Diet affects the gut microbiota – hospital germs multiply
Low-calorie diets are a popular way to lose weight. According to a recent study, it also has an effect on the composition of the intestinal microflora or the intestinal flora. Thus, the decrease in calories leads, among other things, to the accumulation of the bacteria Clostridioides difficile, which is known as hospital germs, which in turn has an effect on weight regulation.
An international research team led by Professor Dr. Joachim Spranger from Charité – Universitätsmedizin Berlin investigated the question of how low-calorie diets affect the body and, in particular, the formation of the intestinal flora. It became clear that diet can profoundly alter the composition of microorganisms in the human gut. The results of the corresponding study were published in the specialized journal “natureChest.
Individual composition of the intestinal flora
Trillions of gut microorganisms, also known as the microbiome or gut flora, differ from person to person and in people who are overweight and obese, for example, the microbiome is made up differently than people of normal weight, Charity explains in a press release The current study.
Studying the effects of a low-calorie diet
For the study, researchers examined the effects of a significantly reduced calorie diet in 80 slightly overweight elderly women. For this purpose, the women either lost weight on a so-called diet (based on ready-made drinks with less than 800 calories per day) under medical supervision or kept their weight stable over 16 weeks.
Test subjects were accompanied at the Center for Experimental and Clinical Research (ECRC), a joint facility between Charité and the Max Delbrück Center for Molecular Medicine at the Helmholtz Association (MDC), according to the Charité Society. Regular analysis of stool samples showed “that the diet reduces the number of microorganisms in the intestines of women and alters the composition of the intestinal flora”.
The gut microbiota has profoundly changed
“We have been able to show for the first time how a very low-calorie diet profoundly alters the composition of the gut microbiota and thus has a lasting effect on the energy balance of the human host,” confirms Professor D. Springer.
The first author, Dr. Reiner Jumpertz von Schwartzenberg from Charité. You could say that a hungry microbiome is evolving.
Weight loss from bacteria?
In other experiments, scientists transferred stool samples taken from test subjects before and after the diet into germ-free mice without intestinal flora. Surprisingly, when the stool was removed after the diet was transferred, the animals showed weight loss — “more than 10 percent of their body mass in just two days,” Charity reports. In contrast, transplantation of stool samples before the diet had no effect.
According to Professor Dr. Spranger, the results indicate that “this phenomenon may be explained primarily by a change in food absorption in the intestines of animals.” Here it is clear that the intestinal microflora has a decisive influence on the absorption of food.
Hospital germs with a growing presence
During a detailed analysis of stool composition, the researchers found an increase in colonization with the bacterium Clostridioides difficile. This is relatively common and can also be found in the intestines of healthy people and animals. However, if they multiply in the gastrointestinal tract, for example after treatment with antibiotics, there is a risk of acute inflammation of the intestine. Since Clostridium difficile is a major problem in the clinical sector, the bacteria is also known as hospital germs.
C. Saab responsible for losing weight?
In the current study, both test subjects who were fed a diet and mice cultured with the corresponding human intestinal bacteria after diet showed an increased presence of Clostridioides difficile. “We were also able to show that Clostridium difficile produces toxins typical of bacteria – even weight loss for animals depends on it,” explains Professor Spranger.
Despite the increased presence of Clostridium difficile, neither the test subjects nor the animals showed clinical signs of gastroenteritis, the expert continues. A low-calorie diet means that “the bacteria known as hospital germs can multiply more easily and make food absorption through the intestinal wall less efficient – but without causing symptoms of disease.”
Can new treatment options be developed?
The extent to which asymptomatic colonization with bacteria can harm or perhaps even enhance health is not yet clear and must now be investigated in larger studies. The team would also like to investigate how gut bacteria are affected in order to have beneficial effects on body weight and metabolism in humans. The knowledge gained can also lead to possible treatment options for metabolic diseases such as obesity or diabetes.
“The present findings underscore the importance of interactions between nutrition and the microbiome in modulating the host’s energy balance and illustrate the need to understand the role of nutrition in the interaction between pathogens and beneficial symbionts,” the researchers summarized. (fp)
Author and source information
This text complies with the requirements of the specialized medical literature, clinical guidelines and current studies and has been examined by medical professionals.
- Rainer Gembertz von Schwarzenberg, Jordan E. Paysans, Svetlana Lyalina, Peter Spanougianopoulos, Kee Yan Ang, Jingwe Kai, Sophia Dickmann, Marie Friedrich, Su Yang Liu, Stephanie L. Collins, Daniel Ingbrigtsen, Steve Miller, Jesse A. Andrew D. Patterson, Catherine S.; Pollard, Knut May, Joachim Springer, Peter J. Turnbu: Calorie restriction disrupts microbes and anti-colonization; In: Nature (23.06.2021), Nature.com
- Charité – Universitätsmedizin Berlin: hospital germs play an important role in weight regulation (published 23 June 2021), charite.de
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. It cannot replace a visit to the doctor.