Mitochondria and our other cells are just as sensitive to emotion, thought and sense of being as the immune system. Incarnation is one of the hardest tasks imposed on us, the instinct is to back away from the edge of our incarnation. We tend to hang out halfway here on planet earth, not sure if we want to stay or go. To the degree that we do this, our immune system and mitochondria are diminished.
If you turn your feeling-sense, emotion and thought toward coming forth in "good faith" to the n'th degree without hesitation or doubt, then you will automatically increase both the strength and the number of mitochondria and immune cells.
I am proposing conscious and fully intentional incarnation, as a form of mindfulness meditation in consort with breath. Imagine...Embodiment practice or purposeful incarnation! Not as a visualization or affirmation, but as an allowing, a letting the universe permeate one's being to the max. When you do this you can actually feel your cells respond.
As the head-brain, the heart-brain and the stomach-brain become one in the light of spirit as it pours through the body...the knot of control in the belly is released and we transcend the fear of the unknown and come home to the truth of our being. Then we see the suffering of the separate-self-sense is an illusion.
The background fear and knot of control is largely organic and can be worked out of the system thru raw diet, green food, exercise, nature, exodus from cities, exhaustive use of the body, social connection, music-drumming-dance, meditation, communion with the planet and Kosmos etc... This fear is organic programming. After kundalini the body is restructured and is orientated less thru the fear filter.
Once we have dealt with this organic fear, then existential fear reduces and we no longer fear for our fate, the fate of our family or planet. Kundalini changes the chemistry over to a background of love and cosmic connection...one may still have the question of "what to do?" but it becomes more of a case of whatever we do is ok.
The fear that we are doing wrong--is the fear that we do not love enough--this is symptomatic of the division between body, mind and soul, and perhaps the frustration of being unable to live our highest subtle awareness in this 'stepped down world." Like we are stuck in between, waiting for reality to catch up to us or us to catch up to reality and all our visions and love is laid to waste, in this wasteland of material existence. With conscious embodiment practice this sense of separation can ease, and we can melt ourselves whole into existence.