Bacteria-Free Mice

Bacteria-free mice have malfunctioning digestive systems and immune systems. Sarkis Mazmanian, an assistant professor at Caltech, has found that as little as one bacterial-surface molecule can make their immune systems work much better. Exposure to this molecule also protects the mice against a bacterium that would otherwise cause a mouse model of irritable bowel syndrome.

So far, so good: More evidence that we need bacteria for our digestive and immune systems to work properly. But then things get murky:

The Human Microbiome Project, an undertaking funded by the National Institutes of Health (NIH) to sequence the microbiota from hundreds of humans, has challenged itself with determining the relative quantities of all bacteria present in the human gut. With a known baseline of the bacteria present in healthy individuals, it will be much easier to understand which bacteria might be missing in diseased patients.

How we will find “healthy individuals”? I believe that almost everyone in America eats too little bacteria and has suboptimal health. Mazarian continues:

With a known baseline of the bacteria present in healthy individuals, it will be much easier to understand which bacteria might be missing in diseased patients. Hopefully, the Human Microbiome Project will lead to the discovery of other beneficial bacteria [in addition to the bacteria that Mazarian is studying].

“Much easier”? The bacteria that people need to be healthy must have been abundant in our environment long ago. We got vast amounts of bacteria from what we ate — bacteria that grew on food. To test the idea that these bacteria are beneficial you merely need to feed people bacteria-rich food (such as fermented food) and see if their health improves. This has been done hundreds of times, with highly positive results.