How the resident microbes restructure body chemistry, The composition of our microbiome is a unique community of bacteria, viruses, and other microbes that live in and around us and has been linked to various levels of evidence, from inflammatory bowel disease to athletic performance.
Researchers at the University of California at San Diego have made the first map of all the molecules in each mouse organ and how they have been changed by germs.
In a surprising example, they found that microbes control the structure of bile acids in mice and humans.
If you change the structure of molecules such as bile acids, you can change the way cells talk to each other and which genes are turned on or off at certain times, researchers say.
This can have enormous consequences for the functioning of the body and the development of disease.
The team compared embryonic mice (sterile) and mice with normal germs. They used a laboratory technique called mass spectrometry to characterize non-living molecules in every mouse organ. How the resident microbes restructure body chemistry.
They identified as many molecules as possible by comparing them with reference structures in the GNPS database, the mass spectrometry repository that Dorrestine et al.
They also determine which living microbes are located within these molecules by sorting certain genetic regions that act as barcodes for types of bacteria.
In total, they analyzed 768 samples from 96 sites in 29 different organs from four non-embryonic mice and four mice with normal germs.
The result is a map of all molecules found in normal mouse bodies with germs and a map of mouse molecules without germs.
Card comparisons show that up to 70 percent of rat intestinal chemistry is determined by intestinal microbiomas. Even in distant organs such as the uterus or brain, about 20 percent of the molecules in mice with intestinal microbes are different. How the resident microbes restructure body chemistry.
After making these maps, the researchers created a specific group of molecules that looked significantly different in the presence of germs: bile acids.
Bile acids are mainly produced by mice or human livers and help absorb fats and oils. You can also carry messages throughout your body.
The team so far found bile acids with an unknown structure in mice with normal germs, but not in mice without embryos. It has long been known that liver enzymes add bile acids to amino acids, especially the amino acids glycine and taurine. However, in mice with normal microbiomas, the team found that the bacteria labeled bile acids with other amino acids – phenylalanine, tyrosine, and leucine. How the resident microbes restructure body chemistry.
More than 42,000 research papers have been published on bile acids for more than 170 years, the researchers said.
One way bile acids send messages from the intestine to other parts of the body is through specific intestinal receptors called Farnesoid X receptors. Bile acids bind and activate receptors, which then inhibit the genes responsible for producing more bile acids.
Receptors also help regulate triglyceride levels in the liver and intestinal fluids, which makes it important for liver disease and possible obesity. Several drugs are currently being developed to treat liver disease by activating the Farnesoid X receptor. How the resident microbes restructure body chemistry.
The study provides a clear example of how germs can affect human gene expression, researchers say. What we don’t yet know is the consequences of this downstream or how we can intervene to improve human health.