To add some context, this is a relatively common form of gastritis impacting depending on location 3-5% of the population called Autoimmune Gastritis.
Now his biohacking might be related it might not, the issue with the guy is that he does too many interventions at the same time so it’s hard to really tell what’s going on. He also has a core belief of equating looking younger with his interventions working, to his defence he also runs more rigorous analysis on his body. Overall he isn’t the most interesting bio hacker out there, but he is the loudest.