UNITED KINGDOM: Yale University researchers have made a breakthrough in understanding how to promote the growth of beneficial bacteria in the human gut. This may have significant effects on enhancing gut health and general human health. Their findings are published in the journal Science.
The researchers, who were led by geneticist Eduardo Groisman, found that when carbon is scarce, a common gut bacterium called Bacteroides thetaiotaomicron stores molecules for an important transcription factor in a membrane-less compartment. This makes the transcription factor work harder, which changes the way hundreds of bacterial genes are expressed. Some of these genes help bacteria colonise the gut and control metabolic pathways.
Researchers think that these compartments without membranes are a key way for “good” bacteria to take over the guts of mammals. This is because, although gut bacteria have access to nutrients ingested by the host, there are also long periods of time when the host organism does not eat. Lack of nutrients, particularly carbon, causes the growth of colonization factors in good gut flora.
The breakthrough came after Groisman noticed that the transcription factor from Bacteroides thetaiotaomicron was much larger than those of other homologous proteins from other bacterial species. Scientists later found that germs couldn’t live in the intestines of a mouse if homologous proteins didn’t have an extra part that was missing.
The process of sequestering the transcription factor takes place through liquid-liquid phase separation, a ubiquitous phenomenon present in a wide variety of cells, including those of humans.
This has been known for over a hundred years but was usually associated with stress in eukaryotic organisms. The researchers have now established that it occurs in commensal gut bacteria, which require it for survival in the gut.
This breakthrough could help develop new probiotic therapies for gut health. The researchers believe that by manipulating organisms prone to this effect, it may be possible to improve organisms that are beneficial to humans.
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