The Applications of Nanocellulose and Its Modulation of Gut Microbiota in Relation to Obesity and Diabetes

Obesity and type 2 diabetes are closely linked and often referred to as diabesity. Therapies of diabesity include improving intestinal health and reducing intake of fat and sugars. Diagnosis of diabesity-related metabolic disorders would involve monitoring of glucose and other factors. Nanocellulose, also known as cellulose nanomaterials, is emerging as a potential material for various applications. It has unique properties, such as high surface area, biodegradable, biocompatibility and tunable surface chemistry. In this review, we initially provided a brief description of differently produced nanocellulose and their potential applications in different areas, including therapeutics and diagnostics, by focusing on obesity and diabetes. Then, the uptake, absorption, distribution, metabolism and excretion of nanocellulose were discussed. Further, the mechanisms of nanocellulose in modulating diabesity were summarized by emphasizing the role of gut microbiota. Finally, we discussed gut microbiota-related health effects of nanocellulose, both beneficial and detrimental. It was found that the interactions between nanocellulose and gut were complex, with alterations of microbial composition, metabolic activity, and the immune functions both locally and systemically. There seemed to be many beneficial changes following short-term exposure to nanocellulose (e.g., increased beneficial bacteria and decreased pathogenic ones); however, some of these effects were no longer seen after long-term consumption. Importantly, long-term nanocellulose consumption may be associated with certain detrimental health effects, e.g., malnutrition and its associated neurotoxicity, although additional studies are needed to substantiate such health implications. This information is critical for developing safe and effective nanocellulose derivatives that can be applied in food and medicine as well as to harness the benefits of the gut microbiota.