Everyday remedies sustainably affect the intestinal flora

Not only antibiotics inhibit our gut bacteria

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

Important protection against infections

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

As researchers have now found, not only antibiotics, but also many other common drugs can damage our intestinal flora. (Image: Alex / fotolia.com)

Every fourth drug inhibits the growth of bacteria

As reported by the European Molecular Biology Laboratory (EMBL) in Heidelberg, one in four medicines used in human medicine inhibits the growth of bacteria naturally occurring in the human gut.

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

To get these results, the research team investigated the effect of more than 1,000 drugs available on the market for 40 representative bacteria from the human gut.

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

The results of the study were recently published in the journal Nature.

Composition of the intestinal microbiome is changed

The human gut contains a variety of bacterial species, the entirety of which is termed the intestinal microbiome. Over the past decade, the composition of the gut microbiome has been shown to affect health.

Thus, it is known that antibiotics have a high impact on this microbiome and cause, among other things, gastrointestinal side effects

In addition, it has recently been reported that some common non-antibiotics also alter the composition of the gut microbiome, but the full extent of this phenomenon has been unknown.

For the first time, the Heidelberg scientists systematically investigated the direct effects of available drugs on 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 intestinal 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 it can also be part of the positive effects of the drugs. "

His colleague Kiran Patil added: "This is only the beginning. We do not yet know how most of these drugs affect the microbes, how these effects manifest themselves in the human host, and how this affects, for example, the health of patients. "

And: "We need to study these relationships closely, because this knowledge could greatly improve our understanding and the effectiveness of existing drugs."

Unrecognized risks

The study also highlighted the hitherto unnoticed risk that taking non-antibiotics may contribute to antibiotic resistance.

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

"That's really scary," says Nassos Typas, "considering that people use medication their entire lives, often over long periods of time."

The EMBL group leader continued, "Fortunately, not all non-antibiotics affect intestinal bacteria and not all resistance will continue to spread. Interestingly, resistance to certain non-antibiotics can increase the efficacy 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 investigations, which aim to better understand the interactions between drugs and microbes in the context of the intestine," said Georg Zeller.

"All humans differ in the composition of their microbiome, which may explain why different patients respond differently to the same drugs."

We all have different types of bacteria - besides some species that we all share - and we also have different variants within a species called strains.

These strains can have very different functions, including the response to medication. Thus, the likelihood is high that many interactions between drugs and microbes will be individually different.

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