Tag: microbiome

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Which came first, antibiotics, or antibiotic-resistance? A study of Uncontacted Amerindians.

The geographical location of the Yanomami tribe as a whole. The specific village exists in the highlighted region.   (Image courtesy of Viralfast)

Background

The Yanomami people are patches of isolated South American tribes who occupy mountainous regions of southern Venezuela. Recently, a Yanomami tribe of 34 subjects discovered by helicopter, was investigated by a team of researchers who accompanied medical care professionals who were providing care to the villagers. These researchers, Clemente et. al. (2015), then wrote the paper, “The microbiome of uncontacted Amerindians’ to analyze this population which was uniquely untouched by Western Society. An interesting topic that this research paper addresses is antibiotic-resistant bacteria. Antibiotic-resistance are the adaptations of a bacterial species in response to antibiotics. Antibiotics are medications that have been developed in more recent times to destroy bacteria cells but not human cells. They do this by targeting specific differences between the two types of cells, for instance, penicillin inhibits the synthesis of the peptidoglycan layer of bacterial cell walls a feature not present in animal cells. Other bacteria have distinct DNA replication processes and some antibiotics are able to interrupt that function as well. This Yanomami population is intriguing because their microbiomes are likely the most accurate representation of an ancient human microbiome due to their isolation from the Western world. The presence of antibiotic-resistant bacteria in the Yanomami gut provides evidence for the claim that antibiotic-resistant bacteria have been around since before the invention of antibiotics, so stay tuned for a persuasive evidentiary argument further down. Clemente et. al.  also state that the Yanomami population that is sampled is the most diverse microbiome ever recorded. It is important to understand what kind of diversity the researchers are talking about. The Yanomami show extremely high beta diversity when compared to Guahibo, Malawi, and U.S. populations but exhibit low alpha diversity amongst individuals in the village population. Beta diversity represents the differences in species composition among samples while alpha diversity is just the diversity of each sample. This means that the Yanomami microbiome sample is extremely unique but microbiomes within that sample are very similar, this is most likely due to the Yanomami leading vastly different lifestyles than Western societies and individuals in the village being in extremely close quarters with each other (eating the same food, drinking from the same water source, no waste removal, etc.). Continue reading “Which came first, antibiotics, or antibiotic-resistance? A study of Uncontacted Amerindians.”

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The Human Salivary Microbiome: Where the environment trumps genetics

Background

Genetics and the environment; how do these interact? Do they always interact, or do genetics sometimes overrule characteristics learned from our environment? The question of nature, generally thought of to be our genetic make-up, versus nurture, the environments we’re exposed to in our developmental years,  has been the topic of debate by scientists and philosophers for centuries. Yet, the definitive answer still frustratingly eludes us. Some things, like the number of limbs we’re born with, are entirely decided by genetic factors. Other things, like many of our behaviors, rely on an interaction between genetics and developmental environment. Continue reading “The Human Salivary Microbiome: Where the environment trumps genetics”

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Individual Response to Drugs May Be Influenced by Your Gut Microbes

You probably know someone — or are someone — who says ‘____ drug just doesn’t work for me.’ or, ‘____ drug really messes me up’. Individual response to drug dosage is a pervasive confounding issue in health care. We know some of the pieces of the puzzle; age, metabolism, activity, and overall health are all factors contributing to individual drug response, but what if your guts have something to do with it, too? Bacteria present in the human gut make up what is called the ‘Human microbiome’, and it is the newest frontier in health research. Continue reading “Individual Response to Drugs May Be Influenced by Your Gut Microbes”

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Could the Amish have it Right?

Asthma can be regulated by microbes.
Asthma can be regulated by microbes (credit: t3.ftcdn.net ).

 

Background:  Can leading a simple traditional life correlate to health in non intuitive ways such as acting as a buffer against the development of asthma? Recent studies have shown that asthma is less prominent when microbial diversity is high (Genuneit, 2012); this trend has been observed in children involved in farming (Mutius,2010). Genuneit demonstrate that children who are exposed to farming have a 25% decreased chance of experiencing asthma (Genuneit, 2012). Logically it is sensible that the diversity of microbes would be higher in children exposed to farming, with all the dirt, hay and animals that comes with it, than children who are not exposed to that environment and live in more consistent sanitary lifestyle. In other words the diversity of a bacterial community across subjects (farm children vs. non-farm children) is much higher in children exposed to farming than those who were not. But how is such a phenomenon achieved? Continue reading “Could the Amish have it Right?”

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Hitting Malaria where it hurts: how to eradicate the Malaria carrying mosquito.

Picture of a mosquito
Anopheles gambiae, the mosquito responsible for carrying the Malaria causing Plasmodium falciparum. Image from Scientists Against Malaria.

Why should you care?

When talking about the leading causes of mortality (discounting war and starvation) a few big causes pop into most people’s minds: heart disease, cancer, and HIV-AIDS. In the westernized world, one that doesn’t come to mind is malaria, largely due to our advanced medical care and simply not having a large population of the malaria carrying mosquitoes in the genus Anopheles. However, malaria still infects roughly 225 million people per year and causes roughly 1 million deaths, the majority of which are in Africa (Murray et. al, 2012). A major field of medical research is devising methods of intercepting insect-borne diseases such as malaria, yellow fever, and the insidious Zika virus before human infection. That is, somehow preventing the mosquitoes from spreading the disease or even being infected in the first place, rather than treating the symptoms of the diseases in humans. One such experimental method is to cause significant mosquito mortality by spreading the bacterium Wolbachia, a parasite that is harmless to humans but lethal to mosquitoes after a blood meal. What would this mean for the rest of the environment and organisms? In an ideal scenario the Wolbachia parasite would target and swiftly execute only Anopheles mosquitoes, which are the ones carrying the malaria causing Plasmodium, while leaving all other types of mosquitoes that help sustain an ecosystem unharmed. There is still a lot of research to be done, but we are finding out some things about this potential biocontrol already. Continue reading “Hitting Malaria where it hurts: how to eradicate the Malaria carrying mosquito.”

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What happens to your microbiome when you stop eating gluten?

The Gluten-free Diet

Celiac Disease is an autoimmune condition in which the immune system mistakenly attacks and damages the villi of the small intestine when it detects gluten. This damage can cause pain, fatigue, and diarrhea. If left untreated it can lead to complications such as infertility or cancer. Only a small number of people- around one percent of the population- actually suffer from Celiac Disease. A gluten-free diet is used as treatment for both celiac disease and non-celiac gluten sensitivity. Even though it is unknown whether a gluten-free diet is beneficial to people who do not have Celiac Disease, many people have adopted a gluten-free diet to eat healthier or lose weight. The number of people eating gluten-free is rising, with 17% of Americans actively avoid including gluten in their diet (Riffkin 2015). Continue reading “What happens to your microbiome when you stop eating gluten?”

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Does your gut control your brain?

When studying mental illness, the brain has long been the focal organ of interest. Psychiatry and neurobiology examine communication from the brain and how its chemical imbalance produces central nervous system (CNS) disorders such as depression and anxiety. However, microbiology presents a new avenue of inquiry that is looking from the opposite direction: how is communication to the brain affecting mental health? This is a provocative question under investigation through recent studies of the microbiota of our gut. Continue reading “Does your gut control your brain?”

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Fixing itchy scalps could be as easy as balancing bacterial communities

Background

Microbes are everywhere. They live in our backyards, on our pets, in our homes and even on and inside of us! Microbes are the bacteria, fungi and viruses that exist in a particular environment, including the human body, soil, plants and the kitchen counter (Marchesi & Ravel, 2015). Our first experience with microbes is usually at home, where we are taught to wash our hands to prevent us from getting sick. “You can’t eat without washing,’ your aunt might say, “there are germs all over your hands!’ Your aunt is right. For every human cell in our body, there is a microbe cell to match it (Sender et al., 2016). However not all of these microbes are harmful.

Continue reading “Fixing itchy scalps could be as easy as balancing bacterial communities”