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Category: microbes

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Published on 6 Comments on Daily Use of Probiotics Can Hurt Gut Health

Researchers are starting to raise concerns about routine daily intake of probiotics for "gut health". Much is still unknown, but problems are starting to appear. A healthy gut contains hundreds of species (bacteria, fungi, viruses), and taking megadoses of a few species (a probiotic supplement) can overwhelm the normal gut microbial community. A healthy gut is one with a greater diversity of species, not just some species.

For example, one study found that daily probiotic ingestion can result in overgrowth of some bacterial species in the intestines, resulting in such symptoms as brain fogginess, bloating, and gas. Successful treatment was antibiotics and stopping the use of probiotics.   Another recent study found that after using antibiotics, those who took probiotics (thinking it would help microbial recolonization of the gut microbes) actually had slower recovery of the gut microbiome (microbial community).  The best recovery was in those who took nothing, no supplements at all, or those who received a fecal microbial transplant (where an entire microbial community is transplanted).

The evidence is showing that for gut microbial health, the best thing to do is eat a variety of real whole foods (and not highly processed foods) that have lots of fiber, such as whole grains, fruits, vegetables, seeds, nuts, and legumes (beans). In other words, feed the beneficial bacteria. A Mediterranean style diet is good.

A recent article in Medscape (the medical site) highlights these same concerns. [See below.] A study that looked at the gut microbiome of people who were about to undergo treatment for melanoma found that those who were taking probiotics actually had worse gut microbial diversity. [Remember, gut microbial diversity is considered an indicator of gut health.] And the cancer treatment (immunotherapy) did not work as well on them.

Bottom line: The evidence is showing that for gut microbial health, the best thing to do is eat a variety of real whole foods (and not highly processed foods) that have lots of fiber, such as whole grains, fruits, vegetables, seeds, nuts, and legumes (beans). In other words, feed the beneficial bacteria. A Mediterranean style diet is good. Don't take routine daily supplements or probiotics for  "gut health" - they won't help. Instead, if you want - only take probiotics for a short while for a specific symptom or problem.

Dr. Lorenzo Cohen wrote a piece for the Wall Street Journal laying out those same points. Excerpts from: Those Probiotics May Actually Be Hurting Your ‘Gut Health’  ...continue reading "Daily Use of Probiotics Can Hurt Gut Health"

Published on Leave a comment on High Fiber Foods, Yogurt, and Lung Cancer

Food is all important for health. A recent study (that analyzed data from 10 large studies in the US, Europe, and Asia) found an association between high fiber intake from foods and also frequent eating of yogurt with a lower incidence of lung cancer. Persons with the highest yogurt and fiber consumption had a 33% reduced risk of lung cancer (when compared to the group who did not consume yogurt and consumed the least amount of fiber).

Think of it this way: The fiber in foods feeds the beneficial bacteria in the gut. High fiber foods that feed microbes in the gut are known as prebiotics. It is good to eat a variety of foods, because they provide a variety of fibers. High fiber foods are whole grains, fruits, vegetables, seed, nuts, and legumes (beans).

Gut microbes use fiber to generate short-chain fatty acids, and these are anti-inflammatory. Evidence suggests that the beneficial effects are not restricted to the gut, but reach organs throughout the body, including the lungs. The researchers suggest that both fiber and yogurt have anti-inflammatory effects, and the combination of fiber and yogurt is stronger against lung cancer than either alone. They also thought that the Lactobacillus and Bifidobacterium species in yogurt somehow help improve the gut microbial system.

From Medical Xpress:  High fiber, yogurt diet associated with lower lung cancer risk  ...continue reading "High Fiber Foods, Yogurt, and Lung Cancer"

Published on Leave a comment on Vaginal Fluid Transplants Successfully Treat Bacterial Vaginosis

Bacterial vaginosis is a problem for many women, with estimates that up to a third of women of reproductive age get it at some point in life. Bacterial vaginosis is a condition where the microbes in the vagina are imbalanced or out-of-whack, especially with diminishing numbers and types of Lactobacillus species. Lactobacillus species are typically the dominant bacteria in healthy vaginal microbiomes.

Unfortunately, some women have recurring bacterial vaginosis (BV), many who wind up taking course after course of antibiotics to try to deal with it. Symptoms can include thin gray, white, or green vaginal discharge, vaginal itching, burning during urinbation, and a smelly fishy vaginal odor. Which is why a small study done in Israel finding success with vaginal microbial transplantation (VMT) from healthy donors to women with BV is very exciting.

Researchers transplanted vaginal fluid (with all its microbes) from 3 healthy women (and thus a healthy vaginal microbial community) into 5 women with severe BV that did not respond well to antibiotics. Afterwards four of the  recipients had long-lasting (up to 21 months) vaginal microbial changes and complete remission of BV (2 after the first transplant, 2 after 3 transplants) - becoming more like the donors' vaginal microbiome, and also rich in Lactobacillus. The 5th person had partial improvement of BV, but there were complications - she took a course of antibiotics for a throat infection, her BV symptoms returned, and then she received another vaginal microbiome transplant, after which her vaginal microbes were a mix of her original and the donors.

Of course larger studies are now needed, especially because there can be risks when receiving another person's microbes (e.g. accidental transfer of viruses). But I also want to point out that some of these Lactobacillus species (especially Lactobacillus crispatus) are easily available without a prescription, and women have been self-experimenting with them, many with good success.

Excerpts from Ars Technica - Vaginal-fluid transplants treat incurable condition in pilot study   ...continue reading "Vaginal Fluid Transplants Successfully Treat Bacterial Vaginosis"

Published on Leave a comment on Antibiotics May Not Work If Bacteria Change Their Shape

Everyone is concerned with the problem of antibiotics not working due to antibiotic resistance, that is, when bacteria resist the effects of antibiotics. Researchers typically study genetic changes that occur in bacteria over time, but researchers at Newcastle University in the UK found evidence for a another reason that antibiotics may not work in treating an infection. They found that bacteria can change shape and shed their cell walls, which are their outermost defense and the primary target of most antibiotics. Then when the antibiotics are stopped, they can go back to their original shape. Sneaky!

The researchers suggest that in the future we may have to treat infections with combined antibiotics, that is use antibiotics that kill bacteria with cell walls and also antibiotics that kill bacteria forms without cell walls (called L-forms).

Excerpts from  the study researcher Katarzyna Mickiewicz's post in The Conversation: Antibiotic resistance: researchers have directly proven that bacteria can change shape inside humans to avoid antibiotics   ...continue reading "Antibiotics May Not Work If Bacteria Change Their Shape"

Published on Leave a comment on Valley Fever Infections Are Increasing In the United States

The number of people diagnosed with the infection Valley fever is increasing. According to a CDC (Centers for Disease Control and Prevention) report released this week, individuals diagnosed with the infection called Valley fever or Coccidioidomycosis has increased 74% since 2014.

Valley Fever is an infection caused by the fungus Coccidioides spp., which is typically found in the soil of warm, arid regions of the southwestern US (Arizona, California). It is found in a lesser degree in Nevada, New Mexico, Utah, and Texas, but has even been found as far north as central Washington. The fungus is inhaled and goes to the lungs, where it can cause a respiratory illness, but sometimes can also lead to disease throughout the body.

The CDC says on the Valley fever page: "People can get Valley fever by breathing in the microscopic fungal spores from the air, although most people who breathe in the spores don’t get sick. Usually, people who get sick with Valley fever will get better on their own within weeks to months, but some people will need antifungal medication. Certain groups of people are at higher risk for becoming severely ill. It’s difficult to prevent exposure to Coccidioides in areas where it’s common in the environment, but people who are at higher risk for severe Valley fever should try to avoid breathing in large amounts of dust if they’re in these areas."

What are the symptoms? Many people infected don't have any symptoms, while others (about 40%) may have flu-like symptoms lasting weeks to months, which may go away on their own. Valley fever can include symptoms such as: fatigue, cough, fever, shortness of breath, headache, night sweats, muscle aches or joint pain, and perhaps a rash on the upper body or legs. There is usually a 1 to 3 week incubation period. Unfortunately it may look like pneumonia, but typical pneumonia treatment with antibiotics does not help.

Much is still unknown in how to treat the illness, including whether antifungal medications lessen symptom duration or intensity in patients with uncomplicated Valley fever. [Antifungal medications are used to treat complicated cases.] About 5 to 10% of patients develop life-threatening severe lung (pulmonary) disease and in about 1% of people the infection spreads from the lungs to other parts of the body (e.g. brain and spinal cord, skin, or bones and joints). Some people may need lifelong treatment. While anyone can get Valley fever, the CDC says some risk factors include: immunosuppression (e.g. have had an organ transplant, have HIV, are on corticosteroids), being pregnant, having diabetes, people who are black or Filipino. The CDC lists some tips in preventing getting this fungus.

From Medscape: Valley Fever on the Rise and Spreading, CDC Says  ...continue reading "Valley Fever Infections Are Increasing In the United States"

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 Children, Animals, and Gut Microbes

The evidence is growing. Another recent study found that exposure to dirt and animals in the first year of life is beneficial for development of a a rich and diverse gut microbiome - that is, for greater species "richness" as well as more beneficial microbes. This is linked to lower levels of allergies and asthma in children.

So don't worry about children being exposed to animal "germs" and getting dirty! Instead, consider the microbes as having health benefits, such as developing a "robust immune system". In summary, it now appears that in the first year of life the immune system needs lots of exposure to all sorts of microbes (e.g. from pets, animals, dirt)  to "train it" to develop normally.

The Ohio State University researchers compared 5 healthy rural Amish infants to 5 healthy non-Amish urban infants in Ohio, also found that all of the rural (Amish) children were breastfed, while 2 of the urban (non-Amish) children were only formula fed (some microbial differences there). The Amish households had farm animals (cattle, sheep, and/or horses) and pets (dogs and/or cats), while the non-Amish households had no contact with livestock, but did have a pet dog or cat. Just like in other studies, one pet doesn't seem to be enough - even more animal exposure in early childhood is best for the gut microbiome. [One study found a dose-dependent effect with exposure to 5 furry pets in early childhood was needed to prevent all allergies.]

Studies find that rural (Amish) children have a low incidence of allergies and asthma, while urban children have a high incidence of allergies and asthma. In this study, an example of microbial differences in the 2 groups of children was that Bifidobacterium bacteria were "enriched" in non-Amish (urban) infants, while Roseburia species were "enriched" in Amish (rural, farm-raised) infants. Similar gut microbe differences have been observed in other studies comparing rural and urban children, and both dietary differences (e.g. farm raised children eat lots of homegrown produce) and environmental differences (animal exposure) are thought to be responsible for the differences.

From Science Daily: Keeping livestock in the yard just might help your baby's immune system  ...continue reading "Children, Animals, and Gut Microbes"

Published on Leave a comment on Problems With Paleo Diet?

The Paleo diet has been around for years and yet it continues to be controversial. The debate is whether following the Paleo diet long-term has health benefits or not? Supporters of the Paleo (Paleolothic) diet say it promotes gut health and is good for gut microbes, but recent research findings are a strike against this claim. The Paleo diet is based on the hypothesis that humans have not adapted to eating products of agricultural farming such as grains, dairy products, or legumes (beans), as well as all processed foods, so they should be avoided. Instead it stresses eating meat, fish, eggs, nuts, (some) fruits, and vegetables.

So what were the new research findings?  Australian researchers found that people who had been on a Paleo diet for more than a year ate lower amounts of resistant starch, and so had a different bacteria profile in the gut - with lower levels of some beneficial species. They also had high levels of a biomarker in the blood (trimethylamine-n-oxide or TMAO) that is linked to heart disease.

The problem seems to be the lower intake of resistant starch - which is a carbohydrate that resists digestion in the small intestine and ferments in the large intestine. As the fibers ferment they act as a prebiotic and feed the beneficial bacteria in the gut. More than one type of resistant starch can be present in a single food. And what foods contain resistant starches? Precisely some foods avoided in the Paleo diet: grains, rice, beans, peas, lentils, plantains, and green bananas. A number of studies find health benefits (e.g. gut health) from eating foods with resistant starches.

From Medical Xpress: Heart disease biomarker linked to paleo diet

People who follow the paleo diet have twice the amount of a key blood biomarker linked closely to heart disease, the world's first major study examining the impact of the diet on gut bacteria has found.  ...continue reading "Problems With Paleo Diet?"

Published on Leave a comment on Excellent Reason To Eat Apples: The Bacteria

New research once again confirms that raw fruits and vegetables result in a person ingesting lots of microbes. Millions of bacteria. Which is considered beneficial for our gut microbiome! What's interesting in the latest study looking at bacteria in both conventionally and organically grown apples is that organic apples are a better source of bacteria - that their bacteria are more diverse, distinct, and balanced (when compared to conventionally grown apples).

The Austrian researchers (Wassermann et al) wrote in the Frontiers In Microbiology: "Our results suggest that we consume about 100 million bacterial cells with one apple. Although this amount was the same, the bacterial composition was significantly different in conventionally and organically produced apples."

Interestingly, there were a lot of beneficial Lactobacillus species in the organic apples, but not conventionally grown ones. The researchers thought that the diverse microbiome of organic apples probably limits or hampers harmful microbes (human pathogens). The researchers also wrote: "The described microbial patterns in organic apples resemble the impact of apple polyphenols on human health, which have not only been shown to alleviate allergic symptoms (Zuercher et al., 2010), but also to promote growth of Lactobacillus and Bifidobacterium in the human gut and to reduce abundance of food-borne pathogens."

Another bonus of eating organic apples is that it means avoiding pesticides that are routinely sprayed on conventional fruit. So eat away! Microbes, fiber, and nutrients all in one small fruit!

Fun fact: The researchers write that apples are the most consumed fruit world-wide. Excerpts from Science Daily: An apple carries about 100 million bacteria -- good luck washing them off  ...continue reading "Excellent Reason To Eat Apples: The Bacteria"

Published on Leave a comment on Outdoor Soil Microbes In the Home and Asthma

Want to prevent your children from having allergies or asthma? A recent study adds support to increasing evidence that growing up on a farm, or living among multiple pets in the first year of life is protective against developing allergies and asthma. This is because exposure to lots of animal and outdoor soil bacteria in early childhood is good for the developing immune system. The study, which was conducted by Finland's National Institute  of Health and Welfare, carried this line of work further and found that this type of beneficial farm microbial exposure could be duplicated in non-farm homes.

They found that children's risk of developing asthma decreased as the similarity of their home's bacteria became more similar to that of farm homes. The researchers analyzed living room dust from homes and found that certain types of outdoor soil microbes were beneficial for preventing asthma. They found higher levels of these bacteria (and archaea, another microbe) in homes where people wore their outdoor shoes in the house, as well as 3 or more children, and increased moisture in houses. The types of fungi found in the dust of farm and non-farm houses didn't seem to matter. The researchers mention that the same kind of protective (for asthma) results of soil microbes has also been shown in mice.

Additional thoughts reading this: The study results can be interpreted as playing and crawling outdoors is definitely beneficial to children's health, especially young children. Exposure to soil microbes! And, of course, having pets. But wearing outdoor shoes indoors is problematic in areas with high lawn and garden pesticide use (e.g. suburban NY and NJ!) because studies show the pesticides get tracked indoors. This same problem occurs in areas with high lead levels (around older homes) or other heavy metals.

From Science Daily: Farm-like indoor microbiota may protect children from asthma also in urban homes   ...continue reading "Outdoor Soil Microbes In the Home and Asthma"