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Everyday medicines have a lasting effect on the intestinal flora


Not only antibiotics inhibit our intestinal bacteria

It has been known for years that antibiotics can damage the intestinal flora. However, researchers have now found that many other common drugs also inhibit the growth of bacteria that are naturally found in the intestine. Accordingly, these drugs cause antibiotic-like side effects and can even contribute to antibiotic resistance.

Important protection against infections

It has long been known that healthy intestinal flora makes an important contribution to protection against infections, allergies and other diseases. According to health experts, numerous complaints such as joint diseases and even depression can be attributed to disorders of the intestinal flora. It is also known that taking antibiotics can upset the beneficial microbial community in our gut. But other common drugs can also have a similar effect, as researchers have now discovered.

Every fourth drug inhibits the growth of bacteria

As reported by the European Molecular Biology Laboratory (EMBL) in Heidelberg in a communication, every fourth drug used in human medicine inhibits the growth of bacteria that occur naturally in the human intestine.

According to the researchers, these drugs cause antibiotic-like side effects and can contribute to antibiotic resistance.

To arrive at these results, the research team examined the effects of more than 1,000 drugs on the market on 40 representative bacteria from the human intestine.

They found that more than a quarter of the non-antibiotics (250 out of 923) inhibit the growth of at least one species of the microbiome.

The results of the study were recently published in the "Nature" magazine.

The composition of the gut microbiome is changed

The human intestine contains a large number of bacterial species, the entirety of which is referred to as the intestinal microbiome. Over the past decade, it has been shown that the composition of the gut microbiome affects health.

It is known that antibiotics have a major impact on this microbiome and cause, among other things, side effects in the gastrointestinal area

It has also recently been reported that some commonly used non-antibiotics change the composition of the gut microbiome, but the full extent of this phenomenon has been unknown.

For the first time, the Heidelberg scientists have systematically investigated the direct effects of the drugs available on the market for individual intestinal bacteria.

Impact on patient health still unclear

They found that not only anti-infectives, but drugs from all therapeutic classes inhibited the growth of various intestinal microbes.

"How many different types of drugs affect gut microbes was really surprising," said Peer Bork of EMBL.

“Especially because our data suggests that the actual number is probably even higher. This change in the composition of our intestinal bacteria contributes to drug side effects, but can also be part of the positive effects of the drugs. ”

His colleague Kiran Patil added: “This is just the beginning. We do not yet know how most of these drugs affect the microbes, how these effects come to light in the human host, and how this affects the health of patients, for example. ”

And: "We need to examine these relationships in depth, as this knowledge could enormously improve our understanding and the effectiveness of existing medications."

Undetected risks

The study also highlighted the previously undetected risk that taking non-antibiotics could contribute to antibiotic resistance.

This is because general resistance mechanisms seem to play a major role that work against both antibiotics and other drugs.

"It's really scary," says Nassos Typas, "when you consider that people take medication all their lives, often over long periods of time."

The EMBL group leader further explained: “Fortunately, not all non-antibiotics have an effect on intestinal bacteria and not all resistances will spread further. Interestingly, resistance to certain non-antibiotics can increase the effectiveness of certain antibiotics, which in turn opens up opportunities for creating optimal drug combinations. ”

Personalized medicine

"We are looking forward to the results of further studies that aim to better understand the interactions between drugs and microbes in the context of the intestine," said Georg Zeller.

"All people differ in the composition of their microbiome, which could explain why different patients react differently to the same medication."

We all have different types of bacteria - in addition to some species that we all have in common - and we also have different variants within a species called strains.

These strains can have very different functions, including the response to medication. This means that there is a high probability that many interactions between drugs and microbes will differ individually.

This in turn opens up opportunities for personalized medication treatments tailored to the patient's individual gut microbiome. (ad)

Author and source information

Video: A gut microbiome feeling about stress and brain development - John Cryan (August 2020).