Soluble dietary fiber modulates the rodent gut microbiota linked to decreased adiposity

Obesity and its associated metabolic syndrome constitute a global health challenge. The use of food components that reduce high calorie intake has been proposed as a viable strategy for controlling the obesity pandemic. Dietary fibres have been identified as food components that induce satiety and reduce high calorie intake thereby decreasing weight gain. These dietary fibers can be insoluble molecules such as cellulose that are poorly fermented by the gut microbiota as well as soluble molecules (pectin, fructooligosaccharides, beta-glucan) that are more highly fermentable leading to the production of useful metabolites such as short chain fatty acids (acetate, propionate and butyrate). It is claimed that these short chain fatty acids activate receptors (ffar2 and ffar3) located in the enteroendocrine cells of the gut leading to the release of gut satiety hormones (PYY and GLP-1). Studies carried out in murine models have demonstrated that diets containing various amounts of dietary fibres can result in decreased body weight gain and adiposity albeit these inhibitory effect of dietary fiber on food intake and weight gain are not always observed.

肥胖及其相关代谢综合征是一项全球性公共卫生挑战。已有研究提出，利用可降低高热量摄入的食品成分，是管控肥胖大流行的可行策略。膳食纤维（dietary fibres）已被证实为一类可诱导饱腹感、减少高热量摄入，进而降低体重增长的食品成分。此类膳食纤维可分为两类：一类是难以被肠道菌群发酵的不溶性分子，例如纤维素（cellulose）；另一类是更易发酵的可溶性分子，包括果胶（pectin）、低聚果糖（fructooligosaccharides）与β-葡聚糖（beta-glucan），这类可溶性分子经发酵后可生成乙酸（acetate）、丙酸（propionate）与丁酸（butyrate）等有益代谢产物。有研究指出，这类短链脂肪酸（short chain fatty acids）可激活肠道肠内分泌细胞（enteroendocrine cells）上的受体（ffar2与ffar3），进而促使肠道饱腹感激素肽YY（PYY）与胰高血糖素样肽-1（GLP-1）释放。在小鼠模型中开展的研究表明，饲喂添加不同剂量膳食纤维的膳食，可降低小鼠的体重增长与脂肪堆积，尽管膳食纤维对食物摄入与体重增长的此类抑制作用并非总能被观测到。