Written by Ruairi Robertson, PhD on June 27, 2017
Your body is full of trillions of bacteria, viruses and fungi. They are collectively known as the microbiome.
While some bacteria are associated with disease, others are actually extremely important for your immune system, heart, weight and many other aspects of health.
This article serves as a guide to the gut microbiome and explains why it's so important for your health.
- 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 (1, 2).
What's 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 (3).
Altogether, these microbes may weigh as much as 2–5 pounds (1–2 kg), 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 that's crucial for your health.
Humans have evolved to live with microbes for millions of years.
During this time, microbes have learned to play very important roles in the human body. In fact, without the gut microbiome, it would be very difficult to survive.
The gut microbiome begins to affect your body the moment you are born.
You are first exposed to microbes when you pass through your mother's birth canal. However, new evidence suggests that babies may come in contact with some microbes while inside the womb (4, 5, 6).
As you grow, your gut microbiome begins to diversify, meaning it starts to contain many different types of microbial species. Higher microbiome diversity is considered good for your health (7).
Interestingly, the food you eat affects the diversity of your gut bacteria.
As your microbiome grows, it affects your body in a number of ways, including:
- Digesting breast milk: Some of the bacteria that first begin to grow inside babies' intestines are called Bifidobacteria. They digest the healthy sugars in breast milk that are important for growth (8, 9, 10).
- Digesting fiber: Certain bacteria digest fiber, producing short-chain fatty acids, which are important for gut health. Fiber may help prevent weight gain, diabetes, heart disease and the risk of cancer (11, 12, 13, 14, 15, 16, 17).
- Helping control your immune system: The gut microbiome also controls how your immune system works. By communicating with immune cells, the gut microbiome can control how your body responds to infection (18, 19).
- Helping control brain health: New research suggests that the gut microbiome may also affect the central nervous system, which controls brain function (20).
Therefore, there are a number of different ways in which the gut microbiome can affect key bodily functions and influence your health.
Summary: The gut microbiome affects the body from birth and throughout life by controlling the digestion of food, immune system, central nervous system and other bodily processes.
- There are thousands of different types of bacteria in your intestines, most of which benefit your health.
- However, having too many unhealthy microbes can lead to disease.
- An imbalance of healthy and unhealthy microbes is sometimes called gut dysbiosis, and it may contribute to weight gain (21).
Several well-known studies have shown that the gut microbiome differed completely between identical twins, one of whom was obese and one of whom was healthy. This demonstrated that differences in the microbiome were not genetic (22, 23).
Interestingly, in one study, when the microbiome from the obese twin was transferred to mice, they gained more weight those that had received the microbiome of the lean twin, despite both groups eating the same diet (22).
These studies show that microbiome dysbiosis may play a role in weight gain.
Fortunately, probiotics are good for a healthy microbiome and can help with weight loss. Nevertheless, studies suggest that the effects of probiotics on weight loss are probably quite small, with people losing less than 2.2 pounds (1 kg) (24).
The gut microbiome
Credit: Antoine Doré
We are not alone in our bodies. Living inside every person are trillions of microorganisms — bacteria, viruses, fungi and other life forms that are collectively known as the microbiome. Various organs have distinct microbial inhabitants, but the group that has attracted the most attention in biomedical research is the one in the gut.
To better grasp the part that gut microbes play in health and disease, researchers from around the globe are investigating what makes a ‘good’ gut microbiome. There are, after all, hundreds of distinct bacterial species in the gut — some pathogenic and some beneficial.
Computational biologist Eran Segal argues that collecting microbiome data would allow a ‘deep phenotyping’ approach that could transform drug discovery.
And the study of some health-promoting probiotic species is yielding biological insights that might promote drug development.
Several diseases are now thought to be influenced by processes in the gut microbiome. Those include cancer, autoimmune disorders such as multiple sclerosis and autism spectrum disorder. The gut microbiome also strongly interacts with certain drugs, including some mental-health therapeutics, and influences their effects.
With evidence mounting of the gut microbiome’s health significance, synthetic biologists are looking to engineer the microbiome — both at the individual-species level and as an ecosystem — to thwart the development of disease.
There is also growing public interest in how the gut microbiome can be influenced — often focused on personal dietary choices.
Microbiologist Peter Turnbaugh reframes this as a question not of which foods will benefit our health, but rather what medical insights might be gleaned from the interactions between our gut microbes and what we eat.
Much more research is under way on the gut microbiome than can be covered in this Outlook, but this supplement gives a taste of the breadth of this robust field.
We are pleased to acknowledge the financial support of Danone Nutricia Research in producing this Outlook. As always, Nature retains sole responsibility for all editorial content.
Nature 577, S5 (2020)
This article is part of Nature Outlook: The gut microbiome, an editorially independent supplement produced with the financial support of third parties. About this content.
The Human Gut Microbiome – A Potential Controller of Wellness and Disease
The human microbiome comprises of collective genomes of microbiota inhabiting us, namely protozoa, archaea, eukaryotes, viruses and predominantly bacteria that live symbiotically on and within various sites of the human body. Examples of occupied habitats include our oral cavity, genital organs, respiratory tract, skin and gastrointestinal system (Lloyd-Price et al., 2016).
The human microbiota is estimated to be ∼1013–1014 microbial cells, with around 1:1 microbial cells to human cells ratio (Sender et al., 2016). These numbers are derived from the total bacterial cells in colon (3.8 × 1013 bacteria), the organ that harbors the densest number of microbes (Sender et al., 2016).
The diverse gastrointestinal microbiota is predominantly composed of bacteria from three major phyla, namely Firmicutes, Bacteroidetes, and Actinobacteria (Tap et al., 2009). This diverse and complex microbiome serves as a functional expansion of host genomes, and is estimated to harbor 50- to 100-fold more genes, compared to the host.
These extra genes have added various types of enzymatic proteins which were non-encoded by the host, and play a critical role in facilitating host metabolism, thus contributing to the regulation of host physiology (Hooper and Gordon, 2001).
Until recent decades, the properties of the human microbiome and the host–microbiota interactions have been largely unknown due to technology limitations especially in examining non-cultivable microbes of interest, and lack of population-scale data depicting the microbiota compositions and functions.
However, advances in sequencing technologies and subsequent large-scale sequence-based microbiome projects such as the Human Microbiome Project (HMP) consortium funded by The United States National Institutes of Health (NIH), as well as the MetaHIT (Metagenomics of the Human Intestinal Tract) consortium funded by the European Commission, have served as catalysts in nourishing research on the human microbiome. These large-scale endeavors both share similar missions in characterizing the human microbiome and their roles in health and disease states, with MetaHIT solely focusing on gut microbiome. Several analyses have been incorporated in these meta-omics projects including 16S ribosomal RNA (rRNA) sequencing to taxonomically characterize the microbiota communities; Whole Genome Shotgun (WGS) metagenomic sequencing of body-site specific whole community DNA, followed by reference genome mapping, metagenomic assembly, gene cataloging and metabolic reconstruction, to facilitate maximal capture of organismal and functional data of human microbiota (The Human Microbiome Project Consortium, 2012).
Due to the inherent complexity and heterogeneity of the human microbiome, experiments are required to counteract the limitation of empirical methods in examining the causation or correlation links between microbiota disequilibrium (dysbiosis) and human diseases.
Robust experimental modeling enables systematic manipulation of variables to investigate hypotheses deduced from “omics” studies. For this, the application of ‘humanized’ gnotobiotic animal model that harbors defined collection of sequenced microbial communities, has gained momentum in recent years in microbiome research (Faith et al., 2010).
This allows proof-of-mechanism study to examine the potential impacts of diet (Turnbaugh et al., 2009b), antibiotic, environmental toxicants (Stedtfeld et al., 2017) and host genotypic variation (Ley et al.
, 2005) on the microbiota and disease manifestation, due to changes in microbiota composition, transcriptomes, proteomes or metabolomes post-induced variations can be extracted and characterized to understand the operation of the microbiota.
Besides, ‘humanized’ gnotobiotic mice can be used in preliminary testing of the therapeutic efficacy in treating dysbiosis-associated diseases, as they allow monitoring of the pharmacokinetic–pharmacodynamic changes in microbial communities, thus facilitating optimization of treatment and dosage regime (Mahe et al., 1987; Silva et al., 1999).
Undoubtedly, these efforts shed light on the clinical significance of the human microbiome which is pretty much a ‘black box.
’ Although the human microbiome research is still at its preliminary stage, the findings are deemed intriguing yet promising in terms of filling the knowledge gap in microbiome-host relationships, and their role in disease pathogenesis, as well as therapeutic value, which requires more in-depth investigations to uncover this exciting yet mysterious field of research. Below, we review recent investigations specifically related to the bacterial microbiome in the GIT – the largest microbial reservoir of the human body. Gut microbiota and the microbial-synthesized metabolites are discussed along with their roles in human wellness and normal functioning. Further, we review several studies related to the gut microbiome dysbiosis and its association with specific human diseases. We introduce novel microbiome-based therapy employed in specific disease conditions to ‘restore’ wellness and ameliorating dysbiosis-associated diseases. Finally, we discuss future directions and research areas that require further elucidation in order to better understand the human microbiome and its relationship with the host.
The Gut Microbiome and Its Multifarious Functions
The symbiotic relationship between the gut microbiota and the host is regulated and stabilized by a complex network of interactions that encompass metabolic, immune, and neuroendocrine crosstalk between them.
This crosstalk is potentially mediated by microbial-synthesized metabolites which exhibit pleiotropic effects, including acting as signaling molecules in regulating host neuro-immune-inflammatory axes that could physiologically link gut with other organ systems.
The predominant functions of gut microbiota and the associated key metabolites in governing host wellness are depicted in the following subsections, with some other microbial metabolites being described in Table 1.
TABLE 1. Metabolites contributed by gut microbiota and their respective functions.
Human fecal sample analysis using 16S ribosomal RNA and metagenomic sequencing techniques reveal significant enrichment in metabolism of polysaccharides, amino acids, xenobiotics and micronutrients conferred by gut microbiota, suggest that these indigenous microbes facilitate host energy harvesting and metabolic efficiency (Gill et al., 2006).
These findings were further validated by germ-free (GF) mice experiments where it was found that germ-free mice had 40% lower epididymal fat and an additional 10–30% food consumption was needed to maintain the same body mass as mice with normal microbiota (Backhed et al., 2004).
Gut microbiota is important in fermenting unabsorbed starch and soluble dietary fiber. The fermented end products exist in the form of a SCFAs. SCFA (such as butyrate, propionate, acetate and pentanoate) act as one of the energy substrates for the host (Salminen et al.
, 1998) thereby contributing an extra 10% daily dietary energy for utilization by the host for other metabolic processes (Payne et al., 2012). Microbial-synthesized SCFAs contribute 70% of ATP production in colon, with butyrate as the preferred fuel for colonocytes (Firmansyah et al., 1989; Donohoe et al., 2011).
Butyrate-producing microbes rescued the deficit mitochondrial respiration, ATP synthesis and autophagy in colonocytes of germ-free mice (Donohoe et al., 2011), proving the importance of butyrate in colonic cellular respiration and energy production.
Furthermore, SCFAs which are the ligands for G protein-coupled receptor 41 (GPR41) expressed by a subset of the gut epithelial enteroendocrine cells, had been shown to regulate energy homeostasis by stimulating GPR41-mediated leptin production in mouse adipocytes, in which this multifunctional circulating hormone, leptin exhibits pleiotropic effects on a vast range of host physiological functions such as energy metabolism, appetite, as well as sympathetic nerve activity and immune response, potentially giving rise to interactive host-microbe signaling and gut-brain axis immune-inflammatory crosstalk (Xiong et al., 2004; Samuel et al., 2008).
Besides SCFA, gut microbiota-synthesized micronutrients such as vitamins exhibit beneficial value for both microbial and host metabolisms.
Vitamin-K-producing gut bacteria namely Bacteroides fragilis, Eubacterium lentum, Enterobacter agglomerans, Serratia marcescens, and Enterococcus faecium (Fernandez and Collins, 1987; Cooke et al.
, 2006) anaerobically synthesize vitamin K2 (menaquinone) which is essential in decreasing vascular calcification, elevating HDL and lowering cholesterol levels, contributing to lower risk of cardiovascular disorders such as atherosclerosis and coronary heart disease (Kawashima et al., 1997; Geleijnse et al., 2004).
Gut microbiota also serves as an important source of vitamins B for the host (Salminen et al., 1998; Degnan et al., 2014).
Among them, vitamins B5 and B12, which are exclusively synthesized by intestinal microbiota, act as coenzyme for extensive range of host biochemical processes including production of acetylcholine and cortisol which are required for normal functioning of the nervous system. Deficiency of vitamins B5 and B12 have been linked to several disorders such as gastrointestinal discomfort, insomnia, neuropsychological and hematological disorders (Andres et al., 2004; Gominak, 2016). However, the possible link between loss of vitamin-producing gut microbiota and disease onset has not yet been elucidated.
Gut microbiota also plays an important role in the co-metabolism of bile acids with the host. These cholesterol derivatives are synthesized in the liver, followed by conjugation with taurine or glycine prior to storage in the gall bladder and subsequent secretion into duodenum to aid digestion, cholesterol and lipid metabolisms.
In humans, 95% of bile acids are reabsorbed at distal ileum (Staels and Fonseca, 2009).
The 5% unabsorbed primary bile acids are then bioconverted or deconjugated to secondary bile acids (predominantly DCA and LCA) by bile salt hydrolases secreted by several colonic microbiota such as Clostridium perfringens and Clostridium scindens
Gut microbiota: Definition, importance, and medical uses
The human body is host to around 100 trillion microbes. They outnumber the human cells in the body 10 to 1.
Recent scientific advances in genetics mean that humans know a lot more about the microbes in the body.
Many countries have invested a lot in researching the interactions within the human body’s ecosystem and their relevance to health and disease.
The two terms microbiota and microbiome are often used to mean the same thing and are used interchangeably. This article will explain the differences between them and how both are being used and research in modern medicine.
Share on PinterestThe gut microbiota is with humans from birth and affects function throughout the body.
The human microbiota consists of a wide variety of bacteria, viruses, fungi, and other single-celled animals that live in the body.
The microbiome is the name given to all of the genes inside these microbial cells.
Every human being harbors anywhere between 10 trillion and 100 trillion microbial cells in a symbiotic relationship. This benefits both the microbes and their hosts, as long as the body is in a healthy state. Estimates vary, but there could be over 1,000 different species of microorganism making up the human microbiota.
There are plenty of projects trying to decode the human genome by sequencing all human genes. In a similar way, the microbiome has been subject to intensive efforts to unravel all its genetic information.
- The following video about the human ecosystem, produced by the Genetic Science Learning Center of the University of Utah, Salt Lake City, will help create a picture of this delicate but vital relationship.
- It is a good introduction to the range of habitats for different types of microbe in the body, including the differences between the dry environment of the forearm and the wet and oily environment of the armpit.
- The microbes in the body are so small that they make up only about 2 to 3 percent of the total weight of the human body, despite outnumbering the cells.[S2]
- A 2012 study published in Nature by the Human Microbiome Project Consortium found the following:
- Samples of mouth and stool microbial communities are particularly diverse
- In contrast, samples from vaginal sites show particularly simple microbial communities.
The study demonstrated the great diversity of the human microbiome across a large group of healthy Western people but poses questions for further research. How do microbial populations within each of us vary across a lifetime, and are patterns of colonization by beneficial microbes the same as those shown by disease-causing microbes?
The gut microbiota used to be called the microflora of the gut.
Around this time, in 1996, Dr. Rodney Berg, of Louisiana State University’s Microbiology and Immunology department, wrote about the gut microbiota, summing up its “profound” importance.
“The indigenous gastrointestinal tract microflora has profound effects on the anatomical, physiological, and immunological development of the host,” Dr. Berg wrote, in a paper published in Trends in Microbiology.
The paper adds:
“The indigenous microflora stimulates the host immune system to respond more quickly to pathogen challenge and, through bacterial antagonism, inhibits colonization of the GI tract by overt exogenous pathogens.”
This symbiotic relationship benefits humans, and the presence of this normal flora includes microorganisms that are so present in the environment that they can be found in practically all animals from the same habitat.
However, these native microbes also include harmful bacteria that can overcome the body’s defenses that separate them from vital systems and organs. Examples include
In summary, there are beneficial bacteria in the gut, and there are harmful bacteria that can cross into wider systems and can cause local infections of the GI tract. These infections include food poisoning and other GI diseases that result in diarrhea and vomiting.
The gut microbiota contains over 3 million genes, making it 150 times more genetically varied than the human body.
The gut microbiota of each individual is unique. It can heavily contribute to how a person fights disease, digests food, and even their mood and psychological processes.
- Microorganisms have evolved alongside humans and form an integral part of life, carrying out a range of vital functions.
- They are implicated in both health and disease, and research has found links between bacterial populations, whether normal or disturbed, and the following diseases:
- The human microbiome has an influence on the following four broad areas of importance to health:
As well as absorbing energy from food, gut microbes are essential to helping humans take in nutrients. Gut bacteria help us break down complex molecules in meats and vegetables, for example. Without the aid of gut bacteria, plant cellulose is indigestible.
Gut microbes may also use their metabolic activities influence food cravings and feelings of being full.
The diversity of the microbiota is related to the diversity of the diet. Younger adults trying out a wide variety of foods display a more varied gut microbiota than adults who follow a distinct dietary pattern.
From the moment an animal is born, they start building their microbiome. Humans acquire their first microbes from the entrance of their mother’s cervix on arrival into the world.
Without these early microbial guests, adaptive immunity would not exist. This is a vital defensive mechanism that learns how to respond to microbes after encountering them. This allows for a quicker and more effective response to disease-causing organisms.
Rodents that are completely clean of microorganisms show a range of pathological effects, and an underdeveloped immune system is among them.
Gut microbiota in health and disease
Gut microbiota is the community of live microorganisms residing in the digestive tract. There are many groups of researchers worldwide that are working at deciphering the collective genome of the human microbiota.
Modern techniques for studying the microbiota have made us aware of an important number of nonculturable bacteria and of the relation between the microorganisms that live inside us and our homeostasis. The microbiota is essential for correct body growth, the development of immunity, and nutrition.
Certain epidemics affecting humanity such as asthma and obesity may possibly be explained, at least partially, by alterations in the microbiota. Dysbiosis has been associated with a series of gastrointestinal disorders that include non-alcoholic fatty liver disease, celiac disease, and irritable bowel syndrome.
The present article deals with the nomenclature, modern study techniques, and functions of gut microbiota, and its relation to health and disease.
La microbiota intestinal es la comunidad de microorganismos vivos residentes en el tubo digestivo. Muchos grupos de investigadores a nivel mundial trabajan descifrando el genoma de la microbiota.
Las técnicas modernas de estudio de la microbiota nos han acercado al conocimiento de un número importante de bacterias que no son cultivables, y de la relación entre los microorganismos que nos habitan y nuestra homeostasis. La microbiota es indispensable para el correcto crecimiento corporal, el desarrollo de la inmunidad y la nutrición.
Las alteraciones en la microbiota podrían explicar, por lo menos en parte, algunas epidemias de la humanidad como el asma y la obesidad. La disbiosis se ha asociado a una serie de trastornos gastrointestinales que incluyen el hígado graso no alcohólico, la enfermedad celíaca y el síndrome de intestino irritable.
En el presente trabajo trataremos sobre la nomenclatura, las técnicas de estudio modernas, las funciones de la microbiota intestinal y la relación que tiene con la salud y la enfermedad.
Síndrome de intestino irritable Introduction
Our knowledge of the interesting relationship between human beings and the microorganisms we harbor has greatly increased over the past years. We no longer call these living entities «intestinal flora», nor do we regard them as simply commensal. In fact, we humans are «super organisms» governed in part by the microorganisms living inside us.
1 The aim of this review is to familiarize the reader with the current terms used in the thriving field of the human microbiota, in particular the gut microbiota, to know the profound implications of diet and the environment on the normal and abnormal microbiota, and to outline a panorama of the relation between the microbiota and gastrointestinal diseases.
The literature review was carried out by consulting the PubMed database of information encompassing the last 15 years, as well as the studies presented at the 2012 Digestive Diseases Week in San Diego, California, and the 2012 United European Gastroenterology Week in Amsterdam.
Microbiota and other concepts
It is worthwhile to become familiar with a series of terms that are currently employed in this field. The term microbiota refers to the community of living organisms residing in a determined ecologic niche.
The microbiota living in the human gut is one of the most densely populated communities,2 surpassing that of the soil, the subsoil, and the oceans. In the mammalian large intestine the number of microorganisms reaches 1012-1014, even more than the number of human cells.
3 The microbial ecosystem of the intestine (gut microbiota) includes many native species that permanently colonize in the gastrointestinal tract and a variable series of microorganisms that only do so transitorily. The whole of the microorganisms, their genes, and their metabolites is called the microbiome.
The human microbiome refers to the total population of microbes colonizing the human body, including the gastrointestinal tract, genitourinary tract, oral cavity, nasopharynx, respiratory tract, and skin.
4 The Human Microbiome Project has identified approximately 30% of the gut microbiota5 and together with the Metagenomics of the Human Intestinal Tract in Europe and many other groups, is actively working to identify all of the genes of the microbiota.
Dysbiosis is defined as the alterations in the gut microbiota and the adverse response of the host to these changes. It has been associated with diseases as dissimilar as asthma, chronic inflammatory disease, obesity, and non-alcoholic steatohepatitis (NASH). 6–8
There have been several challenges involved in the study of the microbiome in the past: not all the microorganisms are easy to grow. Nevertheless, the modern techniques for studying genetic material have revolutionized our understanding of the microbiome.
Some components of the microbiota require special conditions for their growth in culture media and therefore they went undetected or were unknown in the past.
For example, the colonic microbiota have approximately 800 to 1,000 species per individual, but 62% of them were unknown and 80% of the bacteria identified by metagenomics are regarded as unculturable.9
The concepts and advances in «metanomics» have opened a window into the understanding of the gut microbiota 10 (Table 1):
- •Metagenomics is the analysis of the genetic material of bacteria taken directly from a sample of the environment that is being studied, making it possible to identify bacteria that cannot be detected in culture media.
- •Metatranscriptomics studies the transcribed total RNA.
- •Metaproteomics focuses on protein levels.
- •Metabolomics studies metabolic profiles.
- •The metagenome is the complex formed by the host and the microbiome.
Various classification systems of the biologic kingdoms have been described (Table 2). In 1990 Woese introduced the term «domain» to substitute «kingdom» as the highest taxonomic order, dividing all living beings into Bacteria, Archaea, and Eucarya.
11 The archaea, unicellular organisms formerly grouped in the bacteria domain, possess a sufficiently distinct genetic material from the bacteria to be classified in a separate domain.12 A recent discovery is the presence of members of the Archaea domain in the gut microbiota, currently regarded as distinct from the Bacteria domain.
An example of the archaea is the methane-producing Methanobrevibacter smithii, and in recent studies it has been implicated in irritable bowel syndrome (IBS) with constipation.13
Microbiome Vs Microbiota: What’s The Difference For Your Gut Bacteria?
So, you’re feeling inquisitive and you perform a quick internet search. You type definition of microbiome or define microbiota – the words are different but the results are pretty similar. Well, let us explain.
Table of contents
Animals, plants, and even oceans and soils have their own individual biomes made up of specific inhabitants.
Our bodies are not just ours, they are home to a vast collection of microorganisms. Ask most people to define microbiome, and a handful might say that it refers to a bacterial ecosystem that lives in a specific place. They may even mention the gut.
For scientists, a biome is an ecosystem made up of flora and fauna. They use the word micro to indicate that this ecosystem is invisible to the human eye. It is made up of mostly bacteria, but also viruses, archaea, and fungi, which all play a role in maintaining the environment's stability.
The microbiome explained. Video by the Microbiology Society
The human microbiome encompasses trillions of microbes that can be separated into subsections dependent on their location. When we say gut microbiome, we mean the microorganisms (and their genes) that reside in your colon.
But the microbiome isn’t just a feature of human beings – animals, plants, soils, and oceans have their own ones too. And no matter how you look at it, the gut microbiome plays a major role in human health.
Home to trillions of microbial cells, it is an essential part of our biology that supports many physiological functions, helps maintain the integrity of our gut lining, and protects us from disease and illness.
Although the terms are used interchangeably, there is a slight difference between microbiome and microbiota.