Wednesday, 13 May 2015

Preventing antibiotics from killing beneficial bacteria

The microorganisms in the human gut can help the body to maintain a state of health. One problem with antibiotics, when used to fight pathogens, is that they can indiscriminately kill off beneficial bacteria. A new compound can help address this concern.

Scientists have discovered that a chemical signal called autoinducer-2 (AI-2), which bacteria use to communicate with each other, is able to promote an appropriate level of beneficial gut microbes.
Bacterial communication is termed “quorum sensing.” This is a complex system of is a system of stimulae and response within a given bacterial population. Bacteria use quorum sensing to coordinate certain behaviors such as biofilm formation, virulence, and antibiotic resistance.
The discovery is important in relation to antibiotic use. The over-use of antibiotics can trigger the make-up of the microorganisms in the intestines. This can lead to health issues, especially if those bacteria killed are those that help to –off-set auto-immune diseases.
Instead do using indiscriminate antibiotics, the researchers hope to use chemical signalling to push microorganisms in a disease state to a healthy state.
Representative image of bacteria


Studies have been successfully carried out using antibiotic-treated mice. By using the AI-2 chemical signal produced by one species it was shown that this can influence gene expression in another species, enabling a beneficial bacterial population to grow and multiply and thus avoid being killed by the antibiotic.
The implications of the research are for a new generation of drugs that use the chemical signals produced by bacteria to protect the beneficial bacteria in the human gut. The research group aim to examine further if AI-2 accelerates the recovery of the protective functions of gut microbes against pathogens and infectious diseases after antibiotic treatment.
The findings have been reported to the journal Cell Reports. The article is titled “Manipulation of the Quorum Sensing Signal AI-2 Affects the Antibiotic-Treated Gut Microbiota.”

Posted by Tim Sandle