嗜酸乳杆菌和酪酸梭菌协同抑制痢疾杆菌的活性研究

以嗜酸乳杆菌和酪酸梭菌为研究对象，用琼脂扩散法检测其纯培养和共培养后的发酵液对福氏痢疾杆菌的体外抑菌活性。结果表明，嗜酸乳杆菌和酪酸梭菌共培养液对福氏痢疾杆菌具有良好的协同抑制作用，其共培养液抑菌作用较嗜酸乳杆菌和酪酸梭菌纯培养，其抑菌作用分别增强了17.2%和22.4%。同时，嗜酸乳杆菌和酪酸梭菌存在共生关系，共培养后生物量可达4.27 g/L(干重)，较嗜酸乳杆菌和酪酸梭菌纯培养生物量分别提高6.0%和30.6%，且共生可使产酸增多，从而达到协同抑菌效果。对福氏痢疾杆菌黏附人结肠腺癌Caco-2细胞的研究表明，嗜酸乳杆菌和酪酸梭菌能协同抑制福氏痢疾杆菌对Caco-2细胞的黏附，Caco-2与混合益生菌、嗜酸乳杆菌和酪酸梭菌共孵育的组别，其福氏痢疾杆菌的相对黏附率分别降低了84.2%，81.2%和75.8%，相对应的Caco-2细胞的活力分别提高了22.9%，12.5%和11.5%。本研究首次发现两种益生菌嗜酸乳杆菌和酪酸梭菌具有共生关系，并且在体外能够协同抑制肠道致病菌福氏痢疾杆菌的生长和黏附，对于由福氏痢疾杆菌引起的细菌性痢疾治疗具有临床应用前景。

Synergistic inhibition of Lactobacillus acidophilus and Clostridium butyricum against Shigella flexneri in vitro

An agar diffusion method was used to investigate the antimicrobial activities of fermentation broth of Lactobacillus acidophilus(L. acidophilus), and Clostridium butyricum(C. butyricum)against Shigella flexneri(S. flexneri)infection in vitro. It was found that cell-free culture supernatants(CFCSs)of L. acidophilus and C. butyricum possessed remarkable synergistic anti-S. flexneri activity in vitro and the antimicrobial activity of the mixed culture was 17. 2% and 22. 4% greater, than single strains alone, respectively. Meanwhile, there was a symbiotic relationship between L. acidophilus and C. butyricum. The result showed that the biomass accumulation of the mixed culture reached 4. 27 g/L(DCW)and increased by 6. 0% and 30. 6% compared to the L. acidophilus and C. butyricum, respectively. Moreover, L. acidophilus and C. butyricum clearly inhibited S. flexneri adhesion to Caco-2 cells by 75. 8% and 81. 2%, and the combination of these two probiotic strains demonstrated the highest inhibition rate, reaching 84. 2%, while the viability of Caco-2 cells treated with L. acidophilus, C. butyricum or their combination was increased by 11. 5%, 12. 5% and 22. 9%, respectively. The synergistic effect of L. acidophilus and C. butyricum provided better protection against Shigella flexneri infection, which represents a promising alternative therapy for shigellosis.