Part 24
Gut, Inflammation, and Immunity
Picture a man of 68 who has spent $400 on a stool test. The report tells him his “microbiome age” is 74 and recommends the company’s custom probiotic. He has not had his shingles vaccine, his pneumonia vaccine, or a colonoscopy. One of these gaps could kill him. It is not the probiotic.
Clinical scenes in this edition are explicitly labeled illustrations. They describe imagined situations used to explain medical decisions, not documented patients, diagnoses, conversations, or treatment outcomes. They should not be read as evidence that a particular intervention works. Personal recollections are recollections, not medical records.
Evidence grade (draft mapping). 10 questions; a question with mixed evidence counts under each grade.
- 355. What is the microbiome, and does it affect aging?It is the trillions of bacteria living in your gut. They digest fiber, train the immune system, and produce chemicals that affect the whole body. Their balance shifts with age, and that shift is now counted as a hallmark of aging.CObservational
- 356. How do I improve my gut bacteria?Eat many kinds of plants, eat fermented foods, and avoid unnecessary antibiotics.BLimited or small human studies
- 357. Should I buy a microbiome test or take a probiotic?Skip the test. Use probiotics only for specific problems.Grade pending
- 358. What is “inflammaging”?A slow, low-grade inflammation that rises with age and contributes to heart disease, diabetes, dementia, frailty, and cancer.DPreclinical / mechanistic
- 359. How do I lower inflammation?Lose belly fat, exercise, sleep, eat the Mediterranean way, take care of your gums, and do not smoke.Grade pending
- 360. Does the immune system age?Yes. With age we make fewer fresh immune cells, respond less to vaccines and new infections, and clear abnormal cells less well.EEstablished clinical knowledge
- 361. Are vaccines longevity medicine?Yes, and they are among the most underrated tools we have.ARobust human trials
- 362. Is it true that the shingles vaccine may protect against dementia?The evidence is surprisingly good. In a natural experiment in Wales, people who became eligible for the shingles vaccine were about 20 percent less likely to develop dementia over the next seven years.CObservational
- 363. Why do my teeth matter for longevity?Gum disease is a chronic infection, and it is linked to heart disease, diabetes, and dementia.CObservational
- 364. Does air quality matter?More than most people realize. Fine particle pollution is a recognized cause of heart attacks, strokes, lung disease, and dementia.CObservational