Hi Jonathan,
There are several ways in which low carb diets can work besides Ebringer's Klebsiella theory, we discussed this in het diet forum. The TNF producing fat cells is one of them. We can also see this in extreme long distance runners. I remember an article in Pubmed for instance called something like "TNF levels in extreme long distance runners: how low can you go". Also the blood sugar levels will tend to be higher and more irregular in people with high carbohydrate consumption. The activity of several parts of the immune system is dependant on glucose levels. For instance I myself did some experiments on the activity of neutrophils in media with different glucose concentrations and can say the difference is big. Further out of my own experience I can say that weight loss will indeed be the result of low carb eating, if you want it or not (I didn't want it). The dramatic results I got however in the first weeks of my diet cannot be caused by weight loss as I hadn't started loosing weight yet. Later in the diet there were periods that I didn't feel good but was on the mimimum of my weight. So there is not much of relation for me but I can imagine that in people with overweight to start with there will be some.
Best Regards,
Gerard