The intestinal flora is able to significantly change amino acid and glucose metabolism and thus acts like an additional liver. This finding could open up new possibilities for the treatment of inflammatory bowel disease and diabetes.
In a new study, experts at Cornell University in the USA examined how the microbes of the intestinal flora influence the absorption of nutrients from the food consumed. The results can be read in the English-language specialist journal “Cell Host & Microbe”.
How microbes influence physiology
Billions of microbes live on and in the human body and have a profound impact on physiology, the team reports. These microbes first cover their own nutrient needs from the nutrients in the food they eat before leaving the rest to the body, explains study author Dr. Chun Jun Guo.
To better understand this process, the team examined how efficiently different bacteria in the intestine break down amino acids, the building blocks of proteins.
Since the metabolic functions of many intestinal bacteria are poorly described, the experts experimented with different settings to find the optimal conditions for the study.
Certain microbes are very efficient
After screening more than 100 different human gut microbes, the team managed to identify some microbes that are particularly efficient at metabolizing various amino acids from food.
When the gastrointestinal tract of germ-free mice was colonized with these microbes, the content of these amino acids in the mice's intestines and blood was significantly reduced. In this way, the researchers were able to identify a large number of specific bacterial metabolic genes that break down amino acids.
“We found that there are over 20 different genes in a single bacterium that code for a similar enzymatic function,” reports Dr. Guo in a recent press release.
“We can now precisely manipulate individual genes for the breakdown of amino acids in the intestine. This allows us to assess the individual function of these genes and see how they actually affect the amino acid homeostasis of the host, adds the doctor.
According to the team, the new findings show that the consumption of a certain class of amino acids can cause the intestinal microbes to change the so-called glucose homeostasis of the host.
Like a second liver
“Many of these metabolic functions can be handled by the liver, but now we have found that there are functionally comparable enzymes encoded by the gut microbiota that can do the same or similar things. “It’s like there’s a second liver working in the intestines,” explains Dr. Guo.
According to the researchers, the results indicate that some of the genes identified in the study are also dysregulated in the intestinal flora of people with digestive and metabolic diseases. This could open up new possibilities for the treatment of such diseases.
New possible targets for diabetes
The researchers explain that these metabolic genes could be potential biomarkers for diseases such as type 2 diabetes or inflammatory bowel disease and could also serve as possible treatment targets. The study shows that the intestinal flora can be specifically manipulated to regulate the host's metabolism and improve its metabolic functions.
Not only does it become clear how strongly the intestinal flora influences physiology in general, but new strategies for the treatment of diseases such as inflammatory bowel disease and diabetes could also be derived. (as)
