Inflammatory bowel disease (IBD) is inflammatory intestinal disorders associated with dysregulated gut microbiota. Bacteriotherapy that leverages bacteria as therapeutics has shown tremendous promise in resolving gut dysbiosis and reducing inflammatory mediators to treat IBD. Orally delivered probiotics, such as Escherichia coli Nissle 1917 (EcN), can produce beneficial ingredients, competitively inhibit the proliferation of pathogens, and promote the restoration of gut microbiome homeostasis. However, environmental stresses (such as gastric acids) in the gastrointestinal (GI) tract pose an enormous challenge to the probiotics following oral administration, leading to decreases in viability and activity of probiotics. Meanwhile, the inferior mucoadhesive capability of probiotics results in low colonization efficacy, further compromising their therapeutic effect. Coating probiotics with functional biomaterials may protect them from elimination and prolong their retention in the GI tract. Here, we developed a facile double-layer electrostatic assembly technique to encapsulate EcN bacteria in protective layers of mucoadhesive chitosan (CS) and immunomodulatory hyaluronic acid (HA) to generate HA-CS-EcN. These biomaterials confer the coated EcN resistance to environmental assault and enhanced mucoadhesion in the GI tract. The probiotics equipped with the multifunctional shield can thus suppress inflammation and reshape the intestinal microenvironment to enhance therapeutic efficacy for the prevention and treatment of IBD. Collectively, this study presents a novel probiotic coating strategy to augment the outcome of bacteriotherapy to combat IBD.

炎症性肠病（IBD）是与肠道菌群失调相关的炎症性肠道疾病。利用细菌作为治疗剂的细菌疗法在解决肠道菌群失调和减少炎症介质以治疗 IBD 方面显示出巨大的前景。口服益生菌，如大肠杆菌 Nissle 1917 (EcN)，可以产生有益成分，竞争性抑制病原体增殖，促进肠道微生物组稳态的恢复。然而，胃肠道的环境压力（如胃酸）对口服益生菌提出了巨大的挑战，导致益生菌的活力和活性下降。同时，益生菌的粘膜粘附能力较差，导致其定植效率较低，进一步影响了其治疗效果。用功能性生物材料涂覆益生菌可以保护它们免遭消除并延长它们在胃肠道中的保留时间。在这里，我们开发了一种简便的双层静电组装技术，将 EcN 细菌封装在粘膜粘附壳聚糖 (CS) 和免疫调节透明质酸 (HA) 的保护层中，以生成 HA-CS-EcN。这些生物材料赋予涂层 EcN 对环境攻击的抵抗力，并增强胃肠道中的粘膜粘附力。配备多功能盾牌的益生菌可以抑制炎症，重塑肠道微环境，从而增强IBD预防和治疗的疗效。总的来说，这项研究提出了一种新型益生菌涂层策略，以增强细菌疗法对抗 IBD 的效果。