HUMAN MICROBIOME: social game changer

What is Microbiome? 

SOCIETAL GAME CHANGER

Microbes are part of humans from the initial stage of development and play an important role in the functioning of the human body. 

• The collective genome of all micro-organisms

contained within the human body, residing

inside tissues & bio-fluids is called Human

Microbiome. 

It includes bacteria, archaea, fungi, protists and viruses.

• Most of them have either commensal (coexist

without harming humans) or mutualistic

(each benefit from the other) relation.

• Understanding the microbiome

This invisible organ is modulated by disparate factors including

•  genetics,
•  dietary habits,
•  Lifestyle
•  age,
•  geographic location and 
•  ethnicity.

• Human microbiome makes up around 2% of

the body mass of the adult. There are 10 times

as many outside organisms as there are

human cells in human body.

The microbiome is the largest organ you may have never heard of, weighing up to three kilograms. Human Microbes: The Power within (2018), Author provided

The human microbiome is one of the largest organs, weighing approximately two to three kilograms in an adult. Although it is invisible, the microbiome makes its physical presence evident with occasional noises and smells.

The microbiome bestows on us the unique traits we possess. The make-up of the microbiome changes during our life span, and a decrease in the number and diversity of its constituents is associated with diseases and ageing. In fact, healthy individuals and centenarians are known to house a wider diversity of microbial partners than unhealthy individuals.

• Importance of the Human Microbiome

 Microbial communities play a key role in many

aspects of host physiology:

o Metabolism of otherwise complex

indigestible carbohydrates and fats

o Production of essential vitamins

o Maintaining immune systems

o Acting as a first line of defense against

pathogens.

o Determines how one responds to a

particular drug treatment

• Location-specific functions

The microbiome works in harmony with various organs in the body and aids in the proper functioning of a human being. For example, microbes living on the surface of the skin guard against invasion from opportunistic bacteria and pathogens. These microbes also help in healing wounds, fortifying the immune system and producing volatile signalling molecules essential for communication within the body and the nervous system.

The gut, which harbours the highest amount of microbes, would not be able to carry out its digestive duty without microbial assistance. Microbes in the gut possess a variety of enzymes dedicated to the digestion of complex carbohydrates and the extraction of nutrients from the foods we consume. An average person consumes up to 60 tonnes of food during his or her lifespan. A digestive tract devoid of microbes would require even more food, a situation the world would prefer to do without.

Intestinal microbes also produce vitamins like B12 (pivotal for metabolic activity), hormones, neurotransmitters and a plethora of metabolites integral to normal bodily processes. They also play an active role in the fate of medications we ingest. In fact, drugs taken orally interact with the gut microbiome first before reaching their intended targets.

The molecular entities, like short-chain fatty acids, derived from the microbiome are part of our normal development process.

Microbes are unique to both the individual and the site on the body where they are lodged. For instance, the oily forehead tends to be the preferred residence of Propionibacteria while the moist nose is populated by Corynebacteria. The stomach possesses acid-tolerant bacteria while the colon harbours anaerobic dwellers.

Although microbiome finger-printing is in its infancy, it is clear that an individual living in an urban area will house a different microbial community relative to a rural inhabitant. As the microbiome is like any other organ, the disruption of its cellular components — known as dysbiosis — can trigger a range of ailments like obesity, irritable bowel syndrome, dermatitis and neurological imbalance. Some of these diseases can be cured by the use of probiotics and prebiotics designed to adjust microbial imbalance.

Although this expansive invisible organ was visualized only recently, the unravelling of its functions, coupled with the understanding of its origins, could lead to major changes in health care, health education, nutrition and personal traits.

Understanding the human microbiome and the role it plays in health and well-being will revolutionize our approach to our bodies and their care. Springer

The identification of each microbial constituent and its role will enable the classification of each individual according to his or her microbe type; this has the potential to be as revolutionary as the discovery of blood groups in the twentieth century. Microbial fingerprinting would result in a seismic shift in health quality and delivery.

Manipulation and enrichment of select microbial communities — referred to as microbiome engineering - would improve health, rejuvenate organs, enhance character traits and lead to more effective medications.

Microbe-supplemented creams for skin diseases and microbe-fortified nutritional supplements are already being routinely touted as personalized cures. The tracking of microbes and their metabolites may become a common molecular strategy to identify individuals and even their behaviours.Even though these microbes have always been part of the human anatomy, they were visualized only recently with technological advances like molecular imaging tools and next-generation genetic sequencing. We can now visualize these microbial entities as they operate and execute vital tasks. 

About Human Microbiome Project (HMP)

• It is a research initiative of US’s National

Institute of Health with the mission to

generate the resources and expertise needed to characterize the human microbiome and

analyze its role in health and disease.

• Launched in 2007, it is focused on identifying

and characterizing human microbial fauna and

elucidating their roles in health and diseases.

• Some methodologies used in HMP are:

o Metagenomics, a sequence-based

approach that allows the genetic material

from the complete collection of microbes

to be analyzed in their natural

environment without needing to cultivate

the microorganisms.

o Whole Genome Sequencing (WGS) to

provide a "deep" genetic perspective on

aspects of a given microbial

community, i.e. individual bacterial

species.

o It is faster, cheaper, more accurate, an

more efficient than other existing

 genome editing methods

o CRISPR is the DNA-targeting part of the

system which consists of an RNA

molecule, or ‘guide’, designed to bind to

specific DNA bases through

complementary base-pairing.

o Cas9 is the nuclease part that cuts the

DNA

Related news

SALSA

• Recently, an international team of scientists began

a research named SALSA (SUBGLACIAL

ANTARCTIC LAKES SCIENTIFIC ACCESS) for study

of microbes and living specimens in a Subglacial

Lake Mercer of Antarctica.

• This project could add to understanding of the

evolution of life in these extreme environments on

earth and other celestial bodies such as habitats

deep inside Mars or on the ice-covered moons of

Jupiter and Saturn.

• A subglacial lake is a body of liquid water located in

between an ice sheet and the continental land

mass. The water remains liquid because the ice

sheet above the water acts as an insulator and

traps geothermal heat from the Earth’s crust.

We are just at the dawn of a health revolution that has the potential to be a societal-game changer.