마이크로바이옴이 호스트에게 끼치는 영향

https://phys.org/news/2020-06-gut-bacteria-behavior-worms-habits.html

Gut bacteria are tiny but may play an outsized role not only in the host animal's digestive health, but in their overall well-being. According to a new study in Nature, specific gut bacteria in the worm may modify the animal's behavior, directing its dining decisions.

were interested in seeing whether it was possible for gut bacteria to control a host animal's behavior. The group investigated the effects of gut bacteria on how worms, called C. elegans, sniff out and choose their next meal. 

Bacteria are the worms' primary food. In this study, the researchers measured how worms fed different strains of bacteria reacted to octanol, a large alcohol molecule secreted by some bacteria, which worms normally avoid when it is present at high concentrations.

Dr. O'Donnell and his colleagues discovered that worms grown on Providencia alcalifaciens (JUb39) were less likely to avoid octanol compared to animals grown on other bacteria. Curiously, they found that live JUb39 bacteria were present in the gut of the worms that moved toward octanol, suggesting that the behavior may be determined in part by a substance produced by these bacteria.

The brain chemical tyramine may play an important role in this response. In the worms, tyramine is transformed into the chemical octopamine, which targets a receptor on sensory neurons that controls avoidance behavior. The results of this study suggested that tyramine produced by bacteria increased levels of octopamine, which made the worms more tolerant of octanol by suppressing the avoidance of octanol that is driven by these neurons.

"In this way, the bacteria can take control over the host animal's sensory decision-making process, which affects their responses to odors and may influence food choices" said Dr. Sengupta.

Future studies will identify additional brain chemicals produced by bacteria that may be involved in changing other worm behaviors. In addition, it is unknown whether specific combinations of bacterial strains present in the gut will result in different responses to environmental cues. Although worms and mammals share many of the same genes and biochemical processes, it is not known whether similar pathways and outcomes exist in higher order animals.

 

제목만 봐서는 PNAS, PLOS ONE 약간 이런 느낌이었는데 Nature였다.

microbiome이 host의 행동에 영향을 줄 수 있다는 내용이다. C.elegans에서 실험되었다.

 

 

reference

 MP O'Donnell et al. Modulation of olfactory behavior by a gut bacteria-produced neurotransmitter. Nature, 2020. DOI: 10.1038/s41586-020-2395-5