by Camille Schindler
In the wake of new scientific information about the therapeutic benefits of probiotics, there has been an onslaught of pills, drinks, and yogurts promising to ‘help regulate your digestive system’, ‘balance bacteria in your gut’ and support ‘immune health’.[1] Companies seeking to attract health conscious consumers have begun putting probiotics in yogurt, juices, muffins, and even pizza. Journalist Laura Johhannes, from The Wall Street Journal, reports, “Last year, 231 new probiotic-containing products hit grocery and pharmacy shelves, up from just 34 in 2005.”[2] Supplements and pills, which can cost up to 1$/serving, are considered food products by the FDA, and, therefore, subject to far less scrutiny then pharmaceuticals. With minimal regulation and growing demand, there has been a surge in corporate advertisement fraud, as companies, like Dannon, are accused of making unfounded health claims about their products. Still, probiotics are becoming more popular. Global probiotic sales are expected to jump from $28 billion in 2011 to $42 billion in 2016. So what is all the fuss over probiotics about?
The human body has evolved in a close alliance with microbes. Even mitochondria, an intracellular structure responsible for ATP (a chemical utilized in almost all energetic reactions in the body), was adopted from endosymbiotic prokaryotes that had the metabolic capacity for oxidative phosphorylation.[3] Bacteria exist on our skin, gastrointestinal tracts, and even our urogenital tracts in breathtaking numbers, both in quantitative mass and diversity.
“Humans have been proposed to be “meta-organisms” consisting of 10-fold greater numbers of bacterial than animal cells that are metabolically and immunologically integrated. The human meta-organism includes approximately 10 to the 14th prokaryotic organisms, with a biomass of >1 kg. The population composition is remarkably stable at different anatomic locations along the gut, but absolute numbers vary greatly, ranging from 10 to the 11th cells/g content in the ascending colon to 10x 10 to the 7 or 8 in the distal ileum and 10 x 10 to the 2–3 in the proximal ileum and jejunum”[4]
[5]Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
In the bacterial community found co-habitating with humans, 60-90% are anaerobes of the genus Bacteroidetes and Firmcutes. These anaerobes are several orders of magnitude more abundant then their aerobe counterparts. Eukaryotic fungal species have also been identified as components of the symbiotic microbiota. The small bowel has similar microbes to the large bowel, differing only in the Bacillus strain (predominantly Lactobacillales), which is more abundant in the small intestine, and the Bacteroidetes from the family Lachnospiraceae, which are more abundant in the colon.[6]
At birth, the gut is sterile. As a baby exits the birth canal, the first inoculation of symbiotic microbes, one of which is Lactobacillus Johnsonii, is given thru contact with the vaginal wall. This microbe enables babies to metabolize breast milk. Deficiencies in L. Johnsonii and other vaginal bacteria is linked to a myriad of health problems for C-section babies, including susceptibility to skin infections, allergies, and asthma.[7] Other strains of bacteria are introduced through food, soil…and, well, poop. Microbiologist, Dr. Andrew S. Neish, writes, “The term ‘old friends’ has been used to describe the gut-inhabiting microbes originating from soil, plants, and especially domesticated animals that humans have co-evolved with.”[8] The acquired bacteria develop quickly into a stable community that supports the human body in many physiological functions, ranging from digestion and nutrient absorption to immune system support.
The microbial ecosystem in the GI helps the human body with digestion and nutrient absorption. The bacterium, Firmicutes (like the Clostridium species) and Bifidobacterium are primarily responsible for microbial assistance in carbohydrate digestion. Complex carbohydrates, poorly digested by the human GI system, require microbiota for breakdown by fermentation. Up to 10% of an individual's daily energy needs are derived from bacteria.[9] The end products of fermentation are organic acids, such as butyrate, succinate, and propionate, as well as other products such as lactate. These provide an energy source for the colonic epithelium and the human body. [10] Moreover, bacteria assist the GI in nutrient absorption. Dr. Andrew S. Neish, illustrates this idea, writing, “The combined biochemical capacity of the microbiota has been called a “forgotten organ,” mediating diverse beneficial roles including vitamin synthesis, bile salt metabolism, and xenobiotic degradation.”[11] Symbiotic microbes assist the colon in absorbing nutrients, like vitamin K, B12, riboflavin, and thiamine. Beyond the benefits to digestion, bacteria also assist the immune system.
The immunological importance of bacteria cannot be overstated. GI microbial ecosystems assist the human body in reducing inflammation, competitively eliminating pathogenic bacteria, and bolstering the integument system.
Gut bacteria regulate the body’s inflammatory response.[12] The intestines, which have co-evolved with gut inhabiting bacteria, have acquired homeostatic mechanisms that allow native bacteria to control local inflammation. These controls are designed to inhibit immune response to “good” bacteria, while becoming activated when encountering “bad” bacteria. Deficiencies in symbiotic microbiota, especially during the development of the immune system, underlie many allergenic and inflammatory disease patterns. According to Dr. Andrew S. Neish, insufficient bacterial colonization leads to “dysregulation of immune effector cells, accounting for changes in systemic allergic conditions. Symbiotic bacteria regulate adaptive immunity, and, at the mucosal level, reduce inflammatory ‘tone.’”[13] In other words, a lack of bacteria promotes epithelial dysfunction and results in intestinal inflammation.
Native GI bacteria also prevent pathogenic bacterial infection through competition and the creation of antimicrobial compounds. Invasion by foreign pathogens such as Salmonella, Shigella, various strains of enteropathogenic Escherichia coli, and Yersinia, are the cause of many enteric infectious diseases. Symbiotic microbiota are important in providing “colonization resistance” to pathogenic attack. A mechanism of bacterial immune contribution includes altering the intestinal “micro-ecology”, or competitively reducing harmful organisms in the intestine. The normal GI flora suppresses encounters with overt pathogens by competing for access to adhesive sites on the epithelial surface and stimulating increased mucin production. Another mechanism of immune support is the production of antimicrobial compounds; substances that destroy or suppress the growth of foreign microorganisms. The metabolic waste created by native bacteria is bacteriostatic for a subset of bacterial species, either directly or by reducing pH (making the environment too acidic for pathogen survival). Some members of the microbiota also generate bacteriocins, small peptide molecules with microbicidal properties.[14] By killing off pathogenic bacteria, symbiotic microbes support the gastrointestinal immune system.
Finally, bacteria are essential for integument (skin) health. The skin’s surface is teeming with bacteria. Flora on the surface of the skin has anti-pathogenic effects and enhances mucosal barrier function.[15] Microbes, like Staphylococcus epidermidis, compete for survival, making anti-microbials that kill off more pathogenic bacterium. This particular bacterium also interacts with the immune system to help heal wounds.[16] These helpful microbes, along with our own thick hydrophobic skin barrier and lysozymes (enzymes in sweat that kill pathogenic bacteria) are what constitute our primary immune defense.
Clearly, bacteria are important participants in human physiology. What, then, are probiotics? Contemporary practices, like the regularity of C-sections in baby delivery, hand sanitizers, antibacterial soaps, mouth wash, antibiotics, overly processed foods, pasteurization (which has eliminated much of the flora found in modern foods), and an obsession with cleanliness (or an underrepresentation of ‘good ol’ fashioned dirt’), has stripped away normal healthy microbes usually found in the body. The human host has co-evolved with microbiota over a millennia, developing and optimizing complex mechanisms that give microbes homeostatic roles directly contributing to health. Microbiota are an integral component of bodily processes.[17] An absence or deficiency of this bacterial ecosystem negates the benefits they provide.
According to the World Gastroenterology Organization Global Guidelines, in 2011, Probiotics are: “live microorganisms that confer a health benefit on the host when administered in adequate amounts”. The National Center for Complementary and Alternative Medicine writes that, “The concept behind probiotics was introduced in the early 20th century, when Nobel laureate Elie Metchnikoff, known as the ‘father of probiotics,’ proposed that ingesting microorganisms could have substantial health benefits for humans”.[18] In Chinese Medicine, probiotics are considered SP Qi. They help the Middle Jiao with digestion, and support the transformation and transportation of Qi around the body. Increasing SP Qi, or promoting digestion, effects health by increasing energy, decreasing gas and bloat, diminishing fullness in the chest, epigastric, and abdominal region, transforming damp, increasing appetite, and promoting better sleep. SP Qi circulates through the whole body giving it the energy required for life, and is a basic component for the creation and movement of blood.
Probiotics are live microorganisms, bacteria, that are either the same or similar to microorganisms found naturally in the human body. By ingesting them, we supplement our preexisting bacterial colonies in order to repopulate and recreate a healthy bacterial ecosystem. Gastroenterologist, Dr. Richard R. Sharp writes that, “The intended result of probiotic therapy is that exogenous bacteria will enter the host GI tract and regulate local immunity, modify inflammatory response, improve the barrier function of the gut epithelium, inhibit pathogenic bacteria colonization, or otherwise improve physiological function.”[19]
Probiotics, now the subject of intense scientific research, have proven to confer numerous health advantages. Most definitively, they have been effective with GI diseases and treating urogenital imbalances, like vaginal yeast and urinary tract infections.[20] Andrew S. Neish, MD, writes on the diversity of treatments offered by probiotic supplements:
“Based on data from animal models, probiotics offer great benefits and might be used to treat intestinal functional and inflammatory disorders, systemic immune/allergic conditions, and metabolic syndromes, as well as to even modulate intestinal nociception, psychological stress responses, and longevity (an original claim made for probiotics by Elie Metchnikoff a century ago). Clinical evidence indicates that probiotics are effective in the treatment or prevention of acute viral gastroenteritis, postantibiotic-associated diarrhea, certain pediatric allergic disorders, necrotizing enterocolitis, and IBD such as Crohn's and postsurgical pouchitis.”[21]
Probiotics are proven to treat diseases of the GI tract. Often, gastrointestinal diseases are the result of an imbalance in normally occurring gut flora. Lacking the microbes needed to maintain health in the GI tract, pathogenic bacteria can overpopulate and disturb homeostasis. This can lead to inflammation, produce toxins, or interrupt membranous surfaces and thereby increase susceptibility to other pathogens. Probiotics are live microorganisms that restore the microbial ecosystem to a healthy functional balance.[22] These supplemental bacteria treat various GI diseases: including inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), antibiotic-associated diarrhea, including Clostridium difficile colitis; acute diarrhea in children; and chronic liver disease. Dr. Richard R. Sharp writes that,
“Evidence supporting the use of probiotics for chronic GI diseases includes studies demonstrating reduction of local gut inflammatory response and symptomatic benefit in patients with IBD using specific strains of Escherichia coli (e.g., Nissle 1917), Lactobacillus, Saccharomyces boulardii, and Bifidobacterium. Similarly, studies in IBS patients have demonstrated that probiotics have an anti-inflammatory effect, resulting in decreased levels of muscle hypercontractility and pain-related symptoms, and that probiotics can produce more prolonged remissions of IBS-related symptoms as compared with traditional therapies.”[23]
Research pointing to the successful therapeutic use of probiotics in treating GI disorders is welcome news to patients with illnesses of uncertain etiology, with symptoms ranging from diarrhea and weight loss to ulceration, perforation, and complete obstruction of the GI tract. Often, Western treatment of these diseases is ineffectual, even after extensive medical and surgical management. For an illness like IBD, even treatment with antibiotics, anti-inflammatories, and immunosuppressive drugs, is not curative.[24] Probiotic treatment is far less invasive and destructive then the Western options in treating GI disease.
Furthermore, probiotics are useful in maintaining urogenital health. Like the intestinal tract, the vagina is a finely balanced ecosystem. The dominant native bacterial strain, Lactobacilli, creates lactic acid as a byproduct of metabolism, decreasing the vaginal pH. Competition for resources, and an acidic environment, normally makes it difficult for harmful microorganisms to survive. But the system can be thrown out of balance by a number of factors, including antibiotics, spermicides, and birth control pills. Probiotic treatments restore the balance of micro flora, treating common female urogenital problems like bacterial vaginosis (BV), yeast infections, and urinary tract infections (UTIs). The Harvard Medical School Review writes, “Many women eat yogurt or insert it into the vagina to treat recurring yeast infections, a “folk” remedy... Oral and vaginal administration of Lactobacilli help in the treatment of bacterial vaginosis.”[25] Supplemental Lactobacillus probiotics (suppository or oral) reestablishes a healthy urogenital microbial ecosystem, decreasing the vaginal pH and providing resource competition, staving off invasive pathogens.
Other scientifically supported applications for probiotic use are: preventing tooth decay and treating oral health problems such as gingivitis and periodontitis. There is also substantial evidence supporting probiotic treatment of atopic eczema (a skin condition most commonly seen in infants), childhood respiratory infections, eradicating nasal pathogens (bacteria harbored in the nose), as well as reducing the risk of necrotizing enterocolitis, a severe intestinal condition of premature newborns. Also, current research has had promising breakthroughs in the therapeutic use of probiotics to reduce cholesterol levels, and treating obesity.[26]
In order to achieve therapeutic benefits, it is important to know where to find probiotics, as well as the quantity and quality of the microbes ingested.
Where do you find probiotics? Lactic acid–producing bacteria have been used for centuries in food fermentation. Historically, Northern Europeans consumed these beneficial microorganisms because of their tradition of eating foods fermented with bacteria, such as yogurt. Fermented soy, like the base of miso soup, has been a staple food in Japan, and probiotic-enhanced beverages are now very common.[27] As popularity continues to grow, so does the availability, variety, and cost associated with probiotic products. In the United States, probiotics are available as dietary supplements (including capsules, tablets, and powders), suppositories, creams, and a variety of foods.[28] Raw, unpasteurized fermented foods like sauerkraut, sour pickles, miso and kimchi are naturally high in good bacteria, as are some yogurts, kefirs, and stinky cheeses. Cultured foods can come with hundreds of diverse strains of bacteria and yeast, the number of microbes multiplying as the stages of fermentation evolve. Further, these foods come with the added benefit of vitamins and nutrients.
Probiotics can also be found in pills, powders and suppositories. Here are a few examples of commercially available probiotics and their anatomical areas of influence.
Unlike probiotics found in fermented foods, probiotic pills and powders often do not recolonize your gut, making their effect temporary. Most pill probiotics are eliminated in the feces after approximately one month. Aside from not being sustained in the GI, supplemental probiotics inherently lack diversity. “The few dozen strains that are commercially available”, says Moises Velasquez-Manoff, "are a pittance compared to the 1,000 species within. What you'd really want is to get microbes native to the gut and replenish them. We haven't figured out which ones are the right ones or how to implant them."[29] Maddie Oatman, from Mother Jones, reports on the difference between microbes in pill/powder form as opposed to food, in her interview with gastroenterologist, Dr Katz. Dr. Katz reveals that fermented foods, because of their inherent diversity and abundance in bacterial strains, are more beneficial then pills. He says, "… bacteria are not fixed…To me, that's the flaw with the probiotic idea. It seems like diverse bacterial stimulation will always be better than a single strain."[30] Inoculating the gut with microbes from a diet of fermented foods (which is historically consistent in our relationship with symbiotic bacteria) is preferable to pill probiotics, which lack diversity and are not sustained within the gastrointestinal tract.
In order to see therapeutic effects, it is important to ingest the right quantity and diversity of supplemental probiotics. Many yogurts contain active lactobacillus cultures and are considered functional food products. Labeling a food “probiotic”, however, is reserved for products with an adequate number of live microorganisms at the time of consumption. The number of microbes must be quantifiably enough to confer health benefits in controlled human trials.[31] For both food and supplements alike, it is important to look for the word "live" on the package, since organisms killed by processing are ineffective. Gary B. Huffnagle, a professor at the University of Michigan Medical Center in Ann Arbor, reports, “Respecting the expiration date is particularly important, because even if a product still tastes good the bacteria may no longer be alive. ”[32] The quantity of CFUs (colony-forming units), or how many live cultures are available in a serving, determines the quality of a probiotic. "You should be getting 3-5 billion CFUs a day," [33] advises Gary B. Huffnagle. In addition to consuming the appropriate number of live cultures, for maximum benefit it is important to have a variety of different strains of microbes, either from a diversity of foods or a variety of supplements, as each contributes something slightly different.
Another approach to therapeutically manipulating microbiota involves enhancing its energy sources. Prebiotics and synbiotics influence probiotic effectiveness. According to World Gastroenterology Organization Global Guidelines, Prebiotics are: “dietary substances that nurture specific changes in the composition and/or activity of the GI microbiota (favoring beneficial bacteria), thus conferring benefit(s) upon host health.” In other words, bacterial growth is encouraged with the dietary supplementation of indigestible carbohydrates or bacterial fermentative substrates (like inulin and oligofructose) that act as food for probiotics. ConsumerLabs' president, Tod Cooperman, says that, “Prebiotics are indigestible fibers that serve as food for probiotics and our inherent microbes. They already come to us via much of the food we eat.” Although prebiotics can be found in supplements labeled FOS (fructooligosaccharides), eating foods rich in prebiotics is a more effective approach. Cooperman, reports: "You're only getting what, a gram or two a pill?" he says, referring to prebiotics. "How much can that help you compared to eating lunch?"[34] When probiotics and prebiotics are combined, they form a synbiotic. Fermented dairy products, such as yogurt and kefir, are considered synbiotic because they contain live bacteria and the fuel they need to survive. Prebiotics are found in whole grains, bananas, onions, garlic, honey and artichokes.[35] These alterations in bacterial diet affect the composition and the collective metabolic output of the microbiota.
Despite the encouraging therapeutic rewards of probiotics, there also concerns, such as: false advertisement of product quality and unsubstantiated therapeutic claims. One rising concern for consumers is product quality. As a ‘food’ there are far less restrictions and regulations on marketing and labeling. It is common to find inaccurately labeled CFUs due to false advertisement or improper product care. Several companies have been accused of reporting inaccurate quantities of active cultures in their products. Gary B. Huffnagle illustrates this, saying, "95% of probiotic supplements… won't have 10% of the CFUs they say they have."[36] ConsumerLab.com, an agency that evaluates the accuracy of food product advertising, tested 13 popular brands sold in the United States. Nutrition Now PB8 and i-Flora Kids Multi-Probiotic contained only 56.8% and 65%, respectively, of the cells claimed on the label. Of the 13 products tested, only 8 products contained the amounts advertised. "Like any supplement, it's kind of a buyer-beware situation," says Tod Cooperman. "There really aren't a lot of rules from the FDA on how the products are tested."[37] Aside from false advertisement, colony death can happen with improper care. Many probiotics require refrigeration, and sometimes they aren't kept cold during transit or on the shelves of grocery stores. Without proper refrigeration, probiotic cultures rapidly die, leaving the supplement ineffectual.
In addition to inaccurately advertised CFU numbers, there have been unsubstantiated health claims made about probiotic products. Gregor Reid, a professor of microbiology at the University of Western Ontario's Lawson Research Institute, writes, “Companies that sell products with added probiotics claim they offer a range of health benefits... Some of the claims are based on reputable scientific study. But others are unproved, and advertising pitches are sometimes exaggerated.”[38] Of several hundred probiotic-product lines on the market in North America, 15 to 20 have clinical studies behind them. Maddie Oatman, writer for Mother Jones, illustrates advertisement fraud, reporting that: “Dannon was sued in 2010 for deceptive advertising about its probiotic-boosted yogurt products, including Activia (it settled but never admitted to wrongdoing), and Europe cracked down on claims made by the probiotic industry.”[39] Although probiotics are an incredible resource to optimizing the health and efficiency of the GI tract, finding high quality, scientifically substantiated products is challenging.
Probiotic foods and supplements designed to recolonize native gut bacteria, have proven to be incredible therapeutic resources in a variety of GI and urogenital disease. The highest quality probiotics are found in fermented food labeled “live” with high CFU’s. Furthermore, prebiotics and synbiotics enhance microbial effectiveness by acting as food for beneficial bacteria. Hopefully, as probiotic popularity continues to rise, demand for regulation of companies and honest advertisement will allow health conscious consumers to take full advantage of the amazing health properties of these beneficial microbes.
1.) Should You Take a Probiotic? The popular supplements might be more about marketing than beneficial microbes.
Maddie Oatman, research editor at Mother Jones.
Copyright ©2014 Mother Jones and the Foundation for National Progress.
Mon Apr. 22, 2013 3:30 AM GMT
2.) Bug Crazy: Assessing The Benefits of Probiotics
By Laura Johannes; The Wall Street Journal
Updated Jan. 13, 2009 12:01 a.m. ET
Copywrite: @2014 Dow Jones and Co.
http://online.wsj.com/news/articles/SB123180831081775767
3.) Is it important to Include Probiotics and Prebiotics in a Healthy Diet?; By Katherine Zeratsky, R.D., L.D.; Healthy lifestyle, Consumer Health
© 1998-2014 Mayo Foundation for Medical Education and Research. FAQ-20058065
http://www.mayoclinic.org/healthy-living/consumer-health/expert-answers/probiotics/faq-20058065
4.) Probiotics
National Center for Complementary and Alternative Medicine (NCCAM)
Pub No.: D345; Date Created: January 2007; Last Updated: December 2012
http://nccam.nih.gov/health/probiotics/introduction.htm
5.) Helping Patients Make Informed Choices About Probiotics: A Need For Research; Richard R. Sharp, PhD,1 Jean-Paul Achkar, MD,2 Margaret A. Brinich, BA,1 and Ruth M. Farrell, MD1
Author manuscript; available in PMC Sep 18, 2009. Published in final edited form as: Am J Gastroenterol. Apr 2009; 104(4): 809–813.; doi: 10.1038/ajg.2008.68
PMCID: PMC2746707; NIHMSID: NIHMS124892
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2746707/
6.) Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases; Daniel N. Frank,* Allison L. St. Amand,* Robert A. Feldman,† Edgar C. Boedeker,‡ Noam Harpaz,§ and Norman R. Pace; Journal ListProc Natl Acad Sci U S Av.104(34); Aug 21, 2007
PMC195945; Proc Natl Acad Sci U S A. Aug 21, 2007; 104(34): 13780–13785.
Published online Aug 15, 2007. doi: 10.1073/pnas.0706625104;
US National Library of Medicine; National Institutes of Health
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1959459/
7.) Probiotic Lactobacillus acidophilus enhances the immunogenicity of an oral rotavirus vaccine in gnotobiotic pigs; Wei Zhang, Marli S.P. Azevedo, [...], and Lijuan Yuan
Author manuscript; available in PMC Jul 4, 2009. Published in final edited form as:Vaccine. Jul 4, 2008; 26(29-30): 3655–3661.PMCID: PMC2491559; NIHMSID: NIHMS55497
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2491559/
8.) Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD, Department of Pathology, Emory University School of Medicine
Gastroenterology. Jan 2009; 136(1): 65–80.PMCID: PMC2892787; NIHMSID:
9.) Health Benefits of Taking Probiotics; The Harvard Medical School Family Health Guide. Last updated Sept 2005, Copy write @2000-2006 President and Fellows at Harvard College http://www.health.harvard.edu/fhg/updates/update0905c.shtml
10.) A Gastroenterologist's Guide to Probiotics; By Matthew A Ciorba.
Clinical Gastroenterology and Hepatology; Volume 10, Issue 9 , Pages 960-968,
Published April 2012. Department of Medicine, Division of Gastroenterology, Washington University, St Louis School of Medicine, St Louis, Missouri
11.) This Is Your Body on Microbes: Meet the complex bacterial ecosystems instrumental to a healthy body; By Sarah Zhang
updated: Mon Apr. 22, 2013 3:00 AM GMT; Copyright ©2014 Mother Jones and the Foundation for National Progress.
http://www.motherjones.com/environment/2013/04/bacteria-in-human-body
[1] Should You Take a Probiotic? The Popular supplements might be more about marketing than beneficial microbes; By Maddie Oatman; Mother Jones
[2] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[3] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[4] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[5] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[6] Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases; Daniel N. Frank
[7] This Is Your Body on Microbes: Meet the complex bacterial ecosystems instrumental to a healthy body; By Sarah Zhang
[8] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[9] A Gastroenterologist's Guide to Probiotics; By Matthew A Ciorba
[10] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[11] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[12] Probiotics; National Center for Complementary and Alternative Medicine (NCCAM)
[13] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[14] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[15] This Is Your Body on Microbes: Meet the complex bacterial ecosystems instrumental to a healthy body; By Sarah Zhang
[16] This Is Your Body on Microbes: Meet the complex bacterial ecosystems instrumental to a healthy body; By Sarah Zhang
[17] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[18] Probiotics; National Center for Complementary and Alternative Medicine (NCCAM)
[19] Helping Patients Make Informed Choices About Probiotics: A Need For Research; Richard R. Sharp
[20] Is it important to Include Probiotics and Prebiotics in a Healthy Diet?; By Katherine Zeratsky, R.D., L.D.; Healthy lifestyle, Consumer Health
[21] Microbes in gastrointestinal health and disease; by Andrew S. Neish, MD
[22] Helping Patients Make Informed Choices About Probiotics: A Need For Research; Richard R. Sharp
[23] Helping Patients Make Informed Choices About Probiotics: A Need For Research; Richard R. Sharp
[24] Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases; Daniel N. Frank
[25] Health Benefits of Taking Probiotics; The Harvard Medical School Family
[26] Probiotics; National Center for Complementary and Alternative Medicine (NCCAM)
[27] Health Benefits of Taking Probiotics; The Harvard Medical School Family
[28] Probiotics; National Center for Complementary and Alternative Medicine (NCCAM)
[29] Should You Take a Probiotic? The Popular supplements might be more about marketing than beneficial microbes; By Maddie Oatman; Mother Jones
[30] Should You Take a Probiotic? The Popular supplements might be more about marketing than beneficial microbes; By Maddie Oatman; Mother Jones
[31] A Gastroenterologist's Guide to Probiotics; By Matthew A Ciorba
[32] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[33] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[34] Should You Take a Probiotic? The Popular supplements might be more about marketing than beneficial microbes; By Maddie Oatman; Mother Jones
[35] Is it important to Include Probiotics and Prebiotics in a Healthy Diet?; By Katherine Zeratsky, R.D., L.D.; Healthy lifestyle, Consumer Health
[36] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[37] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[38] Bug Crazy: Assessing the Benefits of Probiotics
By Laura Johhannes; The Wall Street Journal
[39] Should You Take a Probiotic? The Popular supplements might be more about marketing than beneficial microbes; By Maddie Oatman; Mother Jones