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This month more research from researcher JJ Goedert about gut microbes in postmenopausal women and breast cancer. Very suggestive research was published September 2014 about the possibility of increasing a person's gut bacteria diversity to lower breast cancer risk. And even earlier research found that the human breast has a microbiome (community of microbes) that is different in healthy breasts as compared to cancerous breasts.

Now JJGoedert and others investigated whether the gut microbiota differed in 48 postmenopausal breast cancer case patients (before treatment) as compared to 48 control patients (women without breast cancer). The average age of both groups was 62 years.The researchers analyzed the estrogens in the women's urine and the bacterial diversity in fecal samples using modern genetic analysis (such as 16S rRNA sequencing). They found in this study that postmenopausal women with breast cancer had lower gut bacteria diversity and somewhat different composition of gut bacteria as compared to women without breast cancer. They also said that what this means is unknown, that is,"whether these affect breast cancer risk and prognosis is unknown." Some differences in gut bacteria composition: women with breast cancer had lower levels of Clostridiaceae, Faecalibacterium, and Ruminococcaceae; and they had higher levels of Dorea and Lachnospiraceae.

Excerpt is from the Journal of the National Cancer Institute:

Investigation of the association between the fecal microbiota and breast cancer in postmenopausal women: a population-based case-control pilot study.

We investigated whether the gut microbiota differed in 48 postmenopausal breast cancer case patients, pretreatment, vs 48 control patients. Microbiota profiles in fecal DNA were determined by Illumina sequencing and taxonomy of 16S rRNA genes. Estrogens were quantified in urine....  Compared with control patients, case patients had statistically significantly altered microbiota composition  and lower α-diversity. Adjusted for estrogens and other covariates, odds ratio of cancer was 0.50 per α-diversity tertile. Differences in specific taxa were not statistically significant when adjusted for multiple comparisons. This pilot study shows that postmenopausal women with breast cancer have altered composition and estrogen-independent low diversity of their gut microbiota. Whether these affect breast cancer risk and prognosis is unknown.

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Study after study finds health benefits from exercise of all sorts, but what about those people who are so fit that they run marathons longer than normal marathons of 26.2 miles?

This study looked at those who participate in extreme events include ultramarathons, which tend to be 30 to 50 miles long, but can be more than 100 miles long or even last 24 hours. One study published in 2014 found that "compared with the general population, ultramarathon runners appear healthier and report fewer missed work or school days due to illness or injury...have a higher prevalence of asthma and allergies than the general population" and they may get some "exercise-related injuries such as stress fractures involving the foot."

But this newly published study found that the effects of extreme exercise (because it causes changes in the gut wall and allows bacteria to leak into the bloodstream) can be very serious if you haven't trained properly and over a long period of time.

From Medical Xpress: Extreme exercise linked to blood poisoning

Researchers have discovered that extreme exercise can cause intestinal bacteria to leak into the bloodstream, leading to blood poisoning. Experts at Monash University monitored people participating in a range of extreme endurance events, including 24-hour ultra-marathons and multi-stage ultra-marathons, run on consecutive days.

"Blood samples taken before and after the events, compared with a control group, proved that exercise over a prolonged period of time causes the gut wall to change, allowing the naturally present bacteria, known as endotoxins, in the gut to leak into the bloodstream. This then triggers a systemic inflammatory response from the body's immune cells, similar to a serious infection episode. Significantly the study found that individuals who are fit, healthy and follow a steady training program to build up to extreme endurance events, develop immune mechanisms to counteract this, without any side effects.

However individuals who take part in extreme endurance events, especially in the heat and with little training, put their bodies under enormous strain above the body's protective capacity. With elevated levels of endotoxins in the blood, the immune system's response can be far greater than the body's protective counter-action. In extreme cases, it leads to sepsis induced systemic inflammatory response syndrome, which can be fatal if it is not diagnosed and treated promptly.

The study, led by Dr Ricardo Costa, from the Department of Nutrition and Dietetics, is the first to identify a link between extreme endurance exercise and the stress it may place on gut integrity. "Nearly all of the participants in our study had blood markers identical to patients admitted to hospital with sepsis. That's because the bacterial endotoxins that leach into the blood as a result of extreme exercise, triggers the body's immune cells into action."

Dr Costa said anything over four hours of exercise and repetitive days of endurance exercise is considered extreme...."It's crucial that anyone who signs up to an event, gets a health check first and builds a slow and steady training program, rather than jumping straight into a marathon, for example, with only a month's training," he said.

The research team found that people who were fitter and trained over a longer period of time leading into the ultra-marathon event had higher levels of Interleukin 10 – an anti-inflammatory agent, which allowed them to dampen down the negative health impacting immune response.

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The good news is that not every tick is infected, but the bad news is that the CDC says that there are 14 known tick-borne diseases in the United States, and possibly 15 (if newly discovered Bourbon virus is included). Lyme disease is the most common, but people can be infected with more than one tick-borne illness simultaneously.  Three new diseases to watch for: Borrelia miyamotoi (bacteria carried by deer ticks), Heartland virus (carried by Lone Star Tick), and Bourbon virus. From Medical Xpress;

Beyond Lyme, new illnesses, more reason to watch for ticks

Lyme disease makes the headlines but there are plenty of additional reasons to avoid tick bites. New research highlights the latest in a growing list of tick-borne threats—a distant relative of Lyme that's easy to confuse with other illnesses.Monday's study suggests a kind of bacteria with an unwieldy name—Borrelia miyamotoi—should be on the radar when people in Lyme-endemic areas get otherwise unexplained summertime fevers. It's one of several recently discovered diseases linked to ticks in different parts of the country, a reminder to get tick-savvy no matter where you live.

The first U.S. case was reported in 2013 in New Jersey, an 80-year-old cancer survivor who over four months became increasingly confused, had difficulty walking and lost 30 pounds. Doctors found spiral-shaped bacteria in her spinal fluid that looked like Lyme but caused a relapsing fever more closely related to some other tick-borne illnesses. While treatable by antibiotics—the woman recovered—doctors know little about B. miyamotoi.

Researchers with Imugen Inc., a Massachusetts testing lab, tested blood samples from patients in Massachusetts, Rhode Island, New Jersey and New York whose doctors suspected tick-borne illnesses and used that lab. During the 2013 and 2014 tick seasons the lab found 97 cases of the new infection. That's roughly 1 percent of samples tested and close to the lab's detection of a better-known tick disease named anaplasmosis. ...Researchers then analyzed medical records from 51 of those patients, and found symptoms typically include a high fever, severe headache, chills and blood abnormalities—decreases in infection-fighting and blood-clotting cells. 

The bacterium is carried by deer ticks, also known as blacklegged ticks, which also can spread Lyme and two other illnesses, babesiosis and anaplasmosis.

 Two new tick-borne viruses were recently discovered in the Midwest, and neither has a specific treatment.The Centers for Disease Control and Prevention has confirmed nine cases of Heartland virus, and one death, with other reports under investigation, said CDC entomologist Roger Nasci. Symptoms include fever, fatigue, headaches, muscle aches, diarrhea and low blood counts. Identified in Missouri, the virus also was reported in Tennessee and Oklahoma, although the Lone Star tick that spreads it lives around the East and Southeast.

Then there's the Bourbon virus, with similar symptoms, discovered last year after the death of a Kansas man and named for his home county. Another patient, in Oklahoma, recovered. The Kansas man had found an embedded tick days before getting sick, and CDC researchers are searching for the culprit species.

The CDC counts 14 illnesses linked to specific U.S. tick species, not including the Bourbon virus still being studied. Lyme is the most common, with about 30,000 cases reported each year, although CDC has estimated that the true number could be 10 times higher. It's too early to know how widespread the newly discovered illnesses are. But people can be infected with more than one tick-borne illness simultaneously, complicating care.

Deer tick            Lone Star Tick   Credit:Wikipedia

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A wonderful commentary by Dr. Mandrola about recent research of almost 500,000 UK citizens. Researchers found that just asking the patient several basic questions was a better predictor of 5 year mortality than all sorts of blood tests, measurements, and analyses. The best basic questions were: Is your health excellent, good, average, or poor? Is your walking pace slow, average, or brisk? Along with smoking, those two basic questions were the best predictors of staying alive in the next 5 years. These excerpts are from Medscape:

Health Is Not Complicated—Just Ask the Patient

It turns out predicting health is not so complicated. Nor is it digital at all. For persons of middle age (40 to 70 years), self-reported overall health and walking speed were the best predictors of death in the next 5 years, according to a study published this week in the Lancet.[1]

In an analysis of nearly 500,000 UK citizens followed for 5 years, these two simple questions outperformed 655 measurements of demographics, health, and lifestyle. Is your health excellent, good, average, or poor? Is your walking pace slow, average, or brisk? Along with smoking, those two basic questions, inquiries that hardly require a digital device, were the best predictors of staying alive in the next 5 years.

Pause for a moment here and ponder the beauty of that top-line result. Half a million people followed for 5 years; 655 measures of health, including heart rate, blood pressure, and lab tests, and the best predictors were that simple.

In the 5 years of follow-up, 8532 (1.7%) subjects died. Overall, cancer was the most common cause of death (53% in men; 69% in women). The most common cancer-related cause of death was lung cancer in men (n=546) and breast cancer in women (n=489). Cardiovascular disease was the second leading cause of death (26% in men; 33% in women).

 

There were gender differences in predictors of death. Self-reported health was the strongest predictor of death in men (C index 0.74). In women, a previous cancer diagnosis was the strongest predictor (C index 0.73).Self-reported walking pace was a strong predictor of death in both men and women (C index 0.72 and 0.69, respectively.) For example, a man aged 40 to 52 years who reported a slow walking pace was 3.7 times more likely to die than a similarly aged man who reported a steady walking pace. In a large subset of subjects with no reported health conditions, smoking was the best predictor of mortality.

 

The final, and perhaps niftiest, aspect of this study was that researchers developed an 11 to 13 question risk prediction score, which they then put on an interactive website. Anyone can answer these simple questions and get their health-related age relative to the UK population. The researchers call this age the UK Longevity Explorer (UbbLE) age.

I am drawn to these findings because they emphasize something that is increasingly lost on both doctors and patients. True health is not complicated. And the big picture is still useful.Any experienced clinician will testify that patients know when they are well and when they are not. The finding that self-reported health predicts death urges clinicians, generalists and specialists alike, to ask our patients how they feel about their health.

Then there is the matter of self-reported walking pace. How easy it is to be distracted by digital data. We walk into the exam room to see our patient. He is still. We look at him. We poke and listen to his body. We assess his ECG and other measures. Soon we will review his smartphone metrics and DNA data. Yet we tend to forget the obvious: to move is to be healthy. Drs Ganna and Ingelsson teach us that to move briskly may be healthier.

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Stop drinking soda every day! Research finds that a daily sugar-sweetened beverage habit may increase the risk for non-alcoholic fatty liver disease (NAFLD). Earlier research has already linked daily sugar-sweetened beverages (typically soda) to type 2 diabetes and cardiovascular disease. And try to avoid high-fructose corn syrup in general (found in many highly processed foods) . From Medical Xpress:

Daily sugar-sweetened beverage habit linked to non-alcoholic fatty liver disease

A daily sugar-sweetened beverage habit may increase the risk for non-alcoholic fatty liver disease (NAFLD), researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HRNCA) at Tufts University report today in the Journal of Hepatology.

The researchers analyzed 2,634 self-reported dietary questionnaires from mostly Caucasian middle-aged men and women enrolled in the National Heart Lunch and Blood Institute (NHLBI) Framingham Heart Study's Offspring and Third Generation cohorts....The participants underwent a computed tomography (CT) scan to measure the amount of fat in the liver and the authors of the current study used a previously defined cut-point to identify NAFLD. They saw a higher prevalence of NAFLD among people who reported drinking more than one sugar-sweetened beverage per day compared to people who said they drank no sugar-sweetened beverages.

The relationships between sugar-sweetened beverages and NAFLD persisted after the authors accounted for age, sex, body mass index (BMI), and dietary and lifestyle factors such as calorie intake, alcohol, and smoking. In contrast, after accounting for these factors the authors found no association between diet cola and NAFLD.

NAFLD is characterized by an accumulation of fat in the liver cells that is unrelated to alcohol consumption. NAFLD is diagnosed by ultrasounds, CT, MRI, or biopsy, and many of the approximately 25% of Americans with the disease don't experience any symptoms. Being obese or overweight increases the risk for NAFLD and people with NAFLD are at greater risk of developing cardiovascular disease and type 2 diabetes.Sugar-sweetened beverages are a major dietary source of fructose, the sugar that is suspected of increasing risk of NAFLD because of how our bodies process it.

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Textbooks will have to be rewritten with the recent discovery of a system of lymphatic vessels that are a direct link from the immune system to the brain. Amazing that after centuries of studying people, that only now was this system detected (but they are very small and they follow a major blood vessel down into the sinuses). After extensive research,  the researchers determined that these vessels carry both fluid and immune cells from the cerobrospinal fluid, and that they exist in humans. The discovery reinforces findings that immune cells are present even within healthy brains, a notion that was doubted until recently.From Medical Daily:

Discovery Of 'Missing Link' Between Brain And Immune System Could Change How Disease Is Studied

The recent discovery of a "missing link" between the brain and the immune system may lead to a complete revision of biology textbooks. The link, vessels of the lymphatic system that run through the sinuses, were previously unidentified and thought not to exist. However, the true significance of the discovery lies in the potential effects this finding could have on both the study and treatment of neurological diseases such as Alzheimer’s disease and multiple sclerosis.  

The newly discovered "central nervous system lymphatic system vessels" follow a major blood vessel down into the sinuses, an area that has been traditionally difficult to obtain images of. Their presence is causing a stir in the medical world, as the researchers responsible believe the vessels may help to explain current medical mysteries, such as why patients with Alzheimer’s disease have accumulations of large protein plaques in the brain.

The fascinating discovery was made by researchers at the University of Virginia School of Medicine, and a study on the finding is currently available in the online journal Nature....Using a recently developed method, the team mounted the meninges, the membranes covering the brain, on a single slide so that they could be better observed. Only after doing this were they able to notice the brain’s elusive lymphatic vessels.   "It's so close to the blood vessel, you just miss it," Kipnis said. "If you don't know what you're after, you just miss it."

The team believes that the “missing link” between the brain and the immune system could explain why some diseases like Alzheimer’s can cause plaque buildup in the brain. Kipnis believes this plaque may be the result of the meningeal lymphatic vessels not efficiently removing buildup before it reaches the brain. Although scientists are currently not sure what causes cell death and tissue loss in the brains of those with Alzheimer’s, this plaque buildup is believed to play a role.

It’s not just the presence of plaque in the brain that the researchers hope this discovery can shed light on. According to Kipnis, this discovery could completely change the way we perceive the neuro-immune interaction.“We believe that for every neurological disease that has an immune component to it, these vessels may play a major role,” Kipnis said. “Hard to imagine that these vessels would not be involved in a [neurological] disease with an immune component.”The vessels also appear to look different with age, which has lead the researchers to suggest that they may play a role in the aging process.

 

Maps of the lymphatic system: old (left) and updated to reflect UVA's discovery.   Credit: University of Virginia Health System

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New noteworthy research links commonly used household pyrethroid pesticides to attention deficit hyperactive disorder (ADHD) in children and young teens, especially boys. Ome drawback was that the results were based on a single urine sample.Since pyrethroids are non-persistent and rapidly metabolized, then looking at numerous samples over time would have provided a more accurate assessment of typical long-term exposure. Given how many households use pyrethroid pesticides and that there are seasonal variations in pesticide use, then it wouldn't be surprising if there are times when pyrethroid exposure is higher and so the link to ADHD may even be stronger than seen in this original study.From Medical Xpress:

Study links exposure to common pesticide with ADHD in boys

A new study links a commonly used household pesticide with attention deficit hyperactivity disorder (ADHD) in children and young teens.The study found an association between pyrethroid pesticide exposure and ADHD, particularly in terms of hyperactivity and impulsivity, rather than inattentiveness. The association was stronger in boys than in girls.

Due to concerns about adverse health consequences, the United States Environmental Protection Agency banned the two most commonly used organophosphate (organic compounds containing phosphorus) pesticides from residential use in 2000-2001. The ban led to the increased use of pyrethroid pesticides, which are now the most commonly used pesticides for residential pest control and public health purposes. They also are used increasingly in agriculture.

Pyrethroids have often been considered a safer choice because they are not as acutely toxic as the banned organophosphates. Animal studies, on the other hand, suggested a heightened vulnerability to the effects of pyrethroid exposure on hyperactivity, impulsivity and abnormalities in the dopamine system in male mice. Dopamine is a neurochemical in the brain thought to be involved in many activities, including those that govern ADHD.

The researchers studied data on 687 children between the ages of 8 and 15. The data came from the 2000-2001 National Health and Nutrition Examination Survey (NHANES),...included a diagnostic interview of children's ADHD symptoms and pyrethroid pesticide biomarkers. Pesticide exposure measurements were collected in a random sample of the urine of half the 8-11 year olds and a third of the 12-15 year olds. ADHD was determined by meeting criteria on the Diagnosic Interview Schedule for Children,...

Boys with detectable urinary 3-PBA, a biomarker of exposure to pyrethroids, were three times as likely to have ADHD compared with those without detectable 3-PBA. Hyperactivity and impulsivity increased by 50 percent for every 10-fold increase in 3-PBA levels in boys. Biomarkers were not associated with increased odds of ADHD diagnosis or symptoms in girls.

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New research shows that wearing contact lenses could significantly change the bacteria of the eye’s surface, making it more susceptible to infection. NYU Langone Medical Center researchers analyzed swabs from both contact-wearers and non-wearers to determine the number and type of bacterial species that lived on the surface of their eyes—the eye’s microbiome as well as the skin below the eye.

They found that the eye microbiome of contact lens wearers is more similar in composition to the microbiome of their skin than the eye microbiome of non-lens wearers.

Note that infections often come when people don’t take proper care of their lenses—sleeping in them overnight, or not cleaning them well or often enough so most eye doctors have shifted to recommending daily lenses. 

From Medical News Today: Alterations to the eye microbiome of contact lens wearers may increase infections

Contact lens wearers - ever wondered why you are more likely to experience eye infections than your contacts-less friends? Researchers from NYU Langone Medical Center in New York City think they may have found the answer, in a study that used high-precision genetic tests to map the human microbiome....the NYU Langone researchers report that micro-organisms residing in the eyes of people who wear contact lenses daily more closely resemble micro-organisms residing in eyelid skin than the bacteria usually found in the eyes of people who do not wear contacts.

The researchers took hundreds of swabs of different parts of the eye, including the skin directly beneath the eye. Genetic analysis of swabs and used contact lenses allowed the team to identify which bacteria were present. Comparing nine contact lens wearers with 11 non-contacts users, the team found three times the usual proportion of the bacteria Methylobacterium, Lactobacillus, Acinetobacter and Pseudomonas on the eye surfaces (conjunctiva) of contact lens wearers than on the eye surfaces of the control group.

Examining the bacterial diversity using a plotted graph, the team observed that the eye microbiome of contact lens wearers is more similar in composition to the microbiome of their skin than the eye microbiome of non-lens wearers. 

Interestingly, the researchers say, Staphylococcus bacteria was found in greater amounts in the eyes of non-lens wearers. Staphylococcus is linked with eye infections, but is usually more prominent on the skin. However, the researchers are unable to explain why non-lens wearers have greater amounts of this bacteria, despite this group traditionally having fewer eye infections than people who wear contacts.

Study author Dr. Jack Dodick, professor and chair of ophthalmology at NYU Langone, says:"There has been an increase in the prevalence of corneal ulcers following the introduction of soft contact lenses in the 1970s. A common pathogen implicated has been Pseudomonas. This study suggests that because the offending organisms seem to emanate from the skin, greater attention should be directed to eyelid and hand hygiene to decrease the incidence of this serious occurrence."

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Prostate cancer diagnosis is scary enough, but knowing that dietary changes can increase favorable odds is good. Once again a Mediterranean style diet  or "healthy diet"(whole grains, fruits, vegetables, seeds, nuts, legumes, olive oil, and fish) is beneficial, while a Western diet (highly processed foods, red meat, processed meat, and dairy) is linked to higher rates of death. This study was from the Harvard School of Public Health and followed male physicians for an average of 14 years after prostate cancer diagnosis. From Science Daily:

Western diet may increase risk of death after prostate cancer diagnosis

After a prostate cancer diagnosis, eating a diet higher in red and processed meat, high-fat dairy foods, and refined grains--known as a Western diet--may lead to a significantly higher risk of both prostate cancer-related mortality and overall mortality compared with eating a diet rich in vegetables, fruits, fish, whole grains, legumes, and healthy oils, according to a new study from Harvard T.H. Chan School of Public Health.

The study, which appears online June 1, 2015 in the journal Cancer Prevention Research, offers insight on how diet may help improve survivorship for the nearly three million men living with prostate cancer in the U.S."There is currently very little evidence to counsel men living with prostate cancer on how they can modify their lifestyle to improve survival. Our results suggest that a heart-healthy diet may benefit these men by specifically reducing their chances of dying of prostate cancer," said Jorge Chavarro, assistant professor of nutrition and epidemiology at the Harvard Chan School and senior author of the study.

Researchers examined health and diet data from 926 men participating in the Physicians' Health Study I and II who were diagnosed with prostate cancer. They followed the men for an average of 14 years after their diagnosis, grouping them into quartiles according to whether they followed a Western dietary pattern or a "prudent" (higher consumption of vegetables, fruits, fish, legumes, and whole grains) dietary pattern.

They found that men who ate mostly a Western diet (those in the highest quartile of the Western dietary pattern) had two-and-a-half times higher risk of prostate cancer-related death--and a 67% increased risk of death from any cause--than those in the lowest quartile. Men who ate mostly a "prudent" diet had a 36% lower risk of death from all causes.

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I know of a number of people in NY and NJ who have been struggling for years with persistent Lyme disease. So this research with the possibility of treatments that actually work is fantastic. And it gives support to all those people who say they still have Lyme disease after antibiotic treatment, but the medical establishment says they're wrong -  that it's all their mind or due to something else. Yes, they still have Lyme disease from persister cells that avoided the antibiotic treatment! Persister cells are drug-tolerant,dormant variants of Borrelia burgdorferi  (the bacterium that causes Lyme disease). And perhaps pulse-dosing antibiotics may work to get rid of the persister cells. The antibiotic they successfully used in the research is ceftriaxone (a cephalosporin antibiotic) - but only in cultures grown in a lab. Further research is needed. From Science Daily:

Researchers' discovery may explain difficulty in treating Lyme disease

North­eastern Uni­ver­sity researchers have found that the bac­terium that causes Lyme dis­ease forms dor­mant per­sister cells, which are known to evade antibi­otics. This sig­nif­i­cant finding, they said, could help explain why it's so dif­fi­cult to treat the infec­tion in some patients.

In other chronic infec­tions, Lewis' lab has tracked the resis­tance to antibi­otic therapy to the pres­ence of per­sister cells--which are drug-tolerant, dor­mant vari­ants of reg­ular cells. These per­sister cells are exactly what they've iden­ti­fied here in Bor­relia burgdor­feri, the bac­terium that causes Lyme disease.The researchers have also reported two approaches--one of them quite promising--to erad­i­cate Lyme dis­ease, as well as poten­tially other nasty infections.

Lyme dis­ease affects 300,000 people annu­ally in the U.S., according to the Cen­ters for Dis­ease Con­trol and Pre­ven­tion, and is trans­mitted to people via bites from infected black­legged ticks. If caught early, patients treated with antibi­otics usu­ally recover quickly. How­ever, about 10 to 20 per­cent of patients, par­tic­u­larly those diag­nosed later, who have received antibi­otic treat­ment may have per­sis­tent and recur­ring symp­toms including arthritis, muscle pain, fatigue, and neu­ro­log­ical prob­lems. These patients are diag­nosed with Post-treatment Lyme Dis­ease Syndrome.

In addi­tion to iden­ti­fying the pres­ence of these per­sister cells, Lewis' team also pre­sented two methods for wiping out the infection--both of which were suc­cessful in lab tests. One involved an anti-cancer agent called Mit­o­mycin C, which com­pletely erad­i­cated all cul­tures of the bac­terium in one fell swoop. How­ever, Lewis stressed that, given Mit­o­mycin C's tox­i­city, it isn't a rec­om­mended option for treating Lyme dis­ease, though his team's find­ings are useful to helping to better under­stand the disease.

The second approach, which Lewis noted is much more prac­tical, involved pulse-dosing an antibi­otic to elim­i­nate per­sis­ters. The researchers intro­duced the antibi­otic a first time, which killed the growing cells but not the dor­mant per­sis­ters. But once the antibi­otic washed away, the per­sis­ters woke up, and before they had time to restore their pop­u­la­tion the researchers hit them with the antibi­otic again. Four rounds of antibi­otic treat­ments com­pletely erad­i­cated the per­sis­ters in a test tube.

"This is the first time, we think, that pulse-dosing has been pub­lished as a method for erad­i­cating the pop­u­la­tion of a pathogen with antibi­otics that don't kill dor­mant cells," Lewis said. "The trick to doing this is to allow the dor­mant cells to wake up.