Microbiome

The microbiome refers to the diverse community of microorganisms, including bacteria, viruses, fungi, and other microbes, that live within and on the human body and in various environments. Read here to learn more about them.

The human microbiome plays a crucial role in human health and disease.

These include not only bacteria but fungi, parasites, and viruses. In a healthy person, these microorganisms coexist peacefully, with the largest numbers found in the small and large intestines and 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.

Human Microbiome

The human microbiome is incredibly diverse, with trillions of microorganisms residing in different parts of the body, such as the skin, mouth, gut, and reproductive organs.

• Each person has a unique network of microbiota that is originally determined by one’s DNA.
• A person is first exposed to microorganisms as an infant, during delivery in the birth canal, and through the mother’s 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 one’s microbiome to be either beneficial to health or place one at greater risk for disease.

The gut microbiome, in the intestines, is one of the most extensively studied and influential components of the human microbiome.

• It is essential for digestion, and the synthesis of vitamins and other bioactive compounds, and it helps maintain a balanced immune system.
• Microbes in the microbiome interact with the host (the human body) in various ways, including aiding in digestion, training the immune system, and helping protect against pathogenic invaders.
• They also play a role in regulating metabolism and producing important molecules.

Large families of bacteria in the human gut include Prevotella, Ruminococcus, Bacteroides, and Firmicutes.

• In the colon, in a low-oxygen environment, you will find the anaerobic bacteria Peptostreptococcus, Bifidobacterium, Lactobacillus, and Clostridium.
• These microbes are believed to prevent the overgrowth of harmful bacteria by competing for nutrients and attachment sites to the mucus membranes of the gut, a major site of immune activity and the production of antimicrobial proteins.

Influence on Health

The composition and balance of the microbiome have been linked to various aspects of health. An imbalance or dysbiosis in the microbiome has been associated with conditions such as obesity, diabetes, autoimmune diseases, and gastrointestinal disorders.

• Microbiota stimulates the immune system, breaks down potentially toxic food compounds, and synthesizes certain vitamins and amino acids.
• Antibiotic use can disrupt the balance of the microbiome by killing both harmful and beneficial bacteria.
• The diet also plays a significant role in shaping the composition of the microbiome. High-fiber diets, for example, promote the growth of beneficial bacteria.
• The highest amounts are found in raw versions of the following: garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed.
• In general, fruits, vegetables, beans, and whole grains like wheat, oats, and barley are all good sources of prebiotic fibers.
• Ongoing research is exploring the therapeutic potential of manipulating the microbiome to treat various health conditions. This includes the use of probiotics, prebiotics, fecal microbiota transplantation (FMT), and other interventions.

Read: Microbes in Human Welfare

Environmental Microbiomes

Beyond the human microbiome, microbiomes exist in various environmental settings, such as soil, water, and air. These environmental microbiomes play essential roles in ecological processes, nutrient cycling, and ecosystem health.

The environmental microbiome refers to the diverse communities of microorganisms (bacteria, archaea, fungi, viruses, and other microorganisms) that inhabit various ecosystems on Earth.

• These microorganisms play crucial roles in maintaining the health and functioning of the environment.
• The environmental microbiome is incredibly diverse, with countless species of microorganisms inhabiting various environments such as soil, water, air, sediments, and extreme environments like hot springs and deep-sea hydrothermal vents.

Microorganisms in the environment provide essential ecosystem services, including nutrient cycling, decomposition of organic matter, soil fertility, and detoxification of pollutants. They play a fundamental role in sustaining life on Earth.

• Nutrient Cycling: Microbes are involved in the cycling of essential nutrients like carbon, nitrogen, and phosphorus. For example, they decompose dead organic matter, returning nutrients to the ecosystem for use by plants and other organisms.
• Bioremediation: Certain microorganisms can break down and degrade pollutants, making them valuable for bioremediation efforts to clean up contaminated environments. This includes the degradation of oil spills, industrial waste, and chemical contaminants.
• Plant-Microbe Interactions: Microbes in the soil form symbiotic relationships with plants, such as mycorrhizal fungi that enhance nutrient uptake, and nitrogen-fixing bacteria that provide plants with essential nitrogen. These interactions are critical for plant growth and ecosystem productivity.
• Climate Regulation: Microbes play a role in regulating greenhouse gas emissions. They are involved in processes like carbon sequestration, methane production, and nitrous oxide emissions, all of which influence the Earth’s climate.
• Human Impact: Human activities, such as deforestation, agriculture, and pollution, can significantly impact the composition and functioning of environmental microbiomes. These changes can have far-reaching ecological consequences.
• Microbiome Research: Advances in DNA sequencing and metagenomic analysis have allowed scientists better to understand the complexity and diversity of environmental microbiomes. Research in this field is uncovering new insights into microbial communities and their ecological roles.
• Microbiome Conservation: Recognizing the importance of the environmental microbiome, conservation efforts are increasingly focused on protecting microbial diversity and ecosystem health. This includes strategies to prevent habitat destruction and reduce pollution.

Understanding the environmental microbiome has practical applications in fields such as agriculture (e.g., soil microbiome management for sustainable farming), biotechnology (e.g., bioprospecting for novel microbial products), and environmental management (e.g., using microbes for wastewater treatment).

Microbiome Studies and Ethical Considerations

Advances in DNA sequencing technology have enabled the study of microbial communities in unprecedented detail. Techniques like metagenomics allow researchers to analyze the genetic material of entire microbiomes.

The study and manipulation of the microbiome raise ethical questions related to consent, privacy, and the potential consequences of altering microbial communities.

Conclusion

Understanding the microbiome and its role in human health is an area of active research with the potential to revolutionize medicine and our understanding of the complex relationship between microorganisms and their hosts. It also underscores the importance of maintaining a balanced and diverse microbiome for overall health and well-being.

The environmental microbiome is a complex and essential component of ecosystems, providing critical services that sustain life on Earth. Ongoing research in this field continues to reveal the intricate relationships between microorganisms and their environments, offering insights into how we can better manage and protect our planet’s ecosystems.

Previous Year questions

Q. Consider the following statements: (Prelims 2023)

1. Some microorganisms can grow in environments with temperatures above the boiling point of water.
2. Some microorganisms can grow in environments with temperatures below the freezing point of water.
3. Some microorganisms can grow in a highly acidic environment with a pH below 3.

How many of the above statements are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Q. Consider the following statements in respect of probiotics: (Prelims 2022)

1. Probiotics are made of both bacteria and yeast.

2. The organisms in probiotics are found in foods we ingest but they do not naturally occur in our gut.

3. Probiotics help in the digestion of milk sugars.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) 1 and 3

(d) 2 and 3

Q. Consider the following: (Prelims 2021)

1. Bacteria
2. Fungi
3. Virus

Which of the above can be cultured in an artificial/synthetic medium?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Q. In the context of the developments in Bioinformatics, the term ‘transcriptome’, sometimes seen in the news, refers to (Prelims 2016)

(a) a range of enzymes used in genome editing

(b) the full range of mRNA molecules expressed by an organism

(c) the description of the mechanism of gene expression

(d) a mechanism of genetic mutation taking place in cells

-Article by Swathi Satish