Free Now I Know More by Dan Lewis Page B

Southerners were, therefore, left untreated for a few days. When night came, the wounds of some of the injured soldiers, still left unattended, began emanating a faint blue light. They created a soft glow in the otherwise-dark battlefield. When the wounded soldiers finally received treatment, many claimed that those who had the glowing injuries healed more thoroughly than those without the apparently supernatural halo.
    It wasn’t a gift from the heavens, of course. It came from Photorhabdus luminescens , a type of bacteria. P. luminescens , as the cool kids call it, is a bioluminescent microbe that has a symbiotic relationship with roundworms, a parasitic nematode that infects insects. The roundworm invades an insect and, effectively, throws up a gut full of P. luminescens . The bacteria releases a toxin that kills the insect within forty-eight hours and an enzyme that breaks down the insect’s body. The nematode then eats the liquefied insect, returning much of the bacteria to its home inside the roundworm’s body.
    The roundworms—and therefore the bacteria—were most likely present in the mud and dirt of the Shiloh battlefield. It’s further likely that the microbes made their way into the wounds of many of the injured Confederate soldiers and, because of other conditions, were able to thrive there. Even that required a bit of luck, which explains why only some of the soldiers began to glow.
    While P. luminescens typically can’t survive in a human host because our body temperature is too warm for them, according to MentalFloss.com, prolonged exposure to the rainy and wet conditions of the battlefield caused many soldiers to suffer from hypothermia. This dropped the body temperature of those fighters, allowing P. luminescens to invade their wounds—and, being a bioluminescent creature with a blueish hue, to create the glow.
    The good news for those soldiers is that P. luminescens isn’t all that infectious, and our bodies’ immune systems can typically handle the microbe. But before that happens, the P. luminescens do their human hosts a favor typically reserved for the roundworms. The toxins they produce that kill insects also happen to kill other bacteria in the area, keeping the P. luminescens and its host safe from infection. That’s almost certainly what happened in this case, which is why the glowing soldiers recovered more quickly than their standard-hued comrades-at-arms.
    BONUS FACT
    The gene of P. luminescens associated with the insect-killing toxin was discovered by a team of British researchers in 2002. They named the gene “mcf”—short for “make caterpillars floppy,” because that’s what the toxin does.

MISTER BEER BELLY
HOW TO ACCIDENTALLY BREW BEER WHEREVER YOU ARE
    The human body contains roughly 10 trillion cells—and roughly 100 trillion bacteria. These bacteria—life forms in their own right—constitute as much as 2 percent of our body mass. Most of the bacteria operate, effectively, independent of us, having little to no effect on our health or well-being. Some are actually symbiotic, aiding in the digestion of food and perhaps even making us smarter (although that study is controversial). Others are harmful—one type may make depression symptoms worse—while others cause illnesses such as strep throat.
    And others turn our stomachs into breweries.
    Well, once at least.
    Sometime in the late summer or early fall of 2013, a sixty-one-year-old Texas man walked into an emergency room drunk out of his mind. Nurses administered a Breathalyzer exam and determined that the patient’s blood-alcohol level was 0.37 (which can lead to serious impairment). Normally he’d be given some time to sober up. But there was one weird variable in this case: the man hadn’t been drinking. To make sure that he wasn’t sneaking a shot or two, doctors searched him for booze and, finding none, stuck him in a hospital room,