Dietitian With Autoimmune Gastritis Shares Debilitating Symptoms, Hopes Bryan Johnson Raises Awareness

Lori Taylor was sitting in a boba tea shop when her mind simply stopped working. The shop had run out of the flavor she wanted, and when she stepped up to the counter to order something else, the words vanished. Her brain felt wiped clean. She broke down in tears right there, convinced she was losing her mind.

That moment, in 2018, came just before a diagnosis that would finally explain eight years of creeping illness. Taylor, a registered dietitian and adjunct professor at Saybrook University living on Whidbey Island, Washington, had autoimmune gastritis—the same condition that tech entrepreneur Bryan Johnson recently announced he had. The disease works by turning the immune system against parietal cells, the ones responsible for producing stomach acid. Without enough acid, the body cannot properly absorb the vitamins and minerals it needs. A 2024 study found that AIG creates deficiencies not just in B12 and iron, but also in vitamin C and calcium.

Looking back, Taylor could trace the disease's fingerprints across her entire life. In her twenties, she had struggled with low-grade stomach problems and an unexplained iron deficiency that no one could quite pin down. But the real deterioration began in her late forties. Around 2016, working as a clinical dietitian in an oncology unit at a hospital, she watched her hair break and fall out in alarming quantities. "I felt like I was one of my chemo patients," she said. The fatigue became so severe that one day, facing a single flight of stairs to reach her office on the second floor, she found herself talking herself out of it. The energy simply wasn't there.

The cognitive symptoms were the most frightening. Brain fog rolled in and settled. Complex thoughts became difficult to hold. Simple words disappeared from her vocabulary at random moments. She developed dysgraphia—her handwriting became illegible after the first sentence, as though her hand had disconnected from her mind. When ordering Christmas gifts, she made basic mistakes, sending presents to her own address instead of their intended recipients. The disease was stealing her ability to function in the world.

Diagnosis proved elusive. When Taylor's care team began testing, her B12 levels sat in the lower range of normal, and her iron was low. Because she had IBS and was moving through perimenopause with what she described as "periods from hell," everyone assumed the iron deficiency came from heavy menstrual bleeding—a reasonable conclusion supported by medical literature. Her doctors ran test after test, chasing down rabbit holes. It wasn't until a colleague suggested looking specifically for autoimmune gastritis that the pieces fell into place. A blood test revealed elevated parietal cell antibodies. An endoscopy showed inflammation consistent with early AIG. Finally, she had an answer.

Treatment required experimentation. Before diagnosis, she had tried elimination diets, FODMAP restrictions, and carbohydrate-cutting protocols. Nothing stuck. She suffered from severe bloating so pronounced it made her look pregnant. Once diagnosed, she began supplementing every meal and snack with betaine hydrochloride, a compound that can temporarily increase stomach acid. Within three days, she said, ten years of IBS symptoms vanished. She has maintained this regimen since 2018. She also received iron infusions—four sets over eight years—which she described as life-changing, since oral iron supplements couldn't be absorbed properly. B12 shots followed, and once she found the right dosing, the transformation was dramatic. "I got my cognitive functioning back," she said. The neuropathy that had felt like stepping on hot Legos disappeared.

Now Taylor is channeling her experience into research. She co-authored a 2024 review paper proposing that replacing lost stomach acid should be investigated as a treatment approach. In the fall, she plans to begin her doctorate in clinical nutrition at Rutgers University, with autoimmune gastritis as her focus. She hopes Bryan Johnson's public platform will raise awareness of a condition that affects roughly 3.85% of the global population but remains poorly understood by many clinicians. She is particularly interested in his mention of stem cells as a potential solution, since parietal cells typically do not regenerate once destroyed. But she also knows that not everyone can afford iron infusions and frequent injections. "Not everyone can afford to engage in vitamin infusions," she said. The real revolution in AIG treatment, she believes, will come from patients like herself—and from public figures willing to use their visibility to shine light on diseases that medicine has largely overlooked.