Bacteria ‘Fight Club’: Guardians of the Gut Fight it Out
Fight! Fight! Fight!
A tale of survival in the Microbial Jungle proceeds.
There’s a war going on that you’re completely oblivious to, even though it’s all happening right under your nose- well, actually inside of you. Rival Strains of Escherichia coli compete for precious real estate within the damp linings of your gut.
You cannot really ever guess how
much bacteria like a good fight until you’ve seen this video, scientists at the University of Oxford have made. They literally stab, shove and poison each other in pursuit of the best territory.For the first time, scientists have observed in real-time the ability of bacteria within a colony to collectively predict and respond to an incoming attack by another colony. This discovery has important implications for understanding both the healthy bacteria that live in the human body and the bacteria responsible for spreading disease.
Animals have evolved a wide diversity of aggressive behavior often based upon the careful monitoring of other individuals. Bacteria are also capable of aggression, with many species using toxins to kill or inhibit their competitors. Like animals, bacteria also have systems to monitor others during antagonistic encounters, but how this translates into behavior remains poorly understood.
However, now the researchers have observed such behaviour through warring microbes. They used two strains of Escherichia coli, pitting them against each other. Both strains were engineered to have either fluorescent green or red colors so the Oxford scientists could “follow their combat in real time.” They saw that each strain produced their own toxin as a weapon against the other strain, but the bacteria were not negatively affected by their own toxin.
The findings revealed that not all strains of bacteria fight the same way. In addition to these basic differences in aggression, the research also shows that some strains can not only detect an attack from an incoming toxin, but they can also respond quickly to warn the rest of the colony.
Cells on the edge of the colony will detect the incoming attack, and share this information with the cells behind the battlefront, allowing them to respond as a collective, in a coordinated and surprisingly sophisticated fashion.
Professor Kevin Foster, senior author on the work and Professor of Evolutionary Biology in the Department of Zoology at the University of Oxford, said: “Our research shows that what appear to be simple organisms can function in a very sophisticated manner. Their behaviour is more complex than we have previously given them credit for. Much like social insects, such as honey bees and wasps and social animals like birds and mammals who use alarm calls, when under predation, they are capable of generating a coordinated attack.”
Given how the human body is home to vast numbers of bacteria, particularly our gut microbiome, this effectively means that there is a bacterial war going on inside us. Understanding bacterial competition can help us to understand how bacteria spread, where and why. Professor Foster explains: “We know from other studies that toxins are important for whether or not a particular strain will establish in a community. But understanding how bacteria release toxins and outcompete others is very important for understanding the spread of infection.”
Witness the two epic colonies (of bacteria) engaging in battle, Game of Thrones style, here:
