Why Bryan Johnson's autoimmune diagnosis is challenging his longevity mission

Bryan Johnson has spent years trying to slow ageing, yet a hidden autoimmune disease was damaging his stomach lining while he tracked his health in extraordinary detail. The 48-year-old tech entrepreneur says he was diagnosed in May with autoimmune gastritis after years of low iron stores and months of medical testing. His next move is equally characteristic: rather than accept long-term management alone, he says his team will pursue experimental approaches aimed at the immune cells attacking his stomach.

What We Know So Far

Johnson said the condition was discovered after doctors investigated an iron deficiency that had resisted food changes and supplementation. He has said his ferritin, a marker of stored iron, had been low for 11 years without anaemia. A colonoscopy reportedly ruled out causes including cancer and unnoticed blood loss, while an upper endoscopy and five stomach biopsies showed early autoimmune gastritis.

Autoimmune gastritis, or AIG, occurs when the immune system attacks cells in the stomach lining. The disease can reduce the stomach's ability to absorb key nutrients and is associated with iron deficiency, vitamin B12 deficiency, anaemia and an increased long-term risk of gastric cancer. Early symptoms can be vague or absent, which helps explain why the condition may go undetected.

The diagnosis has attracted attention because Johnson is known for spending around US$2 million a year on longevity treatments, strict routines and frequent medical testing. He works with a team of more than 30 doctors and has explored interventions including plasma exchange and experimental gene therapies. Despite that level of monitoring, he says the autoimmune condition was not identified until this year.

Johnson has also disclosed a history of autoimmune thyroid disease. He has linked the timeline of his health problems to earlier periods of poor diet, weight gain and chronic stress, although the exact cause of autoimmune gastritis is not known. His current plan includes repeat biopsies, immune profiling and monitoring markers such as iron, B12, gastrin and pepsinogen ratios.

Autoimmune gastritis

A chronic disease in which the immune system attacks the stomach lining.

Ferritin

A protein that stores iron and can reveal low iron reserves before anaemia develops.

Biopsy

A tissue sample examined for signs of disease or damage.

Voices & Opinions

Johnson has framed the diagnosis as another problem for his longevity project to confront rather than a reason to abandon it.

Current medical standards treat AIG as something to be managed, not resolved. We want to change that.

He has said some of the approaches being considered are supported by what he described as investigational preclinical evidence at best. Those ideas include attempts to reset immune cells attacking the stomach lining and the possible use of AI-designed antibodies.

Medical responses to his announcement have been mixed. Autoimmune specialist Justin Janoska commented that the relentless pursuit of perfect health through constant testing and biohacking can contribute to chronic stress on the body, while physician Dr Bradley Campbell said emotional health should also be considered as part of overall wellbeing.

Local Impact

For Canadians following the booming longevity and biohacking movement, Johnson's diagnosis is a reminder that intensive tracking does not guarantee every condition will be caught early. The practical lesson from the published accounts is narrower and more useful: persistent iron deficiency can have an underlying cause even when anaemia has not developed.

The story also puts a spotlight on the difference between experimental health interventions and established care. According to the sourced reports, there is currently no approved cure for autoimmune gastritis; standard treatment focuses on symptom relief, correcting deficiencies such as iron or B12, managing anaemia and monitoring complications.

Coming Up

Johnson says his team will continue monitoring the disease, repeat biopsies and carry out deeper immune testing before deciding which experimental interventions to pursue. He has also said he plans to document the process and share future updates.

No confirmed timeline has been given for a treatment trial, and no source provided evidence that the experimental approaches Johnson described have been shown to cure autoimmune gastritis in people.

At a Glance

• Bryan Johnson says he was diagnosed with autoimmune gastritis in May.
• The disease causes the immune system to attack the stomach lining.
• Johnson says low ferritin had persisted for 11 years.
• Five stomach biopsies reportedly showed early-stage disease.
• There is currently no approved cure for autoimmune gastritis.
• Johnson plans further immune testing and experimental treatment research.