Zago Miriam, Massimiliano Lucia, Bonvini Barbara, Penna Giuseppe, Giraffa Giorgio, Rescigno Maria
CREA Research Centre for Animal Production and Aquaculture (CREA-ZA), Lodi, Italy.
Department of Experimental Oncology, European Institute of Oncology, Milan, Italy.
PLoS One. 2021 Jan 25;16(1):e0245903. doi: 10.1371/journal.pone.0245903. eCollection 2021.
Lactobacillus helveticus carries many properties such as the ability to survive gastrointestinal transit, modulate the host immune response, accumulate biopeptides in milk, and adhere to the epithelial cells that could contribute to improving host health. In this study, the applicability as functional cultures of four L. helveticus strains isolated from Italian hard cheeses was investigated. A preliminary strain characterization showed that the ability to produce folate was generally low while antioxidant, proteolytic, peptidase, and β-galactosidase activities resulted high, although very variable, between strains. When stimulated moDCs were incubated in the presence of live cells, a dose-dependent release of both the pro-inflammatory cytokine IL-12p70 and the anti-inflammatory cytokine IL-10, was shown for all the four strains. In the presence of cell-free culture supernatants (postbiotics), a dose-dependent, decrease of IL-12p70 and an increase of IL-10 was generally observed. The immunomodulatory effect took place also in Caciotta-like cheese made with strains SIM12 and SIS16 as bifunctional (i.e., immunomodulant and acidifying) starter cultures, thus confirming tests in culture media. Given that the growth of bacteria in the cheese was not necessary (they were killed by pasteurization), the results indicated that some constituents of non-viable bacteria had immunomodulatory properties. This study adds additional evidence for the positive role of L. helveticus on human health and suggests cheese as a suitable food for delivering candidate strains and modulating their anti-inflammatory properties.
瑞士乳杆菌具有许多特性，如能够在胃肠道中存活、调节宿主免疫反应、在牛奶中积累生物活性肽以及黏附于上皮细胞，这些特性有助于改善宿主健康。在本研究中，对从意大利硬奶酪中分离出的四株瑞士乳杆菌作为功能性培养物的适用性进行了研究。初步的菌株特性分析表明，虽然菌株间叶酸生成能力普遍较低，但抗氧化、蛋白水解、肽酶和β-半乳糖苷酶活性较高，不过差异很大。当将活化的树突状细胞（moDCs）与活细胞一起孵育时，所有四株菌株均呈现促炎细胞因子IL-12p70和抗炎细胞因子IL-10的剂量依赖性释放。在无细胞培养上清液（后生元）存在的情况下，通常观察到IL-12p70呈剂量依赖性下降，IL-10增加。以SIM12和SIS16菌株作为双功能（即免疫调节和酸化）发酵剂制作的类似卡乔塔奶酪中也出现了免疫调节作用，从而证实了在培养基中的试验结果。鉴于奶酪中细菌的生长并非必要条件（它们在巴氏杀菌过程中被杀死），结果表明非存活细菌的某些成分具有免疫调节特性。本研究为瑞士乳杆菌对人类健康的积极作用增添了更多证据，并表明奶酪是递送候选菌株并调节其抗炎特性的合适食物。
