Understanding how microbiota thrive in their human hosts

Scientists from the Max Planck Institute for Biology, Tbingen, Germany, have made significant progress in understanding how gutbacteria succeed in their human hosts. Inositol lipids, substances vital for many cellular processes in humans and other organisms, are rarely seen inbacteria. The results of the study show that inositol lipids have implications for the relationship between the host and the colonizer.

The human gut contains many organisms that contribute to many biological functions. In order to understand the influence of the microbiome on humans, researchers have been trying to identify which organisms are present in the human gut. Scientists from the Max Planck Institute for Biology in Tbingen have improved our understanding of these processes by investigating how gutbacteria produce a certain family of chemical compounds.

Inflammation and cell signaling can be affected by inositol.

Inositol lipids play an important role in many cellular processes in humans and most other non-bacterial life forms. Polycystic ovary syndrome is one of the most common hormone disorders in women of reproductive age.

Humans and other eukaryotes have inositol lipids that are essential, butbacteria rarely produce them. A research team led by Ruth Ley, scientific director of the Department of Microbiome Science at the MPI for Biology, has been able to describe inositol lipid synthesis in Bacteroides thetaiotaomicron, a common bacterium in the large intestine.

By developing a strain of Bacteroides thetaiotaomicron, they were able to control whether inositol lipids were produced. "Although we don't fully understand the precise role of inositol lipids for bacterial fitness yet, we have seen that they are necessary for a bacterium to succeed in the gut of their host," says Heaver.

Inositol was found in the capsule of thebacteria, which protects them against the immune cells of the host. Bacteroides thetaiotaomicron's resistance to antibiotics is changed by inositol lipids.

There is a possibility of cross-talk between the two.

There is a chain of chemical reactions that lead to the production of inositol lipids. They found a second pathway for the production of these lipids. The pathways are interesting because they allow us to predict which other microbes will be able to make inositol. This knowledge could allow us to engineer or manipulate inositol production.

She says that it is possible that there is a cross-talk between the inositol lipids produced by the mammal and thebacterial inositol lipids. We have come a long way to understand the scale of such interactions.

More information: Stacey L. Heaver et al, Characterization of inositol lipid metabolism in gut-associated Bacteroidetes, Nature Microbiology (2022). DOI: 10.1038/s41564-022-01152-6 Journal information: Nature Microbiology