The Surprising Role of Gut Bacteria

The Surprising Role of Gut Bacteria
The Surprising Role of Gut Bacteria - Many physiological functions in the human body are affected by our microbiome. According to a recent study, when the microbiome changes, as with the use of antibiotics, the liver's ability to regenerate is suppressed. Image courtesy of Klaus-Peter Janssen/TUM

According to recent studies, the microbiota serves as crucial building blocks for cell division.

When part of the liver is removed, the body can restore the missing tissue. However, as recent research from the Technical University of Munich (TUM) has shown, the intestinal flora plays an important role in the effectiveness of this process. The outcomes of liver surgery for patients with liver cancer and other conditions may be improved by these discoveries.

For example, the human liver, unlike the heart, has an incredible regenerative capacity. An example of the role our gut bacteria play in activities occurring in other organs are the underlying biological mechanisms. New research by an interdisciplinary team at TUM University Hospital Klinikum and TUM Faculty of Life Sciences provides proof of this.

Short chain fatty acids required for growth

Many types of bacteria make up a balanced gut microbiome. They actively participate in digestion. For example, some convert carbohydrates into short-chain fatty acids (SCFAs). According to the study's principal investigator, Professor Klaus-Peter Janssen, from the Department of Surgery at Klinikum rechts der Isar, liver cells need these fatty acids to thrive and multiply. “We were able to show for the first time that gut bacteria affect the lipid metabolism of liver cells and thus their regenerative capacity.”

Antibiotics prevent liver regrowth

Dr. Janssen and his group conducted tests on mice to find out how an impaired microbiome affects liver regeneration. Antibiotics, which disrupted the microbiota in mice, significantly slowed the growth of new liver cells. The relationship between antibiotic use and impaired liver regeneration was already known to scientists. According to Klaus-Peter Janssen, this has previously been linked to the body's immune response or the negative side effects of antibiotics on liver cells.

Liver Regeneration

The TUM study is the first to describe the mechanical link with gut bacteria. Mice born without a microbiome also did not experience liver cell regeneration, compared to mice given antibiotics.

Anna Sichler, one of the study's first two authors, says that not all gut bacteria are eradicated by antibiotics. But the drug changes the structure of the microbiome because the surviving bacterial species now produce far fewer short-chain fatty acids. Within a few weeks of receiving antibiotic therapy, the microbiota usually improves. According to the current study, liver regeneration also took place in mice treated with antibiotics, albeit much later. Mice lacking intestinal flora did not regrow. Still, the researchers were able to promote liver regeneration by applying a properly designed “microbiome starter kit.”

Experiments with Human Cells and Organoids

Using organoids produced from mouse cells, which are effectively miniature livers in a Petri dish, the researchers demonstrated that SCFAs provide important building blocks for the cell membrane in liver cells. Insufficient SCFA levels inhibit the proliferation and growth of cells. The team discovered that an enzyme called SCD1 was particularly active when cells were enlarged because enough fatty acids were available.

“We then studied the processes using human liver cells and tissue samples,” explains Yuhan Yin, who is also one of the study's principal authors. In humans, SCD1 is also activated when the liver regenerates.

Potential uses before and after surgery
It is very important to remember that the function of gut bacteria in our body is extremely complex. According to Klaus-Peter Janssen, there is still more work to be done before we fully understand this. As a result, the study does not offer any recommendations for additional actions or the creation of new drugs. However, our findings can be applied to new research into which microbiome compositions support superior liver regeneration conditions.

To decide whether it's better to wait for the microbiome to heal or perform surgery, doctors can examine their patients' gut flora. A particular diet can also affect recovery.

Dr. Janssen continues, “On the other hand, doctors can check the microbiome through stool samples to detect how effectively the liver is healing after an operation. The team will conduct additional research on this.

source: scitechdaily

📩 17/03/2023 14:33