As pointed out in past TotalHealth articles, many fungi and bacteria found in foods are beneficial to health. Whether one is discussing breads, cheeses, fermented tofu, wines, yoghurt, sauerkraut, kimchi or a number of other items, very often it turns out that traditional cooking and preserving techniques involving fungi and bacteria offer many benefits that are lost with modern alternatives.
This having been said, a major benefit of modern food science is the ability to supply beneficial bacteria in concentrated forms. The following discussion is intended to answer questions regarding the class of dietary supplements referred to as probiotics. Readers who wonder why some products have single strains and others offer many, why there often are numbers or other designations after Latin names of the bacteria, what benefits might be expected and how soon, etc., should read on. The species and strains mentioned happen to be ones with which the author is most familiar.
Do different probiotic strains affect the body in different ways? Do people benefit from having more of one strain than another?
The human gut consists of a series of microenvironments. Except for the stomach and the upper two thirds of the small intestine, there are differing bacteria and ratios of bacteria in each of these areas, starting with the mouth. In fact, the human gastrointestinal tract contains a large and diverse population of microorganisms—over 800 different bacterial species comprising nearly 100 trillion living organisms. The composition of this gut flora varies among individuals depending on diet, age, medication (antibiotics), stress, and physiological conditions. Not surprisingly, different probiotics perform different functions and offer different benefits. One big divide, of course, is between the two most important groups of typical probiotic bacterial species, Lactobacilli, found mostly in the lower small intestine and upper large intestine, and Bifidobacteria, found mostly in the large intestine, i.e., the areas of lower pH (meaning more acidic).
Broadly speaking, the Lactobacilli act on sugars and starches to create lactic acid, among other things. For instance, L. acidophilus La-14 (La-14 indicates the strain within the particular species) assists in breaking down lactose (milk sugar) and 15 other carbohydrates and this may improve digestion of dairy products by those individuals who are lactose intolerant. Clinical trials have shown that this strain may improve immune response and bowel regularity. It works especially well in conjunction with another bacteria strain, L. rhamnosus R0011. Interestingly, L. rhamnosus R0011 in conjunction with L. helveticus R0052 in humans enhances the eradication of H. pylori (a cause of stomach ulcers) when ingested in combination with conventional medical treatment.
Bifidobacteria, especially such as B. longum BB536 (Morinaga strain), have been shown to colonize the intestine, stimulate immune response, and promote the growth of other beneficial bacteria. BB536 also decreased the incidence of influenza in seniors in trials. Blood analysis showed significantly higher bactericidal activity of neutrophils and higher NK cell activity at the fifth week of administration compared to pre-administration. There has also been evidence reported that suggests BB536 can help modulate allergies and possess antiallergenic effects. Even more recent research is looking at the benefits of this strain in the areas of brain inflammation and dementia.
The finding that certain strains of probiotics reduce excessive inflammation by means of modulation of immune and other responses via the gut is one of the major advances in the knowledge of probiotics in recent years.
Inasmuch as different probiotic species and different strains of the same species often provide different and distinct benefits and also often interact to lead to yet other results, there are good reasons for supplementing with more than one strain and/or species (I refer loosely and not entirely scientifically to "species" here to distinguish also, for instance, Saccharomyces boulardii, which is not another bacterial strain, but instead a probiotic yeast). Similarly, different supplemental probiotics may be more to be desired at certain ages or under particular conditions. No single strain can easily fulfill all these requirements. A mixture of species, therefore, is usually most suitable for supplementation. The most desirable properties of a good probiotic are:
- Compatibility among the strains
- Ability to survive passage through the digestive tract
- Stability under normal gastric conditions
- Resistance to bile salts
- Adherence to intestinal mucosa
- Colonization of the human intestinal tract and/or extended residence time
- Safety with regard to human use
- Production of natural antimicrobial substances
- Antagonism against unfriendly and putrefactive bacteria
- Stability during storage under normal conditions
When purchasing a probiotic supplement, how many different strains should be in supplement and are all the strains in equal parts?
There is no one answer to this question. The probiotic yeast, Saccharomyces boulardii, typically is supplemented by itself before, during and immediately after antibiotic treatment, but otherwise may be supplemented in general with a mixture with bacterial probiotics. As a rule, it is best to supplement at least the two primary species of probiotics, Lactobacilli, found mostly in the lower small intestine and upper large intestine, and Bifidobacteria, found mostly in the large intestine. Three to eight species and/or strains is a common number. Keep in mind that these species and strains must be compatible both in the delivery format and after administered.
What fibers are effective prebiotics?
Let's start by defining the role of prebiotics. According to researchers in the field, "Prebiotics are supplements or foods that contain a nondigestible food ingredient that selectively stimulates the favorable growth and/or activity of indigenous probiotic bacteria. Human milk contains substantial quantities of prebiotics." 1 Some researched prebiotic fibers include trans-galactooligosaccharide, oligofructose, inulin, larch arabinogalactin, resistant starch, pectin, beta-glucans, xylooligosaccharides, and oligofructose-enriched inulin. Recently, scientists have begun to recognize that a number of polyphenols have prebiotic properties, although there as yet is no consensus as to the amounts required for benefits. For instance, proanthocyanidins and other compounds found in grape seed and red wine can positively affect gut microbial health, as can related compounds found in dark/minimally processed chocolate and in cranberries. This is an emerging area of knowledge.
What is the importance of pH in digestive health and how can dietary supplements support a balanced pH?
The degree of acidity or alkalinity of a given region of the gut can be given as its pH. The stomach should have a very low pH (relatively acidic) prior to meals, e.g., a pH of 2 or below, because this is needed to digest proteins and to provide a protective barrier against bacterial invasion of the rest of the gastrointestinal tract. A low pH in the stomach also is required to maintain the tonus of the esophageal sphincter to avoid "heartburn" and other gastrointestinal reflux conditions. The upper small intestine may approach a neutral pH of 6 and slightly above after pancreatic digestive fluids are mixed into foods coming from the stomach; this higher pH is required for the digestion of fats and for the actions of pancreatic enzymes. As foods proceed through the small intestine, the pH should slowly decrease as a result of bacterial action producing lactic and other acids. Short-chain fatty acids produced in the intestines exert a number of health effects. The return to a lower pH in the large intestine is required to produce peristalsis to maintain the proper passage of food through the bowel.
Hydrochloric acid precursor supplements can be taken to improve the production of gastric acid in the stomach. Betain HCl commonly is used for this purpose.
How do enzymes, herbs and botanicals affect acute symptoms like heartburn, indigestion, nausea or diarrhea?
Herbs can help for a variety of reasons. Chamomile is famous for calming properties and typically is taken as an antispasmodic and anti-inflammatory. Peppermint, especially the oil delivered by enteric soft gelatin capsules, is another item for calming the GI-tract. Type "peppermint irritable bowel" into PubMed and there will be 60 or more hits. Again, it is an antispasmodic. Ginger is widely touted—and human trials confirm this—as being good for several forms of nausea. Readers of past TotalHealth articles may recall that the Asian herb/food known as bitter melon, especially in its wild forms, improves various aspects of gastrointestinal health. (Bitter melon is best consumed with small amounts of "warming" herbs such as ginger or turmeric.)
A review published in 2012 concluded, "Amongst the most important we can find [with digestion-enhancing properties] [are] ginger, peppermint, aniseed and fennel, citrus fruits, dandelion and artichoke, melissa and chamomile, but many more have a significant body of experimental data available."2
Pancreatin, which includes trypsin, amylase and lipase, is specifically produced by the body to digest proteins, carbohydrates and fats under the relatively neutral pH conditions found in the stomach at the end of acid digestion and, primarily, in the small intestine. What most people do not realize is that the body tends to conserve digestive enzymes. Long-term use of digestive enzymes can help increase the body's own reserves of these enzymes for better digestion.
Although enzymes can help acutely with indigestion, this may not be the best way of conceptualizing their benefits. Retailers should try to find ways to highlight the contrast between treating the symptoms of poor digestion and actually improving digestion. For instance, as a practical matter, no one has too much acid in the stomach, so quite obviously taking proton pump inhibitors makes worse an underlying condition—too little gastric acid. Blocking acid release may make gastroesophageal reflux disease (GERD) temporarily less painful, but it does not address why GERD exists.
How does "cleansing" support digestive health? What is a safe and effective cleanse?
It is important to distinguish between detoxification and cleansing approaches. Detoxification programs typically focus on the liver and involve the endogenous Phase I and Phase II detoxification systems. Cleansing programs, in contrast, focus on the large intestine and are based on theories of autointoxication from partially digested foods, especially meat and other animal foods, leading to the build-up of mucus and other wastes in the intestines with the absorption of these toxins into the blood.
There is a grain of truth to cleansing theories. A considerable part of the toxins and waste products of the body, such as spent hormones, are eliminated through the bile and thus via the stool. Likewise, it certainly is true that a lack of fiber in the diet and dysbiosis in the gut can lead to toxins being reabsorbed multiple times before being fully excreted from the body. These two pieces fit together because in its detoxification processes, the body binds toxins in a variety of ways, two of which are glucuronidation and sulfation, and then disposes of the toxins via the bile. Without adequate fiber, including fiber that can support the growth of friendly bacteria in the gut, toxins disposed via the bile can be reabsorbed many times before eventually being eliminated from the body. Similarly, without the proper fiber, toxins can influence the health of the cells lining the large intestine. Especially important in this light are synbiotics, meaning combinations of prebiotics (such as fiber) and probiotics that work well together to deliver greater health benefits.
Nevertheless, many of the claims of cleansing programs seem suspect. For instance, the large intestine turns over the cells that make up the intestinal lumen roughly every three days, so claims of a build-up of impacted fecal matter (as opposed to constipation, something entirely different) do not match the evidence.
What can a cleansing program accomplish? First, it can mark a transition to a new general diet. Consuming more fiber (soluble, semisoluble and insoluble) is well established to improve constipation, diverticulosis, some forms of irritable bowel, and to protect against colorectal cancer. How much is needed? Most estimates are 20–35 grams per day rather than the usual American consumption of only 10–15 grams per day. Some health writers suggest consuming herbal gums such as frankincense, myrrh and mastic gum during this period.
Second, dysbiosis is a real issue and a turnover in the make-up of the stool through the addition of fiber and probiotics—a synbiotic approach—can help to change the intestinal milieu. Again, constipation, diverticular disease and forms of inflammatory and irritable bowel can be improved by this combination approach.
The best reason to undertake a cleanse is to transition to a diet higher in vegetables, whole grains, legumes and fiber-rich foods in general. This also should help the system move to a different make-up of intestinal bacteria. A very simple way to accomplish this is to add approximately 10 grams of good quality fiber to each meal and, assuming that one does not have a blocked bile duct, to take supplements that increase the release of bile. These include gentian, artichoke leaf, chicory root, dandelion root and yellow dock. At the same time, a good probiotic should be started to positively influence the composition of the bacteria found in the gut. The first few days of such a cleanse may be a bit uncomfortable and be characterized by unusual gas and bloating, but by the end of one or two weeks things should stabilize. Higher fiber intake from whole fruit (not juice), vegetables, legumes and whole grains should continue.
HOW MANY BACTERIA IS ENOUGH AND HOW MANY IS TOO MUCH?
Too often the impression is that if one or two billion colony forming units (CFU) of a probiotic species is good, then 50 or 100 billion must be better. Research and real life experience do not always agree with this! There is a strong argument to be made that approximately two billion CFU of any given strain is quite enough for everyday usage if the species and its strain is, in fact, appropriate for the intended purpose. Formulas containing multiple species and multiple strains might supply CFU in the range of 10–15 billion using this reasoning.
Lactobacillus acidophilus is generally considered safe for most people. Gas, upset stomach, and diarrhea are potential side effects in some people (not on antibiotic therapy) who take more than 1 to 2 billion L. acidophilus CFUs daily.3
Supplement shoppers examining probiotic products need to keep in mind that there are many more types of desirable organisms in the gastrointestinal tract than merely Bifidobacilli and Lactobacilli. For instance, according to Tim Spector, professor of genetic epidemiology at Kings College London and director of the British Gut Microbiome project, a "healthy gut is like a perfect English garden. You've got a diversity of microbes of all types, all living together and feeding off each other's by products—nothing is wasted."4
Overloading the GI-tract with huge numbers of probiotic bacteria can crowd out the diversity of bacteria that should be found in the gut. The result can be so-called "cleansing" episodes of either or both diarrhea and constipation. Moreover, excess supplementation or supplementation with probiotic strains that do not match a person's constitution, rather than addressing the issues of gas and bloating, actually can increase these. If a probiotic supplement program still continues to cause gas and bloating after two weeks, a different source of probiotics may be found to be more appropriate.
Finally, do not overlook the fact that actual food sources of probiotics often are the best sources. This means real cheeses with live cultures, live yoghurt, real rather than artificially soured sauerkraut, traditionally prepared kimchi and other Asian soured vegetables, traditionally prepared and preserved pickles (all of these will be in the refrigeration section of the store), live sour creams and sour milks, naturally yeast-leavened breads made the traditional way, and so forth and so on. Among other benefits, these foods not only often are more nutritious, but also simply generally taste better.
- Pediatrics. 2010 Dec;126(6):1217–31.)
- Int J Food Sci Nutr. 2012 Mar;63 Suppl 1:82–9.)
Probiotics for Digestive Health
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Dallas Clouatre, PhD
Dallas Clouatre, Ph.D. earned his A.B. from Stanford and his Ph.D. from the University of California at Berkeley. A Fellow of the American College of Nutrition, he is a prominent industry consultant in the US, Europe, and Asia, and is a sought-after speaker and spokesperson. He is the author of numerous books. Recent publications include "Tocotrienols in Vitamin E: Hype or Science?" and "Vitamin E – Natural vs. Synthetic" in Tocotrienols: Vitamin E Beyond Tocopherols (2008), "Grape Seed Extract" in the Encyclopedia Of Dietary Supplements (2005), "Kava Kava: Examining New Reports of Toxicity" in Toxicology Letters (2004) and Anti-Fat Nutrients (4th edition).