BioQuakes

AP Biology class blog for discussing current research in Biology

Category: Student Post (Page 1 of 48)

What’s Happening with Human Gut Microbiome Research?

Researchers are on the brink of reveling strong links between the human gut biome and the health of the individual. The potential of this research seems limitless. The human gut biome is responsible for all sorts of conditions, ranging from inflammatory bowel disease to diabetes, multiple sclerosis, autism, cancer, and AIDS. Furthering our understanding of this biome could lead to cures for these conditions.

Soon, the first microbiome therapies will be available on the market for purchase. Rebiotix, the first acquisition of a microbiome company, is currently working on developing a therapy for C. difficile infections. In an interview, Lee Jones, founder and CEO of Rebiotix, said

It has become evident through research that the microbiota that humans carry have a significant impact on human health, [The C. difficile therapy] has the potential to be the first human gut microbiome product approved anywhere in the world.”

The C. difficile therapy would mark the first human gut biome therapy on the market, a major advance in medicine. This year is supposed to be an inflection point for human gut biome research. It is expected that research will finally show results proving that the therapies have effects on humans. If this comes true, the future for microbiome medicine is bright.

 

Are Antibiotics Truly Good?

Antibiotics are also known as antibacterials. They can destroy or slow down the growth of bacteria in the body. They’re used to fight against certain infections that attack the immune system. Although the use of antibiotics can save a person’s life, the use of them can have repercussions. Most gut bacteria can recover quickly from the use of antibiotics, however there can be long-lasting effects. The changes it makes isn’t necessarily harmful, but that isn’t always the case. 

 

The gut microbiome, has roughly 10 trillion to 100 trillion bacteria and other microorganisms that live in the digestive tract, contributes to health by synthesizing vitamins, metabolizing drugs and fighting pathogens. Anything that disrupts the balance of microorganisms, such as antibiotics, which can kill both “good” and “bad” bacteria, has the potential to cause disease.” 

Research done in a 2016 study shows that being exposed to antibiotics as an infant can alter the gut microbiome in a baby and “weaken the immune response for years to come.” The duration of breastfeeding reduces the frequency of infections, and the risk of being overweight. Conclusions of the study conveyed antibiotic use in a child during the breastfeeding period could weaken the beneficial effects of long term breastfeeding. In addition, the results suggest that intestinal microbiota is affected by the long term metabolic benefits breastfeeding has. 

Antibiotics are the most common type of medicine prescribed to young children in the Western world. As mentioned previously, antibiotics can dramatically alter the gut microbial composition. Research shows, “…the gut microbiota plays crucial roles in immunity, metabolism and endocrinology, the effects of antibiotics on the microbiota may lead to further health complications.” Exposure to environmental microorganisms and parasites is important for healthy development and maintenance of the immune system. In Western countries contact with microorganisms has significantly decreased over the recent decades. “ As antibiotics are a factor that reduces exposure to microorganisms and disrupts the body’s natural microbiota, this… may help explain the observed effects of antibiotics on the immune system.”

“Since infancy is a crucial time for microbial establishment, it is necessary to evaluate the influence of antibiotics given quite liberally during this period. Antibiotic treatment given to both infants and toddlers has already been shown to strongly affect microbiome composition. In an attempt to understand the effects of antibiotics on the microbiome, both human reports and experiments in animal models have been employed”.

Although, antibiotics are a powerful source of medication that can fight off infections and save lives when used properly, it is essential to not overuse or become too reliant on them. Overuse contributes to the resistance to fighting bacterial infections, and hurts the body’s natural microbiota.

 

Your Gut Microbiota Could be Influencing Mental Health Disorders: Could Psychiatric Medications Change This?

Mental Health and Gut Bacteria 

Newly published research in rodents and continuing research in humans explores the effects of psychiatric drugs, including antidepressants, on the composition of gut bacteria. They have examined how the effects on gut microbiota, typically caused by naturally occurring metabolic changes in the gut, may influence connection with the nervous system rendering some negative effects on mental health. The most common mental health conditions connected to changing composition of the gut microbiome are anxiety and depression. 

This comes from a recent study that Medical News Today has released, reporting on different bacteria that play a part in synthesizing neuroactive compounds in the gut. These neuroactive substances interact with the nervous system, influencing the likelihood of developing depression or anxiety. This research has been proved more extensively and directly in rodents, but the research in humans provides similar conclusions, allowing scientists to partially conclude the effects in humans–research on this topic in humans is likely to expand greatly in the near future. 

How can gut microbiota be affected by different psychotropics? 

The Study and Results:  

Provided this link between changing gut bacteria and mental health, researchers from University College Cork, in Ireland, set out to investigate this in rodents. First, the team “investigated the antimicrobial activity of psychotropics against two bacterial strain residents in the human gut, Lactobacillus rhamnosus and Escherichia coli.“The psychotropics that the researchers conducted this study with included fluoxetine, escitalopram, venlafaxine, lithium, valproate, and aripiprazole.

Then, the scientists studied “the impact of chronic treatment with these drugs” on the rats’ microbiota. The scientists gave the rodents psychiatric drugs for a period of 4 weeks, ending the study by inspecting the effects of the drugs on the rodents gut bacteria. They found that lithium and valproate, mood stabilizers that can treat conditions including bipolar disorder, raised the numbers of certain types of bacteria. These included Clostridium, Peptoclostridium. On the other hand, selective serotonin reuptake inhibitors (SSRIs), fluoxetine and escitalopram (both antidepressants), ceased the growth of bacterial strains such as Escherichia coli.

“We found that certain drugs, including the mood stabilizer lithium and the antidepressant fluoxetine, influenced the composition and richness of the gut microbiota,” says head researcher Sofia Cussotto. 

Conclusions from the Study, and what the Future Holds 

Dr. Serguei Fetissov, a professor of physiology at Rouen University, in France commented on the study, saying: “At the moment, it would be premature to ascribe a direct role of gut bacteria in the action of antidepressant drugs until this work can be reproduced in humans, which is what the authors now hope to do.”

However, the implications and further goals and hopes of this research is to directly prove that “psychotropic drugs might work on intestinal microbes as part of their mechanisms of action,” says Cussotto

Do you think it is too early to assume a direct connection between gut bacteria and mental health in humans? Comment about this below.

Further Research

https://www.medicalnewstoday.com/articles/amp/326299 

https://www.medicalnewstoday.com/articles/319117.php#1 

 

 

 

NASA Conducts Twin Study As We Approach Space Travel

NASA found a pair of twins that were both astronauts and sent one into space while the other stayed home. As space travel increasingly becomes more feasible, this study examing the gut microbiome is significant.

Here’s what happened:

You probably didn’t know that in 2015, Scott Kelly was sent into space, and in 2016, became the first American astronaut to spend almost one full year in space. Scott has a twin brother Mark Kelly who is a retired astronaut (yes, two astronauts in one family); Mark remained on Earth during his brother’s trip to space to act as a control for the study.

Turek and Vitaterna, two researchers that worked on the Twin Study from NASA’s Human Research Program, examined Scott and the changes in his gut once he returned. They also collected 2 fecal samples before he left for space, 4 samples during the year, and 3 once he returned.

Turek says the comparison between Scott’s fecal samples before and after the trip is more valuable to the study than the comparison between Mark and Scott.

Researchers found that Scott’s gut bacteria shifted while in space. 90% of gut bacteria are classified as Firmicutes or Bacteroidetes; Scott’s post-space trip fecal samples found that Firmicutes increased and Bacteroidetes decreased but returned to normal when he returned to Earth. Vitaterna says this was a “shift in the remodeling of the structure of this community of microorganisms.” Researchers don’t know if this is good or bad. However, going forward, they are going to investigate microgravity as the main suspect.

Image result for scott kelly astronaut

“On Jan. 19, 2015 Expedition 45/46 Commander, Astronaut Scott Kelly along with his brother, former Astronaut Mark Kelly at the Johnson Space Center speak to news media outlets about Scott Kelly’s 1-year mission aboard the International Space Station.” 19 January 2015  Photograph by Robert Markowitz

So what is the gut and why does it matter anyway? The gut microbiome is home to a complex and diverse community of microorganisms. The microorganisms such as bacteria, viruses, and fungi, live in the digestive tract. Vitaterna mentions how powerful bacteria is to our body and says, “There are studies that link changes in the gut microbiome with neurological and physiological conditions, like Alzheimer’s disease, Parkinson’s disease, autism, and schizophrenia.” Vitaterna believes that we can protect other parts of our body by protecting the gut. The gut has a huge influence on digestion, metabolism, and immunity, especially. Researchers have only recently found that when the gut microbiome experiences changes, bones, muscles, and the brain do as well.

This research can be used to protect astronauts and “space tourists” in their travels using lithium hydride. Earth’s planetary magnetic field can no longer protect humans from radiation from solar and cosmic particles once travelers leave earth’s orbit. However, this research into the microbiome will provide more insight into what scientists can do to make space travel safe.

 

Why We Should Embrace the Bacteria in our Gut

Surprisingly enough, through research conducted in the California Institute of Technology, it was discovered that EC cells depend on Microbes found in the gut to produce Serotonin. EC Cell stands for Enterochromaffin Cell, and they can typically and easily be found in the small intestine, colon and appendix. They are shaped like polygons or cones. Serotonin is a neurotransmitter, with defects related to diseases ranging from Osteoporosis, Cardiovascular Disease, and even depression. According to Merriam Webster, a famous online dictionary, Microbes are microorganisms and “germs”. This oversimplified understanding of the significance of a microbe is representative of the overall population’s ignorance on the matter. Bacterium are forms of Microbes, and thus have very negative connotations. That is why this discovery regarding the correlation between the germs in EC cells and Serotonin (a neurotransmitter we can attribute much of our good mood) levels is so important.

To begin with, the peripheral Serotonin levels in mice with standard EC cells, and peripheral Serotonin levels in mice with microbe/bacteria/germ free cells were tested and compared. Astonishingly, the mice with standard EC cells had 60% higher levels of Serotonin than mice with germ free EC cells. The newly tested levels of Serotonin were affirmed by the side effects typically associated with increased levels of Serotonin. For example, the mouse’s gastrointestinal motility would increase overtime if their EC cells were unaltered, as opposed to if their EC cells were germ-free. Overall, it is safe to conclude that having Bacteria in the gut can actually make someone less depressed, and healthier all in all.

How our day-to-day food intake shapes our gut microbiota

Our diet is a significant modulator of changes in our gut microbiota structure, particularly at an individual level. The concept that what we eat is related to health is not a new idea. With new studies and experiments on the human gut microbiota, scientists are finally beginning to truly understand how exactly food impacts our health. The commonly heard phrase “you are what you eat” has been proven true. If you were to et a strawberry or hamburger, the food enters your digestive system and comes across the intestinal microbes. The way your body processes the food is influenced by the microbes that are living in your gut.

This is an image of food items that would help to create a balanced healthy diet.

Other than only being related to diet, levels of physical activity and sleep patterns can also affect the human gut microbiota. In a recent study, “for 17 consecutive days, 34 healthy participants were asked to self-record their food consumption using a food report.” From the results, the researches concluded that the variation in the daily microbiome is related to food choices, and not to standard nutrients.

For example, a vegetable such as spinach, which is rich in iron and also contains many other nutrients, such as fiber, minerals, and carbohydrates. All of these nutrients help to strengthen spinach’s relationship with the gut microbiome. Therefore, “nutritional advice should focus more on recommending people combine fruit and vegetables in their daily diet instead of prioritizing specific fibers.”

To conclude, a varied diet helps to maintain a well-balanced microbiome while also at the same time also giving your body the nutrients it needs in order to stay healthy.

How can we survive on raw foods out in the wild? Microbes may help.

In a recent study, Vayu Maini Rekdal was ordered to create a menu with foods that could be eaten either cooked or raw. He made chia seed breakfast puddings for volunteers who would eat the food cooked or eat the food raw. Their stool samples would then be taken so that Professor Rachel Carmody could analyze the microbes that had a role in the digestion in the different styles of food. She had previously found out that the microbiomes within mice quickly changed when they went from raw sweet potatoes to cooked sweet potatoes and she wanted to see if that rang true in humans as well.

The results of her human experiment showed that the microbiomes within the human gut changed rapidly like that of the mice once the diet was changed. However, she found that the microbiomes didn’t change drastically between raw and cooked meat, unlike the sweet potatoes. Dr. Carmody explained that it is necessary for the microbiomes to shift when eating raw sweet potatoes because it is harder for humans to digest them when they are raw and cooking them changes the types of molecules that need to be digested.

Dr. Carmody believes that the microbiomes are able to change so quickly because our ancestors might have needed to change diets quickly when they didn’t have access to a certain type of food. Even though we could be eating food that is uncooked, less tasty, and harder to eat, our gut microbes allow us to adapt to those types of food in order to stay alive. Therefore, it could be thought that our microbiomes have evolved alongside humans. However, she also found that mice are able to survive on the microbes that are found within humans, which leads some to believe that humans haven’t totally co-evolved with our microbiomes.

More research must be conducted in order to get a better understanding on the interactions between humans and their microbiomes since it is a very complex relationship. Why do you think it is important to learn more about our microbiomes? Maybe one day we can start eating foods that were previously unable to be eaten.

 

 

The Effect of Malnutrition on the Gut Microbiome

Malnutrition is a brutal issue that has plagued the world for years and affects communities that can’t afford to help themselves. Recently there has been a link between malnutrition and the condition of the gut microbiome. The gut microbiome describes the microbiota, micro organisms, that live in the digestive tract and have  David Relman, a microbiologist at Stanford University School of Medicine, explained the two studies that believe that tailoring a specific diet for people suffering from malnutrition can improve their gut microbiomes and subsequently improve their health.  Tahmeed Ahmed, director of nutrition research at the International Centre for Diarrhoeal Disease Research, and Jeffrey Gordon, a gastroenterologist and microbiome researcher at Washington University, started two studies into how malnutrition effects the microbiome. After observing healthy and malnutrition babies grow into toddlers, the two noticed how malnutrition causes the micro biome to remain immature and stay in the same state as a babies instead of maturing like a normal person’s. The two then conducted studies on mice looking for changes in mice with malnutrition and found that the mice had weaker bones, less muscle mass, and impaired metabolism. From these results the two scientists have deduced certain foods that should be given to help fix immature mircobiomes. Current food in care packages do not have these necessary requirements to fix microbiomes. They contain food like rice and powedered milk, but chickpea, soy, peanut flours, and bananas have been proven to help the microbiome and should be added into care packages. By targeting the microbiome in malnutrition, these scientists have been able to reverse the negative affects and force the body to catch up on lost growth. The leading obstacle with this discovery is that malnutrition effects the poor, who do not have access to the healthier kinds of food required to repair their crippled microbiomes.

CAP v.s. HAP: Pneumonia in the Microbiome

While many may not know this, there are various types of pneumonia.  The most common variant, CAP (community-acquired pneumonia), is the most prevalent strain of the infectious disease.  As the name may suggest, CAP is acquired through daily interactions (whether that may be contact or inhalation of pathogens which could later travel to the lungs) with any surface that has bacteria such as Streptococcus pneumoniae and Haemophilus influenzae.

While pneumonia is a well-known infectious disease among the population in 2019 due to the plethora of literature and research done on it, most people do not know that other variants of pneumonia are contracted in different ways, through different strands of bacteria.  HAP (hospital-acquired pneumonia or healthcare-associated pneumonia) can be contracted from extended periods of time in a hospital, nursing home, or rehabilitation center.  This pneumonia variant is a result of the P. aeruginosa and Staphylococcus aureus bacteria, which are completely different from the bacteria that cause CAP.

The demographics of people who suffer from each of these variants appear to be mostly similar with the only difference being that CAP has a stronger association with COPD whereas HAP still has an association with COPD, but in a smaller portion of the demographic.  Similarities between the two are the increased risk if one uses tobacco products or suffers from COPD, however, aside from these shared risk factors, the two variants are different in treatment methods (effectiveness of certain antibiotics) and contraction.

Relative to the microbiome, the major differences in the diseases can be found when testing biomarkers.  According to Ann Transl and Thomas Tschernig of the “Annals of Translational Medicine”, “lower levels in HAP as compared to CAP were found for MMP-8 and soluble E-selection, higher levels in HAP as compared to CAP were found for protein C”.

The significance of this discovery lies in the fact that the different variants of pneumonia could not be prevented, diagnosed, or treated in the same ways, thus exemplifying the dangers that would arise if the different variants were not classified and identified.

Additional resources.

 

 

Discovering and Using Your Personal, Biological, Tiny Army

Bacteria is an important part of our biology, so important that we are essentially 99% bacteria. A lot of this bacteria is part of the human gut microbiome. This topic has been picking up interest in the field of biology, and have shown linkage to many diseases such as inflammatory bowel disease and obesity. Not only do the bacteria in our gut play a role in preventing these diseases, but their symbiotic relationship helps us maintain metabolic functions.

File:The first and second phases of the NIH Human Microbiome Project.png

This is a depiction of the numerous types of bacteria in our microbiome.

Until recently we were unable to study these bacteria due to our inability to cultivate them in a lab; however, due to new advancements in sequencing technology we can now see how big of  role they play in our biology and our functions. These bacteria are “estimated to harbor 50- to 100-fold more genes, compared to the hose. These extra genes have added various type of enzymatic proteins which were non-encoded by the host, and play a critical role in facilitating host metabolism.” For example, gut microbiata is very important in fermenting unabsorbed starches. These bacteria also aid in the production of ATP. A certain type of bacteria generates about 70% of ATP for the colon with a substance called butyrate as the fuel.

File:Immune Response to Exotoxins.png

This image shows the interaction between the gut and the immune system. The immune system targets bacteria, but somehow not our gut bacteria. 

Another large role of the gut microbiome is its interactions with out immune system and nervous system. The bacteria in our gut suppress the inflammatory response in order to not be targeted by the immune system. This allows for a symbiotic relationship between us and the bacteria inside of us. This allows the gut bacteria to help regulate the inflammatory response without being stopped by the very thing it’s regulating. Without these bacteria our inflammatory responses would be completely out of the ordinary.

These findings with gut bacteria are fairly new and there is much more to come regarding their use in the field of medicine. Something to think about that I found fun was how little of us is really human. Ninety nine percent of you is bacteria, which essentially means that we are pretty much just giant colonies of bacteria. Kind of gross/amazing when you think about it.

Is it Time For a Raw Food Diet?

A recent article details a study by scientists at UC San Francisco details the effects of cooked food versus raw food on the gut microbiomes of mice. By feeding some mice raw potato and others cooked potato, scientists discovered that in mice, raw food damages certain microbes. Scientists discovered that raw foods contain antimicrobial compounds that damaged microbes in mice. Surprisingly, differences between the mice were due to chemicals found in plants. Turnbaugh’s is currently analyzing the specific chemical changes that occur after cooking in order to further understand how cooked food impacts the mice microbiomes.

 

Another interesting effect of the raw food on mice was weight loss. The researchers were curious as to whether the weight loss was due to the altered microbiomes. They were ultimately not due to the microbiomes, because when the altered microbiomes were put into mice eating a normal diet, those mice put on fat. The researchers are currently unsure of why this happens.

Interested in the possible ramifications of his discovery on human diets, Turnbaugh  conducted a second experiment using human test subjects. The raw food diets altered the microbiomes of the human test subjects, an exciting find for the researchers. The effects of these altered microbiomes are still unclear and is being further researched. For now, raw food diets don’t seem to have massive benefits and in cases of contaminated meat can be harmful to humans, but only further research will tell.

The Making of the Largest Human Microbiome Database

Scientists from all over the world, including China, Denmark and Sweden are planning to design a microbiome map of the human body. These scientists will be be analyzing over one million microbial samples from the mouth, skin, reproductive tract and the intestines to complete their goal. This article states that in order to provide a baseline of micro ecology research on a very large population sample, the scientists will explore and use Mouse Genome Informatics to draw their map.

 

Dr. Liu Ruixin from the Shanghai National Clinical Research says, “By studying the changes in the human microbiome between the normal and pathological states, before and after treatment in larger metagenomics datasets, and analyzing its effects on human metabolism and health, in the future we will provide more possibilities for new therapies in many fields such as metabolic diseases, cancer, reproductive health and newborn health.”

So far, scientists have analyzed over 10,000 samples of metagenomic sequencings.

This research will be important for future studies, projects and treatments because it will provide context and specific information about the human microbiome.

 

This photo captures the structure of DNA that will aid the scientists in developing the map.

Running on Bacteria

In a recent article it was found that elite athletes could have a step above average people due to some of the bacteria found in their gut. Researchers took stool samples what from elite runners from the Boston marathon in 2015 and found that there was a spike in appearance of the Veillonella. An in depth definition of what Veillonella is can be found here. For the purposes of the research it was said that these bacteria appears to take lactate produced by the muscles in the body and turns it into a compound that helps out the endurance of a runner. This same trend of increase of Veillonella was also found in 87 ultramarathon runners and Olympic rowers after a workout.

To prove their findings they cultivated one strand of Veillonella called Veillonella atypical from the runners and fed it to mice. They also gave the mice lactate in order to give the Veillonella food to feed on in the mice’s gut. The results to this was a 13 percent increase to the length of time these mice could run. However at the same time not all of the 32 mice that they gave this strand of Veillonella actually reacted to it. With the mice the Veillonella used the carbon from the lactate to grow and ended up producing propionate. An in depth definition of propionate can be found here. Propionate ended up raising the heart rate and oxygen use in the mice. For humans propionate also raises metabolism.

 

The overall take from these experiments give an interesting take on how these elite runners can do what they do. The food that someone eats isn’t the only thing that affects the microbiome in a humans gut. These bacteria could appear in the gut after only one session of working out or it could be something only certain people have and others don’t. It could also just be something that people who don’t focus heavily on running experience but it isn’t quite known yet. These things could also appear to The overall fact that bacteria in the stomach could be a big part of someone being athletically gifted is new and interesting to the scene of science. I find this cool as I’m a runner and a basketball player myself so to see that the bacteria in my stomach is what helps me do everything I do is incredibly interesting. Next time you run a mile or finish a game of your preferred sport thank your gut. The bacteria in there could just be the reason your body can do it at all.

 

Health and Disease in a New Light

Microbiota are groups of organisms that live on and in some mammals. Animals, such as humans, who live in a state of mutualism with these organisms have them mostly on parts of their body with large surface areas. This includes skin and the intestinal tract. The human gut microbiome is a complex community of organisms that have been studied over the past decades and most intensely within the past fifteen years. So far the information on the human gut microbiome is limited and the research on it is somewhat inconclusive, raising more questions than it answers questions; however, that is a side effect of most research that is just beginning to be analyzed more in depth. The idea that we are just now starting to study and understand these organisms that have lived on and in us for centuries is a topic that is cutting edge and very interesting.

Microbiota

A short coverage of information about microbiota in the intestinal tract includes the following. In mammalian animals, these organisms play an important role in the formation of intestinal mucosa as well as a healthy systematic immune system. Animals that lack microbial cells contain abnormal numbers of several immune cell types and immune cell products, as well as have deficits in local and systemic lymphoid structures. Therefore, their spleens and lymph nodes in them are poorly formed and their intestinal mucosa, deficient. Mice with a lack of microbiota were known to have a lower amount of plasma producing cells – which make antibodies of a certain type. This is due to the fact that the microbiota is regulated by the plasma cells in mammals and it is found unnecessary to have a large amount of them in animals lacking the organisms. These mice also exhibited an impaired ability to regulate cytokine levels – any of a number of substances, such as interferon, interleukin, and growth factors, which are secreted by certain cells of the immune system.

In 2010 there was a study done that was comprised of making cultures of these organisms and bacteria in the human intestinal tract outside of the human body because we do not have the necessary technology to study the microbiota in their hosts. This study yielded the publication of a paper titled “Gut Microbiota in Health and Disease” which gives a detailed overview of the findings of this study. Briefly, a colonization of mice lacking microbiota with altered Schaedler flora (ASF) was insufficient to promote differentiation of Th17 cells (which play an important role in defense against infection), despite the fact that ASF includes a number of bacteria from the Bacteroidetes phylum (microbiota). Researchers concluded the there is no way to be sure of the affects of microbiota. Meaning although there was no lack of microbiota, the mice still had an immune system deficiency in the same way that mice lacking any microbiota did. Since the health and abundance of microbiota in the gut microbiome is so closely related with the ability of the immune system of the host, it is concluded that changes in the microbiome can lead to onset of diseases/illnesses in the host. These factors can also change with environmental changes such a dietary choices of the host. Understanding the dynamics of the gut microbiome under different conditions will help us diagnose and treat many diseases that are now known to be associated with microbial communities.

Analyzing the affects of microbiota in the human gut can reveal topics about human pathology that we did not know before. Therefore, scientists look forward to the development of studies on this topic.

Who’s Smarter: Girls vs. Boys?

According to the legendary myth, boys are smarter in science, technology, engineering and mathematic fields due to biological deficiencies in math aptitude. Recent studies show that this is not true. A study, by Jessica Cantlon at Carnegie Mellon University, evaluates 104 young children by scanning their brain activity while watching an educational video. When the scans were compared, it showed that both groups were equally engaged while watching the videos and there was no difference in how boys and girls processed math skills. To further this study, researchers compared brain maturity in connection to skill, by using brain scans of adults who watched the same educational video. Which concluded that the brains scans in adults and children -of both genders-  were statistically equivalent. This study confirmed the idea that math activities, in both genders, take place in the intraparietal suclus, which is the area of the brain involved in processing numbers, addition and subtraction, and estimating.

So, why are mathematic and computer science fields predominantly males? Well, it could be for the held stereotype that women and girls are biologically inferior at mathematics. This conventional image could also be linked to the fact that females were prevented from pursuing higher education until the 19th century. To show this unconscious bias, an Implicit Association Test was taken by employers. This test reveals an unconscious bias by forcing you to quickly group various words together. If the word man was immediately linked to math, then an implicit bias is shown. This study unveiled the prejudice that men were twice as likely to be hired for a simple math job since, men and women employers displayed a prejudice against women for a perceived lack of mathematical skill.

Don’t Kill Me Immune System! I’m a Friend.

Believe it or not, but not all bacteria is out to get you, especially some of your gut bacteria. These helpful bacteria can aid in digestion and overall healthy, but the question is, why doesn’t your immune system kill them just like harmful bacteria? In other words, how does the immune system differentiate between good and bad bacteria? For now, we are not really sure, but a study from March of this year by Immunologist Ivaylo Ivanov and his team at Columbia University could bring us closer to understanding this form of cell signaling.

The study focuses particularly on the interaction between T cells and segmented filamentous bacteria in the gut. Normally, the immune system would produce antibodies that would bind to antigens on the foreign cell’s surface. As a result, the cell would be marked for destruction by the immune system. However, through an experiment on mice, the researchers found that although the T cells were activated by the segmented filamentous bacteria, the T cells did not destroy the bacteria.

These gut bacteria located in human, mouse, and fish intestines cling themselves to the gut wall and have antigens. So why aren’t they killed? Well, the antigens are packaged in tiny vesicles located near the tip of the hook-like appendage that the bacteria uses to cling to the gut wall: the holdfast. Sorry, that’s about all I can give you. The rest is speculation at this point.

Nonetheless, Ivanov and his team discovered something previously unnoticed by finding these vesicles that hold antigens in segmented filamentous bacteria. They speculate that the T cells read antigens in different ways based on whether or not it’s exposed on the outside of the cell or packaged in a vesicle. In the end, this a big discovery that peaks my interest, especially for its implications on the study of cell signaling. What’s your hypothesis as to why the T cells don’t attack the gut bacteria?

Should We Be Carbo-loading? The Effects of Resistant Starches on the Gut Microbiome.

What is Starch?

By definition starch is a polysaccharide composed of a chain of glucose molecules held together by glycosidic bonds. Starch is common in nearly all green plants and is used for short term energy storage.

Different Types of Starches

Starch can come in two distinct forms: amylopectin a compound with a complex system of branching glucoses, and amylose a simple straight chain of glucose molecules. Because of amylopectin’s larger and more complicated nature it has a much larger surface area than amylose making it significantly easier to digest. The amylose cannot effectively be broken down by the enzymes of the digestive system. Instead it is left to be dealt with by the human gut microbiome. For this reason it is commonly referred to as a resistant starch.

How are Resistant Starches Beneficial?

An international research article including authors from Harvard Medical School suggests that resistant starches have a myriad of benefits. Some resistant starches which thwart digestion in the stomach and small intestine, make their way all the way down to the large intestine where they are subject to fermentation by the microscopic bacteria of the human gut. The fermentation process can metabolize a multitude of different useful products. For example some significant and common place output of gut fermentation are simple fatty acids. One key short chain fatty acid created during this process is Butyrate, the preferred fuel oof the cells lining the colon. In addition to Butyrate there exist many other short chain fatty acids that help maintain and fuel the body. These fatty acids can be used for many different purposes, all beneficial to both the gut microbiome and the host. The benefits may range from weight loss to curbing the progression of chronic kidney disease.

In addition to their ability to be changed into more useful forms, resistant starches also serve to enhance the effectiveness of the gut microbiome. Constant ingestion of resistant starches can stimulate an increase in the size and health of gut microbiomes in addition to raising host metabolism.

Common Uses For Resistant Starches

Resistant starches are often used in weight reducing diets in order to encourage an increase in metabolic rates. Although results of these diets are often compelling, a diet must consist of all types of food groups and should contain a variety of vitamins and minerals. Eating only amylose and other resistant polysaccharides will not on its own help you achieve weight loss. It should be paired with exercise and an otherwise healthy diet.

Should resistant starches be used in dieting or do they promote malnutrition? There are many benefits to a diet high in resistant starches, including building up a healthy gut microbiome. However you cannot survive solely on carbohydrates. This is a complex question, and I would be interested in hearing your opinions in the comments.

 

 

 

Can the microbiome influence stem cell growth and effectiveness?

The human microbiome is one of the most overlooked and under appreciated aspects of the human anatomy, mostly because it isn’t technically us. When you think of the microbiome, you instantly think of the stomach. Well, another organ the microbiome can have a large affect on is the large intestine. In my research this summer, I went in depth into how high fat diets can affect cancer and inhibit stem cell growth. Specific fats like arachidonic acid, or any type of lard, can cause stem cells to lyse and become bubble-like structures, instead of the branching structure they are supposed to have. These fats can also cause genetic discrepancies, and cause certain genes like Lgr5, which controls stem cell mitosis, to either be lessened or exponentially greatened, either way it isn’t good.

These stem cells are housed in crypts in the colon, and are surrounded by mainly Paneth cells and enterocytes, and remain dormant in these little holes in the colon until they’re called upon. When they are needed, they are used to repair possible tears in the intestine, or for some other function.

Now, you’re probably wondering what all of this has to do with the microbiome, but that’s what I will now explain. If an unbalanced diet is added to the gastrointestinal tract, it can have a negative effect on the microbiome and cause it to not do its job properly. As I previously stated, this can also inhibit the stem cell growth and reproduction in the colon, and can even cause cancer. Most of the microbiome is found in the small intestine and colon, as stomach acid makes the stomach wall almost completely sterile. Therefore, a poor diet will have the biggest impact on these two organs. If a poor diet is present, this can increase the amount of bad bacteria and parasites found in them. These parasites and bad bacteria can then damage and kill the already compromised stem cells, and can also begin to damage the intestine itself, which then can’t be repaired because of what has been done to the stem cells already.

This goes to show that what we eat can have a much bigger impact throughout our entire bodies than we can possibly imagine, and is a prime example as to why a balanced and healthy diet is necessary.

 

Yes, Some of Us Have Different Human Ecosystems.

Our human ecosystems inside of us are composed of countless quantities of cells. However, only 10% of those cells are human cells.  Jeroen Raes , a Biologist based in Belgium, made a vital and fascinating discovery about the other 90%. He discovered that there are three different possible ecosystems inside individual humans. Each person has one of these three ecosystems: bacteriode, prevotella or ruminococcus. These ecosystems are composed of hundreds of trillions of harmless bacteria. One could explain our relationship with these bacteria as symbiotic, as we give them a share of food and they return the favor by helping us digest food and convert it to energy. Furthermore, these bacteria help us fight disease, and can even make us happier by triggering our neurons to release more serotonin. Raes’ experiment tested people from the US, Japan, and Denmark. Despite each regions unique diets, Raes claims to have found no correlation between diets and their individual ecosystems. Furthermore, Raes found no correlation between their age/genetic makeup and individual ecosystems.

People who have the bacteriode system “have a bias” toward bacteria that get most of their energy from proteins and carbohydrates. Bacteriode ecosystems also have more bacteria that make greater quantities of vitamins C, B2, B5, and H. On the contrary, both prevotella and ruminococcus ecosystems mostly digest proteins that are sugar coated. Both of these ecosystems also have more bacteria that create vitamin B1 and folic acid.

Raes’ findings have yielded very confusing results. Even Raes has conceded that he is unsure as to why only three total human ecosystems exist. Moreover, Raes admits his sample size of only a few hundred people will increase with more time and funding. Raes hopes to further his research on these unique human ecosystems, and potentially find links to obesity, diabetes, Crohn’s disease, and autism.

 

Can Processed Foods Soon Be Harmless?

Any discussion of processed foods usually revolves around the negative effects of consuming them. However, a new study has found a specific human gut bacterial strain called Collinsella intestinalisthat is capable of completely reducing the drawbacks of eating processed foods.

Scientists from Washington University School of Medicine in St. Louis discovered that Collinsella intestinalis breaks down the chemical fructoselysine into pieces that do not affect the host’s body. Fructoselysine is one of the chemicals that are formed during food processing. It is commonly found in numerous processed foods that we eat, such as pasta, chocolate, and cereals. In the study, mice were given samples of Collinsella intestinalis as well as processed foods to see how the human gut bacteria would interact with the fructoselysine.

The primary function of the human gut microbiomes is to “digest food otherwise indigestible by human enzymes and deliver nutrients and metabolites for the biological benefit of the host.”

Results from the study showed that mice with the Collinsella intestinalis in their system showed “an increase in the gut microbial communities’ ability to break down fructoselysine into harmless byproducts.” The fructoselysine was “metabolized more efficiently” in the presence of the Collinsella intestinalis.

One scientist from the study noted that “future studies are required before scientists will be able to identify specific capacities of individual microbes to clean up potentially deleterious chemicals produced during modern food manufacturing.”  Humans aren’t completely immune to processed foods just yet.

However, it is still promising that scientists have found that Collinsella intestinalis is in our foreseeable future in terms of being able to eat processed food without any negative effects. Processed foods are consumed by many people throughout the world, and with this recent study they may not be as harmful as people think.

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