American College of Physicians: Internal Medicine — Doctors for Adults ®

Wednesday, August 20, 2014

Bad breath and oral health--what's new and what's old?

Probiotics for the gut are very popular right now, and well so, since overuse of antibiotics has radically changed the scope of intestinal illness in the U.S. When we take good effective antibiotics they kill not only the intended bacteria causing infection in our sinuses or lungs or bladders or skin but also quite a few of the innocent bystanders elsewhere in the body. Usually we manage to recover from the damage done, but sometimes we get life threatening overgrowth of bacteria or fungus which can have long lasting ill effects. Replacing bacteria killed with supplements containing beneficial organisms can reduce the harm caused by antibiotics.

But that’s not what I’m talking about this time.

I noticed that some of the people who I love most have bad breath. Sometimes, I’ve heard, even I have bad breath. Occasionally, despite having awesome oral hygiene, my mouth tastes kind of skanky and I could definitely believe that it wouldn’t be pleasant to be in intimate conversation with me. So what is in my mouth that is nasty? Definitely not rotting food, because that is gone after I brush my teeth and has no way of magically reappearing. The taste, and smell, is worst after sleeping, during which time salivation is minimal and the natural washing action of the tongue is almost non-existent.

Some people believe that nasty breath smells come from the sinuses or the stomach, but my knowledge of the plumbing of these areas suggests that I need look no further than the actual oral cavity. Genetic methods have identified over 600 species of bacteria in the mouth, most of which have not been well characterized. Some species lead to dental caries, others produce chemicals such as hydrogen sulfide or methyl mercaptan which smell nasty, while others modulate the oral environment to produce a healthy and disease resistant mouth. Dentists have identified Streptococcus mutans and Streptococcus sobrinus as being strongly associated with caries, but other patients with rampant caries did not harbor those bacteria and instead had multiple other identifiable bacterial types which may have been causal in their oral ill health. Still other bacteria may produce nasty smells but have no particular association with tooth or mouth problems. Some bacteria cleave sugars attached to proteins making it possible for other bacteria to digest those proteins, and thus produce smelly chemicals.

The human microbiome project was launched in 2008 to identify the bacteria which colonize us, including those of the mouth, gut, skin, vagina, lung and sinuses. This may well contribute to more effective therapeutics for the chronic diseases of these organs which are at present poorly treated by the heavy hitting pharmacological agents we are so good at developing. Antibiotics, so important in treating serious infection, can also kill bacteria indiscriminately leading to the growth of resistant organisms. They can also cause side effects on the kidneys, liver and bone marrow as well as serious allergic reactions. Immune modulating medications reduce our resistance to infection and cost ridiculous amounts of money. All of these are used to treat conditions of organs which have rich bacterial communities, without addressing the issue of what makes those communities healthy. Characterizing the flora of the mouth in health and disease could lead to novel therapies that might reduce gum disease and cavities as well as preventing things like strep throat and canker sores. Also bad breath.

Fecal transplant, that is introducing the bowel contents of a healthy person into a person with intestinal disease (limited right now to treatment of chronic Clostridium difficile infection) has proven to be powerful, simple and curative for people with bacterial diarrhea in whom antibiotics fail. There is increased interest now in all kinds of natural probiotics, helpful bacteria that are in foods, for overall gut health, with the hope of curing non-specific gut discomfort as well as intolerance of various food substances such as gluten and lactose. Might there be a precedent for oral bacterial transplants? Fecal transplant is abhorrent enough to humans that we have not come close to exploring its potential applications, and I can find nowhere on the internet describing a similar process for the mouth. Why would it not be useful to take oral bacteria from a person with excellent oral health and swab it into the mouth of someone who gets cavities at the drop of a hat or someone with rotten fish breath?

Presently I can’t bring myself to request a sample of mouth bacteria from a friend with awesome oral health. It sounds like a great idea, but I am not adequately motivated and also am not sure I would actually trade up. I have very few cavities and never have mouth or throat infections, so maybe the bacterial community in my mouth, despite not always smelling sweet, is doing a fine job. Still, I haven’t been able to resist trying a few of the easily available treatments that I have read about for sweetening the breath. Oral health experts recommend brushing the back of the tongue, where the taste buds grow high and the bacteria tend to congregate. After brushing and gagging, my mouth does taste better for a while. I have used mouthwashes a bit, but probably will not do so again after thinking about the implications of carpet-bombing my oral flora with chlorhexidine and alcohol. There is absolutely no reason to believe that the random bacteria which grow up after I use chlorhexidine will be any more beneficial than the ones I have now. I have bought oral probiotics which are chewed or dissolved in the mouth and contain beneficial strep strains, such as Streptococcus salivarius, which are purported to outcompete more harmful strep species. They taste nice, but I have not been impressed with any change in what I perceive as my mouth’s health. Perhaps I chose the wrong brand.

I have been most impressed with an ancient remedy, recommended by Hippocrates and Galen for diverse ills and prized by sultans’ wives for sweetening the breath. Mastic gum, from the Pistacia lentiscus tree in Greece, is harvested by allowing the sap to leak from the tree and dry to hard chunks on the ground. When chewed, it tastes a bit like cedar and softens into a substance much like chewing gum. I bought some on Amazon, and it arrived from Greece a couple of weeks ago. I think I like it. It makes the bacterial soft plaque that I notice on my teeth go away and my mouth tastes fresh. My teeth feel like they do after a dental cleaning, more smooth and shiny than they do normally, and the effect lasts for a day at least. A study from 2002 shows an antibacterial affect against S. mutans. I don’t swallow it, but a study over a decade ago showed it to be effective against Helicobacter pylori in the stomach, which can cause ulcers and stomach cancer. It’s not clear that even mastic gum is benign to the good oral bacteria, but it has sure been delightful to have shiny teeth!

Xylitol, a synthetic sugar alcohol that is common in sugarless chewing gums, has attracted quite a bit of attention as a preventative for tooth decay, and probably also for bad breath. A study that was reported in 1995 looked at 277 primarily school aged children given chewing gum flavored with sucrose, sorbitol, xylitol or a combination of xylitol and sorbitol to chew regularly. There was a slight increase in cavities with sugar sweetened gum and a significant decrease when the subjects used non-sucrose sweetened gum, especially xylitol sweetened gum. A more recent controlled trial of xylitol lozenges in adults at high risk of caries did not show significant reduction in cavities, except in the case of root caries. Xylitol use reduces bacteria that cause caries, and possibly bad breath as well, though I don’t find any actual studies to that effect. My own totally unscientific opinion, based on chewing xylitol gum and sucking on the lozenges, is that there doesn’t seem to be any lasting effect at all on breath taste or smell. Xylitol is also toxic to dogs, in whom it causes hypoglycemia and sometimes liver failure. It is not apparently toxic to humans, and doesn’t increase blood sugar in diabetics, which is handy. It is not, however, completely calorie free, but it is so sweet that it takes very little of it to sweeten something.

Bad breath is interesting not only because it is mysterious and socially significant, but also because it is an expression of complex bacterial interactions. The mouth is a small cave, populated with an interdependent community of bacteria whose health can have pretty far reaching consequences. It will be good to see what comes of the Human Biome Project. It has such wide ranging implications for understanding the human body in health and disease. Treatments like mastic gum or dietary probiotics and even ideas like oral bacterial transplant are exciting for treatment of annoying and socially very significant conditions such as tooth decay and bad breath. They unfortunately do not have the driving force of pharmaceutical companies behind their development. Treatments that can be inexpensive and in the control of people who are not in health care professions have the potential to make powerful changes without associated costs. The paucity of research into this sort of thing can be traced to the fact that we do not have a very good mechanism for scientifically exploring therapies that don’t make anybody money.

Janice Boughton, MD, ACP Member, practiced in the Seattle area for four years and in rural Idaho for 17 years before deciding to take a few years off to see more places, learn more about medicine and increase her knowledge base and perspective by practicing hospital and primary care medicine as a locum tenens physician. She lives in Idaho when not traveling. Disturbed by various aspects of the practice of medicine that make no sense and concerned about the cost of providing health care to every American, she blogs at Why is American Health Care So Expensive?, where this post originally appeared.

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Members of the American College of Physicians contribute posts from their own sites to ACP Internistand ACP Hospitalist. Contributors include:

Albert Fuchs, MD
Albert Fuchs, MD, FACP, graduated from the University of California, Los Angeles School of Medicine, where he also did his internal medicine training. Certified by the American Board of Internal Medicine, Dr. Fuchs spent three years as a full-time faculty member at UCLA School of Medicine before opening his private practice in Beverly Hills in 2000.

And Thus, It Begins
Amanda Xi, ACP Medical Student Member, is a first-year medical student at the OUWB School of Medicine, charter class of 2015, in Rochester, Mich., from which she which chronicles her journey through medical training from day 1 of medical school.

Ira S. Nash, MD, FACP, is the senior vice president and executive director of the North Shore-LIJ Medical Group, and a professor of Cardiology and Population Health at Hofstra North Shore-LIJ School of Medicine. He is Board Certified in Internal Medicine and Cardiovascular Diseases and was in the private practice of cardiology before joining the full-time faculty of Massachusetts General Hospital.

Zackary Berger
Zackary Berger, MD, ACP Member, is a primary care doctor and general internist in the Division of General Internal Medicine at Johns Hopkins. His research interests include doctor-patient communication, bioethics, and systematic reviews.

Controversies in Hospital Infection Prevention
Run by three ACP Fellows, this blog ponders vexing issues in infection prevention and control, inside and outside the hospital. Daniel J Diekema, MD, FACP, practices infectious diseases, clinical microbiology, and hospital epidemiology in Iowa City, Iowa, splitting time between seeing patients with infectious diseases, diagnosing infections in the microbiology laboratory, and trying to prevent infections in the hospital. Michael B. Edmond, MD, FACP, is a hospital epidemiologist in Iowa City, IA, with a focus on understanding why infections occur in the hospital and ways to prevent these infections, and sees patients in the inpatient and outpatient settings. Eli N. Perencevich, MD, ACP Member, is an infectious disease physician and epidemiologist in Iowa City, Iowa, who studies methods to halt the spread of resistant bacteria in our hospitals (including novel ways to get everyone to wash their hands).

db's Medical Rants
Robert M. Centor, MD, FACP, contributes short essays contemplating medicine and the health care system.

Suneel Dhand, MD, ACP Member
Suneel Dhand, MD, ACP Member, is a practicing physician in Massachusetts. He has published numerous articles in clinical medicine, covering a wide range of specialty areas including; pulmonology, cardiology, endocrinology, hematology, and infectious disease. He has also authored chapters in the prestigious "5-Minute Clinical Consult" medical textbook. His other clinical interests include quality improvement, hospital safety, hospital utilization, and the use of technology in health care.

Juliet K. Mavromatis, MD, FACP, provides a conversation about health topics for patients and health professionals.

Dr. Mintz' Blog
Matthew Mintz, MD, FACP, has practiced internal medicine for more than a decade and is an Associate Professor of Medicine at an academic medical center on the East Coast. His time is split between teaching medical students and residents, and caring for patients.

Everything Health
Toni Brayer, MD, FACP, blogs about the rapid changes in science, medicine, health and healing in the 21st century.

Vineet Arora, MD, FACP, is Associate Program Director for the Internal Medicine Residency and Assistant Dean of Scholarship & Discovery at the Pritzker School of Medicine for the University of Chicago. Her education and research focus is on resident duty hours, patient handoffs, medical professionalism, and quality of hospital care. She is also an academic hospitalist.

Glass Hospital
John H. Schumann, MD, FACP, provides transparency on the workings of medical practice and the complexities of hospital care, illuminates the emotional and cognitive aspects of caregiving and decision-making from the perspective of an active primary care physician, and offers behind-the-scenes portraits of hospital sanctums and the people who inhabit them.

Gut Check
Ryan Madanick, MD, ACP Member, is a gastroenterologist at the University of North Carolina School of Medicine, and the Program Director for the GI & Hepatology Fellowship Program. He specializes in diseases of the esophagus, with a strong interest in the diagnosis and treatment of patients who have difficult-to-manage esophageal problems such as refractory GERD, heartburn, and chest pain.

I'm dok
Mike Aref, MD, PhD, FACP, is an academic hospitalist with an interest in basic and clinical science and education, with interests in noninvasive monitoring and diagnostic testing using novel bedside imaging modalities, diagnostic reasoning, medical informatics, new medical education modalities, pre-code/code management, palliative care, patient-physician communication, quality improvement, and quantitative biomedical imaging.

Informatics Professor
William Hersh, MD, FACP, Professor and Chair, Department of Medical Informatics & Clinical Epidemiology, Oregon Health & Science University, posts his thoughts on various topics related to biomedical and health informatics.

David Katz, MD
David L. Katz, MD, MPH, FACP, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care.

Just Oncology
Richard Just, MD, ACP Member, has 36 years in clinical practice of hematology and medical oncology. His blog is a joint publication with Gregg Masters, MPH.

Kevin Pho, MD, ACP Member, offers one of the Web's definitive sites for influential health commentary.

MD Whistleblower
Michael Kirsch, MD, FACP, addresses the joys and challenges of medical practice, including controversies in the doctor-patient relationship, medical ethics and measuring medical quality. When he's not writing, he's performing colonoscopies.

Medical Lessons
Elaine Schattner, MD, FACP, shares her ideas on education, ethics in medicine, health care news and culture. Her views on medicine are informed by her past experiences in caring for patients, as a researcher in cancer immunology, and as a patient who's had breast cancer.

Mired in MedEd
Alexander M. Djuricich, MD, FACP, is the Associate Dean for Continuing Medical Education (CME), and a Program Director in Medicine-Pediatrics at the Indiana University School of Medicine in Indianapolis, where he blogs about medical education.

More Musings
Rob Lamberts, MD, ACP Member, a med-peds and general practice internist, returns with "volume 2" of his personal musings about medicine, life, armadillos and Sasquatch at More Musings (of a Distractible Kind).

David M. Sack, MD, FACP, practices general gastroenterology at a small community hospital in Connecticut. His blog is a series of musings on medicine, medical care, the health care system and medical ethics, in no particular order.

Reflections of a Grady Doctor
Kimberly Manning, MD, FACP, reflects on the personal side of being a doctor in a community hospital in Atlanta.

The Blog of Paul Sufka
Paul Sufka, MD, ACP Member, is a board certified rheumatologist in St. Paul, Minn. He was a chief resident in internal medicine with the University of Minnesota and then completed his fellowship training in rheumatology in June 2011 at the University of Minnesota Department of Rheumatology. His interests include the use of technology in medicine.

Technology in (Medical) Education
Neil Mehta, MBBS, MS, FACP, is interested in use of technology in education, social media and networking, practice management and evidence-based medicine tools, personal information and knowledge management.

Peter A. Lipson, MD
Peter A. Lipson, MD, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. The blog, which has been around in various forms since 2007, offers musings on the intersection of science, medicine, and culture.

Why is American Health Care So Expensive?
Janice Boughton, MD, FACP, practiced internal medicine for 20 years before adopting a career in hospital and primary care medicine as a locum tenens physician. She lives in Idaho when not traveling.

World's Best Site
Daniel Ginsberg, MD, FACP, is an internal medicine physician who has avidly applied computers to medicine since 1986, when he first wrote medically oriented computer programs. He is in practice in Tacoma, Washington.

Other blogs of note:

American Journal of Medicine
Also known as the Green Journal, the American Journal of Medicine publishes original clinical articles of interest to physicians in internal medicine and its subspecialities, both in academia and community-based practice.

Clinical Correlations
A collaborative medical blog started by Neil Shapiro, MD, ACP Member, associate program director at New York University Medical Center's internal medicine residency program. Faculty, residents and students contribute case studies, mystery quizzes, news, commentary and more.

Interact MD
Michael Benjamin, MD, ACP member, doesn't accept industry money so he can create an independent, clinician-reviewed space on the Internet for physicians to report and comment on the medical news of the day.

PLoS Blog
The Public Library of Science's open access materials include a blog.

White Coat Rants
One of the most popular anonymous blogs written by an emergency room physician.

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