Diet affects a person’s energy balance by altering the gut microbiota: Study

Charite researchers-University of California, Berkeley and the University of California, San Francisco have been able to show for the first time that a very low-calorie diet significantly alters the composition of the microflora present in the human gut.

A study published in a Journal Nature publication reported that dieting increased Clostridium difficile associated with certain bacteria, especially antibiotic-induced diarrhea and colitis.

These bacteria clearly affect the body’s energy balance by affecting the absorption of nutrients from the intestines.

The human gut microbiota is composed of trillions of microorganisms and varies from person to person. For example, in people who are overweight or obese, their composition is known to be different from that found in people of normal weight. Many of us try to lose weight at some point in our lives.

But how does such a dramatic change in eating habits affect our bodies? An international team of researchers co-led by Charite is addressing this question. “For the first time, we were able to show that a very low-calorie diet can make significant changes in the composition of the gut microbiota, and these changes affect the host’s energy balance,” said Head Professor Joachim Spranger. I am. He is a professor of endocrine and metabolic disorders at Charite and one of the lead authors of the study.

To investigate the effects of the diet, the team studied 80 elderly (postmenopausal) women who weighed from slightly overweight to severe obesity for 16 weeks. Women followed a medically supervised meal replacement regime, consuming a total of less than 800 calories of shakes daily or maintaining weight during the study.

Participants were tested at the Experimental Clinical Research Center (ECRC), a facility jointly run by Charite and the Max Delbrück Center for Molecular Medicine (MDC). Regular stool sample analysis showed that the diet reduced the number of microbes present in the gut and altered the composition of the gut microbiota.

“We were able to observe how bacteria adapt their metabolism to absorb more sugar molecules, thereby making them unavailable to human hosts.” Hungry microbiomes. ” Dr. Reiner Jumpertz von Schwartzenberg, the lead author of the study, is a researcher and clinician in the Department of Endocrine Metabolic Diseases, under the Clinician Scientist program run by Charite and the Berlin Institute of Health (BIH). The research was funded.

Fecal samples taken before and after the diet were transferred to sterile mice, resulting in a complete deficiency of the gut microbiota. The result was amazing. Animals that received post-diet stool lost more than 10 percent of their body weight. The pre-diet stool had no effect.

“Our results show that this phenomenon is mainly explained by changes in the absorption of nutrients from the animal’s gut,” said Professor Spranger. “This highlights the fact that gut bacteria have a significant impact on food absorption,” he added.

When researchers studied the composition of feces in more detail, they were particularly impressed with the signs of increased colonization by the particular bacterium Clostridium difficile. This microorganism is commonly found in the natural environment and in the intestines of healthy humans and animals, but the number of microorganisms in the intestines increases with the use of antibiotics and can cause severe inflammation of the intestinal wall. ..

It is also known as one of the most common in-hospital pathogens. Increased bacterial levels were seen in both participants who completed the weight loss regimen and mice that received post-diet gut bacteria.

“C. Difficile produced a toxin normally associated with this bacterium, which could be shown to be a condition for animal weight loss,” explained Professor Spranger. “Nevertheless, neither participants nor animals showed any associated signs of intestinal inflammation,” he added.

To summarize the results of the study, Professor Spranger said: “A very low-calorie diet appears to significantly alter the gut flora and reduce colonization resistance of the in-hospital bacterium Clostridium difficile. These changes make it efficient, especially relevant, without the gut wall. It does not cause clinical symptoms. The question is whether or to what extent this type of asymptomatic colonization by C. difficile can impair human health, potentially improve it, or to what extent. Do you want to?

The results of the current study, also funded by the German Cardiovascular Disease Center (DZHK), may even create treatment options for metabolic diseases such as obesity and diabetes. For this reason, researchers explore how gut bacteria are affected to have beneficial effects on the weight and metabolism of human hosts.