[neverdem]

I think that, to a large extent, the metabolic conditions cause the change in microflora. Since an obese person's biochemistry is not the same as a thin person's biochemistry, I would expect to see a difference in species prevalence of gut microflora as a result.

Pregnancy alters resident gut microbes

Good hunch, but neither pregnant women nor diabetics are considered as having robust immune systems. In the former, it's considered down regulated. In the latter, it's compromised in ways similar to cancer patients, patients on chronic steroid therapy or chronic alcoholics, at least from a clinical perspective.

[exDemMom]

Good hunch, but neither pregnant women nor diabetics are considered as having robust immune systems. In the former, it's considered down regulated. In the latter, it's compromised in ways similar to cancer patients, patients on chronic steroid therapy or chronic alcoholics, at least from a clinical perspective.

Of course.

My objection is more to the idea that these metabolic conditions can be treated by altering the gut flora, when it looks a lot like the microbial species distribution is a consequence of the conditions. The concept that, e.g., obesity could be cured by altering the gut microflora is very appealing, since there really is no easy way to treat or even prevent it, and it is human nature to want easy solutions. This isn't to say that certain microorganisms don't have an effect; clearly, a bacterial colonization of synovial fluid will cause problems.