Short educational YouTube video (Dr. Nicole Cain) arguing that the oral microbiome influences the brain (an "oral microbiome–brain axis") and that research — including cadaver studies and a 2025 study linking bacteria to brain tumors — supports the existence of a brain microbiome and links to Alzheimer’s disease. The presenter emphasizes that microbes likely influence the brain indirectly, outlines recent studies (including one titled "Oral derived microbiome in the brains of patients with Alzheimer's disease"), and offers practical, non-prescriptive recommendations to support oral microbial balance (avoid strong antiseptic mouthwashes, consider xylitol or hydroxyapatite oral products, and oral probiotics containing Lactobacillus rhamnosus).
Chapters
So, funny thing, there are a lot of people out there that are completely shocked and appalled that I'm talking about research linking the oral microbiome to the brain and even suggesting that the brain has a microbiome. So let's set the record straight. You have an oral microbiome brain axis, and research has showed us that the oral microbiome can actually affect your brain. A lot of different hypotheses on exactly how this happens. And no, your bugs aren't probably crawling from your mouth into your brain, but they affect it. The biggest areas of research your oral microbiome might be actually affecting your brain is in Alzheimer's disease studies. And read this article very carefully. Check it out. Oral derived microbiome in the brains of patients with Alzheimer's disease, AKA those bugs in your mouth, are affecting the bugs in your brain. And please stop replying to the video and saying that we don't have an oral microbiome, because we do. We know a lot about those bugs in the mouth and we know that they cause plaque and all sorts of problems. And getting those bugs back in balance can improve oral hygiene and, and it can improve your mood. And yes, the groundbreaking study that did look at the brain microbiome was done on cadavers. But here's some more evidence from 2025. In this 2025 study, they were looking at brain and microbiome and they found that there's a microbiome brain gut axis. This article talked about bacteria and brain tumors specifically. Okay? And here's the thing. This isn't intended to make us anxious. Our whole body is full of all sorts of bacteria and viruses and fungi, and we have the opportunity to be in community with these critters, to be in balance and to be healthy. And yeah, they're not doing a ton of biopsies and studies in healthy people, because who wants to have their brain biopsied? And so research is done on people who have symptoms and then that helps us go into the world of prevention. And I promised y' all a long time ago that I would talk to you about my favorite solutions. And so here we go. And as a disclaimer, talk to your doctor about this. I'm not your doctor. I'm just here providing education. You want to have a good, healthy oral microbiome, so get rid of the Listerine, get rid of the weird neon colored mouthwashes, and try switching to something that maybe has xylitol in it, but don't swallow the xylitol. Just swish and spit or maybe you'd like something with an hydroxyapatite. The next thing you want to do is increase the happy bugs in your mouth. I'm kind of wondering about doing an experiment is finding your 10 happiest friends and then kissing them and seeing if you get happier maybe. What do you think? Or you can take an oral probiotic. Okay. I love this one because it has Lactobacillus rhamnosis, which has been studied to be antianxiety and microbial diversity is the name of the game. Do you have any favorite solutions or additional questions? Let me know in the comments below.
