I’ve just recorded a few thoughts on the Bryan Johnson story, and I’ve kept them deliberately for this audience, because I think his case says something important about Long COVID that’s easy to miss. The podcast is short. This piece is the written companion to it, and if the ideas here land with you, I’d encourage you to listen.
Here is what caught my attention. This is a man who has built his whole public identity around measuring, optimizing and controlling his biology — and he has now spoken about being diagnosed with autoimmune gastritis. At face value that looks like a contradiction. I don’t think it is. I think it fits a pattern that many people recovering from Long COVID will recognize in themselves.
The fire was probably already there
One of the mistakes we make in medicine is treating autoimmune disease as if it appears from nowhere. In my clinical view, that is rarely how it behaves.
In many people, autoimmunity is more like a fire that smolders quietly before anyone sees flames. The person may look well. Their bloods may be broadly reassuring. But underneath, there can already be immune tension — inflammatory signals pushing in one direction, and regulatory cells holding them back.
Those regulatory cells matter enormously. I think of regulatory T cells as the immune system’s peacekeeping force. Their job isn’t to remove inflammation altogether; it’s to stop the immune system turning its weapons on the body. When they’re doing that job, a person can look and feel stable. When they weaken, the inflammation that was always there can suddenly become visible.
That’s the key point. The inflammation may not have arrived. The control system may have slipped.
Bryan Johnson already had autoimmune thyroid disease. Autoimmune conditions tend to cluster, because the deeper issue isn’t only the organ under attack — it’s a tendency to lose immune tolerance. So a person with thyroid autoimmunity going on to develop autoimmune gastritis isn’t a bolt from the blue. It reads more like a second part of the same underlying picture becoming visible.
Why this matters for Long COVID
This is where his case connects directly to the work I’ve been doing.
The hypothesis I’ve been building — and I want to be clear it is a hypothesis, not settled fact — places macrophages at the centre of Long COVID. These are innate immune cells that, once persistently activated, can keep the whole system inflamed. And one of the things that normally keeps macrophages in check is exactly that regulatory T-cell “brake”.
In our paper, we describe how spike protein appears able to interfere with regulatory T-cell stability, and how the inflammatory environment can skew the immune system away from those peacekeeping cells. When that brake weakens, macrophage activation is left to run on. It’s the same story as Bryan Johnson’s, told from the innate side: the fire doesn’t so much start as become uncontained.
So the reason his case interests me isn’t the diagnosis itself. It’s the mechanism it points to — a system where the balance between inflammation and regulation is disturbed, and previously hidden problems surface.
The spike question, handled honestly
I want to approach the next part carefully, because it’s easily misread.
My concern has never been narrowly about vaccination. It has always been about the spike protein and what repeated immune stimulation can do in susceptible people — and the most common source of that stimulation, by a wide margin, is infection and reinfection itself. Infection can deplete regulatory cells. Repeated immune challenge of any kind can shift the balance. In someone who already carries an autoimmune tendency, that shift can be enough to make a new problem visible.
Within that broader picture, I do think it’s fair to ask whether spike-directed immune stimulation from any source, in some predisposed individuals, can nudge that balance too. A small Italian study (Sacchi and colleagues) followed healthcare workers with samples taken before and after mRNA vaccination, and reported new antibody development in a meaningful proportion of those who started out negative. A signal like that doesn’t prove disease — many people carry autoantibodies and stay perfectly well — but it isn’t nothing either. It suggests the immune system moved.
That is the argument. Not certainty. Plausibility. And it’s a plausibility that applies to infection at least as much as to anything else.
What I take from all of this
The lesson I draw isn’t alarm. It’s that persistence — from whatever source — is the thing that needs addressing if people are to have a real chance of getting back to wellness. If a smoldering immune system can be tipped into visible illness, then calming that system, restoring its regulatory balance, and removing what keeps it activated is exactly where recovery work should focus.
Not everyone’s immune system is the same. Bryan Johnson’s case is a reminder that the immune terrain you start with shapes what happens next — and that’s a question worth taking seriously rather than waving away.
Have a listen to the podcast for the fuller version of the thinking.
