Do antibiotics make us more susceptible to flu viruses?

Do antibiotics weaken our immune system?

It's getting colder again. And with the change in weather, we are becoming more susceptible to colds and infections again. But why is that? Why do viruses have an easy time of it at this time of year?

There are several reasons for this. Viruses love the cold air. However, if indoor spaces are heated during the cold season, our mucous membranes' defenses are weakened as a result. Viruses are also extremely changeable. They can constantly change and put our immune system to the test again. And if that weren't enough, they are also survival artists and can even survive on the palms of our hands and door handles for a certain period of time. 

But that's not all. Researchers from the Francis Crick Institute now seem to have found another reason. According to them, antibiotics paralyze our immune system.

 

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➤ Viruses are everywhere where there is life!

 

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The influence of antibiotics on our immune system

For a long time, antibiotics were regarded as the miracle cure par excellence. This led to misuse, which has serious consequences:

1. antibiotic resistance
2. massive intestinal flora disorders

Antibiotics are supposed to kill harmful bacteria - and they do. But unfortunately, in addition to the harmful bacteria, they also kill off beneficial bacteria that we urgently need for a functioning immune system. A weakened intestinal flora inevitably leads to an inadequately functioning immune system, as around 80 % of the immune system is located in the intestine. This in turn means a weaker defense against pathogens such as viruses and bacteria.

Research results on antibiotics for influenza

You would think that antibiotics would have a positive effect on the flu. However, a study published in the journal Cell Reports in 2019 reports that in animal experiments, the administration of antibiotics led to a significantly weaker immune system and subsequently to significantly worse infections and symptoms. 

In the animal study, it was observed that the intestinal flora makes a huge difference in susceptibility to flu viruses. In mice infected with flu viruses with healthy gut flora, 80% survived. In the mice that had previously received antibiotics and therefore had a weakened immune system, only a third survived.

Based on these results, it is assumed that people who have recently taken antibiotics, for example due to a bacterial infection, are also more susceptible to flu viruses!

 

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➤ Antibiotics make you more susceptible to the flu!

 

When the defense fails ... 

How can viruses be dangerous to us at all? 

We usually first come into contact with viruses via the air we breathe (droplet infection) and therefore via our lung mucosa. With a strong immune system, intact intestinal flora provides certain messenger substances that help the lungs to successfully defend themselves against incoming viruses. The intestinal bacteria send out a signal that keeps the lung cells on standby and thus prevents the virus from spreading quickly.

This is precisely the crux of the matter. The research results from the Francis Crick Institute clearly show that taking antibiotics beforehand weakens the lungs and makes them susceptible to flu viruses. And this in turn makes it so difficult for our body to defend itself against the spread of viruses and thus an infection. According to the results, it takes around two days for the immune cells to take effect. Within this period of time, the virus can spread in the lung mucosa. In the study, the mice treated with antibiotics had five times more viruses in their lungs after two days than the mice in the group that did not come into contact with antibiotics. 

Good functioning of the lungs or the cells that line the lungs is therefore crucial in the immune system. According to the researchers, viruses can either multiply or not. The lungs are considered the first line of defense in the fight against pathogens. 

According to the researchers, misuse of antibiotics can therefore not only promote antibiotic resistance or kill off helpful gut bacteria, but also make us more susceptible to viruses.

 

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➤ Our lungs act as the 1st line of defense!

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Now you know why viruses can be dangerous at this time of year and why antibiotic therapy makes us even weaker and more susceptible.

Conclusion

Especially now, when it is getting colder outside again, we should make sure that we specifically support our immune system. According to study results, antibiotics can massively weaken our defenses against viruses. So make sure that you really only use antibiotics when you absolutely need them, question a lot of things and only use them as prescribed by doctors and alternative practitioners. Unfortunately, antibiotics are still prescribed too frequently and inappropriately these days, which can lead to dangerous resistance. 

It is important, especially after taking antibiotics, to specifically support the intestinal flora with intestinal bacteria and thus build up a diverse intestinal flora. This strengthens your line of defense and prevents infection.

Also air out your heated rooms more often to avoid irritating your mucous membranes even more and go outside a lot. Regular walks are also good for a strong immune system.

 

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Sources (in English)

The Francis Crick Institute. (2019, July 2). Antibiotics weaken flu defenses in the lung. ScienceDaily. Retrieved October 12, 2020

Cell Reports. (2019, July 2). Microbiota-Driven Tonic Interferon Signals in Lung Stromal Cells Protect from Influenza Virus Infection. ScienceDirect, doi: 10.1016/j.celrep.2019.05.105

Belkaid, Y., & Hand, T. W. (2014). Role of the microbiota in immunity and inflammation. Cell, 157(1), 121–141. doi: 10.1016/j.cell.2014.03.011