Scientists just discovered that a high-fat diet can cause gut bacteria to enter the brain. This discovery offers a potential new explanation for how digestive health influences neurological conditions like Alzheimer’s disease and autism.
Scientists just discovered that a high-fat diet can cause gut bacteria to enter the brain
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>Live bacteria from the digestive system can travel directly into the brain when the intestinal barrier is weakened. This discovery offers a potential new explanation for how digestive health influences neurological conditions like Alzheimer’s disease and autism. The research was recently published in the journal PLOS Biology.
>The digestive tract and the central nervous system are intimately connected through a biological communication network called the gut-brain axis. This network helps regulate bodily functions, digestion, and inflammation. Medical professionals have noted associations between the gut microbiome and various neurological conditions.
>The gut microbiome is the massive collection of bacteria and other microorganisms naturally living inside the digestive tract. Changes in the types of bacteria living in the gut often occur alongside a condition called intestinal permeability. This condition happens when the lining of the intestines weakens, allowing substances to leak out into the body.
>High-fat diets are known to alter the bacterial makeup of the gut and contribute to this intestinal leakage. Yet researchers did not fully understand the exact pathways allowing gut bacteria to directly impact the brain and potentially cause neurological diseases. Manoj Thapa, a researcher at the Emory National Primate Research Center at Emory University, led an investigation to explore these physical pathways.
Great. So keto can wreck your brain?
I assume Mediterranean is still the reigning “champion” of healthy diets?
Weird, my brain always feels weird after consuming fatty foods.
Since when is Autism a neurological condition?
Hmm, maybe I missed it but the article didn’t seem to define what a high fat diet looks like. I have tracked calories for my typical diet and I found I was getting about 50% of my calories from fat which was shocking.
My doc literally recommended my alzheimer diabetes mom to buy high fat products
> [B]acteria can translocate directly from the gut to the brain in small numbers when mice are fed an atherogenic, high-fat diet (Paigen diet) that causes alterations in gut microbiome composition and gut barrier permeability. The bacteria were not found in other systemic sites or the blood, but **were detected in the vagus nerve**. Right cervical vagotomy reduced bacterial burden in the brain, implicating the vagus nerve as a conduit for bacterial translocation from the gut to the brain. Antibiotic treatment perturbed the composition of the gut microbiome and correspondingly changed the bacteria that localized to the brain in the setting of Paigen diet feeding. To further establish the gut as the origin of bacterial translocation to the brain, we gavaged exogenous *Enterobacter cloacae* into Paigen diet-fed mice, subsequently detecting the *E. cloacae* in the gut and brain. In addition, we monocolonized germ-free mice with *E. cloacae* and only cultured the bacteria from the brains of mice fed Paigen diet, but not those fed standard diet.
Looks pretty solid. All the more amazing.
So you’re telling me McDonalds causes Autism?
Nobody here has mentioned all of the emulsifiers in processed foods that were shown over a decade ago to cause leaky gut.
So. Just like the first time they demonized high fat diets by force feeding fat to rabbits, they’re doing it again with mice. This is just bad science.
The french have one of the longest life expectancies in europe. All of the french people that are living to 85 today were smoking, drinking, and living primarily off of butter and cheese for most if not all of their life. Make it make sense.
The biggest issue with this study is they fed the mice a high fat AND high carb diet. So how does one come to the conclusion that it was the fat in the diet rather than the carbs? All fat is not created equally either so far as metabolism, same as carbohydrates. You can’t have two different variables that could both cause the problem and infer one is the culprit based on vibes. Either the study was very poorly designed or the article glazes over a lot of important information.
The gut–brain connection keeps getting wilder. But I wonder how direct this actually is in humans vs animal models.
A lot of microbiome studies show correlations, but proving bacteria literally crossing into the brain and causing neurological changes seems like a big step.
Does the paper suggest an actual mechanism for how they cross the blood–brain barrier?
One day we get told that fat is good (as long as you do enough exercise and overall eat healthy) and then the next it’s not good anymore. What kind of fat/oil can we eat at all? And how to avoid? I mean “back in the days” I’m pretty sure most humans must’ve consumed a lot of meat and dairy products with fat in it.
Fun fact: the diet the mice were fed was explicitly and deliberately designed to weaken their intestinal barrier, with the point being to prove that bacteria could travel to the brain.
Its not just a “high fat” diet. Humans do not consume a massive amount of pure cholesterol and bile acid, even in the worst version of SAD.
how does this impact autism?? is it just saying that it can make existing symptoms worse or something? I only skimmed the article so far but I don’t understand the implication for autism. Dementia I get cause that’s something you Develop, usually later in life, but studies suggest that autism develops in the womb so..
Autism? In what way exactly? Are they implying that a mother eating a high fat diet causes bacteria to enter a fetus’s brain?
Honestly a lot of diet trends lead to people overanalyzing what they eat. I feel like the west has this weird trend of over optimising food.
I’d argue that the human body is pretty good at introception. If you eat in balance with your macros complementing each other, with a proper variety of fruits, veggies, and fats with an emphasis on whole foods then you’re good.
According to other papers I’ve seen, low fiber intake along with high sugar intake seems to increase intestinal permeability, as does high omega-6 intake (specifically linoleic acid) with low omega-3 intake.
In this study, they used soybean oil, cocoa butter, and coconut oil, i.e. very low omega 3s.
I’d be interested to see what happens in the gut with a diet rich in fiber and omega 3s, especially since DHA and EPA are often associated in improvements in people with AD.
I there anything about salt?
> High-fat diets are known to alter the bacterial makeup of the gut and contribute to this intestinal leakage. Yet researchers did not fully understand the exact pathways allowing gut bacteria to directly impact the brain and potentially cause neurological diseases. Manoj Thapa, a researcher at the Emory National Primate Research Center at Emory University, led an investigation to explore these physical pathways.
>Thapa and a team of colleagues set out to determine if microbes could physically move from the digestive system directly into the brain.
The title is a bit misleading. They didn’t discover that a High-Fat diet can cause gut bacteria to enter the brain. They were testing if the bacteria could physically move from the gut to the brain.
I’m unsure if I just couldn’t find it or if it wasn’t described, but I’m wondering what exactly the Paigen diet the mice were fed was composed of. Also, how many grams of fat were the mice getting? Was it animal fat? Any carbs? Etcetera.
Dietary fat also impairs endothelial function and is implicated in heart disease.