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Author: Sima

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Lately some articles have been mentioning the amazing possibility of new treatments for psychiatric disorders using bacteria as psychobiotics. Think of probiotics (microorganisms that have beneficial effects when consumed) that affect the brain. Researchers promoting the use of this term define a psychobiotic as "a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness". This new emerging field is just in its infancy. Lots of speculation and anecdotal evidence, and a few tantalizing studies.

I think the following article is a good introduction to this research area of the gut and mind/brain interaction, even though it was published in late 2013. Or you could order the newly published scholarly book "Microbial Endocrinology: The Microbiota-Gut-Brain Axis in Health and Disease" (Editors M.Lyte and J.F.Cryan) with a $189. purchase price (!).  From November 2103 NPR:

Gut Bacteria Might Guide The Workings Of Our Minds

Could the microbes that inhabit our guts help explain that old idea of "gut feelings?" There's growing evidence that gut bacteria really might influence our minds. 

"I'm always by profession a skeptic," says Dr. Emeran Mayer, a professor of medicine and psychiatry at the University of California, Los Angeles. "But I do believe that our gut microbes affect what goes on in our brains." Mayer thinks the bacteria in our digestive systems may help mold brain structure as we're growing up, and possibly influence our moods, behavior and feelings when we're adults. "It opens up a completely new way of looking at brain function and health and disease," he says.

So Mayer is working on just that, doing MRI scans to look at the brains of thousands of volunteers and then comparing brain structure to the types of bacteria in their guts. He thinks he already has the first clues of a connection, from an analysis of about 60 volunteers. Mayer found that the connections between brain regions differed depending on which species of bacteria dominated a person's gut. 

But other researchers have been trying to figure out a possible connection by looking at gut microbes in mice. There they've found changes in both brain chemistry and behavior. One experiment involved replacing the gut bacteria of anxious mice with bacteria from fearless mice. "The mice became less anxious, more gregarious," says Stephen Collins of McMaster University in Hamilton, Ontario, who led a team that conducted the research. It worked the other way around, too — bold mice became timid when they got the microbes of anxious ones. And aggressive mice calmed down when the scientists altered their microbes by changing their diet, feeding them probiotics or dosing them with antibiotics. 

Scientists also have been working on a really obvious question — how the gut microbes could talk to the brain. A big nerve known as the vagus nerve, which runs all the way from the brain to the abdomen, was a prime suspect. And when researchers in Ireland cut the vagus nerve in mice, they no longer saw the brain respond to changes in the gut. "The vagus nerve is the highway of communication between what's going on in the gut and what's going on in the brain," says John Cryan of the University College Cork in Ireland, who has collaborated with Collins.

Gut microbes may also communicate with the brain in other ways, scientists say, by modulating the immune system or by producing their own versions of neurotransmitters. "I'm actually seeing new neurochemicals that have not been described before being produced by certain bacteria," says Mark Lyte of the Texas Tech University Health Sciences Center in Abilene, who studies how microbes affect the endocrine system. "These bacteria are, in effect, mind-altering microorganisms."

This research raises the possibility that scientists could someday create drugs that mimic the signals being sent from the gut to the brain, or just give people the good bacteria — probiotics — to prevent or treat problems involving the brain. Experiments to test whether changing gut microbes in humans could affect the brain are only just beginning. 

One team of researchers in Baltimore is testing a probiotic to see if it can help prevent relapses of mania among patients suffering from bipolar disorder."The idea is that these probiotic treatments may alter what we call the microbiome and then may contribute to an improvement of psychiatric symptoms," says Faith Dickerson, director of psychology at the Sheppard Pratt Health System.

Mayer also has been studying the effects of probiotics on the brain in humans. Along with his colleague Kirsten Tillisch, Mayer gave healthy women yogurt containing a probiotic and then scanned their brains. He found subtle signs that the brain circuits involved in anxiety were less reactive, according to a paper published in the journal Gastroenterology.

But Mayer and others stress that a lot more work will be needed to know whether that probiotic — or any others — really could help people feel less anxious or help solve other problems involving the brain. He says, "We're really in the early stages."

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Overall, this is further evidence that eating natural, real foods  (in moderation) and avoiding supplements is best for health. Don't want to feed any cancers. From Science Daily:

How antioxidants can accelerate cancers, and why they don't protect against them

For decades, health-conscious people around the globe have taken antioxidant supplements and eaten foods rich in antioxidants, figuring this was one of the paths to good health and a long life.Yet clinical trials of antioxidant supplements have repeatedly dashed the hopes of consumers who take them hoping to reduce their cancer risk. Virtually all such trials have failed to show any protective effect against cancer. In fact, in several trials antioxidant supplementation has been linked with increased rates of certain cancers. In one trial, smokers taking extra beta carotene had higher, not lower, rates of lung cancer.

Two cancer researchers have proposed why antioxidant supplements might not be working to reduce cancer development, and why they may actually do more harm than good. Their insights are based on recent advances in the understanding of the system in our cells that establishes a natural balance between oxidizing and anti-oxidizing compounds. These compounds are involved in so-called redox (reduction and oxidation) reactions essential to cellular chemistry.

Drs. Tuveson and Chandel propose that taking antioxidant pills or eating vast quantities of foods rich in antioxidants may be failing to show a beneficial effect against cancer because they do not act at the critical site in cells where tumor-promoting ROS (reactive oxygen species) are produced -- at cellular energy factories called mitochondria. Rather, supplements and dietary antioxidants tend to accumulate at scattered distant sites in the cell, "leaving tumor-promoting ROS relatively unperturbed," the researchers say.

Quantities of both ROS and natural antioxidants are higher in cancer cells -- the paradoxically higher levels of antioxidants being a natural defense by cancer cells to keep their higher levels of oxidants in check, so growth can continue. In fact, say Tuveson and Chandel, therapies that raise the levels of oxidants in cells may be beneficial, whereas those that act as antioxidants may further stimulate the cancer cells. Interestingly, radiation therapy kills cancer cells by dramatically raising levels of oxidants. The same is true of chemotherapeutic drugs -- they kill tumor cells via oxidation.

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Obviously children on farms are exposed to a lot of dirt and animals, both teaming with microorganisms. But I wonder, and it's not discussed, is whether people living on dairy farms are drinking raw milk, which contains lots of microorganisms. After all, the point of milk pasteurization is to kill off bacteria. Will we go back to drinking raw milk to try to prevent allergies? From Science Daily:

Children on dairy farms run one-tenth the risk of developing allergies; Dairy farm exposure also beneficial during pregnancy

Children who live on farms that produce milk run one-tenth the risk of developing allergies as other rural children. According to researchers at The University of Gothenburg in Sweden, pregnant women may benefit from spending time on dairy farms to promote maturation of the fetal and neonatal immune system.

The occurrence of allergic diseases has risen dramatically in Western societies. One frequently cited reason is that children are less exposed to microorganisms and have fewer infections than previous generations, thereby delaying maturation of the immune system.

A study by researchers at Sahlgrenska Academy, University of Gothenburg, monitored children until the age of three to examine maturation of the immune system in relation to allergic disease. All of the children lived in rural areas of the Västra Götaland Region, half of them on farms that produced milk. The study found that children on dairy farms ran a much lower risk of developing allergies than the other children.

"Our study also demonstrated for the first time that delayed maturation of the immune system, specifically B-cells, is a risk factor for development of allergies," says Anna-Carin Lundell, one of the researchers. Children with an allergic disease at the age of 18 and 36 months had a higher percentage of immature B-cells in their blood circulation at birth and during the first month of life. 

"We need to identify the specific factors on dairy farms that strengthen protection against allergies and appear to promote maturation of the immune system as early as the fetal stage," Ms. Lundell says.

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Research reports and articles on the benefits of exercise have been piling up. Here are some worth looking at. From Science Daily:

Sitting too much, not just lack of exercise, is detrimental to cardiovascular health

Cardiologists have found that sedentary behaviors may lower cardiorespiratory fitness levels. New evidence suggests that two hours of sedentary behavior can be just as harmful as 20 minutes of exercise is beneficial.

From Science Daily:

Out of shape? Your memory may suffer

Here's another reason to drop that doughnut and hit the treadmill: A new study suggests aerobic fitness affects long-term memory. "The findings show that lower-fit individuals lose more memory across time," said a co-author. The study is one of the first to investigate young, supposedly healthy adults. 

From Science Daily:

Less exercise, not more calories, responsible for expanding waistlines

Sedentary lifestyle and not caloric intake may be to blame for increased obesity in the US, according to a new analysis. A study reveals that in the past 20 years there has been a sharp decrease in physical exercise and an increase in average body mass index (BMI), while caloric intake has remained steady. 

From Science Daily:

Older adults: Build muscle and you'll live longer

The more muscle mass older Americans have, the less likely they are to die prematurely, new research shows. The findings add to the growing evidence that overall body composition -- and not the widely used body mass index, or BMI -- is a better predictor of all-cause mortality. "In other words, the greater your muscle mass, the lower your risk of death," said the study's co-author. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass."

From Medical Xpress:

Keeping active pays off in your 70s and 80s

Older people who undertake at least 25 minutes of moderate or vigorous exercise everyday need fewer prescriptions and are less likely to be admitted to hospital in an emergency, new research has revealed.

Researchers from the Universities of Bath, Bristol and UWE-Bristol looked at data from 213 people whose average age was 78. Of people studied, those who carried out more than 25 minutes of moderate to vigorous physical activity per day – such as walking quickly, cycling or swimming - received 50 per cent fewer prescriptions than those who were more active over a four to five year period.

Such physical activity leads to a higher metabolism and better circulation, reducing the risk of conditions and diseases common in older age such as high blood presure, type 2 diabetes, coronary heart disease, and strokes.

From Everyday Health:

The Best Anti-Aging Medicine? Exercise

Everyone knows that exercise is good for you — it helps manage weight, improves muscle and bone strength, and even lifts your spirits. It can also add years to your life.“People have been looking for the secret to a long and healthy life for millennia,” said Neil Resnick, MD, chief of the division of geriatrics and director of the University of Pittsburgh Institute on Aging. “It turns out the most powerful intervention is exercise.”

A recent study conducted at Harvard found that exercise can be at least as effective as prescription drugs when it comes to preventing common conditions such as heart disease, stroke, and diabetes.

Exercise at any age is beneficial. From Science Daily:

Seniors who exercise regularly experience less physical decline as they age

Older adults in retirement communities who reported more exercise experienced less physical decline than their peers who reported less exercise, although many adults -- even those who exercised -- did not complete muscle-strengthening exercises, which are another defense against physical decline.

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New discoveries of what is going on in our intestines, plus a new vocabulary to understand it all. Yes, it all is amazingly complex. Bottom line: we have complex communities (bacteria, bacterial viruses or bacteriophages, etc.) living and interacting in our intestines. And only with state-of-the-art genetic analysis (DNA sequencing) can we even "see" what is going on. I highlighted really important items in bold type. From Medical Xpress:

Researchers uncover new knowledge about our intestines

Researchers from Technical University of Denmark Systems Biology have mapped 500 previously unknown microorganisms in human intestinal flora as well as 800 also unknown bacterial viruses (also called bacteriophages) which attack intestinal bacteria.

"Using our method, researchers are now able to identify and collect genomes from previously unknown microorganisms in even highly complex microbial societies. This provides us with an overview we have not enjoyed previously," says Professor Søren Brunak who has co-headed the study together with Associate Professor Henrik Bjørn Nielsen.

So far, 200-300 intestinal bacterial species have been mapped. Now, the number will be more than doubled, which could significantly improve our understanding and treatment of a large number of diseases such as type 2 diabetes, asthma and obesity.

The two researchers have also studied the mutual relations between bacteria and viruses. Previously, bacteria were studied individually in the laboratory, but researchers are becoming increasingly aware that in order to understand the intestinal flora, you need to look at the interaction between the many different bacteria found.

And when we know the intestinal bacteria interactions, we can potentially develop a more selective way to treat a number of diseases. "Ideally we will be able to add or remove specific bacteria in the intestinal system and in this way induce a healthier intestinal flora," says Søren Brunak.

From Science Daily:

Revolutionary approach to studying intestinal microbiota

Analyzing the global genome, or the metagenome of the intestinal microbiota, has taken a turn, thanks to a new approach to study developed by an international research team. This method markedly simplifies microbiome analysis and renders it more powerful. The scientists have thus been able to sequence and assemble the complete genome of 238 intestinal bacteria, 75% of which were previously unknown. 

Research carried out in recent years on the intestinal microbiota has completely overturned our vision of the human gut ecosystem. Indeed, from "simple digesters" of food, these bacteria have become major factors in understanding certain diseases such as obesity, type 2 diabetes, or Crohn's disease. Important and direct links have also been demonstrated between these bacteria and the immune system, as well as with the brain. It is estimated that 100,000 billion bacteria populate the gut of each individual (or 10 to 100 times more than the number of cells in the human body), and their diversity is considerable, estimated to around a thousand different bacterial species in the intestinal human metagenome. However, because only 15% of these bacteria were previously isolated and characterized by genome sequencing, an immense number of the microbial genes previously identified still need to be assigned to a given species.

An analysis of 396 stool samples from Danish and Spanish individuals allowed the researchers to cluster these millions of genes into 7381 co-abundance groups of genes. Approximately 10% of these groups (741) corresponded to bacterial species referred to as metagenomic species (MGS); the others corresponded to bacterial viruses (848 bacteriophages were discovered), plasmids (circular, bacterial DNA fragments) or genes which protected bacteria from viral attack (known as CRISPR sequences). 85% of these MGS constituted unknown bacteria species (or ~630 species).

Using this new approach, the researchers succeeded in reconstituting the complete genome of 238 of these unknown species, without prior culture of these bacteria. Living without oxygen, in an environment that is difficult to characterise and reproduce, most of these gut bacteria cannot be cultured in the laboratory. 

The authors also demonstrated more than 800 dependent relationships within the 7381 gene co-abundance groups; this was the case, for example, of phages which require the presence of a bacterium to survive. These dependent relationships thus enable a clearer understanding of the survival mechanisms of a micro-organism in its ecosystem. 

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Some good foods to eat for their health benefits. The following articles are from Science Daily:

Almonds reduce the risk of heart disease, research shows

Eating almonds can reduce the risk of heart disease by keeping blood vessels healthy, research has shown. Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits... "Our study confirms that almonds are a superfood. Previous studies have shown that they keep your heart healthy, but our research proves that it isn't too late to introduce them into your diet -- adding even a handful (around 50g) every day for a short period can help.

Could grapefruit be good for your kidneys?

A natural product found in grapefruit can prevent kidney cysts from forming, new research indicates. Naringenin, which is also present in other citrus fruits, has been found to successfully block the formation of kidney cysts, an effect that occurs in polycystic kidney disease, by regulating the PKD2 protein responsible for the condition. With few treatments currently available, symptoms include high blood pressure and loss of kidney function, and lead to the need for dialysis.

More evidence that dark chocolate is good for you. From Science Daily:

Polyphenols could yield small benefit for people with PAD

In a small study, people with artery problems in their legs (peripheral artery disease) walked a little longer and farther when they ate dark chocolate -- a food rich in polyphenols.The authors suggest that compounds found in cocoa -- polyphenols -- may reduce oxidative stress and improve blood flow in peripheral arteries....Many other polyphenol-rich foods would offer less added sugar, saturated fats, and calories than dark chocolate, such as cloves, dried peppermint, celery seed, capers, and hazelnuts, to name a few.

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20131201_101300 Several people have recently written to me about kimchi and asked why I originally chose vegan kimchi over kimchi containing a seafood ingredient (typically fish or shrimp sauce) for sinusitis treatment. I have also been asked whether vegan kimchi has enough Lactobacillus sakei bacteria in it as compared to kimchi made with a seafood seasoning. (see Sinusitis Treatment Summary page and/or Sinusitis posts for in-depth discussions of Lactobacillus sakei in successful sinusitis treatment).

Korean kimchi is a fermented food typically made with cabbage and other vegetables and seasonings, and can contain some seafood (perhaps fish or shrimp sauce) as a seasoning, or just be vegan (no seafood ingredients). It can also be made using a starter culture.

These questions arose because Lactobacillus sakei (L.sakei) is commonly found on meat and fish, and plays a role in the fermentation and preservation of meat. L.sakei "outcompetes other spoilage- or disease-causing microorganisms" and so prevents them from growing. Thus it is considered beneficial and is used commercially in lactic acid starter cultures (for example, in making European salami and sausages).

L. sakei was originally isolated from sake or rice wine (thus plant origin), is found in very low levels in some fermented sauerkraut, and according to the studies I looked at, is found during fermentation in most brands of Korean kimchi.

Currently there are over 230 different strains of L.sakei isolated from meat, seafood, or vegetables from all over the world (from S. Chaillou et al 2013 study looking at population genetics of L.sakei). So this bacteria, which is found by using state of the art genetic analysis, turns out to be quite common.

So why did I only use vegan kimchi and only mention vegan kimchi in our Sinusitis Treatment method?

It's because when I first started dabbing kimchi juice in my nose about 1 1/2 years ago, I was in uncharted territory. I was desperate for something with L.sakei in it, and from my reading I found kimchi. However, putting (by dabbing or smearing) a live fermented product in my nostrils was a big unknown. When I first opened some jars, the kimchi juice would bubble and sometimes overflow and run down the sides of the jar. Would the microbes in kimchi harm or benefit me? Obviously I was conducting an experiment with unknown results.

I settled on vegan (no seafood) kimchi because a totally plant-based product sounded safer to me. I wondered what other microbes are in the kimchi with seafood. Could any of them be harmful?  And my choice of vegan kimchi turned out great.

Our experiences with kimchi are that it works amazingly well in treating sinusitis and causes no harm (as far as we can tell). This is the best I've felt in many, many years - back to normal!

But I don't know if other brands of vegan kimchi, with different recipes and ingredients and thus different microbial communities, would have worked out so well. The levels of L.sakei and other beneficial microbes in the many kimchi brands are unknown.

So now I wonder- if L. sakei is so pervasive on meat and seafood, perhaps kimchi with a seafood ingredient in it would be even better, with consistently higher amounts of L. sakei. Or maybe there is no difference between the two kinds of kimchi. Only the very expensive state-of-art genetic testing would give me the answer to that question.

Based on my successful 1 1/2 years of vegan kimchi experience, I may be willing to experiment further and try non-vegan kimchi. Or maybe not. Perhaps it is better. But I'm very cautious.... 

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Lactobacilli

The human vagina is another microbial community that is nowhere as simple as earlier thought - and it's not just Lactobacillus bacteria.

From The Scientist: Characterizing the “Healthy” Vagina

For years, researchers characterized the microbial community of women’s vaginas as being dominated by Lactobacillus bacteria, which ferment carbohydrates to lactic acid, yielding a low pH that is toxic to many pathogenic microbes. When levels of Lactobacillus drop, the pH becomes more neutral, and the risk of infection rises.

But with research revealing notable variation among women’s vaginal microbiomes, as well as some interesting dynamics of the microbial communities within a single organ, “that dogma is changing a little bit,” said Gregory Buck of the Vaginal Microbiome Consortium at Virginia Commonwealth University (VCU).

The composition and stability of the vaginal microbiome varies by race, age, even within an individual—and it’s quickly become clear that the formula for a “normal,” “healthy” microbial community cannot be computed by ratios of bacterial species. “In the past we’ve made some generalizations about what kinds of bacteria are found in the vagina, what kinds of bacteria are good or healthy or protective,” said microbial ecologist Larry Forney of the University of Idaho. “What the research is showing is there are tremendous differences between women in terms of the kinds of bacteria that are present and the changes in the communities that occur over time.”

In June 2010, Forney, Jacques Ravel of the University of Maryland School of Medicine, and their collaborators published a survey of the vaginal microbiomes of nearly 400 women and found that the majority harbored bacterial communities dominated by one of four Lactobacillus strains. More than a quarter of the women studied, however, did not follow this pattern. Instead, their vaginas had fewer Lactobacillus and greater numbers of other anaerobic bacteria, although the bacterial communities always included members of genera known to produce lactic acid.

In many ways, the microbiome of these women resembled the bacterial communities of women suffering from bacterial vaginosis (BV), an infection characterized by an odorous vaginal discharge, Buck noted. “By looking at the microbial components, you’d say they have BV, but they have no clinical symptoms,” he said. “These people are not unhealthy.”

The researchers also found that the composition of a woman’s vaginal microbiome was linked to her race. Eighty percent of Asian women and nearly 90 percent of white women harbored vaginal microbiomes that were dominated by Lactobacillus, while only about 60 percent of Hispanic and black women did. Moreover, vaginal pH varied with ethnicity as well, with Hispanic and black women averaging 5.0 and 4.7, respectively, and Asian and white women averaging 4.4 and 4.2. 

This raises questions about the role of the commensal bacteria and risk of preterm labor , which has been linked to BV—and to low levels of Lactobacillus in particular—and is one-and-a-half times more common among African American women than Caucasian women.

Meanwhile, the researchers continue to sort through 40,000 swabs from more than 6,000 women to better characterize the bacterial communities living in the vagina. But Fettweis and her colleagues face a common problem in microbiome research. “In many samples, only a fraction of [the genetic sequences] align to anything we have in our databases,” she said. “So I think there’s still a lot of work to be done in terms of actually understanding: What are these organisms?”

Another question facing researchers probing the vaginal microbiome is how it is initially colonized. “Where do [the bacteria] come from?” said Forney.

Many suspect that the process occurs during vaginal childbirth. But the adolescent microbiome does not resemble that of a sexually mature woman, having far less Lactobacillus, leading some to suspect that there may be a second colonization of the vagina later in life. And if the birthing process is important to establish the vaginal microbiome, what happens in the case of C-sections? “We have more questions than answers,” Forney said.

The microbiome is also not stable later in life. It is now well known that the vaginal microbiome changes after menopause, containing fewer Lactobacillus than the vaginas of reproductive-aged women, with the notable exception of women on hormone-replacement therapies.

Moreover, recent research has revealed that the composition of the vaginal microbiome can change in as little as 24 hours.

The temporal dynamics of the vaginal microbiome raise important questions about developing microbiota-based diagnostics and therapeutics, said Forney. “If you perform a diagnostic test, would you get a different result tomorrow or the day after? In some cases, yes. How do you incorporate that into [a] decision about whether some kind of intervention is required?”

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Informing pregnant women about environmental health hazards is absolutely necessary, especially because steps can be taken to avoid them (such as pesticides, mercury in fish, lead and BPA). Why isn't it happening routinely? Hey obstetricians - are you listening? From Huffington Post:

Doctors Fail To Counsel Pregnant Women On Toxic Chemical Risks

...dozens of environmental chemicals can course through a pregnant woman's body, cross the umbilical cord and wreck havoc on a developing fetus. Birth defects, IQ losses and childhood cancers are just some of the potential risks scientists have now tied to even low levels of exposure.

Among more than 2,500 doctors consulted for the survey, nearly all of them reported counseling patients on factors such as diet, exercise and cigarette smoking. However, only about 20 percent said they addressed environmental exposures. They pegged their hesitation to a number of factors, from the fear of overwhelming patients with anxiety-inducing worries to limited appointment time to a lack of environmental health education.

Just one in 15 doctors said they had received training on the harmful reproductive effects of toxic chemicals. "Medical school and residencies tend to frame their curriculum around the boards and required licensing exams," said Stotland. "This material is not yet on those tests." ... The American College of Obstetrics and Gynecologists (ACOG) and the American Society for Reproductive Medicine (ASRM) issued a statement in October that underscored mounting evidence of "significant and long-lasting effects" caused by industrial chemicals, and emphasized doctors' role in protecting pregnant women.

The actual study from Plos One summed up the importance of knowing about exposures to environmental hazards during pregnancy very nicely in the introduction:

Counseling Patients on Preventing Prenatal Environmental Exposures - A Mixed-Methods Study of Obstetricians

Exposure to hazardous environmental chemicals, i.e., manufactured chemicals and metals, is linked to adverse health outcomes across all stages of the human life cycle including fertility, conception, pregnancy, child and adolescent development, and adult health [1]–[5]. Human exposure to environmental chemicals is ubiquitous. A population-based study found that virtually all pregnant women in the U.S. had measureable levels of at least 43 different environmental chemicals in their bodies, including chemicals that were measured at levels similar to those associated with adverse developmental and reproductive health outcomes in epidemiologic studies [6]. There are currently over 80,000 chemicals in commerce [7], [8], and exposure occurs through air, water, food and consumer products in the home and workplace. The majority of industrial chemicals have not been tested for potential reproductive/developmental harm [9].

Obstetricians are uniquely positioned to help prevent exposures to environmental chemicals with adverse developmental and reproductive health effects [2]. Pregnancy is a time when exposure to environmental contaminants can disrupt or interfere with the physiology of a cell, tissue, or organ [4], leading to permanent and lifelong adverse health outcomes that may be passed down to future generations [10]. Pregnancy is also an opportune time to prevent harmful exposures as it is a period when patient interest about health can be extremely high.

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The worrisome results are adding up for BPA and BPS. From Environmental Health News:

Miscarriage risk rises with BPA exposure, study finds

Women exposed to high levels of bisphenol A early in their pregnancy had an 83 percent greater risk of miscarriage than women with the lowest levels, according to new research. The scientists said their new study adds to evidence that low levels of the ubiquitous chemical, used to make polycarbonate plastic and found in some food cans and paper receipts, may affect human reproduction. The study involved 115 pregnant women who had visited a Stanford University fertility clinic within about four weeks of fertilization. The more BPA detected in the women’s blood, the higher their risk of miscarriage, according to the researchers.

“Couples suffering from infertility or recurrent miscarriages would be best advised to reduce BPA exposure because it has the potential to adversely affect fetal development,” wrote the scientists, led by Dr. Ruth Lathi, a Stanford University associate professor of obstetrics and gynecology. 

In 2005, a smaller study in Japan found that 45 women who had three or more first-trimester miscarriages had three times more BPA in their blood than 32 women with no history of pregnancy problems. 

From Science Daily:

BPA increases risk of cancer in human prostate tissue, study shows

Fetal exposure to a commonly used plasticizer found in products such as water bottles, soup can liners and paper receipts, can increase the risk for prostate cancer later in life, according to a study. Exposure of the fetus to BPA in utero is of particular concern, because the chemical, which mimics the hormone estrogen, has been linked to several kinds of cancer, including prostate cancer, in rodent models. The new findings show that human prostate tissue is also susceptible.

"Our research provides the first direct evidence that exposure to BPA during development, at the levels we see in our day-to-day lives, increases the risk for prostate cancer in human prostate tissue," Prins said

This study was done in rats, but thought to also apply to humans. From Science Daily:

Common BPA substitute, BPS, disrupts heart rhythms in females

Bisphenol S (BPS), a common substitute for bisphenol A (BPA) in consumer products, may have similar toxic effects on the heart as previously reported for BPA, a new study finds.

There is implied safety in BPA-free products. The thing is, the BPA analogs -- and BPS is one of them -- have not been tested for safety in humans." "Our findings call into question the safety of BPA-free products containing BPS," he said. "BPS and other BPA analogs need to be evaluated before further use by humans."