle, however, is not decisively won until around age 6, at which point your immune system is fully trained. If for any reason your intestinal flora are severely compromised (such as being subjected to a round of antibiotics) before that age, it can negatively impact your health for the rest of your life.
Truth be told, it's a battle that's never totally won; the harmful bacteria are never completely eliminated. But in a healthy body, the bad guys never get a chance to gain a foothold -- to colonize -- to reproduce exponentially and cause illness. One of the problems, of course, is that every second of every single day, we are constantly being exposed to billions and billions of potentially harmful microorganisms with every breath we take or every bit of food that we swallow or swig of water that we drink. (Researchers now realize that one of the chief reasons breast-fed babies get so many fewer infections than formula-fed babies is that mother's milk tends to promote the growth of beneficial bacteria in the gastrointestinal tract, whereas store-bought formulas have no such beneficial effect.)
Anyway, the net result is that in a breast-fed baby, beneficial bacteria (such as acidophilus and bifidobacteria) control over 90% of the intestinal tract. These microorganisms, in turn, produce a large amount of essential byproducts in the intestines, which act as a barrier to the growth of dangerous pathogenic microbes that can cause disease and infection.
When you're healthy, over 100 trillion microorganisms from some 400 different species flourish in your intestinal tract, aiding in digestion, absorption, and the production of significant amounts of B vitamins, vitamin K, and enzymes. (Just as a side note, there are some 40 different types of bacteria resident in a healthy mouth alone.) But even more importantly, these beneficial bacteria cover virtually every square inch of available surface space from your mouth to your anus, thus crowding out all harmful bacteria -- allowing them no place to gain a foothold.
Unfortunately, the levels of beneficial bacteria decline dramatically as the human body ages. Some of the reasons for this decline include:
- Over time, the colonies of friendly bacteria just naturally age and lose their vitality. (Think of it like a royal family that eventually fizzles out after years of inbreeding.)
- Disruptions and changes in the acid/alkaline balance of the bowels can play a major role in reducing the growth of beneficial bacteria. In addition, these changes tend to favor the growth of harmful viral and fungal organisms as well as putrefactive, disease-causing bacteria.
- Non-steroidal anti-inflammatory drugs (NSAIDS) like Advil, Motrin, Midol, etc. are destructive to intestinal flora.
- Chlorine in the drinking water not only serves to kill bacteria in the water; it is equally devastating to the colonies of beneficial bacteria living in the intestines. The problem is that nature abhors a vacuum, and harmful bacteria then move in to occupy the abandoned "plots."
- Radiation and chemotherapy are devastating to your inner bacterial environment.
- Virtually all meat, chicken, and dairy that you eat (other than organic) is loaded with antibiotics, which destroy all of the beneficial bacteria in your gastrointestinal tract.
- A diet high in meats and fats, because they take so long to break down in the human body, promotes the growth of the harmful, putrefying bacteria.
- Constipation, of course, allows harmful bacteria to hang around longer, which allows them to proliferate.
- Cigarettes, alcohol, and stress are also major culprits, as are some antibiotic herbs, such as goldenseal (if taken in sufficient quantity and/or used too frequently).
- And if you've ever been subjected to a round of "medicinal" antibiotics, you can kiss your beneficial bacteria goodbye. The problem is that antibiotics indiscriminately destroy both bad and good bacteria, allowing virulent, mutant strains of harmful microorganisms to emerge and run rampant inside the body. Antibiotics (both medicinal and in our food supply) are the number one culprit in the overgrowth of harmful pathogens in the gastrointestinal tract (a condition called dysbiosis).
Diseases associated with low levels of beneficial bacteria can include: acne, ADHD, allergies, arthritis, asthma, bladder and urinary-tract infections, breast pathologies, cardiac problems, chronic fatigue, colitis, colon cancer, compromised immunity, constipation, diarrhea, diverticulitis, ear and respiratory infections in children, eye, ear, nose and throat diseases, foul breath and body odor, gastritis, headaches, hormonal imbalances, IBS, liver and gallbladder problems, migraine headaches, ovarian and uterine cancers, PMS, sinus problems, spastic colon, stomach bloating, and vaginal yeast infections.
A properly functioning intestinal tract is one of your body's first lines of defense against invaders. In a healthy colon there are, on average, well over 100 billion beneficial bacteria per milliliter (about 1/5 of a teaspoon) that literally consume harmful bacteria and other invaders. In the typical American, because of poor diet and neglect of the colon, the beneficial bacteria count may be as low as four or five per milliliter. Just compare 100 billion to four (not four billion, just plain old four), and you'll have an understanding of the scope of the problem. Many researchers now believe that declining levels of friendly bacteria in the intestinal tract may actually mark the onset of chronic degenerative disease. The benefits of a probiotically optimized intestinal tract include:
- Lower cholesterol.
- Assists in the digestion of carbohydrates.
- Helps prevent constipation.
- Inhibition of cancer.
- Protection against food poisoning.
- Protection against stomach ulcers.
- Protection against lactose intolerance and casein intolerance.
- Enhanced immunity.
- Protection against many harmful bacteria, viruses, and fungi.
- Protection against Candida overgrowth.
- Prevention and correction of constipation and diarrhea, ileitis and colitis, irritable bowel syndrome, and a whole range of other digestive tract dysfunctions.
- Improvement in the health and appearance of the skin.
- Better nutrition from improved absorption and the internal generation of B vitamins and vitamin K.
- Protection against vaginosis and yeast infections.
- By killing off invading pathogens and producing immune boosting bio-chemicals such as transfer factor and lactoferrin, beneficial bacteria are responsible for 60-70% of your immune system's activity.
Are there any studies to support the benefits of probiotics?
And the answer is: "sort of." Certainly, many doctors are skeptical concerning the benefits of probiotic supplements, pointing out that when you take a dose of lactobacillus, 99% are killed by the acid in your stomach before they even reach your gut. (More on this piece of nonsense in the next issue of the newsletter.) The truth, however, is far more nuanced -- and the true answer appears to be that, yes, probiotics do indeed provide the promised benefits (under certain conditions). And, as we will learn later, the negative studies are far less substantive than they might first appear. With that in mind, let's take a look at some of these studies.
Probiotics and irritable bowel syndrome (IBS)
Over the years, studies relating to the benefits of probiotics in dealing with intestinal disorders such as IBS and Crohn's disease have been ambivalent -- but over time, the scientific evidence in support of benefit is becoming preponderant.
For example, researchers at Dundee University tested a probiotic of their own creation on ulcerative colitis patients and found that virtually all benefited. But that was contradicted by a 2004 study in the Drug and Therapeutics Bulletin that found the benefits of probiotics in intestinal disorders inconclusive at best. Then again, other studies have shown that the ingestion of probiotics can play a demonstrably effective role in the prevention of colon cancer.
And just a few days ago, the results of several favorable studies were announced at the annual meeting of the American College of Gastroenterology. One study, in particular, clearly concluded that probiotics were "safe and significantly more effective than the placebo in alleviating IBS-related symptoms (abdominal pain/discomfort, bloating, and stool dysfunction) in children and teenagers."
Probiotics and the immune system
A 1995 study published in the Journal of Dairy Science concluded that Lactobacillus casei could prevent infections and that yogurt could inhibit the growth of intestinal carcinoma through increased activity of IgA, T cells, and macrophages.
Other research has shown that the intake of probiotics has a number of effects on the immune system such as increased production of IgA antibodies, increased macrophage activity, and increased phagocytosis. In addition supplementation of certain beneficial bacteria also decreases the number of inflammatory mediators like TNF-α and α -1-antitrypsin.
Then again, earlier this year, the journal Clinical & Experimental Allergy published the results of a study conducted by the Institute of Food Research that found that probiotic bacteria in a daily drink can modify the immune system's response to grass pollen, a common cause of seasonal hay fever.
And just this month, yet another study found that the DNA of so-called "good bacteria" that normally live in the intestines may help defend the body against infection. As reported by Yasmine Belkaid, Ph.D., and her colleagues in the Laboratory of Parasitic Diseases at the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, "During an infection, we've found that commensals [probiotics] can break this balance in favor of an infection-fighting response."
In effect, Dr. Belkaid found that probiotics can boost the activity of T cells so they destroy invading pathogens.
Probiotics and colon tumors
The use of probiotics and prebiotics to prevent colon cancer has gained much attention due to
positive outcomes from in-vivo and molecular studies. Various mechanisms have been proposed, including their anticarcinogenic effects, antimutagenic properties, modification of differentiation processes in tumor cells, production of short chain fatty acids, and alteration of tumor gene expressions. As with almost all studies on probiotics (as we've already mentioned), study results are mixed. This is not necessarily surprising considering the wide variety in probiotic cultures tested, not to mention the wide variety of strains even within a single culture. Nevertheless, the overwhelming evidence seems to demonstrate that the use of probiotic supplements can indeed offer a small but significant inhibition of colon tumors.
Probiotics and cholesterol
Numerous studies have found a positive link between the consumption of probiotics and improved serum cholesterol numbers. For example: according to a clinical trial published in the European Journal of Clinical Nutrition, women who eat yogurt every day may experience a statistically significant increase in the level of their "good" cholesterol. The study also noted that this beneficial effect can be magnified by supplementing the yogurt with probiotics and a prebiotic such as fructo-oligosaccharides.
Probiotics and constipation
In addition to hundreds of years of anecdotal evidence, there are a number of scientific studies on both the young and the old demonstrating the ability of probiotics to help relieve the symptoms of constipation.
Probiotics and Candida
Then there have been a number of studies that show that probiotic supplements can be an effective adjunct to any program designed to control Candida overgrowth. Interestingly, the benefits of probiotics on Candida appear to be multifaceted. It seems that probiotics can:
- Inhibit the ability of the Candida to adhere to the intestinal wall
- Inhibit the actual growth of Candida
- Produce hydrogen peroxide, makes the gut (and the vaginal area) inhospitable to Candida
- Produce bacteriocins, which are antimicrobial compounds that kill yeasts such as Candida, in addition to viruses and bad bacteria
Probiotics and Crohn's
And finally, just hours ago (literally between drafts of this newsletter), a French study was released that indicated that a shortage of naturally-occurring bacteria, F. prausnitzii, might actually be the determining factor in the onset of Crohn's disease. According to the researchers, F. prausnitzii, when present, secretes a biochemical that helps throttle down the body's immune system response in the gut, thereby helping control inflammation. If levels of the bacteria drop too low, inflammation (i.e. Crohn's) results.
While still only a theory, the research behind it, nevertheless, points once again to the importance of probiotics cultures in maintaining optimum health.
Probiotics and your appendix
Before we wrap up today's alternative health, there's a fun item that recently came to light. A new study has found a potential connection between your appendix and beneficial bacteria in your intestinal tract. It seems the appendix may not be quite as useless as doctors have assumed all these years. Actually, given enough time, it seems that doctors are finding that no part of the body is useless -- that all parts seem to have important (if sometimes obscure) health functions. (Actually, that sentence alone could be worth an entire newsletter when you think about it.)
So what is this newly hypothesized function of the appendix, its raison d'être?
Well, according to William Parker, Ph.D., assistant professor of experimental surgery, who conducted the analysis in collaboration with R. Randal Bollinger, M.D., Ph.D., "While there is no smoking gun, the abundance of circumstantial evidence makes a strong case for the role of the appendix as a place where the good bacteria can live safe and undisturbed until they are needed." In other words, it looks like the human appendix serves as a "safe house" for beneficial bacteria to grow and remain in reserve for such time as they may be needed in "re-inoculating" the colon in the event that the contents of the intestinal tract are purged following exposure to a pathogen. For example, the reserve of beneficial bacteria in the appendix can help the body ride out a bout of diarrhea that completely evacuates the intestines, thus flushing all beneficial bacteria from the gut.
It should be noted that researchers have known for some time the appendix contains immune system tissue. It now appears that the immune system cells found in the appendix are there to protect, rather than harm, the good bacteria.
In addition, this new research confirms the fact that in a healthy intestinal tract, beneficial bacteria are instrumental in creating a biofilm comprised of microbes, mucous, and immune system molecules that coats the lining of the intestines, thus literally preventing harmful bacteria from taking root. As Dr. Parker says, "Our studies have indicated that the immune system protects and nourishes the colonies of microbes living in the biofilm. By protecting these good microbes, the harmful microbes have no place to locate. We have also shown that biofilms are most pronounced in the appendix and their prevalence decreases moving away from it."
The case for probiotics
From what I've presented, it would appear that the case for supplementing with probiotics is very strong -- with many studies supporting their probiotic benefits. But then how do you reconcile all of the studies that claim inconclusive results? Are supplemental probiotics beneficial or not? In fact, most of the studies that claim inconclusive results are based on using a limited number of cultures (often one particular culture), further limited by the use of a single strain, and testing for a one predefined result that may or may not fall within that particular strains actual benefits. In other words, testing L. salivarius for its ability to lower cholesterol (which is not what it does) might lead to a blanket statement that probiotics are not helpful in lowering cholesterol -- whereas the same study using Streptococcus thermophilus, L. acidophilus, or Bifidus would most likely produce entirely different results. On the other hand, testing L. Salivarius for its ability to eat away encrusted fecal matter throughout the entire colon would produce positive results. Testing L. acidophilus for the same benefit -- not so much.
The problem is that after enough of these true but irrelevant studies get published in peer review journals, they acquire validity, as they say in law, by virtue of a preponderance of the evidence. In other words, they appear true because there are so many of them. And in fact, it's interesting to note that virtually, every positive study on probiotics now has to begin with a disclaimer acknowledging the multitude of negative studies out there. For example, here's the background statement leading into a quite positive study on the results of probiotics and childhood constipation.
"Inconsistent data exist about the efficacy of probiotics in the treatment of constipation. Several studies in adults with constipation showed positive effects of probiotics on constipation. Inconsistent data exist regarding the effect of a single probiotic strain in constipated children. The aim of this pilot study was to determine the effect of a mixture of probiotics containing bifidobacteria and lactobacilli in the treatment of childhood constipation."
Don't be fooled. The preponderance of the evidence supports the use of supplemental probiotics for a wide range of health supporting benefits. The so-called inconsistency is a manufactured illusion.
Next newsletter on probiotics
In the next issue of the newsletter, we will conclude our series on probiotics by exploring those situations where using probiotics might not be advisable and by examining in detail how you should go about choosing a probiotic supplement.