Bonnie Bassler discovered that bacteria “talk” to each other, using a chemical language that lets them coordinate defense and mount attacks. The find has stunning implications for medicine, industry — and our understanding of ourselves.
Tag Archive: bacteria
“Allergic diseases have reached pandemic levels,” begins David Artis’s new paper in Nature Medicine. Artis goes on to say that, while everyone knows allergies are caused by a combination of factors involving both nature and nurture, that knowledge doesn’t help us identify what is culpable — it is not at all clear exactly what is involved, or how the relevant players promote allergic responses.
There is some evidence that one of the causes lies within our guts. Epidemiological studies have linked changes in the species present in commensal bacteria — the trillions of microorganisms that reside in our colon — to the development of allergic diseases. (Typically, somewhere between 1,000 and 15,000 different bacterial species inhabit our guts.) And immunologists know that signaling molecules produced by some immune cells mediate allergic inflammation.
There is a vast, unseen marketplace that connects us all. The traders are the trillions of bacteria that live on or within our bodies; the commodities they exchange are genes. This flow of genes around our bodies allows bacteria to rapidly evolve new skills, including the abilities to resist antibiotics, cause disease, or break down environmental chemicals. In the past, scientists have caught glimpses of individual deals, but now the full size of the marketplace is becoming clear.
The human body is home to 100 trillion microbes, whose cells outnumber ours by ten to one, and whose genes outnumber ours by a hundred to one. These genes are not only more numerous than ours, but they operate under different rules. While we can only pass down our DNA to our children, bacteria and other microbes can swap genes between one another. For example, the gut bacteria of Japanese people have a gene that helps them to digest seaweed. They borrowed it from an oceanic species that hitched its way into Japanese bowels, aboard uncooked pieces of sushi. Continue reading