Leñini Cecilia, Rodriguez Ayala Facundo, Goñi Anibal Juan, Rateni Liliana, Nakamura Akira, Grau Roberto Ricardo
Departamento de Microbiología, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
Front Microbiol. 2023 Sep 28;14:1253480. doi: 10.3389/fmicb.2023.1253480. eCollection 2023.
Spore-forming probiotic bacteria offer interesting properties as they have an intrinsic high stability, and when consumed, they are able to survive the adverse conditions encountered during the transit thorough the host gastrointestinal (GI) tract. A traditional healthy food, nattō, exists in Japan consisting of soy fermented by the spore-forming bacterium natto. The consumption of nattō is linked to many beneficial health effects, including the prevention of high blood pressure, osteoporosis, and cardiovascular-associated disease. We hypothesize that the bacterium natto plays a key role in the beneficial effects of nattō for humans. Here, we present the isolation of DG101 from nattō and its characterization as a novel spore-forming probiotic strain for human consumption. DG101 was non-hemolytic and showed high tolerance to lysozyme, low pH, bile salts, and a strong adherence ability to extracellular matrix proteins (i.e., fibronectin and collagen), demonstrating its potential application for competitive exclusion of pathogens. DG101 forms robust liquid and solid biofilms and expresses several extracellular enzymes with activity against food diet-associated macromolecules (i.e., proteins, lipids, and polysaccharides) that would be important to improve food diet digestion by the host. DG101 was able to grow in the presence of toxic metals (i.e., chromium, cadmium, and arsenic) and decreased their bioavailability, a feature that points to this probiotic as an interesting agent for bioremediation in cases of food and water poisoning with metals. In addition, DG101 was sensitive to antibiotics commonly used to treat infections in medical settings, and at the same time, it showed a potent antimicrobial effect against pathogenic bacteria and fungi. In mammalians (i.e., rats), DG101 colonized the GI tract, and improved the lipid and protein serum homeostasis of animals fed on the base of a normal- or a deficient-diet regime (dietary restriction). In the animal model for longevity studies, , DG101 significantly increased the animal lifespan and prevented its age-related behavioral decay. Overall, these results demonstrate that DG101 is the key component of nattō with interesting probiotic properties to improve and protect human health.
形成芽孢的益生菌具有一些有趣的特性，因为它们具有内在的高稳定性，并且在食用时，能够在通过宿主胃肠道的过程中抵御遇到的不利条件。日本有一种传统的健康食品纳豆，它由经形成芽孢的细菌纳豆芽孢杆菌发酵的大豆制成。食用纳豆与许多有益健康的功效相关，包括预防高血压、骨质疏松症和心血管相关疾病。我们假设纳豆芽孢杆菌在纳豆对人类的有益作用中起关键作用。在此，我们展示了从纳豆中分离出DG101并将其鉴定为一种新型的供人类食用的形成芽孢的益生菌菌株。DG101不溶血，对溶菌酶、低pH值、胆盐具有高耐受性，并且对细胞外基质蛋白（即纤连蛋白和胶原蛋白）具有很强的黏附能力，这表明其在竞争性排除病原体方面具有潜在应用价值。DG101能形成坚固的液体和固体生物膜，并表达几种对与食物相关的大分子（即蛋白质、脂质和多糖）具有活性的细胞外酶，这对于改善宿主对食物的消化很重要。DG101能够在有毒金属（即铬、镉和砷）存在的情况下生长，并降低它们的生物利用度，这一特性表明这种益生菌在金属引起的食物和水中毒情况下是一种有趣的生物修复剂。此外，DG101对医疗环境中常用的治疗感染的抗生素敏感，同时，它对病原菌和真菌显示出强大的抗菌作用。在哺乳动物（即大鼠）中，DG101定殖于胃肠道，并改善了以正常或缺乏营养饮食（饮食限制）为基础喂养的动物的脂质和蛋白质血清稳态。在长寿研究的动物模型中，DG101显著延长了动物寿命，并防止其出现与年龄相关的行为衰退。总体而言，这些结果表明DG101是纳豆的关键成分，具有有趣的益生菌特性，可改善和保护人类健康。
