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I went to a lecture today by Tim Read from Emory University. He discussed comparative genomics, specifically of Bacillus and Chlamydiaceae species and strains. The history of the latter is rather interesting: researchers thought these bacteria were actually viruses until the 1960s (due to the advent of electron microscopy, of course) as they couldn't culture them on artificial media. It's a group full of pathogens with wide host ranges but small, highly conserved genomes so it would be useful to know more about.

This review served as a basis for some new additions to the Chlamydophila psittaci Wikipedia page.
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I've been thinking lately about that internet-adage, "if you're not paying anything, you're not the customer, you're the product." It comes up whenever someone, frequently the user of some free or freemium service, complains about sudden changes in terms of use or status of their service. The Instagram fracas last year and the Google Reader shutdown this year serve as good examples. Being a customer or a product of either of the two service may be possible but I'm not convinced that the above adage accurately describes any one individual's relationship with a company.

Every consumer is a customer and a product. We all do the whole exchanging-money-for-goods-and-services thing regularly. We all serve as marketing for these products and services as well. It might be the obvious tag on a pair of jeans or it may be more like membership in a club of fellow consumers (i.e.,  diehard Apple fans or anyone eating at Chik-fil-A after its recent PR issues). This marketing is provided free of charge. So are word-of-mouth recommendations, Facebook likes, discarded packaging, stock purchases, and any other interaction with a corporate entity, public or private. Even if all publicity isn't really good publicity, any continually increasing level of interaction with a company builds identity. That's almost priceless.
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It's all just bacterial media. Photo from Flickr user Jepster.

Here is a paper:


This one looked like it was going to be silly. Most papers with quotations in the title tend to have that sense of "summarizing an idea with an adage" or just "excessive use of punctuation." Describing any observable phenomenon a "glow" rather than a glow really ought to give readers pause. We do live in an age when experimental animals can be engineered to literally glow. Is it a stretch to assume that the authors of this paper are trying out some new GFP-fusions with proteins indicative of healthy animal phenotypes?

Yes. This assumption would be wrong. This paper is about yogurt.

The authors claim that eating probiotic yogurt is associated with what they repeatedly describe as a 'glow of health,' sometimes with quotes and at least once without. I'll give them the benefit of the doubt as far as describing observable phenomena goes: the authors are all affiliated with MIT rather than Yoplait and they primarily discuss mice. For mice, the 'glow of health' includes thick, shiny hair and lustrous skin. These experimental animals were fed Lactobacillus reuteri within yogurt and on its own. As compared with control mice, the bacteria-eating mice were indeed significantly shinier and had thicker skin. All of these effects may be related to levels of the anti-inflammatory cytokine IL-10, as those 'glow'-ing traits weren't seen in mice without IL-10.


Some select quotes:
Taken together with our earlier data, this led us to postulate that probiotic bacteria induce host physiological changes including a more acidic pH resulting in radiant skin and shiny hair signaling peak health and fertility and thus a good reproductive investment.
(A good reproductive investment for the bacteria or the host?)
Extrapolation from data of mice to humans suggests that excessive inflammation in the form of uncontrolled IL-17A subverts scalp hair growth, and this may be remedied by eating probiotic bacteria such as L. reuteri, but interpretation is complicated by disparities in hair on scalp versus other body sites of these species [37]. Nonetheless, aged male mice eating probiotics displayed Il-10-dependent dense fur together with elevated testosterone and increased virility (data not shown) when compared with mice eating control diet alone. It is unknown whether eating of probiotic yogurt may forestall or reverse follicular activities of hormones in human subjects.  

This study leaves me with a bad taste in my mouth. The authors fail to address the actual differences between a probiotic-yogurt-based diet and the control diet; bacteria may just be more nutritive than the usual rat food. The sample size also doesn't appear to be larger than 20 animals in any one group. Last year's GM corn study had some similar issues. Even so, it's always interesting to see product claims (or even conventional wisdom, though I suspect it's still mostly marketing) put to the test.