BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: microbiome (Page 2 of 3)

Microbiome Genes have Macro-significance

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On November 8, 2018

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Ever been told that the little things matter in life? This same proclamation that you’ve been told by your elders rings true in your gut: one small modification to your human gut microbiome (a batch of bacteria that call your digestive tract home) can have drastic effects on your metabolism.

A. Sloan Devlin, assistant professor at Harvard medical school, carried out a study that proved the importance of the gut microbiome. She first located the gene in “an abundant gut bacterium” for an enzyme that processes bile acids. She then removed that gene from the bacterium. Next, she “colonized” “germ-free” mice with one of two types of the gut bacterium: either with the bile-processing enzyme or without the bile-processing enzyme. The results were surprising.

Credit: mcmurryjulie on pixabay

After both mice were fed the same high-fat, high-sugar diet, the mice without the bile-processing enzyme “had more fat in the liver and gained weight much more slowly than the other group. They also used proportionately less fat and more carbohydrate for energy.” Changing one single enzyme in a gut bacterium appears to change “whether the host is using [primarily] fats versus carbohydrates” for energy.

Even more staggering was the “correlation of lean body mass to energy expenditure.” Typically, in humans and mice, the more lean body mass an organism has, the more energy it expends. However, for the mice without the bile-processing enzyme, this relationship “broke down.” Devlin hypothesizes that this change could be due to a “signaling,” a process in which “physical states in the body trigger a cascade of genes to switch on or off.” Researchers can use this knowledge to treat diseases: figure out which microbiome bacteria activate which genetic switches, and better treatment for genetic problems such as, acid imbalances, metabolic disorders and obesity, may become a reality.

Devlin is sure to stress that this groundbreaking microbiome research is just her “first step.” Although this study was carried out on “germ-free” mice, Devlin dreams that one day she may use her research to improve the health of her own species: as Devlin states, her research brings her “one step closer to humans.”

 

Genetic Engineering will Create Super Humans?!

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On November 8, 2018

In Student Post

“Synthetic microbiome? Genetic engineering allows different species of bacteria to communicate”

Before seeking to analyze how genetic engineering enables the alteration of the microbiome, it is essential to understand the nature of the microbiome. Humans’ microbiomes consist of “trillions of microorganisms (also called microbiota or microbes) of thousands of different species.” Initially, peoples’ microbiomes are solely determined by their DNA; however, as time goes on, a person’s microbiome can be shaped by other factors, including the environment in which they live, or their diet. The microbiome contains both helpful and deleterious microbes, but “In a healthy body, pathogenic and symbiotic microbiata coexist without problem.”

According to researchers from the Wyss Institute at Harvard University, Harvard Medical School (HMS), and Brigham and Women’s Hospital, it may now be possible to create a “synthetic microbiome.” The team did a study in which they utilized a particular type of quorum sensing known as acyl-homoserine lactone sensing. Quorum sensing allows bacteria to regulate the expression of genes and to detect the size of bacterial colonies, through signal molecules. First, the team inserted “two new genetic circuits into different colonies of a strain of E. coli bacteria.” One of the circuits acted as a “signaler” and the other acted as a “responder.”

File:E. coli Bacteria (16578744517).jpg Picture of E. Coli bacteria

In short, the team inserted a single copy of luxl, a gene activated by the molecule anhydrotetracycline (ATC), into the signaling circuit. The signaling molecule formed by this gene then binded to the receptor circuit, which activated another gene, known as cro. The cro gene creates Cro proteins, and these proteins triggered a “memory element” within the responder circuit, in which two more genes, LacZ and another cro, were produced. If the signaling molecule is received (which it was), the presence of LacZ causes the bacterium to turn blue. Most importantly, the additional cro gene essentially keeps the “memory element” on, so this cycle continues.

To make sure that this system works in living organisms, the researchers tested it in mice. Signs of signal transmission in the mouse’s gut between the signaler S. Typhimurium bacteria and E. coli responder bacteria were detected. In other words, the engineered circuits allowed the bacteria to communicate with one another.

While these findings are extremely exciting, scientists have yet to discover whether or not other genetically engineered species of bacteria will also be able to facilitate communication between molecules. A Founding Core Faculty member of the Wyss Institute said that “[They] aim to create a synthetic microbiome with completely or mostly engineered bacteria species in our gut, each of which has a specialized function.” If this is achieved, we will move one step closer to becoming super humans!

Feature Image: “Free for Commercial Use” and “No attribution required”

Whole-Grain Bread: The Healthy Choice…or is it?

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On January 18, 2018

In Student Post

Contrary to popular belief, whole-grain bread might not be healthier for everyone. A new study has determined that whether white bread or whole-grain bread is healthier for you depends on the microbes in your gut. After studying 20 people for one week each, researchers found that some people’s blood sugar levels raised after eating standard white bread while others did not. Similarly, they found that some people’s blood sugar rose when eating standard whole grain bread. The researchers, Eran Elinav and Eran Segal, studied the mix of microbes in the stool samples as well as their genetic makeup.

This study is part of a growing group of studies that support personalized nutrition that is customized to your genetic makeup rather than a plan for everyone. The same group has also done other research in the nutrition field in Israel, where they studied how people respond to eating certain foods.

Gut Microbiome is Responsible for PTSD?

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On January 3, 2018

In Student Post

Recently, there have been many studies linking gut microbiome to PTSD. But how exactly are they connected?

Humans have an infinite number of organisms creating a unique composition of bacteria in the gut. It has been suspected before that any number of combinations of these gut microbiome can affect our health in different ways. One way is that they can cause neuropsychiatric disorders like PTSD or even just weaken mental toughness. Either way, the topic of gut microbiomes is definitely worth researching.

A recent study conducted by 22 scientists at Stellenbosch University in South Africa showed that compared to healthy, unaffected people, those with PTSD had noticeably lower levels of three gut bacteria: Actinobacteria, Lentisphaerae, and Verrucomicrobia. However, it was also noted from that study that the loss of these three gut bacteria may have occurred in earlier stages of life rather than the later stages when people generally develop PTSD.

According to a study conducted by researches of Oregon State University, when someone suffers from stress, their gut microbiomes become disordered and start to act oddly. Therefore, the lower levels of the three gut microbiomes could indicate that the levels of those microbiomes are throwing off the balance that is needed to maintain a stress and anxiety free mind which can prevent PTSD.

There is one catch about this result: that correlation does not confirm anything. Scientists conducting studies could only identify a correlation with gut microbiome and PTSD, but could not determine a cause.

Many are hopeful that these results will lead to discovery of future treatments because the microbiome can easily be changed with prebiotics, probiotics, synbiotics, or just dietary changes.

Although we do not know if these three gut microbiomes cause PTSD or come with PTSD, we do know that we are now one step closer to finding a cure or at least a better treatment for PTSD.

For more information click here or here!

Hunter-Gatherer to Westernized Human Gut Biomes

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On January 20, 2017

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Somewhere between the time of early hunter-gatherer humans, and the present-day humans living in modernized Western societies, the human gut biome lost much of its diversity. New research has contributed another clue as to the evolution of the human gut biome.

An international team of scientists studied the fecal samples of an intermediary group between hunter-gatherers and Westernized humans. The Bantu community in Africa is a traditional, agricultural population that has incorporated some available Western practices, including the use of antibiotics and therapeutic drugs.

 

Bantu people; Steve Evans,  https://commons.wikimedia.org/wiki/Bantu#/media/File:Mozambique001.jpg

The scientists compared the Bantu gut biomes to those of the BaAka pygmy population, who resemble early hunter-gatherer populations and have no Western influences, and to the gut biomes of humans living in modern, Westernized societies.

By analyzing the sequence data of the three human biomes, the scientists placed the Bantu’s biome composition in between the BaAka’s and Westernized humans’. The Bantu shared similar bacterial species as the BaAka, but lacked many of the traditional bacteria that the BaAka possessed. In fact, the BaAka had such a different biome composition that their gut more closely resembled wild primate biomes!

 

Based on the functions of the variable bacterial groups between the three populations, the team hypothesizes that the boosted carbohydrate-processing pathways in Bantu and American biomes is a result of the sugars in our diet, whereas the BaAka do not have much access to such foods and thus do not have such bacterial populations.

Ultimately, the scientists have accepted that our diet contributes significantly to our gut biome composition.

Possible Links Between Gut Microbes and Obesity, Cancer & Autism

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On January 17, 2017

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While the bacteria in our gut play a vital role in the digestion process, recent findings have suggested that it could effect much more in our bodies. New studies have found possible links between the bacteria in our gut and obesity, cancer and autism.

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A study done by Cornell University and King’s College London revealed that Christensenellaceae minuta, a strain of gut bacteria, was found more often and in larger quantities in people with lower body masses. To investigate whether the bacteria is actually linked with obesity, researchers added the same bacteria into the guts of mice and compared their weight gain to mice lacking the bacteria. The research showed that the mice with Christensenellaceae minuta gained noticeably less weight than the mice lacking the bacteria. While research is still in its early stages, these results have made an exciting connection between bacteria in our gut and weight gain, which could dramatically impact the future of our health.

In addition to obesity, the bacteria in our gut has also been linked to cancer- in both beneficial and detrimental aspects. Researchers from the National Cancer Institute tested the effect of gut bacteria on chemotherapy in mice and found that the chemotherapy was significantly less effective in the mice lacking the bacteria. Similarly, another study found that cyclophosphamide, an antitumor drug, was less effective in mice with insufficient gut bacteria compared to those with normal levels. While these studies showed positive links between gut bacteria and cancer, other studies have found adverse effects of gut bacteria.

Unfortunately, a study published in The Journal of Cancer Research in 2012 has made a possible connection between Lactobacillus johnsonii, a strain of gut bacteria, and lymphoma, cancer of the white blood cells. The study claims that the presence of this specific strain of bacteria could lead to the development of lymphoma. Another study done in the UK in 2013 found that a specific gut bacterium, Helicobacter pylori, has the ability to deactivate the part of our immune system responsible for regulating inflammation. In effect, this could cause stomach cancer and ulcers.

While it may seem like a stretch, numerous studies have found a possible link to autism and the bacteria in our gut. A study done in 2013 by Arizona State University found that compared to children without autism, children suffering from autism had lower levels of Prevotella, Coprococcus and Veillonellaceae, three strains of gut bacteria. Even more surprisingly, another study revealed that the presence of Bacteroides fragilis in the gut reduced autism-like symptoms in mice. Research in this field is still in its primary stages, as researchers are trying to figure out if these connection are in fact related, and if so, how the bacteria directly effects these conditions.

 

New Reason to Watch Your “Diet”: The Human Gut Microbiome and Competition

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On January 16, 2017

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The human body consists of approximately 100 trillion microbes, and in the digestive tract of the human gut alone it is estimated that there are trillions of microbes. Recent studies done by Athena Aktipis, a researcher at Arizona State University’s Biodesign Institute, have shown that people’s dietary choices either help to increase the cooperation between gut microbes and their human hosts, or they could potentially lead to conflict between the two.

The microbiota consists of bacteria, and the human microbiota contains about 500 different species of microbes. There is a possibility that the composition of these microbes could affect behavior, susceptibility to allergies, and even likelihood for obesity. According to several previous studies, exposure to intestinal bacteria prevents allergies in infants and young children. This has been determined by examining the noticeable difference between the compositions of intestinal bacteria in children who have developed allergies and children who have not. The current study further looks at cooperation and competition between human cells and other cells that coexist with them. Cells are cooperative between the human cells and gut microflora when bacterial cells produce energy and vitamins. It also is beneficial when bacterial cells help to detect pathogens that are dangerous to the host. Conflict on the other hand is more likely to occur when the needs of microbes and the needs of the host are at “cross-purposes”, or they contradict one another. This internal conflict could lead to chronic afflictions such as inflammatory diseases that are caused directly by the body’s attempt to maintain dominance in this “power-struggle” within the host.

These recent studies have also shown that sugar and fat are most likely contributors to conflicts that arise between host cells and microbes. This is due to the fact that fats and simple sugars also can be used by microbes such as E. coli, which further contributes to the conflict. The results of these studies suggest that a diet consisting of low fiber and abundant sugar leads to the conditions where conflict takes place between human cells and microbes. When their interests clash or coincide, the cells in the body trigger immune responses that lead to different afflictions that include a wide range of diseases, some of them being inflammatory. Similar to fats and simple sugars, iron is also potentially dangerous in the sense that a pathogen could steal iron from host cell proteins which would ultimately compromise the health and nutrition of the host. According to the studies, it is recommended to maintain a diet that has high nutritional density but also low concentrations of pathogens in order to promote cooperation and prevent any competition or conflict that could damage your overall health and wellness.

 

Further reading:

Gut microbiota in 2016: A banner year for gut microbiota research

The Effect of Diet on the Human Gut Microbiome: A Metagenomic Analysis in Humanized Gnotobiotic Mice

More Bacteria than Human?

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On January 15, 2017

In Student Post

The well being of humans is best when we are cooperating with others whether that be other humans or bacteria inside of us. According to Matthew Bull “the human gut microbiome and its role in both health and disease has been the subject of extensive research, establishing its involvement in human metabolism, nutrition, physiology, and immune function.” An imbalance in our microbiome will often result in some type of sickness so it is very important to keep our guts healthy. It is likely that there are more bacteria cells in our gut than there are our own cells. So in this image right here  there would be more bacteria cells than human cells. Some people even consider the microbiome a bacteria ecosystem that just happens to be in our gut. While this may sound bad, these bacteria often break down food for us and supply us with energy needed to do daily activities. It is truly fascinating to think that we have many living things inside of us that may even outnumber what is actually considered “us”. But is it possible for these bacteria to take over our bodies? The answer is probably no…we hope, but if we continue to eat well and stay healthy these bacteria should continue to help us. However, if we eat poorly and don’t stay healthy these bacteria can end up being a problem for use. So at the end of the day eating health helps the relationship between us and the bacteria inside of us stay healthy and lets us stay healthy.

The diet that we should have to keep a healthy relationship with these bacteria involve eating less sugar and fat and eating more fiber. A diet with a lot of fat and sugar but little fiber can lead to illness. It is also best to stay away from eating a lot of iron. There are some things that help our microbiomes such as milk, milk has proteins in it that help keep our microbiomes health. So eat less sugar, bad fats, and iron and eat more fiber and drink more milk.

 

The Microbiome’s Role in the Success of a Diet

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On January 11, 2017

In Student Post

Just in time for the many New Years resolutions where people promise to go on a diet to lose weight or get healthier, a new study covered by Huffingtonpost has found that the bacteria in your gut can affect the success of your diet.  This new research has demonstrated that all the diet alterations in the world, whether you give up pizza or ice cream, may do nothing if your intestinal bacteria are out of whack from a life of eating poorly.

Originally published in the journal Cell Host and Microbe, these new findings tell us that switching to a healthier diet may not help much, at least in the beginning, if you still have unhealthy bacteria left over from your non-diet days.

However, according to Dr. Jeffrey Gordon, a biologist at Wash U in St. Louis and senior author of the paper, the scientific community has found a way to “mine the gut microbial communities of different humans to identify the organisms  that help promote the effects of a particular diet in ways that might be beneficial.” In simpler words, research has shown that short-term dietary changes can alter the gut microbial community.

In order to demonstrate these findings, the researchers examined two groups: one that ate the standard, high-calorie American diet and one that ate a more plant-based, lower calorie diet. As expected, they found that those with the standard American diet had less diverse microbiota and that people with a plant-based diet had a more diverse, and healthier, microbiome. Diversity in the gut is important because it aids digestion, nutrient absorption, and immune system function; on the flip side, an unhealthy microbiome can contribute to inflammation, anxiety, depression, poor digestion and even autoimmune diseases.

Link to Image

The next step in the experiment involved analyzing the microbiome set-up in mice who had been colonized with bacteria from the human subject. These mice were either fed the native diet of their human donor (American or healthy), or the opposite diet. Analysis of the results revealed that all mice saw a change in their bacteria in response to the diet, but the bacteria of the American diet showed a weaker response to being changed to a plant-based diet ― their microbial communities didn’t increase and diversify as much as the mice colonized with the bacteria of the humans who ate a plant-based diet.

In conclusion, your gut would definitely benefit from a diet more heavily based on plants and vegetables, but if you have been eating a very unhealthy diet thus far, it may take a little longer to see results, as the makeup of your internal microbiome has to change.

Evolution of the Human Gut Microbiome

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On January 11, 2017

In Student Post

NIH Image Gallery Image Link

According to an article on Science Daily, Westerners have a very different human gut than hunter-gatherers. Research suggests that Westerners tend to have a less diverse human gut. However, the reason for why is still unclear. Researches from this study have observed two particular groups of people. The hunter-gatherers, known as BaAka pygmies, relied on foods such as fish, fruits, and vegetables. Whereas the group of Westernizers, the Bantu, relied on a market economy. The Bantu grew fruits, other plants and raised goats. They also used antibiotics and therapeutic drugs available.

The results of the study revealed that while the  BaAka and Bantu gut microbes were from similar bacterial species, the abundance of traditional bacterial groups was decreased in the Bantu. When researchers delved into what could have caused the difference between the two groups, they found that diets are the most important driver of microbiome composition in humans.

Another study done by evolutionary biologist, Andrew Moelle, suggests that humans and animals have inherited some bacteria from their ancestors. Moelle studied three types of bacteria living in the feces of wild chimps, bonobos, gorilla and a group of people from Connecticut. He concluded that 2 of the three bacterial trees matched primate relationships. Moelle also expressed how these relationships are getting harder to study due to the effect that industrialization and antibiotics have. They have reduced the diversity of bacteria living in and on humans.  Microbial geneticist, Julia Segre, expressed that humans have been exposed to antibiotics and modern life and as a result, Wild African apes might “still have their ancient gut flora, but the people in Connecticut might not.

A study done by Howard Ochman found that human guts most closely resemble the gut of a gorilla. Like the other researchers, Ochman acknowledges that as a result of modern humans there is a loss of microbial diversity. He also explains how this can be a problem because humans have lost a number of bugs that help digest plant matter. However, humans have gained others that help digest meat.

 

The Human Gut Microbiome and Autism Spectrum Disorders

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On January 11, 2017

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Researchers of the human gut microbiome have made connections to the autism spectrum disorder.  A gut microbiome involves the digestive tract microbes.  To learn more general information click here.  Studies tested DNA of children with gastrointestinal complaints.  Researches compared children with Autism Spectrum Disorder, and mainstream children.  It was found that children with Autism Spectrum Disorder had too many Clostridium or Desulfovibrio clusters.  To learn more about these gene clusters click here. Developing fever, receiving oral antibiotics, or ingesting probiotics are all likely to alter the gut microflora.  When children with Autism Spectrum Disorder do the above, they have exhibited improvement in their gastrointestinal pains; however, there hasn’t been scientific research, as it has only been found anecdotally. Research has been limited due to the difficult culture-dependent techniques; however, metagenomic technology could be used to discover and reduce the effects of the gut microbiome as a part in Autism Spectrum Disorder.

A longitudinal study completed in May 2016 shows more progress that scientists have made in discovering different aspects of autism in relation to the microbiome.  For two weeks, stool samples were collected from patients with autism and their siblings without autism in order to be compared. Sarcina ventriculi, Barnesiella intestihominis, and Clostridium bartlettii are organisms that are related to autism. They were found in the stool samples of children with autism, but not their siblings. Gastrointestinal symptoms were reported on days 6-8 of the study for children with Autism Spectrum Disorder, where Haemophilus parainfluenzae was detected at the onset. These patients also exhibited behavioral challenges during these days.

Though scientists have not found a diagnosis for Autism Spectrum Disorder yet, it is clear that the gut microbiome plays a role in the development. Further research that is not merely based off of a handful of patients needs to be completed to learn more.

Photo of Gut Flora

Sometimes less is better. Especially in the case of germs.

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On March 3, 2016

In Student Post

Scanning electron micrograph of Escherichia coli

Photo by NIAID

Apparently we’re healthier than we thought!!

Throughout the 20th century, scientists who studied the microbiome had thought that humans contain around 9000 times more germs than human cells.  Scientists now believe, however, that that number is more like 30 percent.

Micro biologists: Ron Sender, Ron Milo, and Shai Fuchs took on the challenge to actually find out the ratio of bacteria to cells in the human body.  First, its important to know the types of cells that make up the human body.  One might think that muscle and fat cells make up the largest portion of human cells in the body but that is wildly incorrect.  In fact, despite their weight and size dominance, they make up a measly .2 percent of the body’s cells while blood cells make up 90 percent (mostly red blood cells).

The colon houses the most bacteria in the human body by a long shot.  This makes sense as it is the pathway for human feces out of the body and reaches up to 5 feet in length.  The “trio” of scientists estimate that the human body contains somewhere between 30 trillion and 50 trillion cells and that the bacterial count is around 30 to 60 percent higher than the amount of cells.

Now, despite the insightful findings of Sender, Milo, and Fuchs, the microbiome community still has a lot of research to do into the subject of germ:cell ratio in humans and scientists believe that the trio missed some important factors in their experiments and as geneticist Julie Segre points out, “Other researchers also point out that the new paper’s calculations focused on bacteria. Yet the body can host other types of microbes as well. Those include viruses, fungi and archaea (Ar-KEE-uh). Viruses tend to vastly outnumber bacteria, so they could skew the microbe-to-human cell ratio upwards.”

The most important and prevailing part of the trio’s research was that the amount of bacteria that we have in our body and attached to human cells is much less than we had previously believed.

https://student.societyforscience.org/article/cell-recount-people-host-far-fewer-germs?mode=topic&context=79

Original Article 

Trust Your Gut and Exercise

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On January 18, 2016

In Student Post

 

File:Wild garden of the gut bacteria 5.jpg

According to an article on GEN news, the level of Microbiomes contained within the Gut is influenced by exercise as a young child. Microbiota are the organisms that share our body space, and the gut has a particularly concentrated region of these organisms. Scientists estimate that gut microbiomes make up anywhere from 1-3% of total body mass. As it turns out the saying, “trust your gut” has some scientific merit. Microbiomes promote healthy brain function and promote anti-depressant effects, as well as adding up to 5 million genes to the human genome. Having a healthy gut is a key to overall biological health.

A recent study by Colorado University claims a connection between early life exercise and healthy microbiome activity. This study was conducted with rats, with one group young of rats exercising daily contrasted against a control of rats who behaved normally. The younger exercising rats experienced a growth of probiotic bacteria in their guts, more so then the stationary rats or even older rats who exercised. Researchers “emphasize the ability of exercise” to promote a healthy brain and metabolic function. In the future, Colorado University will look for ways to promote healthy microbiome activity in adults who have a much more stagnant microbiome structure.

 

Sources:

1.http://www.genengnews.com/gen-news-highlights/gut-microbiome-influenced-by-early-life-exercise/81252160/

2.http://learn.genetics.utah.edu/content/microbiome/

3.http://patient.info/health/the-gut

 

Overload of Calories

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On January 14, 2016

In Student Post

You may not realize this, but we lose a significant amount of calories while we are asleep. Now imagine if the calories we burned while resting or sleeping did not get burned. If those calories did not burn while we were asleep it could cause us to become obese much more easily. The process of our metabolism rates getting slower does not occur until later on in most people’s lives. Unfortunately, those who have to take antipsychotic drugs may approach this problem sooner than expected.

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New research has been found by the University of Iowa Health care that an antipsychotic drug, risperidone, effects people’s metabolism rates. The reason why is due to the gut microbiome going through an alteration through it’s bacterial anatomy. Kirby Carlarge, University of Iowa pediatrician,  and Justin Grobe, University of Iowa professor in pharmacology, worked together to test mice on risperidone. After two months the mice on risperidone gained an extra 2.5 grams compared to the control group of mice. Carlarge and Grobe used the total calorimetry machine to understand whether aerobic-resting states or non-aerobic resting states in terms of metabolism have been affected. The total calorimetry machine is able to give the exact measurement of the total energy change by inputting exact amounts of oxygen into the mice, outputting exact amounts of carbon dioxide, and the reaction of heat production. The results were the aerobic-resting metabolic rate to remain the same, but the anaerobic-resting metabolic rate had decreased . Therefore, the shift in the mice’s microbiomes does not affect the aerobic-resting metabolic rate, but instead affects the anaerobic-resting metabolic rate.

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Risperidone draws a connection to weight gain due to the alteration in the bacterial anatomy of the microbiome. However, despite this understanding of risperidone there are no definite ways of preventing this situation occurring. Therefore, it is very likely for patients undergoing this treatment to become obese. Do you think there are other variables that could change and prevent risperidone creating this effect?

We Eat What We Are: The Importance of Microbes in Our Gut

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On January 14, 2016

In Student Post

Unknown

Photo of microbes (licensing information here)

Ever since the discovery of the microbes, scientists have become very aware of the miniature world of microbes. This early awareness was later translated to an understating of how bacteria and other microbes effect the world we live in. Of course, early scientific and medical research often focused on microbes that cause diseases and how to treat them. However scientists have become aware that each individual is in fact a biome of microbes living on our exterior and inhabiting our interior organs.  Bacteria also play an important role in digestion helping us break down certain foods, producing vitamin and allowing for efficient absorption of nutrients. Increasingly, investigators have began exploring how the micro biome in our digestive track impacts our health and wellbeing.

Gut bacteria appear to play a role in matters of obesity, the development of certain types of cancer and ulcers. They do so by producing certain chemicals that affect a variety of health outcomes. Gut bacteria also produce a wide variety of neurology related chemicals that affect mental processes such as depression and anxiety disorders. Some studies now point to a relationship between autism and particular levels of gut bacteria.

The recognition of the importance of gut bacteria in health and disease have implications in a number of areas. First of all it suggests that a healthy diet should involve the encouragement of the development of good gut bacteria. It also suggests that gut bacteria diversity is a positive goal. Lastly, the results of many of these studies of the significance of gut bacteria in regard to disease point to the need to incorporate the study of an individuals gut bacteria as part of the treatment regiment to fight particular illnesses

 

 

Possible Connections between the Gut Microbiome and the Brain

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On January 10, 2016

In Student Post

It is not a new concept that gut bacteria affects a person’s health. But this article published in The Atlantic explains how they may even affect the human brain. Some researchers believe that the microbiome may play a role in regulating how people think and feel. Scientists have found evidence that this community of bacteria (trillions of cells that together weigh between one and three pounds) could play a crucial role in autism, anxiety, depression, and other disorders.

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 https://en.wikipedia.org/wiki/Fecal_bacteriotherapy#/media/File:E_coli_at_10000x,_original.jpg

Much of the most intriguing work has been done on autism. For years, it has been noted that about 75 percent of people with autism also have some gastrointestinal abnormality, like digestive issues or food allergies. This has prompted scientists to search for potential connections between the gut microbiome and autism; recent studies find that autistic people’s microbiome differs significantly from those of control groups. Caltech microbiologist Sarkis Mazmanian specifically focuses on a species called Bacteroides fragilis, which is seen in smaller quantities in some children with autism.  Mazmanian and several colleagues fed B. fragilis from humans to mice with symptoms similar to autism. The treatment altered the makeup of the animals’ microbiome, and more importantly, improved their behavior: They became less anxious and communicated more with other mice.

Perhaps the most well-known human study was done by Emeran Mayer, a gastroenterologist at UCLA. He recruited 25 subjects (all healthy women) for four weeks. He had 12 of them eat a cup of commercially available yogurt twice a day, while the rest didn’t. Yogurt is a probiotic, meaning it contains live bacteria. In this case it contained four species: bifidobacterium, streptococcus, lactococcus, and lactobacillus. Before and after the study, subjects were given brain scans to gauge their response to a series of images of facial expressions—happiness, sadness, anger, and so on.

To Mayer’s surprise, the results showed significant differences between the two groups. The yogurt eaters reacted more calmly to the images than the control group. “The contrast was clear,” says Mayer. “This was not what we expected, that eating a yogurt twice a day for a few weeks would do something to your brain.” He thinks the bacteria in the yogurt changed the makeup of the subjects’ gut microbes, and that this led to the production of compounds that modified brain chemistry.

As scientists learn more about how the gut-brain microbial network operates, they think it could be manipulated to treat psychiatric disorders. And because these microbes have eons of experience modifying our brains, they are likely to be more precise and subtle than current pharmacological approaches, which could mean fewer side effects. “I think these microbes will have a real effect on how we treat these disorders,” neuroscientist John Cryan says. “This is a whole new way to modulate brain function.”

Love and happiness really do come from the bottom of your… gut?

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On January 10, 2016

In Student Post

Serotonin is the famous neurotransmitter oft attributed to causing joyous type emotions.  Unlike most neurotransmitters, which are produced predominately in the brain and nervous system, a recent study mentioned in a review article estimate that, “90 percent of the body’s serotonin is made in the digestive tract. […] [C]ertain bacteria in the gut are important for the production of peripheral serotonin.”

uBiome - Microbiome Sequencing Gut Bacteria Sample Kit

 

Interesting play on words of the “Microbiome.” The gut microbiome comprises most of our body but very little of our mass… It outnumbers our cells 10 to 1! [Source]

 

Researchers at the California Institute of Technology (Caltech) sought to identify a link between the gut microbiome and the production of the serotonin neurotransmitter. Peripherally made serotonin is already understood as a product of the digestive tract, however, is there a link between the myriad of bacteria that compose our gut microbiomes and the neurotransmitter? What they found, was surprising; notwithstanding the known communicative link between the nervous system and the microbiome, the researchers found that the microbiome is not directly responsible for most of the production of the neurotransmitter.  The bacteria interact and stimulate the production of serotonin by the intestinal cells.

 

To arrive at this conclusion, the researchers studied the effects of “germ-free” mice.  They found that the mice that exhibited a dearth of flora within. Experimental results indicated that the mice produced around 60% less serotonin than mice with normal gut microbiomes.  The experiments also demonstrated an interesting result that may lead to future studies on the serotonin deficiency treatments–the researchers found that when augmenting the gut microbiomes with bacteria responsible with serotonin production stimulation, the levels of the neurotransmitter increased. Of course, the subject is vastly complicated, and will therefore require extensive research to more fully understand.

Original Article

Study from Article

Serotonin Wikipedia Page

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You Are What You Eat

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On January 9, 2016

In Student Post

8146322408_a76aab3ae2_o

Original Link To Image: https://www.flickr.com/photos/pnnl/8146322408

It has been known for some time by scientists that variations in food intake lead to various different gut floras.  However, that theory had only been tested on mice…Until now.  Lawrence David, assistant professor at the Duke Institute for Genome Sciences and Policy, led an experiment that resulted in the discovery that different foods not only lead to different bacteria, but the bacteria themselves experience gene variations.  Although the discovery itself is truly amazing, the celerity at which the changes occur is the most impressive.  University of Chicago’s professor of medicine Eugene Chang specializes in gastroenterology originally thought the changes would take months or even years but the study showed that the changes started to take place within a couple of hours.  There were also changes in the amount of bile acid secreted into the stomach and that microorganisms native to cheeses and cured meats were stronger against this.  The real question is “Why is this relevant?”  To Chang, the first is evolutionary.  Ancient humans who experienced rapid dietary changes could successfully switch from nuts and berries to meat with little gastric distress and maximum absorption of nutrients from even the most unrecognizable foods.  The second is the effects of diet on certain diseases.  Chang, who has been leading a research team to discover the connection between  B. wadsworthia and colitis in mice is yet to apply these tendencies to humans.  However, he believes there could be a connection.  His experiments show just how sensitive the body is to dietary change.  Dramatic changes in ones diet could lead to a brief exposure to harmful diseases such as inflammatory bowel disease.  The experiments are difficult to conduct however because according to David, it’s hard to find even 10 people willing to dramatically change their diets for science.

original article: http://www.scientificamerican.com/article/the-guts-microbiome-changes-diet/

similar article on the gut micro biome: http://www.medicalnewstoday.com/articles/290747.php

Using Poop to Save the People

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On January 9, 2016

In Student Post

     Bi YO! What’s going on readers? Today I will discuss the recent phenomenon of gut microbiome transplants, and more interestingly, how recent research has allowed patients to be treated through the use of human feces.

Our microbiome, a term coined by Joshua Lederberg, is a system used “to signify the ecological community of commensal, symbiotic, and pathogenic microorganisms that literally share our body space and have been all but ignored as determinants of health and disease.” They are the bacteria insi

Microbiome Chart Explanation (https://commons.wikimedia.org/wiki/File:Microbiome_analysis_flowchart.png)

de of us and are vastly abundant in our body. A Clostridium Difficile infection causes diarrhea and the colon to be inflamed. However, there had not been a truly successful treatment to this issue until recently. But recently, the poop of the people has proven itself to be a powerful panacea. Ari Grinspan became performing FMT’s, fecal transplantations, in 2013, and has done so with a 92% success rate. In these procedures, feces is taking from a healthy, clean donor. It is vital that this happens. Then, they transfer the healthy sample into the colon of the unhealthy patient while the patient is undergoing a colonoscopy. Scientists are actually currently uncertain of why it works so well- one theory is that increased bacterial competition stops growth of Clostridium Difficile. Regardless, the process is groundbreaking- maybe it wasn’t waste after all.

Junk Food Encourages Disease

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On January 9, 2016

In Student Post

According to a recent discovery posted in Science News, a typical American diet, consisting of poorly nutritional foods, leaves one prone to getting sick by weakening their immune system. Interestingly enough, this issue is rooted in cells that are not your own. In your gut microbiome, there are countless varieties and numbers of bacteria, all working away at the food that passes through your gut. Now, these bacteria are actually quite manipulative, and besides from feeding off of the food that you eat, teach your immune system what to attack, like an instructor or tutor for your immune system, albeit a biased one. These bacteria have colonized your body. They’re not just going to let some pathogen get in the way of their free meal ticket.

(What it looks like in there)

What happens when you eat certain foods, like junk foods, is that your gut microbiome changes. Different bacteria thrive on the fatty or sugary foods while other bacteria that survive off of more complex starches and carbs fade away, changing the demographic of your gut microbiome. This limited variety also limits the amount of invaders your immune system knows as hostile, or understands how to deal with, and therefore, you are more susceptible to disease, or medical complications.

(Actual photo of a biofilm found in the gut)

This was proven by taking samples from fit and obese humans and inserting them in otherwise sterile mice. Their resulting microbiomes grew, and the mice with the obese implant suffered more medical problems than the mice with the fit implant. This is because there were not enough “trainer” bacteria in the first mice’s gut to help train it to fend off disease, and thus it got sick more easily. So don’t go blaming your immune system the next time you get sick. It may be your fault for avoiding real, nutritional food (not just salad), and not taking care of it.

The moral of the story is to eat your vegetables and serve the bacterial overlords that have taken host in your body.

They’re good for you.

Trust me.

 

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