Gulp: Adventures on the Alimentary Canal

The average person, of course, is oblivious to all this. With no more formal criteria than the number of Hollywood monsters featuring copious, pendant drool, you can make the case that saliva remains universally upsetting. And thus maligned, even in the medical community. There has long been an assumption among emergency medical personnel that human bites are especially likely to become infected and lead to sepsis—a potentially lethal systemic infection. “Even the simplest of wounds require copious irrigation and wound toilet,” warn the authors of “Managing Human Bites” in the Journal of Emergencies, Trauma, and Shock.

Not so fast, says rival American Journal of Emergency Medicine. The article title says it all: “Low Risk of Infection in Selected Human Bites Treated without Antibiotics.” Only one out of the sixty-two human-bit patients who were not given antibiotics developed an infection. However, the authors excluded high-risk bites, including “fight bites” on the hands. Here it is the aggressor who gets the “bite”—when he splits open his knuckle on another man’s teeth. Fight bites* tend to get infected, but it is the fault of the knuckle as much as the saliva. Relatively little blood flow reaches the tendons and sheaths of the finger joints, so the immune system has fewer resources with which to fight back. (Ear cartilage is similarly underserved by the vascular system, so if you plan on picking a fight with Mike Tyson, do practice good wound toilet.) Even the “deathly drool” of the Komodo dragon, the world’s largest lizard, has likely been overstated. Theory holds that Komodo dragon saliva contains lethal doses of infectious bacteria, enabling the reptiles to take on prey far larger than themselves—wild boar, deer, newspaper editors. (San Francisco Chronicle’s Phil Bronstein spent several days on an antibiotic drip after a Komodo dragon attacked his foot during a behind-the-scenes visit at the Los Angeles Zoo in 2001 with his then wife, Sharon Stone.) Rather than having to tackle and kill their prey on the spot, the theory goes, the reptiles need only deliver a single bite and then wait around for the animal to die of sepsis. The scenario has not been documented in the wild, however. A team of researchers from the University of Texas at Arlington attempted a laboratory simulation, using mice as mock prey and, as predator, injections of bacteria from wild Komodo dragon saliva. The scientists found a high death rate among mice injected with a particular bacteria, Pasteurella multocida. However, Australian researchers point out that P. multocida is common in weakened or stressed mammals. They speculate that the dragons may have picked it up from their prey, rather than the other way around. Current thinking postulates a “sophisticated combined-arsenal killing apparatus,” featuring venom and anticoagulative agents that lead to shock. The latter would explain “the unusual quietness . . . of prey items.” Prey item Phil Bronstein was unusually not quiet.* “I was pretty pissed.”

Though bacteria and general ropy grossness are probably to blame for saliva’s nasty reputation, it may in part be lingering fallout from the writings of Hippocrates and Galen, Western medicine’s most influential early (as in, triple-digit A.D. and B.C.) thinkers. Both believed sweat and saliva to be the body’s way of flushing away disease-causing impurities. Before scientists realized syphilis and malaria were caused by microorganisms, the diseases were treated by putting patients in “salivating rooms.” It was the same medically quaint principle that persists today in the form of taking a steam or a sauna to “sweat out toxins.” Only back then, the steam included vaporized mercury? to coax more saliva from the patient. No one realized that excessive salivation is a symptom of acute mercury poisoning. The salivating room was a standard feature of hospitals in the 1700s. (As was, charmingly, the “apartment for lunatics.”) Patients were left inside until they’d generated six pints of saliva—about three times the amount most people produce in a day.

Not all cultures denigrate saliva. In ancient Taoist medical teachings, stimulated saliva—“the jade juice”—was said to nourish the qi, which boosts the immune defenses and, wrote one seventh-century Taoist, “puts a man beyond the reach of calamities.” Given this tradition of qi-nourishing saliva retention, why do I so often see old Chinese men spitting? Silletti points out that it’s not saliva being expectorated. It’s phlegm from the lungs or sinuses. They spit it out, she added, because they don’t care to use handkerchiefs or Kleenex. They think it’s disgusting that we collect the material in our hands.

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