The Human Microbiome: An Organ In Its Own Right
The human microbiome is composed of communities of bacteria that have a greater complexity than the human genome itself. Large-scale metagenomic projects , such as the European Metagenomics of the Human Intestinal Tract and the Human Microbiome Project, have reported 3.3 million unique protein-encoding genes as compared with the entire human genome, which has around 23000 genes. These studies have described the beneficial functions of the normal gut microbiota on health down to the genetic level. The human microbiome has extensive functions such as development of immunity, defence against pathogens, host nutrition including production of short-chain fatty acids important in host energy metabolism, synthesis of vitamins and fat storage as well as an influence on human behaviour, making it an essential organ of the body without which we would not function correctly .
The human microbiome plays an important role in control of vital homeostatic mechanisms in the body. These include enhanced metabolism, resistance to infection and inflammation, prevention against autoimmunity as well as an effect on the gutbrain axis. SCFA, short-chain fatty acid.
What Is A Microbiome
A microbiome is the community of micro-organisms living together in a particular habitat. Humans, animals and plants have their own unique microbiomes, but so do soils, oceans and even buildings. Watch our short animation to learn more.
The microbiomes of things
But how come we are now suddenly so excited by research into microbiomes and what they do? One of the simplest explanations is that we now have the tools to allow us to capture, at different omic levels, e.g. genomes, transciptomes and metabonomes, a whole microbiome and its microbiota and metagenome. We can look into a system across time and across multiple samples, and for the first time determine whos there and what they are potentially doing, and what we have found is astounding. We are now able to take a holistic rather than reductionist approach to try and explain how different microbiomes are involved in ecosystem and biosystem function.
One of the features of microbiome research is that it is based on a multi-disciplinary research model, unlike traditional microbiology, where a scientist can make a career looking at a single species. In microbiome research, due to the large and complex datasets, the microbiologist needs, for example, biological chemists to create the data for metabolite profiles, and physicists to help make sense of it and answer the research question set in the first place.
You can read more about microbiomes in the current issue of Microbiology Today.
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Microbiota Members Of The Microbiome
The microbiota comprises all living members forming the microbiome. Most microbiome researchers agree bacteria, archaea, fungi, algae, and small protists should be considered as members of the microbiome. The integration of phages, viruses, plasmids, and mobile genetic elements is a more controversial issue in the definition of the microbiome. There is also no clear consensus as to whether extracellular DNA derived from dead cells, so-called “relic DNA”, belongs to the microbiome. Relic DNA can be up to 40% of the sequenced DNA in soil, and was up to 33% of the total bacterial DNA on average in a broader analysis of habitats with the highest proportion of 80% in some samples. Despite its omnipresence and abundance, relic DNA had a minimal effect on estimates of taxonomic and phylogenetic diversity.
When it comes to the use of specific terms, a clear differentiation between microbiome and microbiota helps to avoid the controversy concerning the members of a microbiome. Microbiota is usually defined as the assemblage of living microorganisms present in a defined environment. As phages, viruses, plasmids, prions, viroids, and free DNA are usually not considered as living microorganisms, they do not belong to the microbiota.
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Probiotic 40 Billion Cfu Guaranteed Potency
And since modifications in the microbiota have been connected to intestinal conditions like irritable bowel syndrome, adding “excellent” bacteria in the form of probiotics should enhance your health. However ” You might have 7 people take the exact same probiotic and only have one report a certain distinction.”Officials in the E.U., where supplements are more heavily controlled than in the U.S., have not authorized making use of the word probiotic to back any health claim.
So we asked scientists at the leading edge of probiotic research to help us separate truth from hype, and pros … from cons. Here’s what you need to understand. A lot of the probiotic strains included to foods are chosen because they are safe and can be manufactured inexpensively and easily. They’re not necessarily the ones that are best at preserving health or dealing with disease.
Shoot for 50 to 100 billion CFUs of a combo of lactobcillus and bifidobacterium. Beginning with a large quantity of CFUs will either keep you riding high or set off little but yucky reactions, like gas or nausea. If you see those, scale back to 50 billion, then 20 expense, till you feel like your usual self.
Go the direct path – health benefits. Usage 2 to 5 billion CFUs in an OTC probiotic suppository, or damp an oral capsule to soften, then place it. Pros suggest doing this every other day at the end of your period .
Why Did We Ignore Our Microbiome For So Long
Normally, when people think of bacteria in the body, they think of pathogens. That’s why research focused on these harmful bacteria for a long time and ignored the good bugs.
The reason, argues biologist Sarkis K. Mazmanian of the California Institute of Technology, is our skewed view of the world. Our narcissism held us back we tended to think we had all the functions required for our health, he says. But just because microbes are foreign, just because we acquire them throughout life, doesnt mean theyre any less a fundamental part of us.
Another reason is the lack of modern technology. Although the first studies on the microbiome emerged as early as the 1680s with Antonie von Leewenhoek, who found striking differences between his own fecal and oral microbiota, the methods used in the past weren’t adequate to fully investigate the microbiome. Now the existence of modern techniques allows the isolation of ALL bacteria, even the hard-to-grow anaerobic ones, and the ability to understand what these microbes are good for!
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Who Defined The Word Microbiome And What Exactly Does It Mean
The word microbiome was coined by Joshua Lederberg in 2001. He signified the ecological community of commensal, symbiotic and pathogenic organisms that share our body space.
Although technically the human microbiome was defined as the complete genome of all microorganisms in and on the human body, the term is now usually used synonymously to refer to the community of all microorganisms in this habitat.
Microbial Networks And Interactions
Microbial interactions visualizedthrough microbial co-occurrence networks
Microbes interact with one another, and these symbiotic interactions have diverse consequences for microbial fitness, population dynamics, and functional capacities within the microbiome. These interactions can either be between microorganisms of the same species or between different species, genera, families, and domains of life. The interactive patterns within these webs may be positive ” rel=”nofollow”> mutualism, synergism, or commensalism), negative , or neutralwhere there is no effect on the functional capacities or fitness of interacting species Microbial life strategy concepts can influence outcomes of interactions. For example, microorganisms competing for the same source can also benefit from each other when competing for the same compound at different trophic levels. Stability of a complex microbial ecosystem depends on trophic interactions for the same substrate at different concentration levels. As of 2020 microbial social adaptations in nature have been understudied. Here molecular markers can provide insight into social adaptations by supporting the theories, e.g., of altruists and cheaters in native microbiomes.
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Is It True That The Human Body Wouldn’t Be Able To Function Properly Without Our Microbiome
The human body is a complex ecosystem which has long been thought to be able to exist as its own physiological island. BUT WE WERE SO WRONG!
Without the trillions of microbes we share our body with, we would struggle to break down essential nutrients, to receive signals from the body concerning our state of hunger or satiety, or to keep our immune system in check!
What Is The Gut Microbiome
Bacteria, viruses, fungi and other microscopic living things are referred to as microorganisms, or microbes, for short.
Trillions of these microbes exist mainly inside your intestines and on your skin.
Most of the microbes in your intestines are found in a pocket of your large intestine called the cecum, and they are referred to as the gut microbiome.
Although many different types of microbes live inside you, bacteria are the most studied.
In fact, there are more bacterial cells in your body than human cells. There are roughly 40 trillion bacterial cells in your body and only 30 trillion human cells. That means you are more bacteria than human .
Whats more, there are up to 1,000 species of bacteria in the human gut microbiome, and each of them plays a different role in your body. Most of them are extremely important for your health, while others may cause disease .
Altogether, these microbes may weigh as much as 25 pounds , which is roughly the weight of your brain. Together, they function as an extra organ in your body and play a huge role in your health.
Summary:
The gut microbiome refers to all of the microbes in your intestines, which act as another organ thats crucial for your health.
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What Does The Microbiome Do
The microbiome plays a key role is some very important bodily functions. It assists with immune system regulation, mental health and digestion. Though we are only at the beginning of understanding what other roles the microbiome plays in the body, scientists are clear that it does affect the following systems.
What Is The Human Microbiome
Each of us has an internal complex ecosystem of bacteria located within our bodies that we call the microbiome. The microbiome is defined as as community of microbes. The vast majority of the bacterial species that make up our microbiome live in our digestive systems.
According to the Department of Chemistry & Biochemistry at the University of Colorado, the human microbiota consists of the 10100 trillion symbiotic microbial cells harbored by each person, primarily bacteria in the gut. The human microbiome consists of the genes these cells harbor.
Our individual microbiomes are sometimes called our genetic footprints since they help determine our unique DNA, hereditary factors, predisposition to diseases, body type or body set point weight, and much more. The bacteria that make up our microbiomes can be found everywhere, even outside our own bodies, on nearly every surface we touch and every part of the environment we come into contact with.
The microbiome can be confusing because its different than other organs in that its not just located in one location and is not very large in size, plus it has very far-reaching roles that are tied to so many different bodily functions. Even the word microbiome tells you a lot about how it works and the importance of its roles, since micro means small and biome means a habitat of living things.
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Is It True That We Humans Are Genetically More Similar To Each Other Than Our Individual Microbiomes
Interestingly, our microbiome is what makes us so special: if we compare the human gene catalogue with our microbiome, our human genetic diversity pales in comparison. In the gut alone, where the majority of our microbiota are located, 3.3 million genes are reported to exist, compared to 22,000 genes present in the human genome. Human individuals are 99.9% identical to each other in terms of their own genome, whereas the microbiome of each individual can be 80-90% different from one another.
Picture: Gaby DAllesandro / American Museum of Natural History
Is It True That Damage To The Microbiome Will Cause Allergies
Our immune system is engaged in a constant, highly-sensitivebalancing act between states of aggression and tolerance. Our immune system can only manage this balancing act with the help of microbiota. The microbiota teach the immune system which cells to fight and which cells to leave alone.
A common commensal microorganism called Bacteroides fragilis was found to boost regulatory T cells, and thus stop the pro-inflammatory T cells from becoming too aggressive. These findings show that bacteria are necessary in helping our immune systemnot to react against cells that do not actually harm our body. If these bacteria are missing, our body overreacts on all kinds of cellular material we pick up resulting in allergies and asthma.
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It May Help Control Blood Sugar And Lower The Risk Of Diabetes
The gut microbiome also may help control blood sugar, which could affect the risk of type 1 and 2 diabetes.
One recent study examined 33 infants who had a genetically high risk of developing type 1 diabetes.
It found that the diversity of the microbiome dropped suddenly before the onset of type 1 diabetes. It also found that levels of a number of unhealthy bacterial species increased just before the onset of type 1 diabetes .
Another study found that even when people ate the exact same foods, their blood sugar could vary greatly. This may be due to the types of bacteria in their guts .
Summary:
The gut microbiome plays a role in controlling blood sugar and may also affect the onset of type 1 diabetes in children.
Examples Of Microbiome In A Sentence
microbiomeSmithsonian MagazinemicrobiomeRobb Reportmicrobiome Science | AAASmicrobiomeSELFmicrobiomeForbesmicrobiomeBostonGlobe.commicrobiome Glamourmicrobiome Forbes
These example sentences are selected automatically from various online news sources to reflect current usage of the word ‘microbiome.’ Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
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What Is Niehs Doing
NIEHS studies the microbiome to gain a better understanding of its complex relationships with the environment, and how these interactions may contribute to human health and disease. This knowledge could help us revolutionize the way new chemicals are tested for toxicity, and design prevention and treatment strategies for diseases that have environmental causes.
NIEHS-supported research related to the microbiome includes the environmental factors described below.
Chronic stress NIEHS researchers found chronic stress disturbs the gut microbiome in mice, triggering an immune response and promoting the development of colitis, a chronic digestive disease characterized by inflammation of the inner lining of the colon.4
Artificial sweeteners A NIEHSfunded study found sucralose, a widelyused artificial sweetener, changes the gut microbiome in mice and may increase the risk of developing chronic inflammation.5 In a separate study, they found that acesulfamepotassium, another artificial sweetener, induced weight gain in male, but not female, mice.6
Diet NIEHS researchers showed a highfat diet shaped the gut microbiome of mice in a way that predisposed them to gain weight and develop obesity.7
Caesarean delivery NIEHSfunded research indicates the way a newborn enters the world, by C-section or natural birth, and what is eaten, formula or breast milk, during the first six weeks of life may affect the type of microbes in the gut microbiome.8
The Human Microbiome Project: Extending The Definition Of What Constitutes A Human
One of the surprises of the Human Genome Project
The microbiome is defined as the collective genomes of the microbes that live inside and on the human body. We have about 10 times as many microbial cells as human cells. So, to study the human as a “supraorganism,” composed of both non-human and human cells, in 2007 the National Institutes of Health launched the Human Microbiome Project as a conceptual extension of the Human Genome Project.
Though PubMed includes more than 200 HMP papers to date, this month the HMP Consortium coordinated the publication of two major scientific reports in Nature and a set of 14 Public Library of Science companion papers to report on the research over the past five years.
The results reported in the Nature papers are a subset of a larger cohort study of the microbiomes of 300 healthy adult men and women in the United States from 18 to 40 years of age. The data in these papers came from an analysis of 4,788 clinical specimens from 242 healthy adults: 129 males and 113 females. Male volunteers were sampled at 15 sites and females at 18 sites from the mouth, nose, skin, lower gastrointestinal tract and vagina. Of these individuals, 131 were sampled again approximately 200 days later to assess the stability of their microbiomes. None of these subjects were taking antibiotics or immunomodulators during the study and all subjects were clinically verified to be free of overt disease at all of the body sites before sampling.
Posted: July 16, 2012
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What Conditions Are Associated With The Microbiome
There are a number of conditions that have known associations with microbiome. These conditions seem to be related to dysbiosis of the microbiome. Dysbiosis is defined as an imbalance of microbial material in the body. Those who suffer from the following conditions are more often affected by such microbial imbalances.
- Arthritis
- Obesity
The exact microbes that are associated with each of the proceeding conditions are not yet known. More study of the microbiome must be done to understand what roles specific bacteria play in certain conditions. As of now only the association of microbiome and disease is fairly inexact.
What Is The Microbiome
Picture a bustling city on a weekday morning, the sidewalks flooded with people rushing to get to work or to appointments. Now imagine this at a microscopic level and you have an idea of what the microbiome looks like inside our bodies, consisting of trillions of microorganisms of thousands of different species. These include not only bacteria but fungi, parasites, and viruses. In a healthy person, these bugs coexist peacefully, with the largest numbers found in the small and large intestines but also throughout the body. The microbiome is even labeled a supporting organ because it plays so many key roles in promoting the smooth daily operations of the human body.
Each person has an entirely unique network of microbiota that is originally determined by ones DNA. A person is first exposed to microorganisms as an infant, during delivery in the birth canal and through the mothers breast milk. Exactly which microorganisms the infant is exposed to depends solely on the species found in the mother. Later on, environmental exposures and diet can change ones microbiome to be either beneficial to health or place one at greater risk for disease.
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