Microcystallline cellulose
Also known as: MCC, cellulose powder, Microcrystalline Cellulose
Overview
Microcrystalline Cellulose (MCC) is a purified, partially depolymerized cellulose polymer derived from plant cellulose, typically from wood pulp or cotton linters. It is a linear polysaccharide of β-(1→4)-linked D-glucose units, processed into a fine, white powder. MCC is classified as an insoluble dietary fiber and is widely used as an excipient in pharmaceuticals and as a food additive due to its properties as a bulking agent, anti-caking agent, and binder. It is resistant to digestion in the human gastrointestinal tract and possesses high thermal stability, small particle size, and a large specific surface area. While well-characterized physically and chemically, clinical research on its direct health effects as a dietary fiber supplement in humans is limited, with most data stemming from animal models or indirect evidence related to general insoluble fiber effects.
Benefits
MCC acts as an insoluble dietary fiber, primarily contributing to gut health. Animal models of colitis have shown that MCC can improve gut barrier integrity and modulate gut microbiota, reducing inflammation and enhancing the expression of tight junction proteins like claudin-3 and occludin. These benefits were observed after 21 days of supplementation in mice. While direct human clinical trial evidence is sparse, MCC may contribute to improved bowel regularity and stool bulk due to its insoluble fiber nature. Potential benefits in inflammatory bowel disease (IBD) models are noted, but human data are lacking. Animal studies indicate significant reductions in inflammatory markers and improved gut barrier function, but quantitative human effect sizes are not available.
How it works
MCC primarily functions through mechanical effects as an insoluble fiber within the gastrointestinal tract. It increases stool bulk and can modulate the composition of gut microbiota. Beyond its physical effects, MCC appears to influence the gut's immune response and barrier function. Preclinical studies suggest it downregulates proinflammatory cytokines such as TNF-α and IL-1β, and enhances the expression of tight junction proteins (e.g., claudin-3, occludin), thereby improving intestinal barrier integrity. It also interacts with inflammasome components like NLRP3. MCC is not absorbed by the body; its actions are localized within the gut.
Side effects
Microcrystalline Cellulose (MCC) is generally recognized as safe (GRAS) for use as a food additive and excipient, and is well tolerated with minimal adverse effects. The most common side effects, which may occur when consumed in large amounts, are mild gastrointestinal symptoms such as bloating or gas, consistent with the intake of insoluble fiber. Uncommon or rare side effects have not been well documented in clinical trials. There are no known significant drug interactions. Contraindications are not established, though caution may be warranted for individuals with pre-existing bowel obstruction or severe gastrointestinal disorders. Data on special populations are limited, but MCC is generally considered safe for the general population.
Dosage
The minimum effective dose for health benefits of MCC is not well established in humans; animal studies have used doses of 2.5 g/kg body weight in mice. There is no consensus on optimal dosage ranges for human supplementation. MCC contributes to overall dietary fiber intake, for which general recommendations suggest 25-38 grams daily. There is no defined upper limit for MCC, but excessive fiber intake from any source may lead to gastrointestinal discomfort. No specific timing considerations are required, and it can be consumed with meals. MCC is typically administered as a powder or as an excipient in tablets. It is not absorbed by the body, acting locally in the gut, and no specific cofactors are identified as necessary for its function.
FAQs
Is MCC effective as a dietary fiber supplement?
MCC provides insoluble fiber that can support gut health, but direct human evidence on clinical outcomes is limited. Most evidence comes from animal studies.
Is MCC safe to consume daily?
Yes, MCC is generally safe and well tolerated as a food additive and fiber supplement. It is recognized as GRAS (Generally Recognized As Safe).
Does MCC help with blood sugar control?
No direct evidence supports MCC improving glycemic control. Viscous soluble fibers are generally more effective for this purpose.
Can MCC cause digestive issues?
High doses of MCC may cause mild bloating or gas, which are typical side effects associated with increased insoluble fiber intake.
Is MCC fermented by gut bacteria?
MCC is poorly fermented by gut bacteria compared to soluble fibers like inulin, meaning it passes through the digestive system largely intact.
Research Sources
- https://diabetesjournals.org/care/article/42/5/755/40520/Should-Viscous-Fiber-Supplements-Be-Considered-in – This systematic review and meta-analysis of 28 randomized controlled trials in humans with type 2 diabetes concluded that viscous fiber supplements improve glycemic control. The study focused on soluble fibers and did not directly investigate MCC, indicating that MCC is not considered a viscous fiber for this purpose.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8991927/ – This animal study on DSS-induced colitis mice demonstrated that MCC supplementation for 21 days improved gut barrier integrity, reduced proinflammatory cytokines, and modulated gut microbiota. While providing preclinical evidence for MCC's beneficial effects on gut health, it is an animal model with unclear sample size, limiting direct human applicability.
- https://www.clinicaltrials.gov/study/NCT06515210?term=AREA%5BConditionSearch%5D%28Ulcerative+Colitis%29&rank=6 – This is an ongoing clinical trial evaluating the effects of MCC on inflammation and symptoms in human patients with ulcerative colitis. As of now, no published results are available, so its findings are pending and cannot yet inform the efficacy of MCC in this population.