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Category: human microbiome

Published on Leave a comment on Some Food Additives May Alter Our Gut Microbes

A recent study gives support to eating a diet with real unprocessed foods and avoiding foods with additives as much as possible. The study found that the commonly used food additive known as xanthan gum (E415 in Europe) can cause disruptions to our gut microbiome.

The gut microbiome or microbiota is the community of microbes living in our intestines, and which are critical to good health. The international team of researchers found that the gut microbes changed when exposed to the additive, so as to be able to digest the xanthan gum.

Xanthan gum is used as a thickener or stabilizer in many foods, including ice cream, sweets, chocolate milk, baked goods, ready-made sauces and dressings. [Note: If present, it is listed in the ingredients on food labels.]

Bottom line: Rather than being harmless and not having any effects, food additives may have effects on or disrupt our gut microbes. Food additive effects may be minimal or can actually cause harm. For example, some emulsifiers (e.g., soy lecithin, carrageenan, polysorbate-80) can promote gut inflammation and alter the gut microbiome in a negative or harmful way

From Medical Xpress: Widely used food additive affects the human gut microbiota

Have you heard about the food additive E415? It is also known as xanthan gum. Most likely, you eat it several times a week. Xanthan gum is used in everyday foods such as baked goods, ice cream and salad dressings. The additive is also widely used as a substitute for gluten in gluten-free foods.  ...continue reading "Some Food Additives May Alter Our Gut Microbes"

Published on Leave a comment on Pancreatic Cancer Has a Distinct Gut Microbial Pattern
Pancreas with cancer (red dot) Credit: Wikipedia

Pancreatic cancer is typically discovered only when it is advanced, very hard to treat, and typically with poor outcomes. Interesting recent research found that the gut microbiome is distinctive in persons with pancreatic cancer, even in the early stages. Perhaps this finding will lead to an easy noninvasive way to screen for pancreatic cancer.

Researchers in Spain and Germany looked at both the community of microbes (microbiome) living in the mouth and the gut (shown in a person's feces). They took samples from healthy persons, individuals with pancreatic cancer, and persons with chronic pancreatitis  and found that the bacteria in the stool were predictive for pancreatic cancer (but not those in the mouth).

The "fecal microbiota signature" or pattern of microbes in those with pancreatic cancer had an increase in some microbes (e.g., Fusobacterium nucleatum) and a decrease in others (e.g., Faecalibacterium prausnitzii) - when compared to healthy individuals.

By the way, Fusobacterium nucleatum is found increased in other cancers, such as colon cancer, and beneficial and anti-inflammatory Faecalibacterium prausnitzii is reduced in a number of diseases. Eating a diet rich in high fiber foods (whole grains, fruits, vegetables, legumes, seeds, nuts) increase the numbers of F. prausnitzi in a person's gut microbial community.

From Medical Xpress: Distinct gut microbial profile may identify pancreatic cancer, irrespective of stage

A specific panel of gut microbes may identify pancreatic cancer, irrespective of how far the disease has progressed, suggests research published online in the journal Gut. ...continue reading "Pancreatic Cancer Has a Distinct Gut Microbial Pattern"

Published on Leave a comment on Adding Prunes to the Diet Has Health Benefits
Prunes

A study has given further support to the view that eating prunes (dried plums) has health benefits. Penn State University researchers reviewed studies and found that eating prunes may help protect against bone loss in postmenopausal women, as well as having anti-inflammatory and antioxidative effects. All good!

A good amount to eat (according to the studies reviewed) is about 100 grams or 10 prunes (dried plums) each day.

But... don't just focus on eating prunes (dried plums) as a healthy food. Eating several servings of a variety of fruits every day (whether fresh, frozen, or dried) has numerous health  benefits and should be part of your regular diet. Fruit is anti-inflammatory, great for the gut microbes, high in fiber, and contains minerals and nutrients. Enjoy!

From Science Daily: Eating prunes may help protect against bone loss in older women

It's already well known that prunes are good for your gut, but new Penn State research suggests they may be good for bone health, too. ...continue reading "Adding Prunes to the Diet Has Health Benefits"

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Published on 1 Comment on Some Emulsifiers Harm the Gut Microbiome

Emulsifiers are in many of the processed foods we buy. They are added to the foods to enhance texture and extend shelf life. Animal and human studies find that some emulsifiers (e.g., soy lecithin, carrageenan, polysorbate-80) can promote gut inflammation and alter the gut microbiome in a negative or harmful way. Recent research adds to this list the common emulsifier carboxymethylcellulose (CMC), also known as cellulose gum.

A small study randomly assigned 16 healthy adults to either an emulsifier-free diet or an identical diet with added 15 g per day of CMC for 11 days. No one knew what diet they were eating, and for those 11 days the participants were inpatient - thus no chance for cheating or altering the diet. Extensive testing (even biopsies on day 1 and 11!) was done before, during, and after the study. The Univ. of Pennsylvania researchers found that CMC resulted in several harmful changes, including a negative effect on the gut microbiome (microbial community of bacteria, viruses, fungi).

Results: The researchers found that CMC increased abdominal discomfort after meals, disturbed the gut microbial community and reduced its diversity (not good!). It resulted in reductions of short-chain fatty acids and free amino acids (thus impacted how nutrients are absorbed). One of the beneficial microbes associated with good health, and that was reduced in number was Faecalibacterium prausnitzii.

Two of the subjects who had CMC in their foods had increased microbial "encroachment into the normally sterile inner mucus layer" of the gut, which is a central feature of chronic inflammation diseases (e.g., IBD, type 2 diabetes). They also had large "alterations in microbiota composition". This means that there is variation in how people respond to the emulsifier CMC, with some people more sensitive than others.

The scary part is that the intestinal changes happened after just 11 days with a daily intake of 15 g of CMC - a dose that is approximately the total emulsifier consumption for a person whose diet is largely highly processed food. Yes, that is many of us eating a Western style diet (e.g., highly processed foods, and low in fiber, fresh fruits, vegetables, and whole grains). The scientists believe that long-term consumption of emulsifiers, because they result in gut microbial disruption and inflammation, are contributing to chronic diseases.

Bottom line: Read the ingredients list on food labels. Try to avoid foods that have ingredients listed that you wouldn't normally have in your kitchen. That means soy lecithin, CMC, cellulose gum, carrageenan, artificial colors. Even "natural flavors" (which are laboratory concoctions) should be avoided as much as possible.

From Medical Xpress: Ubiquitous food additive alters human microbiota and intestinal environment

New clinical research indicates that a widely used food additive, carboxymethylcellulose, alters the intestinal environment of healthy persons, perturbing levels of beneficial bacteria and nutrients. These findings, published in Gastroenterology, demonstrate the need for further study of the long-term impacts of this food additive on health.  ...continue reading "Some Emulsifiers Harm the Gut Microbiome"

Published on Leave a comment on Farts and Good Gut Health

Those who enjoy a little "potty humor" will like the results of a recent nutrition study comparing the results of a Western style diet (high fat, low fiber) to a high fiber Mediterranean diet. The high fiber diet resulted in much larger, softer stools, and an increase in stomach noises and farting. (Yes, they weighed their stools and counted daily farts!) There was no change in the number of stools per day.

In the study 18 healthy men followed both types of diets for two week periods (first one diet, then a break, and then the other diet). The high fiber diet (54.2 grams fiber per day) resulted in numerous beneficial changes, especially nurturing healthy gut bacteria and metabolic improvements. The low fiber Western diet only had an intake of 4.7 g fiber per day. Interestingly, all participants were told to avoid fermented dairy products (e.g. yogurts) during the study.

The high fiber diet resulted in greater numbers of beneficial bacteria in the gut without any major changes in the core microbiome (microbial community). There were also numerous gut microbial metabolic improvements while on this diet. Interestingly, men who already had a more diverse gut microbiota (which is a sign of health) and routinely already ate more fiber rich plants foods, had less farting and stomach noises during the study.

Think of it this way: your diet is what feeds and nurtures the microbes living in your gut. Some microbes are associated with chronic diseases, and some with health - so you want to nurture the health-associated bacteria by eating a diet rich in plant foods (Mediterranean style diet).

By the way, a recent study found that eating fermented foods is a quick way to increase gut microbial diversity and health. It's beneficial to add some fermented foods (e.g. yogurt, kimchi, sauerkraut, kefir) to your regular diet.

From New Scientist: Men fart more when eating a plant-based diet due to good gut bacteria

Plant-based diets cause men to fart more and have larger stools, researchers have found – but that seems to be a good thing, because it means these foods are promoting healthy gut bacteria.  ...continue reading "Farts and Good Gut Health"

Published on Leave a comment on Antibiotics and Colon Cancer

Antibiotics can be life-saving, but there are also unintended consequences. One of them is that they disrupt and alter the gut microbiome (the microbial community of the millions of microbes living in the intestines). A large study found that use of antibiotics is linked to a higher risk of colon cancer 5 to 10 years later.

The researchers thought this was due to the antibiotics having negative effects on the gut microbiome. Antibiotics reduce numbers of beneficial bacteria in the intestines, while allowing bacteria linked to colorectal cancer to increase.

Researchers at Unea Univ. in Sweden compared 40,545 colon cancer cases to 202,720 controls (no cancer), and found that as antibiotic use increased, colon cancer increased in those persons during the next 10 years. It is unknown what happens after 10 years, because that is when the study ended. Interestingly, in women - increased use of antibiotics was linked to a lower incidence of rectal cancer.

The researchers analyzed the results with respect to different classes  of antibiotics, and found the strongest association with the use of quinolones, sulfonamides, and trimethoprims. These antibiotics have an effect on bacterial diversity - specifically allowing anaerobic Fusobacteria and Bacteroidetes species to live and become more abundant. Other studies also support the view that Fusobacteria (e.g., Fusobacterium nucleatum) and Bacteroidetes species contribute to colorectal cancer development.

What to do? To increase beneficial species in the gut and lower levels of inflammation in the body, studies support eating a diet rich in fruits, vegetables, whole grains, nuts, seeds, legumes, and fish - which also results in a high fiber intake (e.g., Mediterranean diet). Also, to quickly improve the diversity of microbes in the gut (a sign of health!) and to lower inflammation in the body, increase your intake of fermented foods.

Fermented foods include: yogurt, buttermilk, sour cream, cheese, kefir, fermented vegetables, kimchi, natto, miso, sauerkraut, traditional pickles, traditional sourdough bread, apple cider vinegar, and kombucha. To quickly improve the gut microbiome, try to eat six 1/2 cup servings each day for a few months.

From Science Daily: Antibiotics linked to increased risk of colon cancer

There is a clear link between taking antibiotics and an increased risk of developing colon cancer within the next five to ten years. This has been confirmed by researchers at Umeå University, Sweden, after a study of 40,000 cancer cases. The impact of antibiotics on the intestinal microbiome is thought to lie behind the increased risk of cancer.  ...continue reading "Antibiotics and Colon Cancer"

Published on Leave a comment on Fermented Foods Are Good For Your Gut Microbiome

It has been known for a while that eating fermented foods and high fiber foods is healthy for us. A recent study confirms this view. Researchers at the Stanford Univ. of Medicine found that eating fermented foods actually reduces inflammation and increases the diversity of gut microbes (gut microbiome).

Researchers randomly assigned volunteers to one of 2 groups for 10 weeks: the fermentation foods group, and the high fiber group. Surprisingly, the group eating the high fiber diet for 10 weeks did not have changes in microbial diversity or changes in the 19 inflammatory markers studied. Instead, the researchers reported that the high-fiber diet "changes microbiome function and elicits personalized immune responses".

The fermented foods group ate a diet rich in yogurt, kefir, fermented cottage cheese, kimchi and other fermented vegetables (e.g. sauerkraut, traditional dill pickles), vegetable brine drinks, and kombucha tea. Each day they ate 6 servings (1/2 cup = 1 serving generally). The high fiber diet was rich in legumes, seeds, whole grains, nuts, vegetables, and fruits (increased their fiber intake from about 22 grams per day to 45 grams).

The fermented foods group ate six servings daily (e.g. 1/2 cup yogurt, kefir, fermented cottage cheese, kimchi, sauerkraut, traditional dill pickles, and kombucha tea). The high fiber group increased their fiber intake from about 22 grams per day to 45 grams, by eating a diet rich in legumes, seeds, whole grains, nuts, vegetables, and fruits.

High-fiber diets are associated with numerous health benefits such as lower rates of numerous chronic diseases and mortality. The consumption of fermented foods can help with weight maintenance and may decrease the risk of diabetes, cancer, and cardiovascular disease.

From Futurity: Fermented Food Diet Boosts Microbiome and Cuts Inflammation

In a clinical trial, 36 healthy adults were randomly assigned to a 10-week diet that included either fermented or high-fiber foods. The two diets resulted in different effects on the gut microbiome and the immune system. 
...continue reading "Fermented Foods Are Good For Your Gut Microbiome"

Published on Leave a comment on Missing Birth Canal Bacteria Can Be Restored to Cesarean Birth Babies

There are microbial differences (microbiome) in babies who are born by cesarean vs vaginal deliveries. Research shows that bacterial differences can be minimized by a simple procedure - swabbing the newborn infant with the mother's vaginal fluids (using a gauze pad).

An infant normally picks up bacteria during birth as it passes through the birth canal, and these bacteria "seed" (colonize) the baby's skin and gut microbial community. On the other hand, babies born by C-section are colonized by microbes floating around in the operating room (from doctors, nurses) and these are predominantly skin bacteria. These bacterial differences between babies born by vaginal birth or C-section persist and are thought to explain some health differences between babies born vaginally or by C-section.

Dr. Dominguez-Bello has been doing a long-term study in which babies born by cesarean section are immediately swabbed with a gauze cloth soaked with the mother's vaginal fluids (which contain the mother's microbes). This resulted in the infants' skin and gut microbial community being more like vaginally born babies. These microbial changes persisted during the first year of life.

Such big changes from such a small procedure!

From The Scientist: Maternal Vaginal Fluids Mimic Microbe Transfer of Vaginal Birth

Babies born by C-section carry an increased risk of immune and metabolic disorders later in life, which studies have suggested may be associated with the communities of microbes on and in their bodies at the time of birth.  ...continue reading "Missing Birth Canal Bacteria Can Be Restored to Cesarean Birth Babies"

Published on Leave a comment on Milk Chocolate Has Health Benefits

The findings of a recent study caught my eye - that eating milk chocolate daily was beneficial for health a number of ways. Consuming a 3.5 oz bar of milk chocolate daily did not cause weight gain, that it actually resulted in reducing hunger and desiring fewer sweets the rest of the day, increased beneficial polyphenols, improved the gut microbiome, and morning consumption decreased fasting glucose (good). Overall, it was best to eat the chocolate in the morning (as compared to the evening before bedtime). Yes!!!

The researchers studied postmenopausal women (48 to 62 years old) in Murcia, Spain who ate milk chocolate daily, or no chocolate for 2 weeks while eating as usual (regular dietary pattern), and then did the opposite for 2 weeks after a one week break. (Thus everyone ate chocolate daily at some point). This meant that the chocolate eaters actually ate slightly more calories during the study than those not eating chocolate.

The researchers state that a 2018 review of chocolate studies (clinical trials) found that overall eating chocolate daily for 2 to 24 weeks (each study lasted a different length) "does not change body weight or body fat distribution". Some studies also find that eating chocolate daily slightly reduces waist size (waist circumference reduction). And this is what they also found in this study.

How much chocolate? The women in this study ate 100 grams per day (3.5 ounces) - a normal sized chocolate bar! Chocolate lovers - rejoice!

From Medical Xpress: Starting the day off with chocolate could have unexpected benefits

A new study of postmenopausal women has found that eating a concentrated amount of chocolate during a narrow window of time in the morning may help the body burn fat and decrease blood sugar levels.  ...continue reading "Milk Chocolate Has Health Benefits"

Published on Leave a comment on Bacteria Are In the Developing Baby By the Second Trimester

We've known for a while that exposure to microbes during the baby's first year is important (and good) for the developing immune system. In addition, recent research suggests that during the second trimester of pregnancy the developing fetus already has microbes in its body which help "educate" the developing immune system.

An international team of researchers found that bacterial species are present in the fetus during the second trimester. They examined and found bacteria in the  gut, lungs, skin, and placenta of the fetuses. Gardnerella, Lactobacillus, and Staphylococcus species were found in most of the fetal organs. Streptococcus, Enterococcus, and Prevotella species were also frequently found, as well as other species. The view is that the microbes came from the mother ("vertical transmission of microbes").

What the researchers found exciting was not just that there were microbes living already in the fetus in the second trimester, but that these microbes "educate" the developing immune system, especially memory T cells. This prepares the newborn with all sorts of exposures (including harmful microbes) once it is born.

The researchers used genetic sequencing (16S ribosomal RNA sequencing) on fetal and placental tissues, which were obtained from second trimester (starting with week 13) abortions.

Excerpts from The Scientist: Microbes in Human Fetuses Spur immune Development

Over the last decade, scientists have shown that the fetal immune system comes online much sooner than was initially thought, but what type of antigens train nascent immune cells and how this affects subsequent development remain open questions. In a study published June 1 in Cell, researchers determined that second-trimester human fetuses harbor live bacteria in tissues all over their bodies that can activate fetal T cells.  ...continue reading "Bacteria Are In the Developing Baby By the Second Trimester"