The breakdown of the gut’s mucosal barrier that prevents the infiltration of microorganisms, inflammatory cytokines and toxins into bodily tissues can lead to inflammatory bowel disease and to metabolic and autoimmune diseases. Here we show that the intestinal mucosal barrier can be reinforced via the oral administration of commensal bacteria coated with poly(ethylene glycol) (PEG) to facilitate their penetration into mucus. In mice with intestinal homoeostatic imbalance, mucus-penetrating PEGylated bacteria preferentially localized in mucus at the lower gastrointestinal tract, inhibited the invasion of pathogenic bacteria, maintained homoeostasis of the gut microbiota, stimulated the secretion of mucus and the expression of tight junctions, and prevented the mice from developing colitis and diabetes. Orally delivered PEGylated bacteria may help prevent and treat gastrointestinal disorders.

阻止微生物、炎症细胞因子和毒素渗透到身体组织的肠道粘膜屏障的破坏可能导致炎症性肠病以及代谢和自身免疫性疾病。在这里，我们表明，可以通过口服涂有聚乙二醇（PEG）的共生细菌来增强肠粘膜屏障，以促进其渗透到粘液中。在肠道稳态失衡的小鼠中，粘液穿透性聚乙二醇化细菌优先定位于下胃肠道的粘液中，抑制病原菌的入侵，维持肠道菌群的稳态，刺激粘液的分泌和紧密连接的表达，预防肠道菌群失调。小鼠患上结肠炎和糖尿病。口服聚乙二醇化细菌可能有助于预防和治疗胃肠道疾病。