The human microbiota is the collection of all the microbes living within and on the human body. Most of these microbes live in our gastrointestinal tract. These bacteria in our body are like super-heroes owing to the work they do to help keep us healthy, and their power to adapt and evolve. Even though each individual bacterium has a short life, collectively they have a long-term impact on human health. They help us throughout our lives, starting from birth by aiding in the digestion of the complex sugars and molecules in mother’s milk, stimulating and maintaining the immune system to help protect against infection and helping to overpower the bad bugs. Not all superheroes wear capes, and the bacteria in our body are a perfect example.
We share a symbiotic relationship with the bacteria in our body. Our lifestyle, such as diet, exercise, stress, medication including antibiotics, drives the composition of this microbial community which in turn affects our health. A loss of balance between the good and bad bugs can result in a disease state. But we all wonder when we read the headlines about Anti-Microbial Resistance (AMR) being a threat to human race that why is this such a big issue? Why should we worry? How does it affect us?
Antibiotics have been a lifesaver to humankind since their discovery. They have increased life expectancy and decreased the morbidity and mortality rates. Since Fleming discovered the first commercialized antibiotic ‘Penicillin’ there have been many antibiotics added to the list. Each antibiotic is different in that it either kills the bacteria, or stops them from multiplying, by using different mechanisms providing relief to the patient from the infectious state. Doctors could now quickly and easily treat infections, saving the lives of millions of people. Many of these antibiotics are naturally produced by microbes, which means the bacteria are familiar with these compounds and have evolved mechanisms to resist their effects.
Antimicrobial resistance (AMR) is the resistance of a microorganism to a drug that was originally effective to kill that microorganism, such as bacteria becoming resistant to antibiotics. This is a major concern with common bacteria that cause infections. Many bacteria have evolved techniques to outsmart antibiotics, such as inhibiting their entry into the bacterial cell, pumping it out, destroying it, or changing the shape of the antibiotic target rendering the antibiotic ineffective and making the bacteria resistant. One question that comes to mind is that where does this antimicrobial resistance come from? The answer is not one source. For example, a few individual bacteria may naturally have resistance to an antibiotic and when that antibiotic is used to treat an infection, the resistant bacteria survive and multiply. The resistant bacteria can then pass on the resistance gene to other bacteria like some infections are passed in humans. We know the concept of survival of the fittest; they evolve to survive while becoming resistant in that process. Furthermore, antibiotics only work on bacteria. So, when people take antibiotics for viral infections, such as ‘flu or ear infections, they don’t alleviate symptoms but still contribute to antibiotic resistance as bacteria evolve very rapidly. Many antibiotics are “broad spectrum” which means they kill a broad range of bacteria, including the good bacteria, and so also disrupt the balance of good to bad bacteria in the gut, which may worsen the condition. Thus, antibiotic resistance occurs naturally but misuse of antibiotics accelerates the process. It is a price worth paying if you are being saved from a life-threatening infection but in the long run it makes the treatment more difficult.
Sustainable use of antibiotics doesn’t just apply to humans. Antibiotics are heavily used in veterinary practice to reduce infection and to promote growth in livestock animals. As the same antibiotics are used for animals as for humans, overuse of antibiotics in animals affects humans too. Antibiotics are also spread on crops. There has also been a large gap since the development of new antibiotics because pharmaceutical companies are reluctant to invest in the development of new classes of antibiotic drugs due to the poor economic return and because increasing rate of resistance means the drugs can fail within a few years.
Without the discovery of new antibiotics or other alternative strategies we might return to the pre-antibiotic era. It’s difficult to envisage a world today where common infections and minor injuries could kill a person as the antibiotic treatment will be no longer effective due to AMR. We know that AMR is now an unavoidable issue and we should look for other options, follow antibiotic stewardship programs and prepare ourselves to deal with the AMR crisis. The AMR apocalypse is not coming, its already here!!!