Energy excretion in stools?
We found some very interesting and recent works in this journal, and finally chose one from July 13 titled "Role of energy excretion in the regulation of body weight". The title is a bit misleading: what is "energy excretion"? have we got some kind of glands that excrete energy in the form of liquid or radiation? Obviuosly not. In fact, it goes about to the excretion of caloric nutrients through stools and urine, a topic that, according to the the authors, has not been extensively studied and could explain the differences in weight between individuals with apparently similar caloric intake.
Fecal excretion is quantitatively more important and could range from 1 to 10% of caloric intake of healthy individuals. Urinary caloric excretion, on the other hand, is just 1-2% of total calories. The authors believe that these facts could account for part of variation in energy expenditure. However, studies performed to date do not lead to a clear-cut answer. On the one hand, people with low constitutional weight (healthy individuals with BMI <18 Kg / m2 ,who frequently complain they can't gain weight) have no differences in fetal energy excretion compared to control subjects. On the other hand, there are also no clear studies that confirm that obese people vary in energy excretion compared to lean controls. Therefore, the role of energy excretion as part of the physiopatology of weigh variations remains speculative.
Microbiome and thyroid
There is also other work about the influence of the microbiota (MB) on thyroid pathology. It covers every possible interaction between MB and thyroid metabolism, like the possible influence of MB on the immune system and therefore on thyroid autimmunity, changes in individual or local factors that affect gut MB and their relation to thyroid disease. MB also affects the metabolism of excreted bile acids, which in turn regulate TSH levels. From our point of view, we have not found any clear link between gut MB and the thyroid. We find it very likely that this article is just part of the recent trend to relate gut microbiota to everything in medicine.
