Symptoms of 'silent' autoimmune disease as biohacker Bryan Johnson reveals incurable diagnosis

Biohacker Bryan Johnson revealed he has been diagnosed with an incurable condition that is causing his stomach to 'eat itself', as details of the symptoms emerge.

The American entrepreneur revealed on social media last week that he has been diagnosed with autoimmune gastritis (AIG) - a condition which he claims only two to five percent of people suffer from.

The tech entrepreneur turned biohacker, 48, has become one of the world's most recognizable figures in the longevity movement.

He spends millions of dollars each year on his intensive anti-ageing regimen in an effort to slow down - or even reverse - the ageing process.

But despite his relentless pursuit of optimal health, Johnson has confirmed his diagnosis, and warned others of the symptoms to look out for.

After years of struggling with stress, weight gain and chronic depression, his body began developing an autoimmune process that affected his thyroid and stomach lining, which he admitted to attempting to 'solve' himself - in true Johnson style.

Despite not noticing any obvious symptoms, Johnson believes there were early signs of AIG that he hadn't spotted.

The biohacker has opened up about his condition. (@bryanjohnson_/Instagram)

But he's not alone, as those who suffer with the condition know that it doesn't always show notable symptoms, which can include abdominal pain, iron deficiency, loss of appetite, nausea or unexplained weight loss.

But the condition is also difficult to diagnose.

After a colonoscopy ruled out the possibility of colon cancer, Johnson's medical team performed a bidirectional endoscopy to investigate the rest of his gastrointestinal tract.

His results showed that he was experiencing elevated levels of anti-parietal-cells-antibodies - which pointed them in the direction of considering AIG.

He has spent millions of dollars trying to reverse the ageing process. (Kyle Grillot/Bloomberg via Getty Images

While AIG cannot be cured, it can be managed via B12 injections or iron infusions, the latter of which Johnson recently received a '1,000 mg Monoferric iron infusion'.

His team is set to routinely monitor several diagnostics, including ferritin and iron, B12 and chromogranin A. Gastrin.

The Mayo Clinic writes: "This type of gastritis occurs when your body attacks the cells that make up your stomach lining. This reaction can wear away at your stomach's protective barrier."

Factors that make a person more high risk of developing the condition, according to the Cleveland Clinic, include:

• Are older than age 70
• Eat a high-salt diet
• Smoke
• Have a family history
• Have other autoimmune diseases

Writing on X, Johnson said: "Current medical standards treat AIG as something to be managed, not resolved.

"We want to change that."