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

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

The American entrepreneur, who is famously going to extreme lengths to reverse his biological clock, 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, spending 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)

The symptoms of autoimmune gastritis

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
• Unexplained weight loss

What causes autoimmune gastritis?

The Cleveland Clinic explains that the condition arises when antibodies attack healthy stomach cells. Antibodies may also attack a protein released by the stomach cells (intrinsic factor).

Intrinsic factor usually helps to absorb vitamin B12. Without intrinsic factor, your body may not be able to make healthy red blood cells. This can lead to pernicious anemia. A lack of vitamin B12 may also cause nerve damage.

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.

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

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

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.

What increases the chance of developing autoimmune gastritis?

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."