DGL is deglycyrrhizinated licorice root. The three things that have given me the most noticeable changes are aloe vera (gel extract), inulin and probiotics. Having said that, I am taking many supplements, so there is most likely some degree of synergistic effect.
Interestingly enough, the aloe vera (gel extract) has given me the most noticeable change I think. I noticed significant changes in my gut within 24-48 hours of taking a very low dose of aloe vera. I have slowly worked my way up from 25-50mg a day of a a 200:1 extract, to 2,000mg a day.
I am starting to feel less like an observer in my life and more like a participant. My daily routine keeps expanding so that I feel more productive, and that translates into a much more positive attitude.
I feel very strongly that my gut is my core issue, based on my increased level of health since starting the gut protocol. I have learned a lot through trial and error. I am consistently trying new supplements to see what works and what doesn't. I wish I could give you a single supplement that gave me a big energy boost, but I am not aware of one.
On the mitochondrial issue, I think that stems from the gut as well. From lipopolysaccharides getting into the bloodstream causing a th1-th2 immune imbalance, oxidative stress, impaired methylation (which causes more oxidative stress) and mitochondrial dysfunction (which again, causes even more oxidative stress). This is just my opinion, based on trial, error and a lot of reading. I am having a lot of success though. So like they say, if it ain't broke don't fix it. : ) Jim