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Author: Sima

Published on Leave a comment on Is Exercise the Fountain of Youth?

Once again a great reason to exercise - a study found that adults with the highest levels of weekly physical activity had the longest telomeres, which are markers of overall health and aging. Think of it this way: we all age, but some people seem young for their age, while others seem old for their age. This study looked at differences among groups of people at the cellular level.

The multi-year study looked at both physical activity levels of 5,823 adults and their telomeres. The adults provided DNA samples, from which the researchers measured telomere length. Telomeres are "protein caps positioned at the end of chromosomes". Aging causes telomeres to shorten and results in gradual cell deterioration - thus they are good markers of our biological age, that is, how we're aging (rather than just our chronological age). Study author Larry A. Tucker said “We know that, in general, people with shorter telomeres die sooner and are more likely to develop many of our chronic diseases. It's not perfect, but it's a very good index of biological aging.”

What causes telomeres to shrink faster?  Telomere shortening  can be hastened by things that result in inflammation and oxidative stress, such as obesity, smoking, poor diet, type 2 diabetes, and low socioeconomic levels. On the other hand, this study found that adults with high levels of physical activity had significantly longer telomeres. The longer telomeres found in the active adults reduced cellular aging by about 9 years, as compared to those adults who were sedentary or had low to medium levels of physical activity. Nine years less of biological aging is a lot! The shortest telomeres were in sedentary people.

How much physical activity should one aim for? The study found that activity levels in the study were measured in MET-minutes (metabolic equivalent minutes) - which can sound confusing, but can be achieved by incorporating exercise into daily routines, as well as also doing vigorous activities or exercises. In the present study, men had to attain >1887 MET-minutes per week and women >1375 to be included in the category with the highest activity levels (longest telomeres). It does mean several hours a week of physical activity, which can include gardening, bicycling, walking, vacuuming, exercising, running, etc. From Science Daily:

High levels of exercise linked to nine years of less aging at the cellular level

Despite their best efforts, no scientist has ever come close to stopping humans from aging. But new research from Brigham Young University reveals you may be able to slow one type of aging -- the kind that happens inside your cells. As long as you're willing to sweat. "Just because you're 40, doesn't mean you're 40 years old biologically," Tucker said. "We all know people that seem younger than their actual age. The more physically active we are, the less biological aging takes place in our bodies."

The study, published in the medical journal Preventive Medicine, finds that people who have consistently high levels of physical activity have significantly longer telomeres than those who have sedentary lifestyles, as well as those who are moderately active. Telomeres are the protein endcaps of our chromosomes. They're like our biological clock and they're extremely correlated with age; each time a cell replicates, we lose a tiny bit of the endcaps. Therefore, the older we get, the shorter our telomeres.

Exercise science professor Larry Tucker found adults with high physical activity levels have telomeres with a biological aging advantage of nine years over those who are sedentary, and a seven-year advantage compared to those who are moderately active. To be highly active, women had to engage in 30 minutes of jogging per day (40 minutes for men), five days a week.

Tucker analyzed data from 5,823 adults who participated in the CDC's National Health and Nutrition Examination Survey, one of the few indexes that includes telomere length values for study subjects....His study found the shortest telomeres came from sedentary people -- they had 140 base pairs of DNA less at the end of their telomeres than highly active folks. Surprisingly, he also found there was no significant difference in telomere length between those with low or moderate physical activity and the sedentary people.

Published on Leave a comment on Could Changing Your Diet Prevent Gout?

Gout is something that is not discussed that much, but it has been increasing in recent years and now afflicts about  3.9% of adults in the US. Gout is a form of inflammatory arthritis, characterized by recurrent attacks of pain, tenderness, and swelling of a joint, frequently the joint of the big toe. It is caused by elevated levels of uric acid in the blood (known as hyperuricaemia).

Gout occurs more commonly in men ages 40 and older, who eat a lot of meat and seafood, drink a lot of alcohol (especially beer) or sweetened drinks, have high blood pressure, metabolic syndrome, or are overweight.  Gout used to be known as "the disease of kings" or "rich man's disease". [On the other hand, past research has shown that consumption of coffee, cherries, vitamin C foods, and dairy products, losing weight and physical fitness seems to decrease the risk.]

Recent research showed that the DASH diet reduces blood pressure and reduces uric acid in the blood, which is why a research team (study in The BMJ) now looked at  whether it lowers the risk of gout. The Dietary Approaches to Stop Hypertension or DASH diet is high in fruit, vegetables, whole grains, legumes, nuts, and low-fat dairy, and low in red and processed meats, salt, and sugary drinks. On the other hand, the typical Western diet has higher intakes of red and processed meats, sweetened beverages, sweets, desserts, French fries, and refined grains. The researchers analysed data on a total of 44,444 male health professionals, who had no history of gout at the start of the study. During the 26 years of the observational study, they documented 1731 cases of gout.

The researchers found that eating a more DASH type diet - a diet rich in fruits, vegetables, legumes, nuts, whole grains, and low in salt, sugary drinks, and red and processed meats, is associated with a lower risk of gout. On the other hand, a more 'Western' diet is associated with a higher risk of gout. They found that the effects are dose dependent - the more DASH-type diet, the lower the risk of gout. Bottom line: Once again, eating lots of fruits, vegetables, nuts, legumes, and whole grains is linked to health benefits. From Science Daily:

Diet rich in fruit, vegetables and whole grains may lower risk of gout

A diet rich in fruit and vegetables, nuts and whole grains and low in salt, sugary drinks, and red and processed meats, is associated with a lower risk of gout, whereas a typical 'Western' diet is associated with a higher risk of gout, finds a study published by The BMJ.

Gout is a joint disease which causes extreme pain and swelling. It is most common in men aged 40 and older and is caused by excess uric acid in the blood (known as hyperuricaemia) which leads to uric acid crystals collecting around the joints. The Dietary Approaches to Stop Hypertension (DASH) diet reduces blood pressure and is recommended to prevent heart disease. It has also been found to lower uric acid levels in the blood. Therefore, the DASH diet may lower the risk of gout.

To investigate this further, a team of US and Canada based researchers examined the relationship between the DASH and Western dietary patterns and the risk of gout. They analysed data on over 44,000 men aged 40 to 75 years with no history of gout who completed detailed food questionnaires in 1986 that was updated every four years through to 2012.

Each participant was assigned a DASH score (reflecting high intake of fruits, vegetables, nuts and legumes, such as peas, beans and lentils, low-fat dairy products and whole grains, and low intake of salt, sweetened beverages, and red and processed meats) and a Western pattern score (reflecting higher intake of red and processed meats, French fries, refined grains, sweets and desserts). During 26 years of follow-up, a higher DASH score was associated with a lower risk for gout, while a higher Western pattern was associated with an increased risk for gout.

 Gout. Credit: NHS in the UK

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Published on 7 Comments on Will Snot Transplants Work In Treating Chronic Sinusitis?

An amazing new study is about to start in Sweden - this study will see if "snot transplants" work for the treatment for chronic sinusitis! Will this turn out to be a permanent treatment? While studies show that probiotic supplements tend not to stick around in the gut (they're gone after about a week), people receiving a fecal microbiota transplant (FMT) find that these microbial communities do stick around (colonize).  So there is something about getting an entire microbial community (bacteria, fungi, viruses) that is more effective than just a few species that are in typical probiotic supplements.

We have found the same problem in sinusitis treatment - the Lactobacillus sakei treatment works to treat sinusitis, but then doesn't stick around - as evidenced by having to treat again after a cold or sore throat.  And so we treat again - and again it's successful. And this happens again and again. Sooo.... it's important to find out if a transplant of the entire microbial community of snot (the sinonasal microbiome) works. And if works, will the treatment be a permanent one? I also wonder.... Several people have mentioned this idea to me, but has anyone with sinusitis tried a "snot transplant" at home? (And yes, this is self-experimentation.)

The description and purpose of the study refer to what this site has discussed for several years: the sinus microbiome is out of whack (dysbiosis) in chronic rhinosinusitis (CRS), whether due to antibiotics or something else (viruses, etc). The study will enroll 30 people, start May 15, 2017, and end December 31, 2018. The purpose of the study is to have patients with chronic rhinosinusits without nasal polyps (CRSsNP) receive microbiome transplants from healthy donors without any sinus problems. They would receive a snot transplant for 5 days in a row. Unfortunately we'll have to wait at least 1 1/2 years for any results. Excerpts from clinical trails.gov:

Sinonasal Microbiome Transplant as a Therapy for Chronic Rhinosinusitis Without Nasal Polyps (CRSsNP)

Purpose: Chronic rhinosinusitis (CRS) is a disease associated with impaired quality of life and substantial societal costs. Though sometimes co-appearing with other conditions, such as asthma, allergy, and nasal polyps, many cases present without co-morbidities. Micro-biological diagnostic procedures are frequently undertaken, but the results are often inconclusive. Nevertheless, antibiotics are usually prescribed, but invariably with limited and temporary success. Accordingly, there is a need for new treatments for CRS.

Recent studies indicate that the sinuses are colonized by a commensal microbiome of bacteria and that damage to this natural microbiome, by pathogens or antibiotics, may cause an imbalance that may promote CRS. Therefore, treatments that restore the commensal microbiome may offer an alternative to current protocols. Arguably, as suggested by studies on patients with intestinal infections (next paragraph), one such possibility may be to transfer a "normal microbiome" to patients with CRS.

A disrupted microbiome is linked to intestinal clostridium difficile infections. Probiotic restitution therapy may be effective even in cases recalcitrant to antibiotic treatment. However, a key to effective probiotic restitution is selecting the bacteria that facilitate regrowth of normal microbiome. As an answer to this, researchers have chosen to simply transplant the entire microbiome from a healthy donor. In the case of clostridium difficile infection in the form of faecal transplants.

In this study, we will examine the possibility to treat patients with chronic rhinosinusitis without polyps (CRSsNP) with complete sinonasal microbiomes obtained from healthy donors. Our analysis will focus on symptoms and signs of disease as well as on nasal inflammatory and microbiological indices.

Detailed Description: Over the last few years the theory of a damaged microbiome as a cause or promoting factor behind chronic rhinosinusitis has gained increasing interest from the scientific community. A number of studies aimed at investigating the microbiota of the nose and paranasal sinuses in health and disease has been published with very varying outcomes. Furthermore, other studies have been aimed at probiotic treatment of sinonasal disease either locally or through immunologic manipulation via the gastrointestinal microbiota.

A problem common to all these studies is that studies examining the normal nasal microbiota have identified a great amount of different bacterial species. It is as of today not known which individual species or combinations of species that promotes health. 

In this study the investigators aim at recruiting patients suffering from chronic rhinosinusitis without polyps (CRSsNP) and healthy participants without any history sinonasal disease. The patients and the healthy participants will be examined for infectious diseases in a manner similar to other medical transplant procedures to minimize the risk for the recipients. The patients will then be treated with antibiotics to reduce the bacterial load of the nose and the paranasal sinuses. After the patient has finished the antibiotic treatment a microbiome transplant will be harvested from the healthy participant as a nasal lavage. The raw lavage fluid will then be used to transplant the microbiome to the patient. The procedure will be repeated for five consecutive days. The outcome measures analysed will focus on subjective sinonasal health and symptoms of the patients but also include nasal inflammatory and microbiological indices.

Published on Leave a comment on The Importance of Dirt

Great article about the importance of both dirt (it's alive!) and exposure to nature. Main points: It’s estimated that children now spend less time outside than the average prisoner, and that that the average American adult now spends 93 percent of their life indoors (in our homes, workplaces, cars, etc.). It is now thought that human beings need to be exposed to lots of microbes when young for proper immune system development - and this means exposure to the microbes in dirt (for example, young children benefit from playing in the dirt!). There is much harm on many levels from monocultures (whether huge fields of only one crop or "perfect" lawns) sustained by large amounts of chemicals (pesticides and fertilizers). In contrast, a lawn with diversity (clover, flowering "weeds", etc) avoids the use of dangerous chemicals, has benefits to wildlife and humans, and is also a "bee habitat".

Also, what is rarely discussed, but very important to the health of our environment: An estimated quarter of a million acres are paved or repaved in the United States each year - so that “asphalt is the land’s last crop". Paving over the land is "soil sealing", because this cuts off air and water, and kills the microorganisms and insects that live there. This results in dirt being killed off forever. Yikes! Why isn't this discussed more? Excerpts from National Geographic:

WHY YOU NEED MORE DIRT IN YOUR LIFE

It’s estimated that children now spend less time outside than the average prisoner. This could have devastating effects: Kids need to be exposed to the microbes in the soil to build up their defences against diseases that may attack them later. But it’s not just children, Paul Bogard explains in his new book, The Ground Beneath Us. The EPA estimates that the average American adult now spends 93 percent of their life indoors. As we retreat indoors, more and more of the earth is disappearing, with an estimated quarter of a million acres paved or repaved in the United States each year. 

When National Geographic caught up with Bogard by phone at his home in Minnesota, the author explained why Iowa is the most transformed state in the U.S., how soil is alive but we’re killing it, and how places where terrible things happened can become sacred ground.

You write, “We are only just now beginning to understand the vast life in the soil, what it does, and how our activities on the surface may affect it.” Talk us through some highlights of the new science—and how you became so passionate about dirt.

It began with this statistic: that those of us in the Western world now spend about 90-95 percent of our time inside, in our houses, workplaces, in our cars. We’re living our lives separated from the natural world. When we walk outside, many of us walk on pavement. There’s this literal separation from the natural ground, from the soil, the dirt. It made me think, what are the costs of this separation? And it struck me as symbolic of our separation of these many different kinds of grounds that sustain us. Our food, water, energy, even our spirits come from these different grounds.

One of the first scientific discoveries I found was the hypothesis that human beings need to be exposed to the biota in the dirt, on the ground, especially when they’re kids, as a way of inoculating us to diseases that appear later in life. Kids these days are not being exposed to dirt because they’re not allowed to play outside. Their parents think dirt is dirty. But both the newest science and the oldest traditions tell us the same thing, which is that the ground is alive. The ground gives us life. And in the book, I tried to touch on both of those things.

One expert you quote says, “asphalt is the land’s last crop.” Talk about “soil sealing” and how roads and suburbs are literally eating away at the ground beneath our feet.

Soil sealing is one of the most shocking things I learned about. When we pave over the natural ground, we cut it off from the air and water that the life in the ground needs to stay alive. We essentially kill that ground. There is an argument that, if we pulled up the pavement and worked hard to rejuvenate that ground, we could bring it back. But the scientists I talked to said, when you pave it over, it’s the last crop, the last thing that’s going to grow there. We’re not moving in the direction of pulling pavement up. We’re moving in the opposite direction where we’re paving some of our most fertile ground, the ground that we’re going to need to feed a growing population.

You also had childhood affection for Iowa. But when you went back to research your book, you changed your mind. Why?

As a child, I was enamoured with the beauty of the green corn stalks, the black dirt, and what I thought was the natural topography. Coming back older and with a new understanding of the ground, it made me uncomfortable because Iowa is the most transformed state in the union. Some 97 percent of the natural ground has been altered, changed, or transformed. As one biologist said, “it’s an open air monoculture owned by monopolies.” So, instead of my romantic, childhood view of miles of corn stalks, the beauty of life growing, and the colour green, I saw it as this monoculture where another life isn’t allowed to grow.

Americans love their lawns and spend billions of dollars keeping them green and weed free. But we are also paying a high price for this perfect turf, aren’t we?

Oh my! We really are, certainly ecologically, paying a high price. America’s greatest crop, the thing we grow the most of, is our turf grass lawns. And the amounts of pesticides and chemical fertilisers we dump onto these lawns, and the amount of water that we use to grow them, is enormous. As a result, we have problems with runoff draining into our rivers and the lawns themselves tend to become monocultures, where nothing else grows but the turf grass. What a massive opportunity is being lost! We could have lawns that are more biologically diverse and pollinator-friendly. There’s also evidence that a number of illnesses are associated with coming into contact with these chemical fertilisers and pesticides.

Published on Leave a comment on Living In More Polluted Counties Linked To Higher Cancer Rates

This is a thought-provoking study that looked at environmental quality and cancer incidence in counties throughout the US. The researchers found that the more polluted the county, the higher the cancer incidence. An increase in cancer rates was associated with poorer air quality and the "built environment" (such as major highways). They correctly point out that many things together can contribute to cancer occurring - and this is why looking at how polluted the air, water, etc. together is important.

They looked at the most common causes of cancer death in both men (lung, prostate, and colorectal cancer), and women (lung, breast, and colorectal cancer). They found that prostate and breast cancer demonstrated the strongest associations with poor environmental quality. [Original study.]

The researchers point out that about half of cancers are thought to have a genetic component, but therefore the other half have environmental causes. Other studies already find that environmental exposures (e.g., pesticides, diesel exhaust) are linked to various cancers. But this study was an attempt to look at interactions of various things in the environment with rates of cancer - because we all are exposed to a number of things simultaneously wherever we live, not just to exposures to one thing. Thus this study looked at associations in rates of cancer. 

Of course there is also a lifestyle contribution to many cancers that wasn't looked at here (nutrition, alcohol use, exercise). They also pointed out that many counties in the US are large and encompass both very polluted and non-polluted areas - and that those counties should be broken up into smaller geographic areas when studied. [More air pollution studies.] From Science Daily:

Poor overall environmental quality linked to elevated cancer rates

Nationwide, counties with the poorest quality across five domains -- air, water, land, the built environment and sociodemographic -- had the highest incidence of cancer, according to a new study published in the journal Cancer. Poor air quality and factors of the built environment -- such as the presence of major highways and the availability of public transit and housing -- -- were the most strongly associated with high cancer rates, while water quality and land pollution had no measurable effect.

Previous research has shown that genetics can be blamed for only about half of all cancers, suggesting that exposure to environmental toxins or socioeconomic factors may also play a role. "Most research has focused on single environmental factors like air pollution or toxins in water," said Jyotsna Jagai, research assistant professor of environmental and occupational health in the University of Illinois at Chicago School of Public Health and lead author of the study. "But these single factors don't paint a comprehensive picture of what a person is exposed to in their environment -- and may not be as helpful in predicting cancer risk, which is impacted by multiple factors including the air you breathe, the water you drink, the neighborhood you live in, and your exposure to myriad toxins, chemicals and pollutants."

To investigate the effects of overall environmental quality, the researchers looked at hundreds of variables, including air and water pollution, pesticide and radon levels, neighborhood safety, access to health services and healthy food, presence of heavily-trafficked highways and roads, and sociodemographic factors, such as poverty. Jagai and her colleagues used the U.S. EPA's Environmental Quality Index, a county-level measure incorporating more than 200 of these environmental variables and obtained cancer incidence rates from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program State Cancer Profiles. Cancer data were available for 85 percent of the 3,142 U.S. counties.

The average age-adjusted rate for all types of cancer was 451 cases per 100,000 people. Counties with poor environmental quality had higher incidence of cancer -- on average, 39 more cases per 100,000 people -- than counties with high environmental quality. Increased rates were seen for both males and females, and prostate and breast cancer demonstrated the strongest association with poor environmental quality.

The researchers found that high levels of air pollution, poor quality in the built environment and high levels of sociodemographic risk factors were most strongly associated with increased cancer rates in men and women. The strongest associations were seen in urban areas, especially for the air and built environment domains. Breast and prostate cancer were most strongly associated with poor air quality.

Published on Leave a comment on Higher Arsenic Levels In Babies Who Eat Rice Cereal

The research finding of so many baby foods with elevated arsenic levels (above the legal limit) in the European Union made me wonder about arsenic standards in baby cereals in the US. It turns out that the US has "parallel" standards to the European Union. The EU has "maximum 0.1 milligrams of arsenic per kilogram of rice" (this standard has been in place since January 2016), and in  2016 the US the FDA proposed a "maximum allowed standard of 100 ppb (parts per billion)" in infant rice cereal.

Why is there so much arsenic in baby cereal? It's in the rice - rice plants absorb arsenic from the soil (it may be naturally occurring in the soil or in the soil because of arsenic pesticides that were used for years). And why should we be concerned about arsenic in food? The health effects of regularly consuming infant rice cereal — and other rice-based products —containing traces of arsenic are currently unclear. But...the researchers stated that early-life exposure to arsenic, even at low concentrations, is of particular concern because infants and young children are especially vulnerable to the adverse health effects of arsenic. Arsenic is a carcinogen (causes cancer), and can have "neurological, cardiovascular, respiratory and metabolic" effects.

A Harvard Health Publication (Harvard Medical School) publication in 2016 stated: "In high doses it is lethal, but even small amounts can damage the brain, nerves, blood vessels, or skin — and increase the risk of birth defects and cancer." The FDA found that inorganic arsenic exposure in infants and pregnant women can result in a child’s decreased performance on certain developmental tests that measure learning, based on epidemiological evidence including dietary exposures.

So what should parents do? The American Academy of Pediatricians (AAP) encourages that babies and toddlers eat a variety of foods, and that this will decrease a child's exposure to arsenic from rice. They also encourage other options as first foods (rather than just rice cereal), such as oat, barley, and multigrain cereals - all of which have lower arsenic levels than rice cereal. From Science Daily:

New research shows illegal levels of arsenic found in baby foods

In January 2016, the EU imposed a maximum limit of inorganic arsenic on manufacturers in a bid to mitigate associated health risks. Researchers at the Institute for Global Food Security at Queen's have found that little has changed since this law was passed and that 50 per cent of baby rice food products still contain an illegal level of inorganic arsenic. Professor Meharg, lead author of the study and Professor of Plant and Soil Sciences at Queen's, said: "....Babies are particularly vulnerable to the damaging effects of arsenic that can prevent the healthy development of a baby's growth, IQ and immune system to name but a few."

Rice has, typically, ten times more inorganic arsenic than other foods and chronic exposure can cause a range of health problems including developmental problems, heart disease, diabetes and nervous system damage. As babies are rapidly growing they are at a sensitive stage of development and are known to be more susceptible to the damaging effects of arsenic, which can inhibit their development and cause long-term health problems. Babies and young children under the age of five also eat around three times more food on a body weight basis than adults, which means that, relatively, they have three times greater exposures to inorganic arsenic from the same food item.

The research findings, published in the PLOS ONE journal today, compared the level of arsenic in urine samples among infants who were breast-fed or formula-fed before and after weaning. A higher concentration of arsenic was found in formula-fed infants, particularly among those who were fed non-dairy formulas which includes rice-fortified formulas favoured for infants with dietary requirements such as wheat or dairy intolerance. The weaning process further increased infants' exposure to arsenic, with babies five times more exposed to arsenic after the weaning process, highlighting the clear link between rice-based baby products and exposure to arsenic.

In this new study, researchers at Queen's also compared baby food products containing rice before and after the law was passed and discovered that higher levels of arsenic were in fact found in the products since the new regulations were implemented. Nearly 75 per cent of the rice-based products specifically marketed for infants and young children contained more than the standard level of arsenic stipulated by the EU law.[Original study.]

A 2016 study done in New Hampshire also showed that babies eating rice cereals and other rice-based snacks had higher amounts of arsenic in their urine compared to infants who did not eat rice foods. From JAMA Pediatrics: Association of Rice and Rice-Product Consumption With Arsenic Exposure Early in Life

Published on Leave a comment on We All Have Biofilms In Our Sinuses

Once again a study looked at biofilms in sinuses - but this time in the sinuses of healthy people and not those with sinusitis. Various different species of bacteria and small size "microcolonies" or biofilms were found in the healthy maxillary sinuses of all 30 people - so yes, it appears that the presence of biofilms in the sinuses is normal in healthy people. And yes, the presence of bacteria (even some low levels of species which are typically associated with sinusitis) are normally found in the sinuses of healthy people.  (Earlier research also found this last finding.)

The researchers state that it is normal for people to have "small size bacterial microcolonies" (of different kinds of bacteria) in the sinuses. The researchers theorized that the biofilms are probably "in equilibrium" under the influence of  "inhibiting defensive factors of the body", but they can become a source of infection if there are favorable conditions (such as illness). In other words, the researchers said that these biofilms are more like "bacteria films" in that they contain bacteria, but they live in small colonies that don't cause an inflammatory response with sinusitis symptoms.

One negative of this study was that advanced genetic sequencing was not done on the samples. Instead all samples taken from the people were cultured, which we now know misses a lot of bacterial and other microbial species (fungi, viruses). They looked at the microcolonies (biofilms) with scanning microscopes. Thus, while they found an assortment of bacteria on the sinuses of each person - they only found a total of 41 bacterial species among 30 persons. This is in contrast to studies using modern genetic sequencing that found hundreds of microbial species in healthy sinus microbiomes (microbial communities).

The other issue is that it is not clear to me if there were biofilms or  microcolonies that contained "beneficial" species in any of the samples. Other research suggests that biofilms of beneficial bacteria are also found in humans, and that this is one way beneficial bacteria that normally can't survive with exposure to oxygen can survive oxygen (the slime coating on the colony protects the bacteria within).

Other studies also stress that in healthy people there is "homeostasis" or "equilibrium" among all the microbes living in the sinuses, - a microbial community (which includes biofilms), and which helps maintain sinus health. See post with discussion of Mackenzie et al 2017 study: "A stable network of microbial interactions, established through processes such as niche competition, nutrient cycling, immune evasion, and biofilm formation help maintain homeostasis during health." But, as has been usual in recent sinus research, the current study also stated that much is unknown, that there are theories which are not yet proven one way or another, and more research needs to be done. Of course.... Excerpts from Morawska-Kochman et al research article in PLoS ONE:

The presence of bacterial microcolonies on the maxillary sinus ciliary epithelium in healthy young individuals

The aim of this cross-sectional in vitro study was to evaluate the mucosal surfaces of healthy maxillary sinuses, explore different forms of bacterial microorganism colonies present on the mucous membrane, and determine a mucosal surface area they occupy. Samples of the maxillary sinus mucosa were collected from 30 healthy patients (M = 11; F = 19). The material was obtained during the Le Fort I osteotomy performed during corrective jaw surgery. The morphological and morphometric analysis of sinus mucosa and bacterial film that was grown on it was performed using scanning electron microscopy (SEM) as well as imaging software.

Scanning electron microscopy analysis showed the presence of different bacterium and bacteria-like structures in all the analyzed samples. In most cases, the bacterial film was mostly composed of diplococci-like and streptococci-like structures on the mucosa of the paranasal sinus. In any case, the mucous layer did not cover the whole lining of the evaluated sample. Each colony consists of more than 20 single bacterial cells, which has grown in aggregates.

Under the conditions of normal homeostasis of the body, the maxillary sinuses present diverse bacterial colonization. The bacteria are dispersed or concentrated in single microcolonies of the biofilm on the border of the mucous covering the ciliary epithelium. There is no uniform layer of the biofilm covering the mucosa of the maxillary sinuses. Because the biofilm is detected on healthy individuals sinus mucosa, the clinical question if it may become pathogenic is unclear and require an explanation.

It should also be noted that pathogenic organisms, such as Pseudomonas aeruginosa, Haemophilus influenzae, Streptococcus pneumoniae, or Staphylococcus aureus can be found in patients without active symptoms of the disease. Usually, colonization is defined as the presence of bacteria on the mucous membrane, and the lack of the inflammatory response distinguishes it from an infection.

However, the bacteria film in contrast to typical biofilm might be defined by the presence of bacteria, that growth in colonies without inducing the inflammatory response. Thus, the aim of the study was to evaluate the mucosal surfaces of the healthy maxillary sinuses (without any history of recent acute sinus inflammations or chronic inflammation in the past), to identify different forms of bacterial microorganisms which could, under certain conditions, become opportunistic or pathogenic and determine a mucosal surface of the area they occupy.

Scanning electron microscope investigations revealed the presence of bacterial film on the surface of maxillary sinus mucosa in 30 patients. Moreover, microbiological examinations of specimens taken from study participants revealed the presence of various types of aerobic and anaerobic bacteria in 28 cases (93.34%) out of 30 studied samples. All samples had mixed flora. In total, 41 different microorganisms were isolated. The most frequently found microorganism was Streptococcus spp. in over 90% of all samples, while Propionibacterium acnes were present in 29,2% of samples, and Staphylococcus spp. was present in 17% of the samples.

Scanning electron microscopy analysis showed that the mucous layer has a thickness of 200 nm (± 40), which is covered up to 5% of the surface of each sample. The analysis showed the presence of bacteria-like microcolony structures in all analyzed samples.....Each colony consisted of more than 20 single bacterial cells, that had grown in aggregates. These clearly indicate the existence of a bacterial-like microcolony on maxillary sinus mucosa.

Bacterial microcolonies on the maxillary sinus ciliary epithelium in healthy young individuals. Credit: Morawska-Kochman et al.

Published on Leave a comment on The Importance of Questioning Medical Science

Image result for stethoscope Dr. John Mandrola (physician and medical writer) has once again written thought provoking posts about medicine and the need for people to question tests, procedures, screening, and to look at the harms and benefits. Because YES - all of the above have harms and benefits, even something as "minor" as taking an antibiotic for a week or two (for example, effects on the gut microbes).

Excerpts from his April 20 post at drjohnm.org: Trust and Medical Science

I first addressed the lack of skepticism among my colleagues. I argue that doctors have become a rapturous audience for medical news. We too easily accept flawed evidence. Our embrace of a flawed dissolving coronary stent and a left atrial appendage closure device serve as good examples of misplaced optimism.

In the second section of the essay, I explore the problem with overselling science. Here’s an except: Science does not do itself. Humans—bent on having a successful academic career—do science. This means positive results can become the goal rather than the pursuit of scientific truth.

I spent three paragraphs on evangelism over screening healthy people. It crushes the public trust to say “screening saves lives” when the evidence doesn’t support the claim. This is not a typo. I cite numerous studies that show common screening tests, mammography, PSA tests, colonoscopy, when put to the test of a randomized controlled trial, do not lower overall death rates.

The obfuscation comes when screening advocates tout lower disease-specific death rates. Viz, mammography may (slightly) lower the chance of dying from breast cancer but it has no significant effect on all-cause death. Through a colleague [Dr. B. Mazer] on Twitter, I found a wonderful quote on the folly of trying to reduce your risk of dying from one sort of disease. “If you are a patient contemplating some screening test, and the result of that test or treatment is no measurable reduction in the rate of death at some clinically relevant later point in time, then why have the test or treatment—unless the patient, for some reason, has a desire to die from condition A instead of condition B.”

And excerpts from his commentary on this topic at Medscape: Want More Trust in Medical Science? Embrace Uncertainty and Cut the Hype

I see a lot of overconfidence in medical science. At the bedside, clinicians—myself included—underestimate harms and overestimate benefits of medical intervention. These inaccuracies have many causes. One is a lack of skepticism. It was 10 years into practice before I learned that most of a study's bias comes in its planning, in the questions it asks.

Rarely do I hear a practicing colleague or speaker at a medical meeting cite Dr John Ioannidis's famous 2005 paper "Why most published research findings are false." Ioannidis, a Stanford epidemiologist, argues that small sample sizes, tiny treatment effects, "flexible" study designs (which can transform "negative" into "positive" results), prestudy biases, and conflicts of interest are the root causes of false research findings. Research findings, he argues, may simply be an accurate measure of the prevailing bias.....Richard Horton, the editor of the Lancet, agrees with Ioannidis. In 2015, he wrote that "much of the scientific literature, perhaps half, may simply be untrue." One of the (many) reasons for this crisis, Horton adds, is that "in their quest for telling a compelling story, scientists too often sculpt data to fit their preferred theory of the world." 

Another group of academics that threaten the public trust are screening evangelists. Screening is precarious because it puts doctors close to breaking the golden rule—first, do no harm. Doing things to people-without-complaints and promoting the slogan "screening saves lives" should require clearing the highest bar of evidence. The truth, though, is that the evidence does not support such zealous advocacy.

A systematic review of meta-analyses and randomized clinical trials that studied screening of asymptomatic adults for 19 diseases (39 tests, including mammography) found reductions in disease-specific mortality were uncommon and reductions in all-cause mortality were very rare or nonexistent. Prasad and colleagues explain how screening advocates conflate disease-specific death rates with overall mortality. "Using disease-specific mortality as a proxy for overall mortality," they wrote in the BMJ, "deprives people of information about their chief concern: reducing the risk of dying."

Another good Dr. John Mandrola post: Four Crucial Questions To Ask Your Doctor

Published on Leave a comment on Should We Be Worried That Humans Are Losing Many Species of Gut Microbes?

An article was just published in a research journal to discuss the fact that humans - in part due to lifestyles which include less dietary fiber (due to eating fewer varieties and amounts of plants) and due to medical practices (such as frequent use of antibiotics) has resulted in gut "bacterial extinctions". In other words, humans (especially those living an urban industrialized Western lifestyle) have fewer gut bacterial species than those living a more traditional lifestyle, and this loss of bacterial species is linked to various diseases. Humans can increase the number of certain bacterial species, but the loss of some bacterial species is forever. 

The researchers discuss that humans have the "lowest level of gut bacterial diversity"  of any hominid and primate. They stated that the shrinking of the variety of microbial species in the human gut (the gut microbiome) began early in human evolution (as humans started eating more meat), but that it has accelerated dramatically within industrialized societies. And that evidence is accumulating that this gut bacterial "depauperation" - the loss of a variety of bacterial species - may predispose humans to a range of diseases.  Some of it is due to evolution (as humans ate more meat), and some to lifestyle changes. A term is used throughout this paper: depauperate - which means lacking in numbers or variety of species in the gut microbiome (the microbial community or ecosystem).

Other research has also shown that eating a highly processed Western diet results in gut microbial changes that are linked to various diseases (here, here, here) - that is, the microbes being fed are those associated with diseases. Also, certain diets encourage certain microbial species to flourish (here, here).  Bottom line: studies find health benefits from higher levels of dietary fiber - from fruits, vegetables, seeds, nuts, whole grains, and legumes (beans). From Current Opinion In Microbiology:

The shrinking human gut microbiome

Highlights: Humans harbor the lowest levels of gut bacterial diversity of any hominid. Humans in industrialized nations harbor fewer gut bacterial taxa than any primate. Medical practices and lack of dietary fiber may drive gut bacterial extinctions. Depauperate microbiotas may predispose entire human populations to certain diseases.

Mammals harbor complex assemblages of gut bacteria that are deeply integrated with their hosts’ digestive, immune, and neuroendocrine systems. Recent work has revealed that there has been a substantial loss of gut bacterial diversity from humans since the divergence of humans and chimpanzees. This bacterial depauperation began in humanity’s ancient evolutionary past and has accelerated in recent years with the advent of modern lifestyles. Today, humans living in industrialized societies harbor the lowest levels of gut bacterial diversity of any primate for which metagenomic data are available, a condition that may increase risk of infections, autoimmune disorders, and metabolic syndrome. Some missing gut bacteria may remain within under-sampled human populations, whereas others may be globally extinct and unrecoverable.

A typical human harbors on the order of 1013 bacterial cells in the large intestine. This gut microbiota, which can contain over a thousand species, is deeply integrated with virtually every tissue and organ system in the body. Gut bacteria process difficult to digest components of the diet, promote angiogenesis in the intestine, train the immune system, regulate metabolism, and even influence moods and behaviors.

In contrast to hunter–gatherer to agricultural transitions, adoptions of industrial and post-industrial lifestyles have led to massive reductions in bacterial richness within human gut microbiotas. Individuals living in urban centers in the United States harbor fewer gut bacterial species on average than do individuals living more traditional lifestyles in Malawi , Venezuela, Peru, and Papua New Guinea.....Industrialized and traditional lifestyles differ in many respects, confounding the identification of the specific practices that have led to decreases in gut bacterial diversity within industrialized societies. One potential cause is the rise of food processing and the corresponding reductions in the intake of dietary fiber in favor of simple sugars. Recently, studies in model systems have indicated that long-term reductions in dietary fiber can lead to the extirpation of gut bacterial taxa from host lineages. 

Other potential causes of reduced gut bacterial diversity within industrialized human populations include certain modern medical practices. For example, longitudinal studies in humans have shown that levels of gut bacterial diversity decrease drastically after antibiotic use. Although bacterial richness may recover after treatment is completed, the timeline and extent of the restoration is highly subject-dependent. The consequences of antibiotic use on gut bacterial diversity may be most severe when treatment is administered during the early years of life, before the adult microbiota has fully formed .

Published on Leave a comment on Walking Increases Blood Flow To the Brain

An interesting study looked at what the act of walking does to our brain, and found that it can modify and increase the amount of blood that’s sent to the brain (which is viewed as beneficial for brain function). The study, performed by researchers at New Mexico Highlands University in the United States, found that the foot’s impact on the ground while walking sends pressure waves through the arteries, which can increase the blood supply to the brain. This is referred to as cerebral blood flow or CBF.

These results may help explain other studies that find those that walk frequently (about 6 to 9 miles per week) have "less cognitive impairment" or cognitive decline, fewer memory problems, and greater brain volume with aging.  Another good reason to get out and walk - good for the heart, the body, and the brain. From Science Daily:

How walking benefits the brain

You probably know that walking does your body good, but it's not just your heart and muscles that benefit. Researchers at New Mexico Highlands University (NMHU) found that the foot's impact during walking sends pressure waves through the arteries that significantly modify and can increase the supply of blood to the brain. The research will be presented today at the APS annual meeting at Experimental Biology 2017 in Chicago.

Until recently, the blood supply to the brain (cerebral blood flow or CBF) was thought to be involuntarily regulated by the body and relatively unaffected by changes in the blood pressure caused by exercise or exertion. The NMHU research team and others previously found that the foot's impact during running (4-5 G-forces) caused significant impact-related retrograde (backward-flowing) waves through the arteries that sync with the heart rate and stride rate to dynamically regulate blood circulation to the brain.

In the current study, the research team used non-invasive ultrasound to measure internal carotid artery blood velocity waves and arterial diameters to calculate hemispheric CBF to both sides of the brain of 12 healthy young adults during standing upright rest and steady walking (1 meter/second). The researchers found that though there is lighter foot impact associated with walking compared with running, walking still produces larger pressure waves in the body that significantly increase blood flow to the brain. While the effects of walking on CBF were less dramatic than those caused by running, they were greater than the effects seen during cycling, which involves no foot impact at all.