Can chronic infections drive chronic disease?
Dr. Richard Horowitz has spent more than four decades treating patients with complex chronic illness, including Lyme disease, long COVID, chronic fatigue, neurological symptoms and multi-system disease.
His central argument is controversial: many chronic illnesses cannot be explained by a single diagnosis or a single cause.Instead, Horowitz proposes a framework of interacting factors including persistent infections, environmental toxins, microbiome dysfunction, intestinal permeability, nutrient deficiencies, sleep, mitochondrial dysfunction, dysautonomia and chronic inflammation.
But how much of this is actually proven? And where does association end and causation begin?
In this episode of Return on Health, we push Dr. Horowitz on exactly those questions.
We discuss
• Why some patients remain symptomatic after Lyme disease treatment
• The debate around chronic Lyme disease and post-treatment Lyme disease syndrome
• Borrelia, Bartonella and Babesia
• Biofilms and bacterial persister cells
• His 16-factor MSIDS framework for chronic illness
• Mold exposure, mycotoxin testing and its clinical limitations
• Heavy metals, microbiome dysfunction and intestinal permeability
• Dysautonomia, POTS and mast cell activation
• Why a positive test does not necessarily mean something is causing symptoms
• How Horowitz decides which potential drivers to treat first
• His dapsone combination protocol for chronic Lyme disease
• The risks and required screening before dapsone treatment
• Why observational results and clinical experience are not enough
• The need for randomized controlled trials
• Lyme disease, neuroinflammation and Alzheimer's disease
• His published case involving P-tau217 and other Alzheimer's biomarkers
• Why improving a biomarker is different from proving an effect on dementia
• What conventional medicine may be missing, and where alternative approaches can go too far
Horowitz himself acknowledges one of the central limitations: much of this work still needs stronger evidence capable of moving from association toward causation.
One example is mold testing. A patient may test positive for mycotoxin exposure, but that alone cannot establish that mold is responsible for their symptoms.
The same question comes up when we discuss Alzheimer's biomarkers. Horowitz presents cases in which P-tau217 and other biomarkers changed after treatment, while we challenge what can actually be concluded from a surrogate biomarker without clinical outcome data.
About Dr. Richard Horowitz
Dr. Richard Horowitz is an internal medicine physician focused on Lyme disease and complex chronic illness. He has treated more than 13,000 patients and developed the MSIDS framework discussed throughout this episode.
His new book, Ending Chronic Illness: A Revolutionary New Program to Reverse Inflammation and Heal Persistent Disease, will be released on October 13, 2026.
Richard Horowitz
Website: https://cangetbetter.com/
New book, Ending Chronic Illness: https://cangetbetter.com/Book
Website: https://www.endingchronicillness.com/
Return on Health
Website: https://returnonhealth.de/Watch and listen to all episodes of Return on Health on YouTube, Spotify and Apple Podcasts.
Return on Health is hosted by Niko Hems and Miguel Medina Stanivukovic.
We speak with researchers, physicians, founders and skeptics about longevity, prevention and the future of health, with one rule: strong claims deserve strong questions.
Important
This episode discusses experimental and controversial diagnostic and treatment approaches. The views and clinical claims expressed by guests do not constitute medical advice or endorsement by Return on Health. Some approaches discussed are outside established clinical guidelines and require substantially stronger evidence.
