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Published on Leave a comment on One Course of Antibiotics And Your Microbes

New research found that one course of antibiotics (ciprofloxacin, clindamycin, amoxicillin or minocycline) had varying effects on the gut and saliva microbes, with ciprofloxacin having a negative and disruptive effect on gut microbiome diversity up to 12 months. While the microscopic communities living in the mouth rebound quickly, just one course of antibiotics can disrupt the gut microbiome for months - with amoxicillin the least and ciprofloxacin the most (up to a year).The researchers stressed that for these reasons "antibiotics should only be used when really, really necessary. Even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome."

The scary part is that Americans typically take many courses of antibiotics throughout life. And people with conditions such as chronic sinusitis typically take many more than average. From Medical Xpress:

One course of antibiotics can affect diversity of microorganisms in the gut

A single course of antibiotics has enough strength to disrupt the normal makeup of microorganisms in the gut for as long as a year, potentially leading to antibiotic resistance, European researchers reported this week in mBio, an online open-access journal of the American Society for Microbiology. In a study of 66 healthy adults prescribed different antibiotics, the drugs were found to enrich genes associated with antibiotic resistance and to severely affect microbial diversity in the gut for months after exposure. By contrast, microorganisms in the saliva showed signs of recovery in as little as few weeks.

The microorganisms in study participants' feces were severely affected by most antibiotics for months, said lead study author Egija Zaura, PhD, an associate professor in oral microbial ecology at the Academic Centre for Dentistry in Amsterdam, the Netherlands. In particular, researchers saw a decline in the abundance of health-associated species that produce butyrate, a substance that inhibits inflammation, cancer formation and stress in the gut.

"My message would be that antibiotics should only be used when really, really necessary," Zaura said. "Even a single antibiotic treatment in healthy individuals contributes to the risk of resistance development and leads to long-lasting detrimental shifts in the gut microbiome."

It's not clear why the oral cavity returns to normal sooner than the gut, Zaura said, but it could be because the gut is exposed to a longer period of antibiotics. Another possibility, she said, is that the oral cavity is intrinsically more resilient toward stress because it is exposed to different stressors every day.

The investigators enrolled healthy adult volunteers from the United Kingdom and Sweden. Participants were randomly assigned to receive a full course of one of four antibiotics (ciprofloxacin, clindamycin, amoxicillin or minocycline) or a placebo. The researchers, who did not know which medication participants took, collected fecal and saliva samples from the participants at the start of the study; immediately after taking the study drugs; and one, two, four and 12 months after finishing the medications....

Researchers found that participants from the United Kingdom started the study with more antibiotic resistance than did the participants from Sweden, which could result from cultural differences. There has been a significant decline in antibiotic use in Sweden over the last two decades, Zaura said.

In addition, fecal microbiome diversity was significantly reduced for up to four months in participants taking clindamycin and up to 12 months in those taking ciprofloxacin, though those drugs only altered the oral cavity microbiome up to one week after drug exposure. Exposure to amoxicillin had no significant effect on microbiome diversity in either the gut or oral cavity but was associated with the greatest number of antibiotic-resistant genes.

Gut bacteria. Credit: Med. Mic. Sciences Cardiff Univ, Wellcome Images

Published on Leave a comment on Very Low Levels of Vitamin D and Heart Problems

New research found that negative health effects - 35% increased risk of cardiovascular problems (coronary heart disease, heart attacks, strokes) are when the vitamin D levels are really low (under 15 nanograms per milliliter). Currently many doctors recommend optimal levels for health as somewhere between 35 to 40 ng/ml. One article in Medscape recommended 1,000 IU of vitamin D (preferably D3) daily to achieve this level. Or you can go outside in the sun for 15 to 20 minutes. From Science Daily:

Specific vitamin D levels linked to heart problems

A lack of vitamin D can result in weak bones. Recent studies also show that vitamin D deficiency is linked to more serious health risks such as coronary artery disease, heart attacks, and strokes. And now, a new study shows what level of deficiency puts someone at risk of developing these heart problems.Researchers at the Intermountain Medical Center Heart Institute in Salt Lake City have found that patients are fine from a heart standpoint, and may need no further treatment, if their vitamin D level is anywhere above 15 nanograms per milliliter.

"Although vitamin D levels above 30 were traditionally considered to be normal, more recently, some researchers have proposed that anything above 15 was a safe level. But the numbers hadn't been backed up with research until now," said J. Brent Muhlestein, MD, co-director of cardiovascular research at the Intermountain Medical Center Heart Institute, and lead researcher of the study.

The body naturally produces vitamin D as a result of exposure to the sun, and it's also found in a few foods -- including fish, fish liver oils, and egg yolks as well as some dairy and grain products. Those who don't have enough exposure to sunlight or vitamin D producing foods often have low vitamin D levels. Low levels are also attributed to race because people with dark skin have a natural protectant against ultraviolet light.

Dr. Muhlestein and his team have studied the effects of vitamin D on the heart for several years, looking at smaller numbers of patients. In this study, thanks to Intermountain Healthcare's vast clinical database, they were able to evaluate the impact of vitamin D levels on more than 230,000 patients. The 230,000 patients were split up into four groups (<15 ng/ml, 15-29, 30-44, ≥45) and were followed for the next three years by researchers who looked for major adverse cardiac events, including death, coronary artery disease, heart attacks, stroke, and incidents of heart or kidney failure.

Dr. Muhlestein found that for the nine percent of patients in the lower than 15 group, their risk of cardiovascular events increased by 35 percent compared to the other three groups, and the risks faced by the other three groups weren't very different from each other.

Published on Leave a comment on House Dust Contains a Microhistory of Our Life

Nice update from a large crowd sourced study I posted about September 1, 2015. Main finding: all our homes are teaming with microorganisms, which vary according to sex of occupants, pets, geographical location and humidity. In total, the indoor dust contained more than sixty-three thousand species of fungi and a hundred and sixteen thousand species of bacteria. The scientists have posted it all online and members of the public can download the complete data set and hunt for new correlations and patterns. Just remember that all these microbes in our lives is completely normal, and many species are important partners in maintaining our health. Excerpts from Emily Anthes's article in the New Yorker:

Our Dust, Ourselves

Dust talks. That clump of gray fuzz hiding under the couch may look dull, but it contains multitudes: tiny errant crumbs of toast, microscopic fibres from a winter coat, fragments of dead leaves, dog dander, sidewalk grit, sloughed-off skin cells, grime-loving bacteria. “Each bit of dust is a microhistory of your life,” Rob Dunn, a biologist at North Carolina State University, told me recently. For the past four years, Dunn and two of his colleagues—Noah Fierer, a microbial ecologist at the University of Colorado Boulder, and Holly Menninger, the director of public science at N.C. State—have been deciphering these histories, investigating the microorganisms in our dust and how their lives are intertwined with our own.  ...continue reading "House Dust Contains a Microhistory of Our Life"

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Could this be? Fungal infection being the cause of Alzheimer's disease? Noteworthy from a recent study conducted in Spain: all the Alzheimer's disease (AD) patients had evidence of fungal infections in their brains, central nervous systems, and vascular systems, but none were found in the control subjects (those without Alzheimer's disease). Many of the symptoms of AD (such as inflammation of the central nervous system and activation of the immune system) match those with long-lasting fungal infections. A "microbial cause" has long been suggested as a cause of AD, and interestingly other studies have also found fungal infections in AD patients. The research so far has found several fungal species in AD patients (including Candida albicans). The researchers mention that in one study anti-fungal treatment reversed clinical symptoms of AD in 2 patients (but it was written off  as misdiagnosis).

Another possibility that immediately occurs to  explain the findings is that perhaps Alzheimer's disease somehow results in fungal infections - that the AD makes them more prone to fungal infection. In case you're wondering - all the AD patients and control patients studied had died - this is why their brain tissue could be studied so thoroughly. Excerpts from a research article by D. Pisa et al in Nature:

Different Brain Regions are Infected with Fungi in Alzheimer’s Disease

The possibility that Alzheimer’s disease (AD) has a microbial aetiology has been proposed by several researchers. Here, we provide evidence that tissue from the central nervous system (CNS) of AD patients contain fungal cells and hyphae. Fungal material can be detected both intra- and extracellularly using specific antibodies against several fungi. Different brain regions including external frontal cortex, cerebellar hemisphere, entorhinal cortex/hippocampus and choroid plexus contain fungal material, which is absent in brain tissue from control individuals. Analysis of brain sections from ten additional AD patients reveals that all are infected with fungi. Fungal infection is also observed in blood vessels, which may explain the vascular pathology frequently detected in AD patients. Sequencing of fungal DNA extracted from frozen CNS samples identifies several fungal species. Collectively, our findings provide compelling evidence for the existence of fungal infection in the CNS from AD patients, but not in control individuals.  ...continue reading "Fungal Infections Involved in Alzheimer’s Disease?"

Published on Leave a comment on Nonprescription Cold Meds That Don’t Work

When suffering from cold symptoms or acute sinusitis, there are some products that work for nasal congestion, and thick phlegm and mucus. Mucinex works well for thick phlegm and mucus, and Sudafed containing pseudoephedrine works for nasal congestion. However, that Sudafed is behind the pharmacy counter, can only be bought in limited quantities, and one must show a driver's license and sign for it before getting any. There are also many other easily available nonprescription cold products containing phenylephrine. But this latest research shows clearly that products containing phenylephrine don't work at any dose. Bottom line: when buying a decongestant, get the stuff containing pseudoephedrine that is behind the pharmacy counter. From Forbes:

The Popular Over-The-Counter Cold Medicine That Science Says Doesn't Work

The market for over-the-counter cold medicines is worth $8 billion annually, with a hefty portion of that amount spent on drugs marketed as decongestants....According to University of Florida researchers, the oral decongestant phenylephrine simply doesn’t work at the FDA-approved amount found in popular non-prescription brands, and it may not even work at much higher doses. Their conclusions were presented in an editorial in The Journal of Allergy and Clinical Immunology: In Practice....

The study of 539 adults lasted one week and failed to find a dose of phenylephrine within the 10 mg to 40 mg range that was more effective than a placebo in relieving nasal congestion. The approved Food and Drug Administration (FDA) dose is 10 mg every four hours for “temporary relief of nasal congestion.” Consequently, the UF researchers are asking the FDA to remove oral phenylephrine from the market.

“We think the evidence supports that phenylephrine’s status as a safe and effective over-the-counter product should be changed,” said Randy Hatton, Pharm.D., a clinical professor of pharmacotherapy and translational research. “We are looking out for the consumer, and he or she needs to know that science says that oral phenylephrine does not work for the majority of people.”

Back before methamphetamine cooks started buying up non-prescription decongestants to brew crank, all of us were able to buy effective decongestants right off the store shelf without a problem. The active ingredient in those meds, coveted by meth smurfers and cold sufferers alike, was pseudoephedrine. But then federal legislation was enacted to restrict the sale of pseudoephedrine-containing products (Combat Methamphetamine Epidemic Act of 2005) and they were moved behind the pharmacy counter. You can still buy them, assuming you know they’re available, by presenting identification and signing a statement saying you’re not buying the drugs for nefarious purposes.

To fill the store-shelf void, drug companies substituted the already-FDA approved ingredient phenylephrine for pseudoephedrine. Several studies testing phenylephrine against a placebo produced results that question its effectiveness, and eventually the FDA started to at least listen to critics in the research community asking for greater scrutiny. The latest research adds a boldface exclamation point to the criticism. Whether the FDA will choose to act on the findings is another matter, but the science is there.

The number of brands containing phenylephrine are too many to list, but the majority of on-the-shelf oral decongestants list it as an active ingredient, including many multi-symptom products. Instead of buying products containing phenylephrine, the researchers suggest cold and allergy sufferers choose a pseudoephedrine product from behind the counter or nasal steroids for allergic rhinitis.

Published on Leave a comment on Little Is Known About the Viruses Living On Healthy Skin

The microbes living on healthy human skin include bacteria, fungi, and viruses...but 90% of the viruses found on healthy skin in this study are unknown to researchers - thus "viral "dark matter". The skin virome  is the population of viruses on the skin. It turns out that most of the viruses on healthy skin are phage viruses. called bacteriophages.They infect bacteria and may take up residence within bacteria. From Science Daily:

90 percent of skin-based viruses represent viral 'dark matter,' scientists reveal

Scientists in recent years have made great progress in characterizing the bacterial population that normally lives on human skin and contributes to health and disease. Now researchers from the Perelman School of Medicine at the University of Pennsylvania have used state-of-the-art techniques to survey the skin's virus population, or "virome." The study, published in the online journal mBio last month, reveals that most DNA viruses on healthy human skin are viral "dark matter" that have never been described before. The research also includes the development of a set of virome analysis tools that are now available to researchers for further investigations.

Researchers and the public are increasingly aware that microbes living on and inside us -- our "microbiomes" -- can be crucial in maintaining good health, or in causing disease. Skin-resident bacteria are no exception. Ideally they help ward off harmful infections, and maintain proper skin immunity and wound-healing, but under certain circumstances they can do the opposite.

"Until now, relatively little work has been done in this area, in part because of the technical challenges involved. For example, a skin swab taken for analysis will contain mostly human and bacterial DNA, and only a tiny amount of viral genetic material -- the proverbial needles in the haystack." 

Their analysis of samples from 16 healthy individuals revealed some results that were expected. The most abundant skin-cell infecting virus was human papilloma virus, which causes common warts and has been linked to skin cancers. However, most of the detected DNA from the VLPs did not match viral genes in existing databases. "More than 90 percent was what we call viral dark matter -- it had features of viral genetic material but no taxonomic classification," Grice said. That came as a surprise, although of course it highlighted the importance of mapping this unexplored territory.

The findings also clearly linked the skin virome to the skin microbiome: Most of the detected viral DNA appeared to belong to phage viruses, which infect and often take up long-term residence within bacteria. And when Grice and colleagues sequenced skin bacterial DNA from the same 16 subjects, they found that it often contained tell-tale marks -- called CRISPR spacers -- of prior invasion by the same phage viruses.

The results also showed that the skin virome varies considerably depending on the body site. Grice's team took swabs from the palm, the forehead, the armpit, the navel, and other sites, and found, for example, that the virome was most diverse in the crook of the arm, a site that is intermittently exposed and occluded.

Published on Leave a comment on Exposure to Animals In First Year of Life and Lower Risk of Asthma

Labrador Retriever image Other studies have found this same association - that living with a dog or farm animal has health benefits such as lower risk of allergies and asthma. In a Swedish nationwide study looking at over a million children, the association between early exposure to dogs and farm animals and the risk of asthma was evaluated. All children born in Sweden from January 1, 2001, to December 31, 2010 were included. The researchers found that exposure to dogs and farm animals during the first year of life reduces the risk of asthma in children at age 6 years. From Science Daily:

Early contact with dogs linked to lower risk of asthma

A team of Swedish scientists have used national register information in more than one million Swedish children to study the association of early life contact with dogs and subsequent development of asthma. This question has been studied extensively previously, but conclusive findings have been lacking. The new study showed that children who grew up with dogs had about 15 percent less asthma than children without dogs.

A total of more than one million children were included in the researchers' study linking together nine different national data sources, including two dog ownership registers not previously used for medical research...."Earlier studies have shown that growing up on a farm reduces a child's risk of asthma to about half. We wanted to see if this relationship also was true also for children growing up with dogs in their homes. Our results confirmed the farming effect, and we also saw that children who grew up with dogs had about 15 percent less asthma than children without dogs.

"These kind of epidemiological studies look for associations in large populations but do not provide answers on whether and how animals could protect children from developing asthma. We know that children with established allergy to cats or dogs should avoid them, but our results also indicate that children who grow up with dogs have reduced risks of asthma later in life. Thanks to the population-based design, our results are generalizable to the Swedish population, and probably also to other European populations with similar culture regarding pet ownership and farming" says Catarina Almqvist Malmros, senior author on the study, Paediatrician at Astrid Lindgren Children's Hospital and Professor in Clinical epidemiology at Dept of Medical Epidemiology and Biostatistics at Karolinska Institutet, Stockholm.

Published on Leave a comment on Time to Ditch Personal Care Products Containing Parabens?

Even though many, many personal care products contain parabens, the evidence is accumulating that parabens have negative health effects. And now research suggesting that perhaps they may be a factor in developing breast cancer. This latest study was done "in vitro" - meaning looking at the effects of chemicals on human breast cells (in culture dishes), but the results absolutely should make someone think twice about all the parabens in products, and how they accumulate in us. Research has already found parabens in the human breast, but many thought that the levels were too low to promote cancer.

Parabens are common ingredients in cosmetics, shampoos, body lotions and sunscreens, where they are used to prevent microbial growth and prolong shelf life.  Common names of parabens are: methylparaben, ethylparaben, propylparaben, and butylparaben. Detectable levels of multiple parabens are present in human urine and breast tissue. Bottom line: Parabens are endocrine disrupting chemicals that mimic estrogens and may have effects at very low doses to stimulate breast cancer cell growth. So read labels of personal care products and avoid those with parabens. From Futurity:

New Tests Suggest Parabens Carry Cancer Risk

A group of chemicals called parabens—common ingredients in personal care products—may interact with growth factors in the body to increase the risk of breast cancer, according to new research. Parabens are preservatives widely used in everything from shampoos and cosmetics to body lotions and sunscreens. The chemicals have generated increasing health concerns, however, because they mimic estrogens, which have been linked to an increased risk of breast cancer and reproductive problems.

“Although parabens are known to mimic the growth effects of estrogens on breast cancer cells, some consider their effect too weak to cause harm,” says lead investigator Dale Leitman, a gynecologist and molecular biologist at the University of California, Berkeley, and an adjunct associate professor of nutritional sciences and toxicology. “But this might not be true when parabens are combined with other agents that regulate cell growth.”

Existing chemical safety tests, which measure the effects of chemicals on human cells, look only at parabens in isolation, he says. They fail to take into account that parabens could interact with other types of signaling molecules in the cells to increase breast cancer risk.

To better reflect what goes on in real life, Leitman and his colleagues looked at breast cancer cells expressing two types of receptors: estrogen receptors and HER2. Approximately 25 percent of breast cancers produce an abundance of HER2, or human epidermal growth factor receptor 2. HER2-positive tumors tend to grow and spread more aggressively than other types of breast cancer.

The researchers activated the HER2 receptors in breast cancer cells with a growth factor called heregulin that is naturally made in breast cells, while exposing the cells to parabens. Not only did the parabens trigger the estrogen receptors by turning on genes that caused the cells to proliferate, but also the effect was significant. The parabens in the HER2-activated cells were able to stimulate breast cancer cell growth at concentrations 100 times lower than in cells that were deprived of heregulin.

The study demonstrates that parabens may be more potent at lower doses than previous studies have suggested, which may spur scientists and regulators to rethink the potential impacts of parabens on the development of breast cancer, particularly on HER2 and estrogen receptor positive breast cells. The findings also raise questions about current safety testing methods that may not predict the true potency of parabens and their effects on human health.

Published on

According to a new report, it looks like most people under the age of 50 (throughout the world) have herpes simplex virus infections - whether type 1 or type 2. (Picture is of a herpes simplex virus type 1, at www.virology.net). From Medical Xpress:

An estimated two-thirds of world's population under age of 50 are infected with herpes simplex virus type 1

More than 3.7 billion people under the age of 50 are infected with herpes simplex virus type 1 (HSV-1), which commonly causes 'cold sores' and can also cause genital herpes, according to new research by the University of Bristol and the World Health Organisation [WHO]. The findings, published in the journal PLOS ONE, reveal the first global estimates of HSV-1 infection.

Herpes simplex virus is categorised into two types: herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). Both HSV-1 and HSV-2 are highly infectious and incurable. HSV-1 is primarily transmitted by oral-oral contact and in many cases causes orolabial herpes or "cold sores" around the mouth. HSV-2 is almost entirely sexually transmitted through skin-to-skin contact, causing genital herpes. 

The new estimates highlight, however, that HSV-1 is also an important cause of genital herpes. Some 140 million people aged 15-49 years are estimated to be infected with genital HSV-1 infection, primarily in the Americas, Europe and Western Pacific. Earlier this year, WHO published estimates of herpes simplex virus type 2 (HSV-2) infection showing that an estimated 417 million people between 15-49 years of age have infection caused by HSV-2. Taken together, these estimates suggest that over half a billion people between 15-49 years of age have a genital infection due either to HSV-1 or HSV-2. This highlights the large global burden of genital herpes caused by both HSV types.

Given the lack of a permanent and curative treatment for both HSV-1 and HSV-2, WHO and partners are working to accelerate development of HSV vaccines and topical microbicides, which will have a crucial role in preventing these infections in the future. Several candidate vaccines and microbicides are currently being studied. 

Published on Leave a comment on Report Says Mammograms Haven’t Reduced Rate Of Metastatic Cancer

A report by 3 prominent specialists (including Gilbert Welch - who has been discussed in earlier posts) about trends in metastatic breast and prostate cancer came out today in the New England Journal of Medicine. The biggest finding was that mammograms have not cut the rate of metastatic breast cancer. Mammography screening is based on the hope that cancer that is detected in an early, localized phase can then be treated more easily and that it would reduce the numbers of metastastic cancers (that spread to lymph nodes and to more distant organs) that eventually kill. However, this has not happened.The incidence of metastatic breast cancer has been stable since 1975, and the average age of diagnosis among women older than 40 is still 63.7 years . The authors theorize that "breast cancer is a systemic disease by the time it's detectable". From Medical Xpress:

Study: Mammograms haven't cut rate of advanced breast cancer

A new report raises fresh questions about the value of mammograms. The rate of cancers that have already spread far beyond the breast when they are discovered has stayed stable for decades, suggesting that screening and early detection are not preventing the most dangerous forms of the disease. The report, in Thursday's New England Journal of Medicine, is by three prominent cancer specialists and is based on federal statistics going back to the 1970s.

"We're undergoing what I think for the public is a very confusing debate" about screening, but it's really "a course correction" prompted by more awareness of its risks and benefits to various groups of women, said Dr. H. Gilbert Welch, a health policy expert at Dartmouth Medical School. "All they heard for years was, 'there are only benefits.'" He is the lead author of the report, co-written with Dr. David Gorski of Wayne State University School of Medicine in Detroit and Dr. Peter Albertsen of the University of Connecticut Health Center in Farmington.

"Screening offers hope that cancer can be detected in an early, localized phase when it's more amenable to treatment," they write, but that assumes that cancer starts in one place, grows and then spreads. If that was always true, screening would reduce the rate of advanced cancers. And that has not happened. The rate of breast cancers detected at an advanced stage has been stable since 1975, despite wide use of mammography since the 1980s. The average age of women diagnosed with cancer also has remained around 63, another sign cancers are not being found sooner.

The trends suggest that some breast cancers are already "systemic" or widely spread from the start, and that finding them sooner has limited impact. "Screening mammography has been unable to identify those bad cancers, destined to become metastatic, at an earlier stage. That doesn't say mammography doesn't help less aggressive cancers," but those are less likely to prove deadly, Welch said.

Dr. Barnett Kramer, a screening expert at the National Cancer Institute, said the report shows the limitations of mammography. "I wouldn't want to say it has had no effect but it certainly has not lived up to the anticipated effect," he said. For every tumor detected early because of mammography, "you would hope to see ... an equal reduction in metastatic disease, and that has not occurred."

The situation is very different with prostate cancer. The rate of advanced cases of that disease has been cut in half since screening with PSA blood tests came into wide use around 1988, and the average age at which men are diagnosed has fallen—from 72 to 70, the authors write. However, this does not prove PSA testing is good. Shifting the stage at which a disease is diagnosed is "only the first step for successful screening," which also has to save lives to be worthwhile, Welch said. "Just because you find something earlier doesn't mean you can change its course."

Again, Kramer agreed. Prostate screening, "when put to a definitive test, did not show a clear reduction in prostate cancer mortality" in large, rigorously done trials, he said. The government task force recommends against PSA testing, and says its risks outweigh its benefits for most men.

"Screening is a close call," Welch said. "My guess is few people are helped" by prostate or breast cancer screening while many are harmed by false alarms that trigger unnecessary tests and treatments, he said.

The original report, which also includes a discussion on prostate cancer and the PSA test, in the New England Journal of Medicine:  Trends in Metastatic Breast and Prostate Cancer — Lessons in Cancer Dynamics