Longevity advocate Bryan Johnson discloses diagnosis of autoimmune gastritis

Tech entrepreneur and biohacking advocate Bryan Johnson, 48, revealed that doctors have diagnosed him with autoimmune gastritis (AIG), a chronic disease in which the immune system attacks the stomach's acid-producing parietal cells. The condition reduces stomach acid, hampers vitamin B12 absorption and can lead to iron deficiency, anemia and an elevated risk of stomach cancer, according to medical references.

Johnson disclosed the diagnosis in an Instagram post, describing the disease as causing his stomach to "eat itself" and noting that 2% to 5% of the population may be affected. He said he has experienced low ferritin levels for more than a decade and that attempts to raise his iron through diet and supplements were ineffective, despite his use of intensive biohacking practices such as hard training, sauna and hyperbaric oxygen.

Medical examinations included a colonoscopy, upper endoscopy and five stomach biopsies, which showed early atrophy confined to the acid-producing lining. Johnson said the disease can remain hidden for years, often going undetected until significant damage occurs.

"I’m going to try to solve it," Johnson wrote, adding that he will share his progress publicly.

The entrepreneur, known for promoting longevity research and aiming to extend human lifespan, said he hopes to develop treatments for AIG using advanced technologies such as artificial intelligence, multi-omics and custom-built DNA, proteins and cells. He reiterated his broader goal of slowing biological aging and achieving "longevity escape velocity," where medical advances outpace the aging process.

Johnson concluded by urging people to prioritize health and well-being.