In this popular‑science video, the host introduces a novel pre‑clinical discovery: an acetylated cellulose complex called ACell that delivers acetate directly to the colon and triggers weight loss in obese mice. The speaker explains that ACell outperforms simple acetate solutions because it bypasses small‑intestinal absorption, raising colonic acetate levels. In two genetically distinct mouse models, ACell reduced weight gain, liver mass, and trended toward lower body fat, effects that were not reproduced with cellulose bound to propionate or butyrate. The presenter then outlines a six‑step mechanistic cascade: (1) ACell releases acetate in the colon, (2) acetate reshapes the gut microbiome toward Bacteroidetes that ferment simple sugars, (3) microbial sugar consumption lowers host sugar availability, (4) liver glycogen is depleted, mimicking fasting/ketosis, (5) fatty‑acid‑oxidation genes are up‑regulated, and (6) the net result is reduced liver fat, increased fat burning, and weight loss. Recognizing that ACell is not yet commercially available, the video offers actionable strategies to boost endogenous acetate: consume acetogenic (inulin‑rich) fibers such as chicory root, Jerusalem artichoke, onions, garlic, leeks, and asparagus; support acetate‑producing bacteria—particularly Akkermansia muciniphila—by limiting alcohol, avoiding a high‑sugar Western diet, and (cautiously) noting that metformin and rhubarb extract have shown pre‑clinical benefits for this microbe. Finally, the host recommends oral acetic acid (apple cider vinegar) as a practical way to obtain acetate, citing a human RCT where 1 tsp–1 Tbsp daily for 12 weeks produced dose‑dependent weight loss and metabolic improvements, and suggests a protocol of 1 Tbsp taken ≤30 minutes before meals. The video concludes that fiber can be engineered for metabolic therapeutics, invites viewers to subscribe and join the Stay Curious Metabolism newsletter for deeper data, and encourages questions.
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Brand new research shows that a specific fiber burns fat, partially mimics a ketogenic diet, and can contribute to weight loss. Now this is not your run-of-the-mill granola or chia seed, and if you're here expecting a gimmicky shopping list of your top 10 fat-burning foods, you're going to be disappointed. But if you are receptive to having your expectations broken, and mind awoken, then let's digest these data together. Now, the fat fiber feces story I'm going to tell you is based on new 2025 preclinical studies published in Cell Metabolism, where mice were given a fiber complex called acetylated cellulose, or ACell for short. Now, what is ACell? ACell is the short-chain fatty acid acetate bound to the fiber cellulose. Perhaps you've heard of short-chain fatty acids before? These are little fats between 2 and 4 carbons long, and include acetate, which is 2 carbons, propionate, which is 3 carbons, and butyrate, which is 4 carbons. Basically the short kings of the fat world. Now, in human randomized double-blinded controlled trials, acetate administration to the colon has been shown to improve a vast array of metabolic parameters. But there's a catch. If you just eat acetate, it won't make it all the way to the colon. In the human studies I was referring to, acetate is delivered through a long feeding tube, which does not sound fun. Therefore, as much as you might want to deliver acetate to your colon by simply eating it, you can't. Trying to get acetate to your colon by eating it is kind of like bowling on a slanted alley. Every roll is a gutterball. But ACell, this acetylated cellulose complex, is like walking up with a baseball bat and clearing the pins. Whack! Strike! Now, in this study, ACell allowed acetate to escape absorption in the small intestine and increased acetate levels in the colon, whereas a control acetate sodium solution did not. And impressively— you ready? ACEL fiber, shown here in green, caused significant weight loss relative to mice given a control diet with or without alternative forms of acetate, the acetate sodium solution. ACEL also decreased liver mass and led to a trending decrease in body fat. And these findings were then replicated in another group of genetically distinct obese mice, And the findings were found to be specific to ACEL and did not occur when mice were given cellulose complexed with the other short-chain fatty acids, propionate or butyrate. So I know that was a lot of words, a lot of jargon. Let's pause for a quick summary of what we've learned so far. ACEL delivers acetate to the colon, which suppresses weight gain. The next question is obviously how. How does ACEL contribute to weight loss? What is the mechanism? Well, the mechanism the researchers discovered operates as follows. I'm going to give you 6 steps. A cell effectively delivers acetate to the colon. A cell alters the microbiome to increase levels of Bacteroidetes species of bacteria that ferment and metabolize simple sugars. This decreases the availability of sugars to the host, the mouse, or in theory, you. After this, liver glycogen is depleted because you're not uptaking as much sugar, partially mimicking fasting or a ketogenic diet. Then as a compensatory response, genes involved in fat burning—fatty acid oxidation is the molecular process—they're increased. And the net effect is improvements in fatty liver, fat burning, and weight loss. And if you want more methodological details and walkthrough of some of the graphs from the paper, you can see the associated Stay Curious Metabolism newsletter at staycuriousmetabolism.com for more details. But now, just to reframe the mechanism and what we've learned so far in as simple terms as I can: ACE cell acts like a Trojan horse for acetate, sneaking it past early digestion and releasing it into the deep colon. Once there, the acetate reshapes the microbial landscape, favoring the growth of certain sugar-metabolizing bacteria. Then these bacteria, these microbes, consume simple sugars before your body can absorb them, decreasing the sugar availability to the host, and this forces the body to drain liver glycogen and triggers metabolic adaptations. That kind of resemble fasting or a ketogenic state. And as a result, your body basically flips into fat-burning mode, upregulates the genes needed to oxidize, burn fatty acids. And the ultimate outcome? Less liver fat, more fat burned, and measurable weight loss—at least in mice. All initiated by a smart delivery of a simple molecule acetate to the right place: your colon. So the bottom line here: Acell is not just another fiber, it's a precision tool in production, a prebiotic likely in the process of human clinical trials as we speak. But admittedly, since you can't get Acell available today, I now want to provide you with some hot tips to potentially boost your microbiome's ability to produce acetate and reap its rewards. Again, details and references can all be found in the associated newsletter, which I've linked below. But to begin, one, I want to talk about acetogenic fibers. So, to avoid confusion, let me just reinforce that the cellulose fiber component of Acel acts as a delivery vehicle for the acetate, but the acetate is generated or consumed exogenously from outside the body. However, other fibers are acidogenic, meaning they can be fermented by gut bacteria into acetate inside your body. And chief among these is inulin. Now, the best dietary sources of inulin include chicory root at number 1, with other great sources being Jerusalem artichokes, onions, garlics, leeks, and asparagus. Therefore, consuming these foods could boost the microbiome's production of acetate, your microbiome's production of acetate. Now, with that said, I want to introduce an important caveat. The amount of acetate produced by your gut microbiome in response to acetogenic fibers like inulin will depend on the particularities of the community to which you play host. We are all individuals, so you're going to get a different bang for your buck depending on what microbiome you have. Anyway, moving on, acetate-producing bacteria, which actually builds on that because it may be possible to enrich your gut in acetate producers. There are several, but Akkermansia muciniphila is one acetate producer that can be found in the human microbiome and has been quite studied. Akkermansia muciniphila levels in humans are already known to be positively associated with circulating acetate levels. Because it produces acetate, and negatively associated with blood glucose and waist-to-hip ratio. Overall, if you take a broad scope of the literature, Akkermansia muciniphila is associated with a healthier metabolic profile in humans, which may be due, at least in part, to its ability to produce the short-chain fatty acid acetate. Now, the following interventions based on a combination of animal or human studies are thought to increase acromancy of mucinophilia levels. Some are pretty basic, but I still want to list them. First, reducing or eliminating alcohol intake. Second, avoiding a high-sugar, high-fat, high-processed food Western dietary style pattern. Third, I'll be a little bit careful here, but the first-line diabetes medication metformin has consistently been shown in animal studies to increase acromancy of mucinophilia. Of course, this is not meant to be medical advice. Do not get your medical advice off YouTube. However, I do raise it because it's a consistent finding in the preclinical literature and a popular medication in the growing longevity space. And finally, 4, kinda quirkily, rhubarb extract has shown some promise in preclinical studies for increasing Akkermansia muciniphila levels. This might be related to an anthraquinone pigment that the rhubarb contains. But the jury's still out and more human trials are needed. Now finally, 3. Vinegar, by which I mean acetic acid. Vinegar is a rich dietary source of acetic acid. Now while this form of acetate won't make it en masse to your colon, orally administered acetic acid can still have health benefits, including weight loss, when taken as apple cider vinegar in some human randomized controlled trials. Now, in one of the most impressive RCTs on apple cider vinegar I've seen, they took subjects and gave them 1 teaspoon to 1 tablespoon of apple cider vinegar containing 5% acetic acid for 12 weeks. And this led to weight loss in a dose and time-dependent manner, as well as improvements in body fat, blood glucose, and triglycerides. So, in addition to attempting to increase colonic production of acetate through acetogenic fibers—remember inulin—and microbiome support, you can still reap the rewards of acetate when taken orally—I know, little bit of plot twist, right?—if you can handle a shot of apple cider vinegar. Now, as a protocol, here's what I'd suggest. Here's what I do: 1 tablespoon of apple cider vinegar taken about 30 minutes or less before meals. This will time the acetate peak in your blood to the ingestion of food and could give you some of acetate's benefits while Acel still remains in clinical trials. But in conclusion on this Acel fiber-acetate complex in the primary study that we discussed, what this research teaches us is not that fiber matters so simply—that's a whole separate kettle of fish—but that fiber can be reimagined, reinvented, and repurposed for much more than boring bulking stool. Now, if you want to bulk your brain, click subscribe. And subscribe to my Stay Curious Metabolism newsletter to get extra details and early access to these forms of data. Stay curious, and I look forward to your questions and comments. Peace.
