M.S. Clinical Nutrition
Founder & Formulator Vibrant Health
Probiotics are symbiotic organisms that take up residence outside the body, and help keep us healthy. They reside on the skin, on urogenital tissues and in the gastrointestinal tract from mouth to anus. Even in these latter locations, however, the bacteria are still outside the body. Something swallowed, either friendly nutrient or dangerous poison, can only enter the body after crossing the mucosal linings of the gastrointestinal tract.
We are concerned in this paper with Lactobacillus bacteria that live in the digestive system. They are also in some fermented foods such as yogurt and in dietary supplements. Lactobacilli are used for treating and preventing diarrhea, irritable bowel syndrome, Crohns disease, inflammation of the colon, urinary tract infections, vaginal yeast infections, respiratory infections, and skin disorders.
Bifidobacteria are bacteria that exist primarily in the large intestine although some also inhabit the lower part of the small intestine. To date, 28 species of bifidobacteria have been isolated from the intestines of humans and animals. Among those species, numbers sub-species (strains) have been genetically typed.
Modern genetic typing of probiotic bacteria has now allowed researchers to identify numerous strains of bacteria resident in the human GI tract. Each performs some tasks in common with the others as well as some unique tasks specific to itself. For example, Lactobacillus helveticus (in ) helps break down protein and sugars, but also has an enhanced ability to break down dietary cholesterol. Propionibacterium shermanii breaks down dairy proteins and sugars as do many probiotics, generating metabolites that help feed Lactobacillus helveticus and a few other strains. Eventually, P. shermanii takes up residence in the large intestine (colon) where it is prepared to battle C. difficile if necessary, and carry out the tasks itemized below related to intestinal health and immunity.
The scientific literature is overflowing with research on probiotics. The field is hot now, with additional research papers appearing each year. They continue to be nearly entirely positive as more benefits of probiotics are elucidated.
We have always known they aid digestion by helping to break down proteins, starches, and sugars, and as research has grown, we have, learned that certain of them synthesize vitamin K, and vitamin B12. Indeed, one can become deficient in both vitamins if colonies of probiotics in the intestinal tract are reduced through protracted antibiotic use or poor diet.
When colonization of the intestinal tract with probiotics is less than robust, digestion is understandably one of the first body systems to become flawed. Supplementation with multiple probiotics can help.
Irritable Bowel Syndrome
Irritable bowel syndrome (IBS) is the most common diagnosis in gastroenterology. Supplementation with a blend of Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium shermanii and Bifidobacterium lactis was shown to improve abdominal symptoms of IBS, quality of life, intestinal microbiota and inflammatory markers of IBS. Bifidobacterium infantis as well as Lactobacillus plantarum are additional probiotics with unique abilities to reduce intestinal inflammation
Probiotics alter the intestinal environment, producing beneficial short-chain fatty acids and deconjugating bile acids, and limit the growth of pathogenic bacteria by direct competition. They also exert potent anti-inflammatory effects, controlling inflammatory cell messenger (cytokine) production by interacting with lymphoid tissue in the lining of the intestinal tract. This immunomodulatory effect also weakens the tissue hypersensitivity characteristic of IBS.
Evidence of benefit from probiotics is the strongest for the treatment of antibiotic-associated diarrhea and the resolution of infectious gastroenteritis. Lactobacilli and Bifidobacteria subspecies are able to deconjugate and absorb bile acids, potentially reducing fluid and mucus secretions in the colon that may contribute to functional diarrhea or IBS with diarrhea.
Chronic inflammatory bowel disease is often accompanied by the formation of inflamed pouches in the intestinal wall. A combination of Lactobacillus casei, L. plantarum, L. acidophilus and L. delbrueckii subsp. bulgaricus, plus three strains of bifidobacteria (Bifidobacterium longum, B. breve and B. infantis) and Streptococcus thermophilus was shown effective in preventing the onset of acute pouchitis in patients with newly formed surgical pouches, and in maintaining remission following antibacterial treatment of acute pouchitis in patients with a history of refractory or recurrent pouchitis In mild to moderate ulcerative colitis, the same formula resulted in a combined remission response rate of 77% with no adverse events.
All components of the formula, except B. infantis and L. bulgaricus, are found in at far higher bacteria counts than was used in the research (3.6 billion bacteria per day for 6 weeks). [Bulgaricus in was replaced by Rhamnosus several years ago in favor of Rhamnosus stronger antibacterial properties. Infantis is found in Junior for children.)
Science has now verified significant immune support functions of probiotics. A growing number of probiotic bacteria are now included in the immune support group. Lactobacillus plantarum, for example, exhibits mild immune system activation without setting off immune-stimulated colitis.
The use of probiotics for treatment of Clostridium difficile infections has been tested in randomized controlled clinical trials. The advantages of probiotic therapy include multiple mechanisms of action against pathogens, the ability to interact with our natural defense systems, stimulating beneficial immune response, and a good risk to benefit ratio.
Scouring the literature begins to unveil what may be an unending list of applications where probiotics have delivered benefits. They include respiratory disease and influenza, herpes,
and even HIV/AIDS. Along with the hallmark of HIV infection, decreased immunity, there are a number of other risk factors including opportunistic infection, malnutrition, wasting syndrome, and oxidative stress. Nutritional problems have been shown to be significant and contribute to health if remedied, and death, if not, in HIV/AIDS patients. Weight loss, lean tissue depletion, loss of appetite, diarrhea, and the hypermetabolic state increase risk of death. The optimization of nutrition, intervention with foods and supplements, including nutrients and other bio-active food components, are needed to maintain the immune system. Probiotics with and without prebiotics are sometimes given on the presumed basis that they help maintain integrity of mucosal surfaces, boost immunity by improving antibody responses, and increase white blood cell production.
Disease causing (pathogenic) microbes are most effective at wreaking havoc on the human organism if they adhere to the intestinal lining (the mucosa) and build a colony there. Lactobacillus rhamnosus A, L. rhamnosus B, and Propionibacterium shermanii, in combination with either Bifidobacterium breve or B. lactis have been shown to inhibit pathogen adhesion, to displace pathogens that have already taken up residence on the intestinal wall, and to compete for adhesion against pathogens. Specific probiotic combinations, all of which are represented in , are able to inhibit pathogens adhesion to intestinal mucosa better than individual strains. Bifidobacteria produce a protein that prevents the adhesion of pathogenic Escherichia coli to their normal receptors in the intestinal tract. This suggests that combinations of probiotic strains are useful and more effective at inhibiting pathogen adhesion than individual strains, and provides the rationale for the use of a balanced formula of 12 distinct probiotic strains in .
Healthy colonies of Bifido bacteria are known to protect against and help eradicate infections of Clostridium difficile (C. diff.), an antibiotic resistant pathogen that takes up residence in the colon and can become lethal. Propionibacterium shermanii is especially noteworthy in fighting C. diff.
Intestinal coliform bacterial enzymes beta-glucosidase, beta-glucuronidase, and urease may contribute to the development of colon cancer by generating carcinogens. A reduction in the activity of these enzymes by certain lactic acid bacteria would be beneficial. Lactobacillus rhamnosus together with Propionibacterium shermanii decreased the activity of beta-glucosidase and urease in a dose dependent manner in human test subjects. As Propionibacteria counts increased, beta-glucosidase activity decreased proportionately.
Propionibacterium shermanii is known to produce a series of metabolites that feed other Bifidobacteria in the colon, thereby helping maintain robust colonies. Those same healthy colonies of Bifido bacteria are known to lower the risk of colon cancer that risk beginning its inexorable rise after age 50. At that age marker, the size and vigor of Bifido colonies in the colon normally begin to diminish unless supplemented. Furthermore, probiotics metabolize prebiotic fibers and ellagitannins (a group of polyphenols, condensed tannins) from fruits and berries into equol, butyratre, and ellagic acid, each of which offer protection against cancer. So not only robust colonies of Bifidobacteria in the colon but their metabolites as well help lower the risk of colon cancer as we age.
Zearalenone is a potent toxic estrogen-like metabolite produced by some fungi species. Several Fusarium species produce toxic zearalenone among other toxins. It concerns us because zearalenone can cause infertility, abortion or other breeding problems, especially in swine and humans are biochemically very much like swine (as shocking as that may sound.) Zearalenone is heat-stable and is found worldwide in a number of cereal crops, such as maize, barley, oats, wheat, rice, and sorghum and also in bread. It is through such grains that this fungal toxin (mycotoxin) reaches animals and humans alike.
Thankfully, tests show that Propionibacteria shermanii and freudenreichii can remove zearalenone from liquid medium in vitro. The environment of the large intestine, where supplemental Propionibacteria take up residence, is wet. That means zearalenone, that finds it way there along with the bread and grain we eat, will be vulnerable to annihilation by Propionibacteria.
Indeed, five species of Propionibacteria have shown antifungal properties that reach beyond just zearalenone. Peptides and other antifungal metabolites secreted by the Propionibacteria appear to be the active agents.
The increasing prevalence of obesity and diabetes represents one of the major public health problems in developed countries, leading to intensive research on the causes and possibilities for intervention. Intestinal flora (i.e. probiotics) has become a focus of this research. Probiotic yogurt containing Lactobacillus acidophilus and Bifidobacterium lactis improved total cholesterol and LDL-C concentrations in type 2 diabetic people, and may contribute to the improvement of cardiovascular disease risk factors.
Recent studies established the role of probiotics and prebiotics in weight management by improving gut microbial balance, causing decreased food intake, and leading, therefore, to decreased abdominal adiposity. In the intestine itself, increased mucosal integrity with decreased inflammation was noted. Indeed, probiotics tendency to normalize digestion contributes to the control of pre-diabetic syndromes and type 2 diabetes. Probiotic-enhanced digestion improves absorption of nutrients, leading to greater control over appetite, and a loss of excess adipose tissue in type 2 diabetics.
It seems Bifidobacteria can help reduce the risk of and even help shut down type 2 diabetes. It also appears that supplementing pregnant and lactating mothers, and even their infants, with Lacto and Bifido bacteria may prevent the autoimmune disorder known as type 1 diabetes.
In type 1 diabetes, insulin-producing beta-cells in the pancreas are destroyed by immune-mediated mechanisms. The manifestation of the disease is preceded by a pre-diabetic period that may last several years, and is characterized by the appearance of circulating autoimmune antibodies against pancreatic beta-cell antigens.
The role of the gut as a regulator of type 1 diabetes was suggested in animal studies, in which changes affecting the intestinal immune system modulated the incidence of diabetes. Since the pancreas and the gut belong to the same intestinal immune system, an immune system directly influenced by the health of the intestinal microbiota, the link between autoimmune diabetes and the gut is reasonable.
The gut hypothesis in the development of type 1 diabetes is also supported by observations made in human type 1 diabetes. A childs early diet could affect the development of beta-cell autoimmunity. For example, weaning to hydrolysed casein formula decreased the risk of beta-cell autoimmunity by age 10 in infants at genetic risk.
Increased gut permeability, intestinal inflammation, with its impaired regulatory mechanisms, have been observed in children with type 1 diabetes. The factors that contribute to these intestinal alterations are not precisely known as yet, but interest is focused on the microbial stimuli and function of the patients immunity. Given that probiotics are able to reduce gut inflammation and support healthy and normal immune function, it is likely that a flawed or deficient microbial environment may not support healthy maturation of the gut in the prediabetic period leading to type 1 diabetes.
Bifidobacterium infantis colonizes the infants gastrointestinal tract until weaning, and is delivered to an infants sterile gastrointestinal tract as part of the first inoculations from mothers milk. Complex oligosaccharides (prebiotics) in breast milk are indigestible in the infants gut, but can be metabolized by B. infantis. The metabolites generated by the action of B. infantis, regulate metabolism, protect against pathogens, and educate the immune system. This latter role implies a balancing or preventive effect against the appearance of type 1 diabetes.
It follows that a pregnant or lactating mother who is supplemented with probiotics will pass on to her infant microbes in the form of probiotics that will train up and educate the childs linked pancreas-to-gut immune system. It is not only B. infantis that can improve immunity as we have seen above, indicating that a multi-species probiotic supplement for the mother would be of value in protecting her child from type 1 diabetes. Extra assurance could be delivered nevertheless through the inclusion of B. infantis in a supplemental probiotic formula for pregnant and lactating women.
Before 2008, one could have concluded by saying that probiotics were at least very safe, if not very effective. However, the recent reports of a trial in acute pancreatitis showing an increased mortality in patients given a multi-species probiotic preparation suggests that this may not always be true, particularly where the gut permeability is increased or systemic immunity impaired. For the very ill, whose permeable intestinal lining permits entry into the body of whole probiotics, pathogens, heavy metals, partially broken down proteins, and environmental toxins among other danger, a careful digestive rehabilitation must be applied centered on vegetable based detoxification, predigested protein, vitamin C, Krebs cycle zinc, and other substances before aggressive supplementation is applied.
For the General Good
Robert Martindale, MD, PhD, of Oregon Health & Science University, recently summarized some of the benefits probiotics at the Linus Pauling Institutes Diet and Optimum Health Conference. Dr. Martindale discussed a study showing that probiotics routinely delivered via coated drinking straws halved the number of sick days taken by workers in a car factory. He went on to cover additional studies that in which probiotic use decreased the incidence of ear infections in healthy school children, decreased gestational diabetes, decreased pneumonia and mortality by 50% in patients on ventilators, cleared infections of anti-biotic resistant enterococci in hospital setting.
There are many mechanisms by which probiotics enhance intestinal health, including stimulation of immunity, competition for limited nutrients, inhibition of epithelial and mucosal adherence, inhibition of epithelial invasion and production of antimicrobial substances. Probiotics also vary in the type and amount of antimicrobial substances they synthesize and secrete. Lactobacillus rhamnosus, Propionibacterium shermanii, Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, all generate effective antimicrobial substances, and have been used prophylactically and therapeutically against antibiotic associated diarrhea and Clostridium difficile infections that are frequent complications of broad spectrum antibiotic therapy. These anti-pathogen substances are a primary strategy employed by probiotics to boost immunity and help keep their host humans healthy. Of the immediately aforementioned strains, only infantis is not included in , but is included in Junior. Its use in Junior reflects the normal progression of that bacterias lifecycle. It is abundantly supplied in mothers milk, and resides in a childs intestinal tract through the early years, providing significant immunity, only to slowly fade away as adolescence approaches when ones immune system fully matures.
Supplementing the diet with multiple strains of probiotics, selected for their complementary attributes, is most sound. And it is good to do every day. Human clinical trials have shown that daily supplementation can indeed increase the size and strength of colonies of probiotic bacteria in the intestines while shrinking and suppressing the size and viability of pathogenic colonies. (Both good and bad bacteria reside in the GI tract.) However, within 30 to 90 days following cessation of probiotic supplementation, the balance of probioticto-pathogenic bacteria commonly returns to pre-trial levels.* More recent studies identify a shorter time span of merely seven days to the return of normalcy.
So we must ask if supplemental probiotics themselves actually do attach to intestinal cells and thus proceed to colonize the gut? In vitro, outside the body, laboratory studies using tissue cultures suggest that the answer is yes, and that probiotics do interfere with the adherence of pathogens.,, But currently available evidence suggests that it is not. A growing number of studies indicate that supplemental, exogenous probiotics, both Lactobacilli and Bifidobacteria, pass through the gastrointestinal tract without attaching and colonizing the gut. But along the way, they do remain alive and viable, obviously generating all the health benefits so amply recorded in the scientific literature.
The human trials that revealed the impermanence of probiotic supplementation, turned on its head the former presumption that supplementation with probiotics for a specific period of time could permanently alter intestinal microbiota for the better. Instead, the trials showed that the established microbiological environment in the gut is resistant to change, but can be maintained in an improved state through continual supplementation. Ultimately, it turns out we have to be content with recognizing that certain ingested probiotics do survive their passage through the gastrointestinal tract, and that they are excreted from the colon to the feces without overall multiplication or death. Nevertheless, during such passage, these probiotics continue to be metabolically active, thus providing health benefits to their hosts. Therefore, a potent dose of multiple strains of probiotics are included in , a dietary supplement that can be taken every day.
Can one take too many probiotics? No. The major components of fecal material are sloughed off cells of the intestinal lining (which replaces itself every 7 days) plus expelled probiotic bacteria. The same studies mentioned in the previous paragraph confirmed that a higher intake of probiotic bacteria results in a higher excretion of probiotics in fecal material. No deleterious effects were noted, but marked benefits were received by those using probiotic supplements.