After antibiotic pills, our intestinal flora is no longer the same - but you can do that!

Antibiotics leave permanent traces in the intestinal microbiome

Our intestinal flora, now referred to as intestinal microbiome, contains billions of microorganisms that live in a balanced relationship and have important tasks in digestion and maintaining good health. What happens when this balance is destroyed and how the intestinal flora rebuilds afterwards, an international research team recently investigated in a study.

Broad-spectrum antibiotics are mostly used when other antibiotics fail. The antibacterial lobe not only kills pathogens, but much of the intestinal microbiome is destroyed as a result of such medication. Researchers at the Max Delbrück Center for Molecular Medicine (MDC), together with international colleagues, investigated how the intestinal flora recovers bit by bit after such a stroke. The results were recently published in the journal Nature Microbiology.

What the earth is for us humans is the gut for intestinal bacteria. A whole microcosm of billions of microorganisms live there together in a delicate symbiosis. (Image: Alex / fotolia.com)

Each gut contains its own microcosm

In every human gut, there are as many bacteria as there are humans on Earth, the MDC researchers estimate. In most cases, the tiny creatures are beneficial to the well-being of the owner. For example, they support the digestion of food, produce vitamins, train the immune system and protect against disease-causing conspecifics.

A fragile structure

Diseases or drugs can unbalance or even destroy this susceptible structure. "It unbalances, threatens infectious diseases, obesity and diabetes as well as inflammatory bowel disease or neurological diseases," says research director Dr. med. Sofia Forslund in a press release. Her team now explored the complicated interactions between human and microbiome.

Antibiotics change the intestinal flora permanently

Together with researchers from Denmark, Germany and China, the team led by Forslund investigated how severe treatment with broad-spectrum antibiotics affects the fragile interaction of intestinal bacteria. According to the study team, it takes up to six months for the intestinal flora to recover. However, a complete regeneration could not be determined by the research group. "Some sensitive bacterial species have disappeared permanently," says Forslund.

About the course of the study

During the investigations, twelve healthy men agreed to take a cocktail of the three antibiotics meropenem, gentamicin and vancomycin over four days. Afterwards, her intestinal microbiome was analyzed for six months. Not only the presence of the individual bacterial species was recorded, but also their genes determined by DNA sequencing.

Even after the administration of antibiotics, the intestine was not sterile

The first surprise came shortly after the medication. As the researchers report, some bacteria had even survived the potent antibiotics. Among the survivors, the scientific team found some previously unknown and not further characterized species. Other bacterial species turned into spores. In this form of life, the bacteria can remain in poor conditions for a long time.

How the intestine slowly recovers

Later in the regeneration phase, the second surprise showed up. The first bacteria colonizing the intestine were predominantly associated with pathogenic, ie pathogenic strains such as Enterococcus faecalis and Fusobacterium nucleatum. "This observation explains well why most antibiotics cause gastrointestinal disturbances," concludes Forslund.

Lactic acid bacteria make the turn

Over time, the pathogenic strains are increasingly displaced by beneficial bacterial species such as the lactic acid-producing bifidobacteria, the researchers report. After six months, the intestinal flora was intact again - but not quite the same. Some types of bacteria were missing and did not return. "As expected, the number of resistance genes in the bacteria also increased," explains Forslund.

More consideration in dealing with antibiotics

"Because of the apparently permanent loss of individual species and the increased number of resistance genes, the study shows once again how important it is to administer antibiotics with care," sums up the expert. Now you have to find out how it can be better to protect the sensitive intestinal flora from antibiotics. For more information on the structure and the intestinal rehabilitation, see the articles "Building intestinal flora: How are you" and "The 10 best tips for colon cleansing". (Vb)