Instituto de Lactología Industrial (INLAIN, UNL-CONICET), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe 3000, Argentina.
Instituto Nacional de Tecnología Agropecuaria (INTA), Estación Experimental Agropecuaria, E3101 Oro Verde, Paraná, Entre Ríos, Argentina.
Benef Microbes. 2020 Nov 15;11(7):685-702. doi: 10.3920/BM2020.0054. Epub 2020 Nov 9.
Breast milk can be a source of potential probiotic bacteria, but the technological capacity of isolates obtained from this source is not always guaranteed. We aimed at isolating lactobacilli from breast milk samples collected in Argentina, focusing on isolates with functional and technological potential as probiotics. Fourteen and one isolates were obtained from 164 samples donated by 104 mothers. The isolates preliminarily identified by MALDI-TOF, and then the identity was confirmed by partial 16S rRNA gene sequencing. Hydrophobicity was determined (hexadecane and xylene partition). The strains were also co-cultured with murine RAW 264.7 macrophages for screening the capacity to induce the anti-inflammatory cytokine interleukin (IL)-10. Hydrophobicity ranged from 7.4 and 95.9%. The strains (70a and 70c) and (73a and 73b) were the strains with a higher capacity to induce IL-10 production by macrophages. The technological application was evaluated by freezing dried in 10% lactose or 10% polydextrose. The survival was assessed after accelerated (37 °C, 4 weeks) or long-term (5 and 25 °C, 12 months) storage. Except for 94d, strains lost less than 1 Log10 order cfu/g after long-term (12 months) storage at 5 °C in lactose and polydextrose as protectants. A low correlation between survival to accelerated and long-term storage tests was observed. (70a and 70c) and (73a and 73b) deserve further studies as potential probiotics due to their capacity to induce IL-10 from murine macrophages and their hydrophobicity. In special, 73a was able to confer enhanced protection against infection by promoting the immunity of the small intestine.
母乳可以成为潜在益生菌的来源，但从这种来源获得的分离物的技术能力并不总是有保证的。我们的目的是从阿根廷收集的母乳样本中分离出乳杆菌，重点是具有功能和技术潜力的益生菌分离物。从 104 位母亲捐赠的 164 个样本中获得了 14 个和 1 个分离物。通过 MALDI-TOF 初步鉴定分离物，然后通过部分 16S rRNA 基因测序确认其身份。测定疏水性（十六烷和二甲苯分配）。还将菌株与鼠 RAW 264.7 巨噬细胞共培养，以筛选诱导抗炎细胞因子白细胞介素（IL）-10 的能力。疏水性范围为 7.4%至 95.9%。菌株 （70a 和 70c）和 （73a 和 73b）是诱导巨噬细胞产生更高 IL-10 能力的菌株。通过在 10%乳糖或 10%聚右旋糖中冻干评估了技术应用。在加速（37°C，4 周）或长期（5°C 和 25°C，12 个月）储存后评估生存能力。除 94d 外，在乳糖和聚右旋糖作为保护剂的 5°C 下长期（12 个月）储存后，菌株的损失小于 1Log10 个菌落形成单位/g。加速和长期储存试验的生存能力之间观察到低相关性。由于其诱导鼠巨噬细胞产生 IL-10 的能力及其疏水性， （70a 和 70c）和 （73a 和 73b）值得进一步研究作为潜在的益生菌。特别是 73a 能够通过促进小肠的免疫力来提供针对 感染的增强保护。
