Microbial News at ASM

So what did we all learn at ASM, the American Society for Microbiology meeting 2014?

• Bacteria you eat may prevent osteoporosis (bone thinning). Don’t all go out and buy probiotics, because health foods are unregulated and make outrageous claims. However, Lactobacillus reuteri makes a hormone-like molecule that does prevent bone thinning in mice. We saw slides of bones with and without. Furthermore, the bone-protective molecule inhibits development of cells that eat bone (osteoclasts). The doctors think that if post-menopausal women consume L. reuteri in some form, it may maintain bone density with fewer side effects than estrogen treatments.
• Bacteria have a sense of touch. Before they make biofilms (multicellular communities), bacteria can “feel” the surface they touch using touch-sensitive proteins. How the touch transduction works, we still don’t understand.
• Bacteria tell eukaryotic microbes to become multicellular bodies. Much evidence shows how bacteria and viruses activate key steps of embryonic development and immune system maturation. Now, a case has been shown in which marine bacteria tell unicelled eukaryotes called choanoflagellates to join together in rosettes.

The choanoflagellates then eat the bacteria–or do they? Do some of the bacteria take up residence?
Leading to the hypothesis that bacteria invented multicellular life to provide them a home.

• More evidence for the bacterial home hypothesis: Human placenta contains specific bacteria. A few percent of the placental mass consist of normal bacteria, related to those of our mouths. These normal placental bacteria are actually needed for normal birth.
• Even the deadly fungus Cryptococcus can provide a way to treat brain diseases. Cryptococcus makes an enzyme (a metal-containing protease) that can sneak its way across the blood-brain barrier. We may be able to use this enzyme to help us get therapeutic drugs into the brain.
• Some bacteria may signal the gut via cannabinoid receptors. Getting ahead of my science fiction story, where the alien invaders take over Earth by spreading cannabinoids.

Alas, though, the “don’t floss” suggestion from previous post turned out to be a joke. Yes, keep flossing, despite the researchers who adore the dental bacteria they study.