Archive · 31 Jul 2026
Longevity Millionaire Bryan Johnson Eats Meat, Gut Microbiome Shifts
Bryan Johnson is a wealthy man who studies how to live longer.
He had never eaten meat in six years because he followed a strict plant‑based diet.
While in Australia, he decided to try meat to see how it would affect his body.
After a week, he noticed his gut bacteria changed a lot: good bacteria fell and bad bacteria rose.
He said this was just his own experiment and not a suggestion for others.
He also said people can eat whatever they like.
He shared his results on social media.
The change in his gut happened quickly, within a day of eating meat.
He wants to show that diet can have fast effects on the gut.
Bryan Johnson, 48, a longevity entrepreneur, ate meat for the first time in six years while traveling in Australia.
He reported a 61% drop in fiber‑eating gut bacteria (Roseburia, Agathobacter) and a 154% rise in bile‑tolerant, fat‑handling microbes after one week of animal protein.
Johnson said the change was an experiment and did not intend to influence others’ dietary choices.
He clarified that his findings are personal and not a critique of omnivores, encouraging people to eat what they want.
The experiment highlighted that gut microbiome shifts can occur within a day of consuming animal food.
- Who
- Bryan Johnson, a 48‑year‑old longevity entrepreneur
- What
- Ate meat for the first time in six years and reported gut microbiome changes
- When
- July 30, 2026
- Where
- While traveling in Australia
- Why
- To fit in with social norms and conduct a personal longevity experiment
- Name
- Bryan Johnson
- Age
- 48
- Occupation
- Longevity entrepreneur
- Event
- Ate meat for first time in six years
- Microbiome change
- 61% drop in Roseburia/Agathobacter, 154% increase in bile‑tolerant bacteria