Our large intestine (colon), in a healthy state, has zillions of microorganisms living and thriving in it. Some estimates say that stool is made up of 90% dead microorganisms and sloughed intestinal cells and only 10% undigested fiber and food remnants.
These microorganisms are all competing with each other for survival and frequently they get out of balance and cause diarrhea, constipation or the unhealthy predominance of one or more organisms, such as when a person has a C. difficile infection or a colonic yeast overgrowth.
People do different things to try and get back to a state of intestinal balance, such as eating yogurt every day or eating a certain kind of fiber in specific amounts. Some people take probiotics which are the purified and isolated specific strains of bacteria that someone has decided they want to take. All probiotics are not the same and they are not equal.
Research has shown that certain specific probiotic strains help specific problems, such as L. reuteri for diarrhea and for chronic bladder bacterial infections. Women commonly find that after taking systemic antibiotics they often get a vaginal yeast infection, which is helped or corrected by eating yogurt or taking the probiotics that contain the bacterial strains commonly in yogurt, such as L. acidophilus, L. bulgaris, L. casei and S. thermophilus. Bifidus Regularis® may help with chronic constipation. Research has shown that Irritable bowel syndrome (IBS) may be helped by taking probiotics.
In reality, the situation is infinitely more complicated than this and there are factors going on that many people, including physicians, registered dietitians and other health practitioners, do not understand. For example, it was only recently discovered that one of the roles of the intestinal appendix is to be a reservoir of bacteria and yeast that normally populate a person’s gut. When an individual has food poisoning or something else that causes diarrhea or a die-out of his gut microflora, the appendix may be responsible for re-inoculating the colon with the microorganisms it grew in a healthy state.
Interesting discussion of the appendix’s function: http://news.sciencemag.org/sciencenow/2013/02/appendix-evolved-more-than-30-ti.html?ref=hp
When physicians and labs try to do stool tests to find either pathogenic microorganisms or favorable organisms, it is impossible to measure all the species that are present. And, to make the situation worse, most microorganisms that grow in the colon do not tolerate any light or oxygen. So when a stool sample is collected by a patient and processed by a lab, it is always exposed to some light and oxygen—automatically killing many important organisms. This makes it impossible to say with confidence that someone has or does not have certain microorganisms growing in his gut. DNA analysis is the newest, most sophisticated way to determine which microorganisms are present–but that will take a while before that knowledge makes it into everyday practice.
And, the current trend is to make probiotic products with patented organisms—so that a company can sell it and do studies with it—without any competition. Product examples include Culturelle® and Align® probiotics and Activia yogurt with Bifidus Regularis®. And, to make matters worse, some of the organisms in probiotic preparations are not self-propagating, which means the “effect” of taking them goes away shortly after stopping them. Instead, ideally, a good probiotic is one that will grow well, make the gut healthier and self-propagate itself so that you can eventually stop taking it and still benefit.
Most probiotics we take, or eat in yogurt, are destroyed by our stomach acid. Only a fraction of 1% makes it to the colon to grow. Therefore, you do need to take them frequently and in large amounts—in the billions. An enteric coating probably helps.
My recommendations for a good probiotic are as follows:
Take one with the largest number of different organisms (sometimes up to 10 can be found) and the largest number of total organisms (or CFUs, colony forming units, usually in the billions.) Examples are: (I am not in any way promoting these brands–they are just very good examples of what products are out there. I am not endorsing these products and these companies are not compensating me for mentioning them here.)
- Jarrow’s “Jarro-Dophilus” EPS®, 8 different organisms, 5 billion CFU
- Ultra Jarro-Dophilus®, 10 different organisms, 40 Billion CFU
- Renew Life Ultimate Super Critical Probiotic, 10 different organisms, FOS, 200 Billion CFU
When you rely on yogurt for your probiotic organisms, look at the label for the phrase “Active Cultures,” a listing of which microorganisms are in the yogurt and a statement of how many organisms were present at the time of shipping. Again, you will want as many different organisms as you can get and as large a total number of organisms as possible, too.
“Pre”biotics are the plant materials that intestinal bacteria like to grow on. They are usually sources of soluble fiber. Sometimes prebiotics are added to probiotic preparations, the thinking being that as soon as the probiotic is activated, it will have fuel present with it. That is probably largely symbolic because the probiotic organisms will be dispersed widely and the prebiotic is probably not there in large enough amounts to do a lot. Examples of prebiotics are FructoOligoSaccharides (FOS) and Inulin. A diet high in soluble fiber will also help support the growth of beneficial microorganisms–just one more reason for people to eat a high fiber diet.
For an in-depth, more technical discussion of this subject, please read this summary of the topic from the medical journal: Clinical Gastroenterology and Hepatology.
“A Gastroenterologist’s Guide to Probiotics:” http://www.cghjournal.org/article/S1542-3565%2812%2900369-2/fulltext
© 2012 Ann M. Del Tredici, MS, RD, CDE