What Is Autoimmune Gastritis? The Disease Anti Ageing Millionaire Bryan Johnson Says Is ‘Eating His Stomach’

Longevity entrepreneur Bryan Johnson has revealed he has been diagnosed with autoimmune gastritis, a chronic condition in which the body's own immune system attacks the stomach lining. Johnson, 48, who claims to spend millions of dollars a year tracking and optimising his health, announced the diagnosis on social media, writing that his stomach is "eating itself."

The disclosure has drawn wide attention because Johnson is known for one of the most extensively monitored bodies in the world, raising questions about how such a condition could go undetected for years despite his level of health tracking.

What Is Autoimmune Gastritis

Autoimmune gastritis, or AIG, is a chronic inflammatory disease in which antibodies destroy the acid producing cells in the stomach, which in turn prevents the body from properly absorbing iron. It is not a fatal disease on its own, but it is linked to an increased risk of stomach cancer and eventually to vitamin B12 deficiencies that can cause anemia and neurological problems.

Johnson said he was diagnosed in May after years of unexplained low ferritin, the blood protein that indicates how the body stores iron. The condition causes irreversible damage to the stomach lining and often develops silently and without symptoms over the course of years. What Is Bryan Johnson’s ‘Don’t Die’ Strategy? Is He Really Shutting Down His Anti-Ageing Company Blueprint? Here's What Is Known So Far About the Longevity Enthusiast.

How Doctors Confirmed The Diagnosis

According to Johnson, standard blood markers for anemia initially appeared normal, which made the underlying problem easy to miss. Experts say a definitive diagnosis requires an upper endoscopy along with biopsies, since the stomach can appear visually normal even when the disease is present.

Johnson's medical team ordered five biopsies from three regions of his stomach, which revealed early atrophy confined to the acid producing lining. Doctors say his case highlights the value of biopsy sampling in patients with unexplained iron deficiency, even when other markers look fine. Bryan Johnson Plans To Sell His Anti-Ageing Company Blueprint, Says 'It's a Pain-in-the-A** Company'.

No Approved Cure, But Manageable

There is currently no approved cure for autoimmune gastritis. Experts said treatment mainly involves managing the disease through iron supplementation and long term monitoring for stomach cancers, since patients with the condition face a higher risk of neuroendocrine tumours and adenocarcinomas. Johnson has said he plans to pursue advanced characterisation of his disease and share updates on his approach.

Medical experts note that Johnson also has a 27 year history of autoimmune thyroid disease, and that autoimmune conditions often share underlying immune mechanisms even when they affect different organs.

(The above story first appeared on LatestLY on Jul 09, 2026 07:43 AM IST. For more news and updates on politics, world, sports, entertainment and lifestyle, log on to our website latestly.com).