A Hacker needs intimate and thorough understanding of the internal workings of a system to successfully and elegantly manipulate that system; along with the chutzpah to do so. ;)
Living tissue is active matter; it dissipates free energy while maintaining itself in a viable state. This requires a Control system that reduces the degrees of freedom of the system to only those desired.
All disorders are disorders of control. Either Control allowed physiology to get into a bad state, or Control did not get physiology out of a bad state. Bio-hacking requires understanding physiology from the perspective of Control.
Good design heuristics make modular systems with designed interfaces. Evolution didn't do that. Modern living environments are very different than environments our ancestors evolved in. Not surprising a number of disorders that are common in the urban developed world are rare to unknown in the rural undeveloped world; things like diabetes, obesity, allergies, inflammatory disorders. This observation has lead to the “hygiene hypothesis”; the idea that there is a “factor” associated with “dirt” or lack of “hygiene” that is protective. This presents the hypothesis that the loss of ammonia oxidizing bacteria through modern bathing practices adversely affects the background nitric oxide level and so perturbs all NO-mediated control pathways, with no threshold.
The importance of the background level of nitric oxide will be discussed in the context of a component of the human microbiome; ammonia oxidizing bacteria living on the skin and converting ammonia in sweat into nitrite and nitric oxide so as to set the background NO/NOx level to avoid nitropenia.