Enhanced tolerance to environmental stress of Clostridium butyricum spore encapsulated in citrus peel pectin polysaccharide for colitis therapy

Clostridium butyricum (C. butyricum) has the ability to ferment dietary polysaccharides and produce butyric acid, which plays a crucial role in promoting gut homeostasis, including alleviating colitis and maintaining gut homeostasis. However, C. butyricum is susceptible to oxygen damage and experiences reduced activity due to various environmental stress, which severely restricts their probiotic effects. In this study, a novel synbiotic preparation for colitis treatment by combining dietary polysaccharides (prebiotic) with C. butyricum (probiotic) was developed using microcapsule embedding technology. Firstly, pectin polysaccharide from waste peel was extracted and modified to obtain low-methoxy pectin (DE = 34%) that could be crosslinked in the presence of Ca²⁺. Additionally, this extracted pectin could promote the growth of C. butyricum and fermentation to produce butyric acid. Subsequently, C. butyricum and spores (Spo) were encapsulated within pectin gel (Pec) using microfluidic technology, and then dual microcapsules were prepared through chitosan (Chi) coating on their surface (Chi@Pec@Spo). This type of microcapsule exhibited excellent viability maintenance for both C. butyricum vegetative cells and spores under cold/hot treatments and gastrointestinal stress, with a viable cell count of up to 10⁸∼10⁹ CFU/g. Moreover, Chi@Pec@Spo treatment resulted in a remarkable survival rate (100%) and significantly reduced disease activity index (0.78 ± 0.09) in mice with acute colitis, accompanied by an elongated colon length (7.51 ± 0.15 cm). The inhibitory expression of pro-inflammatory factors (IL-6 and TNF-α) further indicated the excellent therapeutic efficacy of Chi@Pec@Spo against mice colitis. Overall, this microcapsule system provides a new approach for the treatment of intestinal diseases using food assembly systems.