Bacteria are a group of single-celled organisms that are extremely small in size and can thrive in many different environments. When people mention them, they are often thought of as harmful, but there are many beneficial bacteria that are essential for human life.

1. What are bacteria?

Bacteria, also known as germs, are a type of microscopic single-celled prokaryotic microorganisms, many of which are parasites. They belong to the group of single-celled organisms, neither plants nor animals with microscopic size. They have a simple cell structure, with a cytoskeleton, a nucleus and organelles similar to mitochondria and chloroplasts.

This is an extremely large group in the biosphere. They are present everywhere in soil, water sources or inside other organisms, even in radioactive waste. This is the first species of organism to appear on earth about 4 billion years ago.

Bacteria are considered the most populous microorganisms in the world.

The oldest fossil fragment is considered to be of a microbe-like organism. Every gram of soil usually has about 40 million bacterial cells. 1 ml of fresh water usually has up to 1 million bacterial cells. The Earth is estimated to have at least 5 billion microbes and most of the Earth’s biomass is believed to be made up of this species.

When it comes to bacteria, people often think of them as harmful microorganisms, but many types are used with many necessary benefits for humans. They support many forms of life, plants and animals. In addition, they are also used in industrial and pharmaceutical processes.

2. Nutrition of bacteria

Bacteria live in many different ways, specifically:

• Heterotrophs: they collect energy by absorbing organic carbon. Most of them absorb from organic matter, specifically decomposing meat.
• Autotrophs: they will create their own food by photosynthesis, using sunlight, water and CO2. In addition, they will chemically synthesize, using CO2, water, … chemicals such as ammonia, nitrogen gas, sulfur, …

Autotrophic bacteria will create their own food.

• Phototrophs: they use photosynthesis. Such as cyanobacteria, they produce oxygen and play an important role in creating oxygen for the atmosphere.
• Chemotrophs: they obtain energy from chemical synthesis.

3. What are beneficial bacteria?

Many species of bacteria in the human body contribute to the maintenance of human life. Bacteria in the digestive system help humans absorb nutrients such as complex sugars that are converted into forms that the body can use by beneficial bacteria.

Probiotics have the ability to support the human digestive system by metabolizing the nutrients obtained.

In addition, some species help prevent disease by invading the places where harmful bacteria want to attach. They also help protect humans from disease by attacking pathogens.

The number of bacterial cells is 10 times more than the cells in the human body. Some species have a symbiotic or “friendly” lifestyle, sharing living space and resources inside our body without harming the host but also bringing good health.

According to many studies, the intestine is where microorganisms are found in the largest number. The human intestine is considered a good living environment for microorganisms with many available nutrients. In the American Gastroenterology journal, the author informed that intestinal bacteria and some other microorganisms such as E.Coli and Streptococcus bring many benefits to humans.

They support digestive activities, prevent the invasion of harmful pathogens, and support the immune system. Specifically, a patient with Crohn’s disease has an increased immune response against intestinal bacteria, according to a 2003 review in The Lancet.

In addition to their benefits for humans, probiotics also serve many other important fields.

In the food industry, lactic acid bacteria such as Lactobacillus and Lactococcus combined with yeast, mold, … are used to produce foods such as cheese, soy sauce, vinegar, yogurt.

Yogurt has the participation of probiotics in production.

In addition, some types of bacteria have the ability to break down organic compounds, which is very beneficial for waste treatment, toxic substances, cleaning up oil spills at sea, etc. Industries such as pharmaceuticals and chemicals also choose bacteria to produce some chemicals.

Bacteria are used in molecular biology, biochemistry and genetic research because they can grow quickly and are easy to manipulate. Scientists use them to study the activity of genes and enzymes. Probiotics are also an important factor in the preparation of antibiotics.

4. What are harmful bacteria?

In addition to the above benefits, most bacteria are microorganisms that are harmful to humans because they have the ability to cause disease and spread epidemics. There is no organ in the human body that harmful bacteria cannot attack. Some harmful bacteria can cause diseases in humans, such as cholera, diphtheria, dysentery, plague, pneumonia, tuberculosis, etc.

If our body comes into contact with these germs but the body recognizes them as harmful, the immune system will attack them. These reactions can cause many manifestations such as swelling and inflammation that can be observed with the naked eye, such as infected wounds.

Harmful bacteria can attack humans thanks to the internal and external toxins in them. To resist the invasion of harmful bacteria, humans have created many types of antibiotics. These are drugs used to treat infections. However, in recent years, people have gradually used antibiotics incorrectly and unnecessarily, leading to the spread of antibiotic-resistant strains.

The overuse of antibiotics leads to the spread of antibiotic-resistant strains.

In this case, infectious bacteria are no longer as sensitive to effective antibiotics as before. That is why many scientists and health agencies strongly advise doctors not to overuse antibiotics, only when absolutely necessary. Instead, they guide people to implement many other methods to help prevent diseases such as maintaining food hygiene, keeping the body clean, getting vaccinated, etc.

In conclusion, not all bacteria are harmful to humans, but some species are beneficial to us. Learning about bacteria is also a way to protect our own health.