All mucins are highly glycosylated and a key constituent of the mucus layer that is vigilant against pathogens in many organ systems of animals and humans. The viscous layer is organized in bilayers, i.e., an outer layer that is loosely arranged, variable in thickness, home to the commensal microbiota that grows in the complex environment, and an innermost layer that is stratified, non-aspirated, firmly adherent to the epithelial cells and devoid of any microorganisms. The O-glycosylation moiety represents the site of adhesion for pathogens and due to the increase of motility, mucolytic activity, and upregulation of virulence factors, some microorganisms can circumvent the component of the mucus layer and cause disruption in organ homeostasis. A dysbiotic microbiome, defective mucus barrier, and altered immune response often result in various diseases. In this review, paramount emphasis is given to the role played by the bacterial species directly or indirectly involved in mucin degradation, alteration in mucus secretion or its composition or mucin gene expression, which instigates many diseases in the digestive, respiratory, and other organ systems. A systematic view can help better understand the etiology of some complex disorders such as cystic fibrosis, ulcerative colitis and expand our knowledge about mucin degraders to develop new therapeutic approaches to correct ill effects caused by these mucin-dwelling pathogens.

所有粘蛋白都是高度糖基化的，是粘液层的关键成分，对动物和人类许多器官系统中的病原体保持警惕。粘性层组织成双层，即外层松散排列，厚度可变，是在复杂环境中生长的共生微生物群的家园，而最内层是分层的、不吸气的、牢固地附着在上皮细胞，不含任何微生物。该Ø-糖基化部分代表病原体的粘附位点，并且由于运动性、粘液溶解活性和毒力因子的上调的增加，一些微生物可以绕过粘液层的成分并导致器官稳态的破坏。失调的微生物组、有缺陷的粘液屏障和改变的免疫反应通常会导致各种疾病。在这篇综述中，最重要的是细菌物种在直接或间接参与粘蛋白降解、粘液分泌或其组成或粘蛋白基因表达的改变中所发挥的作用，这在消化、呼吸和其他器官系统中引发了许多疾病。 . 系统的观点有助于更好地了解一些复杂疾病的病因，例如囊性纤维化、