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Author: Sima

Published on Leave a comment on There Are Thousands of Human Gut Bacteria Strains

We have trillions of bacterial cells from thousands of different strains of bacteria living in our gut! Researchers at MIT (Massachusetts Institute of Technology) collected stool samples from 90 people living in the Boston area (some for as long as 2 years), did modern genetic sequencing, and in this way isolated nearly 8000 strains of bacteria.  These bacterial strains were from the six major phyla of bacteria (e.g. Bacteroidetes and Firmicutes) that dominate the human gastrointestinal tract. Just remember that the human gut also has fungi, archaea, and viruses living there. Yes, it is crowded in the gut!

The researchers took repeated stool samples from about a dozen of the volunteers and so were able to study bacterial changes within individuals over time. They are making all the data about the gut bacterial strains available to other researchers, with the hope that this will help scientists develop new treatments for a variety of diseases. This data set is called the Broad Institute-OpenBiome Microbiome Library (BIO-ML). This is important information to have because study after study is finding that there are gut microbial differences in people with a number of diseases as compared to healthy individuals.

BOTTOM LINE: The goal should be to feed and nurture beneficial gut microbes, ones that are associated with health. The best way to feed your beneficial gut microbes is to have a diet with lots of whole, real foods and fiber - which means a diet rich in fruits, vegetables, whole grains, nuts, legumes (beans), and seeds. (Think Mediterranean style dietary pattern.) And to eat less (a lot less) highly processed, low fiber, refined grains, and sugary foods. In other words, you don't want to feed microbes linked to chronic inflammation and diseases, but instead want to feed beneficial microbes linked to health (and not chronic inflammation). For example, choose the apple and not the candy bar. Your gut microbes will thank you.

From MIT News Office: A comprehensive catalogue of human digestive tract bacteria   ...continue reading "There Are Thousands of Human Gut Bacteria Strains"

Published on Leave a comment on Microplastics Are Found In Human Stool

There have been a number of studies finding microplastics (tiny bits of plastic smaller than 5mm) in seafood, drinking water, many foods, as well as in the air we breathe (e.g. from the breakdown of vehicle tires and brakes during normal use). There has been some concern over what the microplastics are doing to us because so little research has been done. But there is worry that the smallest sized microplastics are entering our bodies, traveling to different organs, and causing damage. But at least some of the microplastics we ingest are traveling through the gastrointestinal system  and then excreted in our stool, according to a recent study.

The study had 8 healthy volunteers from Europe and Asia (United Kingdom, Italy, Japan, Poland, Russia, Netherlands, Finland, and Austria). keep a food dairy for a week, and then "donate" a stool sample which was analyzed. None of the volunteers were vegetarians, and 6 had consumed fish from oceans in that week. [Note: Studies find that seafood contains microplastics.]

The  stool samples were analyzed for 10 types of plastic. All the stool samples contained microplastics, with polypropylene and polyethylene terephthalate being the most abundant. The samples contained an average of 20 microplastic particles per 10 g of stool. Since 9 types of plastic was detected in the stool, the researchers say that means they come from multiple sources.

Recently Canadian researchers estimated that annual consumption of microplastics ranges from 39,000 to 52,000 particles (depending on age and sex). When they added in inhalation of microplastic particles, the numbers increased to 74,000 to 121,000. And those who only drink bottled water may be getting an additional 90,000 microplastics (versus about 4000 microplastics from tap water). Yikes!

What to do if this concerns you? Since plastic wrappers, containers, and bottles (including water bottles) shed microplastics, then one can try to purchase and store foods in plain cardboard or glass containers. Stainless steel containers are also OK (NOTE: aluminum cans are usually coated with suspect chemicals). Definitely drink more tap water, and less bottled water.

From Medical Xpress: Microplastics detected in human stool   ...continue reading "Microplastics Are Found In Human Stool"

Published on Leave a comment on Antibiotics, Flu Vaccines, and Gut Bacteria

A really interesting study found that in humans, taking antibiotics (which reduces the gut bacteria) may result in the flu vaccine not being as effective as in people who did not take antibiotics. An earlier similar study had found that this was true for mice, which is why the researchers did the study on humans.

The Stanford University and Emory University researchers studied healthy people who had recent (in last few years) flu vaccinations and those who hadn't had a flu vaccine for several years prior to the study. Some individuals took 5 days of broad spectrum antibiotics, and on day 4 received a flu vaccine, while others did not take antibiotics, but did receive the flu vaccine on day 4.

Not surprisingly: The antibiotics lowered the gut-bacterial population by 10,000-fold. While month by month there was increasing recovery, the resulting loss of overall diversity was detectable for up to one year after the antibiotics were taken. Keep in mind that they found that: "Notably, species richness and biodiversity were not fully recovered at 6 months, indicating long-lasting loss of unique bacterial species, consistent with previous studies." [BOTTOM LINE: Only take antibiotics when necessary.]

Interestingly, after antibiotic use, the researchers found other changes besides an alteration in gut bacteria populations. They also found changes within the immune system which resulted in an inflammatory state, which was due to "impairments in bile acid metabolism by the gut flora". In other words, taking antibiotics has a number of effects beyond treating an infection (the reason they were taken).

By the way, those who had taken flu vaccines in prior years had much better responses to the vaccines - they only had a minimal impact on vaccine response, even though they took antibiotics, than those who had not. Those who had not received flu vaccines or the flu in recent years had "low preexisting immunity", and taking the antibiotics (which resulted in loss of gut bacterial species) impaired their antibody response to the flu  vaccine. The researchers said: "The results of this study are consistent with the concept of immune responses in adults being largely determined by immune history and resilient to transient changes in the microbiome."

From Medical Xpress: Individual response to flu vaccine influenced by gut microbes   ...continue reading "Antibiotics, Flu Vaccines, and Gut Bacteria"

Published on Leave a comment on Pets Can Help With Loneliness and Depression Following Loss of a Spouse

This actually may seem obvious to many: that older people cope better in terms of loneliness and depression after a spouse's death or divorce if they have at least 1 pet cat or dog (versus no pets), but it's good to read that an actual study supported this. Other studies support that in general, a companion animal is beneficial for psychological health

The researchers called the pet a "companion animal" and wrote: "In later life, companion animal ownership may buffer against the detrimental consequences of major social losses on psychological health." In the study, depression is measured by  the "depressive symptoms" a person has.

From Medical Xpress: The pet effect: Researchers find furry friends ease depression, loneliness after spousal loss  ...continue reading "Pets Can Help With Loneliness and Depression Following Loss of a Spouse"

Published on Leave a comment on Climate Change and the Future Of Our Earth

Today's post is in response to people asking me about climate change and what it means for the earth. A great book on this topic that was published this year and has received excellent reviews by the NY Times, scientists, and others  is The Uninhabitable Earth: Life After Warming. Written by David Wallace-Wells and published by Tim Duggan Books in 2019. David Wallace-Wells is a columnist and deputy editor of New York magazine, and a national fellow at the New America foundation.

This book is a wake-up call about the dangers of not responding (or not responding enough) to the climate change crisis and what will happen if we don't treat it as an emergency, which it is. The book's first sentence is: "It is worse, much worse, than you think." And then he lays it out for us in detail - the horrors that will happen if we do nothing, or not enough. Descriptions of what we can realistically expect within a few years or decades from climate change and global warming. And yes, there are many scientific references listed - over 200.

Two years ago David Wallace-Wells published an article in New York magazine abut this same topic titled: The Uninhabitable Earth Famine, economic collapse, a sun that cooks us: What climate change could wreak — sooner than you think. The article went viral, was discussed extensively, and got many people talking about climate change as a "climate emergency" or a "climate change crisis".

"Indeed, absent a significant adjustment to how billions of humans conduct their lives, parts of the Earth will likely become close to uninhabitable, and other parts horrifically inhospitable, as soon as the end of this century."

At the beginning of the article is a link to an annotated version of the article, with a full discussion of references and scientists adding their comments to the article.

Both the article and book are absolutely, totally worth reading. Just be warned: it will not be easy reading because  the consequences of not doing enough, or of ignoring the problem, are so bad for the world and all of us.

NY Times review about the book: Two New Books Dramatically Capture the Climate Change Crisis

Published on Leave a comment on Certain Pesticides Linked to Altered Brain Activity In Teenagers

Pesticides are harmful to developing brains, especially during pregnancy. A number of studies have already found that higher exposure to organophosphate pesticides during pregnancy is linked to poorer cognitive functioning and behavior problems in children. A recent University of California study actually looked at the brain activity in 95 teenagers while they were doing a number of mental tasks. Using advanced brain imaging, they found altered brain activity in those teens who had the highest organophosphate pesticide exposure prenatally. These teenagers live in Salinas Valley, California - an agricultural area with many farms.

The researchers point out that "Over 800 million pounds of pesticide active ingredients are applied in the United States each year, with organophosphates (OPs) the most commonly applied class of insecticides. Exposure to OP pesticides, which are endocrine-disrupting compounds, is widespread in the US population, including among pregnant women and children." [PLEASE NOTE: Conventional farming uses organophosphates. Organic farming does not allow the use of organophosphates.]

The main way people get exposed to organophosphate pesticides is diet - especially pesticide residues on fruits and vegetables. Also, if people live near farms where such pesticides are used, or live with a person who works on a farm. They bring home the pesticides on their clothes. People also breathe breathe in pesticides when they are applied on nearby farms or properties due to pesticide drift.

Chlorpyrifos is one example of an organophosphate pesticide. It is considered so dangerous to the developing fetus and children (lower IQs, neurological effects, behavioral effects) that the EPA was going to ban it in the United States. However, the Trump administration overruled the ban (chemical/pesticide lobbyists at work!). Since then, several states (NY, Hawaii, California) have enacted legislation to ban all use of chlorpyrifos in those states, but it will take several years for the bans to become fully in effect.

From Science Daily: Prenatal pesticide exposure linked to changes in teen's brain activity   ...continue reading "Certain Pesticides Linked to Altered Brain Activity In Teenagers"

Published on Leave a comment on Don’t Neglect the Nutrient Choline

A few weeks ago I posted research about the nutrient choline and discussed its importance for brain health. Now Dr. Emma Derbyshire in the United Kingdom has written a piece in the current issue of the journal BMJ Nutrition, Prevention & Health about the necessity of choline in the diet and the health dangers of this nutrient being neglected, especially in people following plant based or vegan diets.

Choline is an essential nutrient that cannot be produced by the body in amounts needed for human requirements. Good sources of choline are meat, dairy products, poultry, and eggs, and it appears that eggs (the egg yolks) are especially beneficial.

From Medical Xpress: Suggested move to plant-based diets risks worsening brain health nutrient deficiency

The momentum behind a move to plant-based and vegan diets for the good of the planet is commendable, but risks worsening an already low intake of an essential nutrient involved in brain health, warns a nutritionist in the online journal BMJ Nutrition, Prevention & Health.  ...continue reading "Don’t Neglect the Nutrient Choline"

Published on Leave a comment on Time to Reassess Spraying Antibiotics On Orange Trees

The issue of antibiotic resistance, that is, of antibiotics no longer working for bacterial infections in humans is a huge concern. So why are we squandering the antibiotic oxytetracycline on orange trees sickened with the disease citrus greening when a recent study by University of Florida researchers says it doesn't work?

The US Environmental Protection Agency gave permission for large-scale agricultural use of 2 antibiotics (streptomycin and oxytetracycline) to try to combat the bacterial infection that is destroying vast numbers of orange trees in Florida, Texas, and other states. However, the 2 antibiotics are also used to treat a number of bacterial infections in humans. And the latest development is that a study found that when oxytetracycline was sprayed on citrus trees for 6 months according to manufacturer's directions, it was no more effective than spraying water against the harmful bacteria (Candidatus Liberibacter asiaticus). 

Public health advocates, the FDA (Food and Drug Administration), and the CDC (Centers for Disease Control and Prevention) were all opposed to the EPA's antibiotic approvals for the citrus tree disease. They are very concerned that such large scale use could result in the development of antibiotic resistant bacteria, thus making these antibiotics useless in treating human illnesses. The CDC states that each year in the U.S., at least 2 million people get an antibiotic-resistant infection, and at least 23,000 people die.

Keep in mind that the European Union has banned the agricultural use of both oxytetracycline and streptomycin. Brazil has also banned these 2 antibiotics for agricultural use, and there citrus growers are battling the same citrus greening bacteria in citrus groves.

Steven Roach, a senior analyst for the advocacy group Keep Antibiotics Working has said:  “To allow such a massive increase of these drugs in agriculture is a recipe for disaster. It’s putting the needs of the citrus industry ahead of human health.”

From the NY Times: Spraying Antibiotics to Fight Citrus Scourge Doesn’t Help, Study Finds   ...continue reading "Time to Reassess Spraying Antibiotics On Orange Trees"

Published on Leave a comment on Fluoridated Drinking Water and Pregnancy

For years there has been a debate about whether adding  fluoride to drinking water was a plus (less tooth decay) versus those who felt there were possible health problems from the fluoride.  Now the results of a Canadian study is raising serious concerns. The researchers followed 601 pregnant women from 6 cities in Canada, and found that pregnant women with higher levels of fluoride in their urine tended to have children with lower average IQs (which was measured at 3 or 4 years of age). As in the USA, some communities added fluoride to municipal drinking water, while others didn't.

The problem is that: "Fluoride crosses the placenta, and laboratory studies show that it accumulates in brain regions involved in learning and memory, and alters proteins and neurotransmitters in the central nervous system." Not good. This is why studies are being done.

The researchers concluded the study with these words: "In this prospective birth cohort study from 6 cities in Canada, higher levels of fluoride exposure during pregnancy were associated with lower IQ scores in children measured at age 3 to 4 years. These findings were observed at fluoride levels typically found in white North American women. This indicates the possible need to reduce fluoride intake during pregnancy." [Note: in this study, the effect appeared to be stronger in boys than girls.]

Just note that this was an observational study (found an association, not a definite cause), but other studies also find such an association. (One study conducted in Mexico found that higher prenatal fluoride exposure was linked to lower IQs in 4 to 6 year old children.) Of course more studies are needed.

But in the meantime, one can try to lower fluoride exposure (in water) during pregnancy. One way is to drink less black tea (has high levels of fluoride) and green tea (varying levels of fluoride). Also, if fluoride is added to tap water, to try to drink less of that and perhaps more unfluoridated bottled water that is in glass bottles (because plastic leaches, and has more microplastics in it).

From The Scientist: Fluoride Exposure During Pregnancy Linked to Lower IQ In Sons   ...continue reading "Fluoridated Drinking Water and Pregnancy"

Published on Leave a comment on Eating Foods Rich In Flavonoids Has Health Benefits

A new large study found that eating a flavonoid rich diet is associated with a lower risk of death. Flavonoids are compounds found in abundance in plant derived foods and beverages, such as fruits, vegetables, dark chocolate, tea, legumes, and red wine. The study followed about 56,000 people in Denmark for 23 years and found that eating higher levels of flavonoid rich foods was associated with a lower risk of death from any cause (all-cause mortality), heart disease (cardiovascular disease), and cancer.

The researchers found that there was an inverse relationship (the more one eats, the lower the risk of death), and that this relationship was strongest among cigarette smokers and people who consume high amounts of alcohol (more than 20 grams per day). Bottom line: Make sure your diet includes lots of fruits, vegetables, legumes, and dark chocolate (yes!).

By the way, while other studies do find a lower incidence of heart disease and cancer in people eating a diet rich in flavonoids, in this study they were not looking at who got the diseases, but looked at deaths. Therefore the following title is misleading. It should instead say "... protects against cancer and heart disease deaths..." From Science Daily: Flavonoid-rich diet protects against cancer and heart disease, study finds  ...continue reading "Eating Foods Rich In Flavonoids Has Health Benefits"