Department of Chemistry Indian Institute of Technology Kanpur UP-208016, India.
ACS Infect Dis. 2021 Apr 9;7(4):733-745. doi: 10.1021/acsinfecdis.0c00413. Epub 2021 Mar 11.
Probiotic yeast exerts direct probiotic action on pathogenic by trapping them on surfaces and inactivating toxic lipopolysaccharides. Using optical dark-field microscopy, we show that nonpathogenic cells also readily bind probiotic More importantly, the adhered nonpathogenic progressively damage cell walls and lyse them. Co-cultured methylene blue-supplemented agar-plate assay indicates that rough lipopolysaccharides might be playing a key role in cell wall damage. When experiments are repeated with lipopolysaccharide-depleted and also lipopolysaccharide-deficient , adhesion decreases substantially. The co-cultured assay further reveals that free lipopolysaccharides, released from , are also causing damage to walls like adhered . These new findings contradict the known - interaction mechanisms. We confirm that cells do not bind or damage human erythrocyte cell walls; therefore, they have not developed pathogenicity. The combined results demonstrate the first example of nonpathogenic being harmful to probiotic yeast . This finding is important because gut microbial flora contain large numbers of nonpathogenic . If they bind or damage probiotic cell walls, then the probiotic efficiency toward pathogenic will be compromised.
益生菌酵母通过在表面捕获它们并使毒性脂多糖失活，对病原体发挥直接益生菌作用。使用暗场光学显微镜，我们表明非致病性酵母也很容易结合益生菌。更重要的是，附着的非致病性酵母逐渐破坏细胞壁并使它们裂解。共培养亚甲基蓝补充琼脂平板测定表明，粗糙脂多糖可能在细胞壁损伤中起关键作用。当用耗尽脂多糖的和也缺乏脂多糖的进行重复实验时，粘附大大减少。共培养测定还表明，从释放的游离脂多糖也像附着的一样对细胞壁造成损伤。这些新发现与已知的相互作用机制相矛盾。我们证实酵母细胞不结合或破坏人红细胞细胞壁；因此，它们没有产生致病性。综合结果表明，第一个无害的非致病性对益生菌酵母有害的例子。这一发现很重要，因为肠道微生物菌群中含有大量的非致病性。如果它们结合或破坏益生菌细胞壁，那么益生菌对致病性的效率将会受到影响。
