Mutant Mice Shed Light on Intestinal Bacteria

"Feedback Loops Keep Gut Bacteria Calibrated"
Ars Technica, Wired (October 14, 2011)

"We tend to get overly focused on bacteria that are trying to kill us (and there's no shortage of those), but there are large populations of bacteria that live in or on us without causing any problems, and some of them are even helpful. This is especially true in the gut, where bacteria help us with the food we eat and provide some essential nutrients; there's even evidence that our gut bacteria can influence our behavior. This creates a bit of a challenge for the immune system, which needs to kill harmful bacteria and avoid killing helpful ones—but still keep their numbers in check. This involves a degree of interaction between the immune system and the bacteria.

"A study in yesterday's Science has described a new way that the gut and bacteria interact to keep things from getting out of hand. Cells in the gut sense when the bacteria get too close, and produce a peptide that kills some of them off when they do. This keeps the space around the cells of the small intestine free of bacteria, which in turn keeps the bacteria from setting off a full-blown immune response...."

The research involved fiddling with mouse genes and seeing what happened. The article is fairly easy reading, but the Lemming wouldn't necessarily recommend perusing it just before a meal. Unless you're on a diet. Or don't mind thinking about the cellular nuts and bolts of digestive activity while you eat.

Fascinating stuff, for the Lemming. Your experience may vary.

Maybe someday medical professionals will realize that antibiotics kill intestinal microcritters, that this messes with normal digestion, and that there's an easy fix available: acidophilus, and that's another topic.

Sort-of-related posts:

• "E. Coli, Sprouts, Caution, and Business"
  (June 5, 2011)
• "Mexico's Crystal Cave and Astrobiologist Boston"
  (June 3, 2011)
• "Apex Chert: Microfossils, Microfractures, or Maybe Both"
  (April 23, 2011)
• "Chocolate, and Bananas: No Kidding"
  (January 17, 2010)
• "Blood Pudding, Steak and Kidney Pie, and Haggis"
  (December 15, 2008)