Chi, the life force: it’s all in the gut
In a supplemental December 2011 issue, Nature published a compendium of opinions on traditional Asian medicine. Some skeptics of traditional medicine might feel edified by a comment from James Mitchell Crow’s contribution, discussing the popular herb gingseng,
“…these compounds have no direct effect on the human body because the gut cannot absorb them1.”
Before you skeptics gloat too deeply, however, note that although your body is incapable of processing the chemicals that comprise ginseng, your gut microbes are not nearly so hapless! The bacteria in your gut break down ginseng (and many other foods, vitamins, and minerals). Their digestive activity produces bits and pieces of molecules, from which you reap the beneficial effects!
However, the more devoted readers of this blog will recall that the microbiome (the not-you organisms that live in you) can vary from person to person. This variation might explain why the supplement that your friend swears by has zero effect for you:
“…according to microbiologist Liping Zhao at Jiao Tong University in Shanghai, China, for around one-fifth of the population, ginseng will have no health benefit because the person doesn’t have the right gut microbes to break it down.”
For my own part, I am fascinated by Eastern medicine. As an equestrian, I have seen the benefits of acupuncture and chiropracting for arthritic or just downright cranky horses – for whom there is no placebo effect! I am pleased with the publication of this issue of Nature because it should spur rigorous, clinical testing to verify the benefits of traditional medicines. Not only would people and their animals benefit from improved medicine, but understanding the interaction between medicine and microbiome will bring us even closer to optimal medicine practices that are personalized, effective, and have few harmful side effects.
biolojoie de vivre 
Are you certain there’s no placebo effect? I could hypothesize an induced placebo effect, either entirely in the human (you think the critter’s better so you perceive it as better), or perhaps the animal responding with some kind of “Clever Hans” riff.
But a blinded study of acupuncture and chiropractic in animals would certainly be interesting!
Totally possible, Tom! Personally, I’m thinking of specific horses I’ve known that were chiropractically adjusted the day before I rode them, but I only learned about the adjustment after I commented on how well they were going. I like the idea of a double-blind study! Maybe I’ll search the lit for one this afternoon. 🙂