Chris Kresser: Yeah, that’s one possible way. Given the association with SIBO and the association of low stomach acid with SIBO and the decline in stomach acid production as we age, and his age, and also you want to think about H. pylori. Almost one in two people over the age of 50 in the US have H. pylori, and that risk increases as you go above 50 years of age. So it’s highly likely that he has low stomach acid in my opinion, just from the numbers, the statistics alone. And the risk of a small dose of HCl assuming he’s not taking NSAIDs or other things that would be contraindicated is pretty low. So you could try that empirically.
A couple other things to think about. There’s some, I think I’ve mentioned this before, but there’s a kind of approach in dentistry that’s relatively new called dental orthopedics. Some people call it functional orthodontics, which involves realigning the jaw, the lower jaw in particular and Dr. Dwight Jennings in Alameda who does this kind of work has had really remarkable results with Parkinson’s in particular with this approach. So I mention this just because if one of my relatives was diagnosed with Parkinson’s I would definitely let them know about that kind of work because I’ve seen some pretty dramatic results in some cases. Also definitely want to check with SIBO. It’s not clear to me whether the association with SIBO is cause or effect or both.
Certainly because of what happens with Parkinson’s, you could see how Parkinson’s would impair the migrating motor complex and could cause SIBO. But given what we know about the gut–brain axis, we could also see that SIBO might predispose people to Parkinson’s. Ketogenic diet is shown to, in some clinical anecdotal work, has been effective for Parkinson’s. But I think you’d want to do the full workup. You’d want to test for B12 deficiency since the B12 deficiency can mimic the signs and symptoms of Parkinson’s. It sounds like he’s already been diagnosed, though, and probably had some scanning that differentiates that from B12 deficiency. But B12 deficiency can contribute to and complicate Parkinson’s, so hopefully that’s helpful.