Highlights
- Bryan Johnson says he has autoimmune gastritis after investigating persistently low ferritin levels.
- Doctors say the condition is often difficult to diagnose and can remain silent for years.
- Treatment focuses on managing nutritional deficiencies and monitoring patients, while experimental therapies are still in the early stages.
Bryan Johnson has revealed that he has autoimmune gastritis, saying he was diagnosed after investigating persistently low ferritin levels. The longevity entrepreneur shared the news on X, writing that his "stomach is eating itself" and adding that he plans to look for better ways to treat the condition. Medical experts say autoimmune gastritis is frequently overlooked because it can develop without obvious symptoms for many years.
What is autoimmune gastritis?
Autoimmune gastritis is a chronic inflammatory condition in which antibodies destroy the stomach's acid-producing cells. As a result, the body is unable to absorb iron efficiently and, over time, can also develop vitamin B12 deficiency.
The condition is associated with an increased risk of stomach cancer as well as anemia and neurological complications linked to vitamin B12 deficiency.
Researchers estimate that autoimmune gastritis affects around 4% of people worldwide, although experts say the true figure may be higher because many cases are not diagnosed.
What are the symptoms of autoimmune gastritis?
Johnson said the earliest sign was consistently low ferritin levels, even though his hemoglobin and hematocrit levels remained normal.
According to Mimi Chang Tan, assistant professor of gastroenterology at Baylor College of Medicine, autoimmune gastritis frequently remains silent for decades. When symptoms develop, they often appear outside the gastrointestinal tract and can include fatigue, weakness and neurological problems.
Tan said low ferritin levels are often an early sign of the condition.
How is autoimmune gastritis diagnosed and treated?
Tan said a definitive diagnosis requires an upper endoscopy with biopsies.
She added that anyone with low ferritin levels or iron deficiency anemia should undergo an upper endoscopy and colonoscopy to investigate autoimmune gastritis as well as other possible causes, including colorectal cancer, colon polyps and Helicobacter pylori infection.
The exact cause of autoimmune gastritis is unknown, although experts say it may involve genetic factors, environmental triggers and chronic inflammation. While Johnson suggested his childhood diet may have contributed, Toby Cornish, a gastrointestinal pathologist at the Medical College of Wisconsin, said there is no research supporting that link.
There is currently no cure for autoimmune gastritis. Treatment focuses on correcting iron deficiency, monitoring patients for stomach cancers and managing complications. Johnson said his team is also exploring experimental approaches, including CAR-T therapy, although Cornish said it has not yet been well studied for this condition and remains at an early stage of investigation.
