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Bacteria We Can Call Our Friends

February 05, 2001|Rosie Mestel

Once in a while, it's fitting we devote some space to praising bacteria, what with all the bad press they get. We just found two new reasons to like the little bugs.

First: Some of them seem to help our guts mature into the fine, efficient nutrient-slurping machines that they are.

Second: Good bacteria sprayed into noses may lower the chances of bad bacteria causing ear infections in kids. (Do not attempt this spraying trick at home.)

The first finding, published in the journal Science, involved the following clever experiment. Scientists gave mice with pristine intestines--ones lacking any gut bacteria at all--a dose of a little beast with a big name: Bacteroides thetaiotaomicron. Gross though this may sound, Bacteroides thetaiotaomicron (we just had to say it again) is in fact a normal resident of both rodent and human guts.

When the scientists took a look at what went on in the gut after B. thetaiotaomicron moved in, they witnessed all kinds of frenzied activity. Genes turning on. Genes turning off. And not just any old genes. Those involved in shunting glucose into our bodies--as well as lipids and micronutients--all turned up their activities, presumably better enabling us to absorb food.

(This, say the scientists, could explain why mice whose intestines are kept free of bacteria need more food to maintain their body weight. Though scrubbing one's guts free of bacteria is not a diet we recommend.)

Bacteroides (one more time) thetaiotaomicron isn't the only beast that induces gut changes--though the changes differ depending on the bacterium in question. That could be why my gut doesn't behave quite the same as your gut--or yours or yours.

Our other pro-bacterial item comes from the British Medical Journal and a study in which 108 kids prone to ear infections were given spritzes of certain bacteria--or a placebo--up their noses. Three months later, those who got the bacteria had half the number of ear infections as the ones who'd gotten a placebo.

The good bacteria, in other words, were inhibiting the growth of the bad, ear-infection-inducing bugs. Kids often get antibiotics for ear infections--and overuse of antibiotics encourages the emergence of antibiotic-resistant strains, point out the scientists. They suggest maybe kids could get bug-sprayed instead.

Medical Schools Not a Hotbed of Ethics

A few weeks back we wrote about medical mnemonics--rhymes and other aids that medical students use to help memorize long, tedious lists of body parts and medical procedures. Mnemonics aren't enough for some med students, it seems.

Again in the British Medical Journal, we read about a survey of some British med students in which they were asked questions about iffy things that they'd either done or would consider doing.

* Only 2% said they'd consider copying answers in an exam--or had actually done it. That's encouraging!

* But many more students--fully 56%--were comfortable with copying text directly from published sources and then listing the source only as a reference. Fourteen percent would do it without even acknowledging said source. Tsk!

* Nearly 10% said they'd be willing to write a report for another student; 24% would lend their work to another student to copy.

* Nearly one-third would entertain writing "nervous system--examination normal" when they hadn't even examined someone's nervous system.

Commenting in the journal on this less-than-stellar state of affairs, a doctor, Shimon M. Glick, writes that med schools haven't traditionally been great places for increasing the morality of their students--in part because their emphasis has been so much on grades and competition. "Indeed," he writes, "moral development may actually stop or even regress." To address the problem, he writes, some med schools have developed screening tests that evaluate "ethical maturity" in their candidates.

To any young whippersnappers tempted to cheat, remember: Always do right. This will gratify some people, and astonish the rest. That's what I like to say.

(Oh, OK. Mark Twain said it first.)


If you have an idea for a topic, write or e-mail Rosie Mestel at the Los Angeles Times, 202 W. 1st. St., Los Angeles, CA 90012,

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