Horie Masanori, Koike Taisuke, Sugino Sakiko, Umeno Aya, Yoshida Yasukazu
Health Research Institute (HRI), National Institute of Advanced Industrial Science and Technology (AIST).
Mitsubishi-Chemical Foods Corporation.
J Gen Appl Microbiol. 2018 Mar 27;64(1):26-33. doi: 10.2323/jgam.2017.03.002. Epub 2017 Dec 8.
The aim of this study was to determine the probiotic and the prebiotic-like properties of Bacillus subtilis BN, a spore-forming bacterium, also known as "natto-kin", which is used for making the Japanese fermented food, natto. We used the spores and vegetative cells of this strain and compared their effects on the growth of lactobacilli. Culture supernatant from B. subtilis BN was added to a glucose-free MRS medium used to culture lactobacilli. When lactobacilli were cultured in the supernatant-containing medium, growth was improved. This effect resulted from the digestion of starch by amylase, which was secreted by B. subtilis. Moreover, improved amylase-independent growth was also observed. Co-culture with B. subtilis improved the growth of lactobacilli, and this effect was only observed with vegetative cells; spores did not improve the growth of lactobacilli. This effect on growth was lost upon heat treatment of the vegetative cells. These results suggest that the surface protein of B. subtilis BN vegetative cells participates in the improved growth effect of lactobacilli. It is possible that B. subtilis BN could improve the intestinal flora. In addition, B. subtilis BN inhibited the growth of Salmonella enterica. Thus, it was shown that B. subtilis BN has both a probiotic and prebiotic potential. This is the first study demonstrating the selective growth improvement of indigenous intestinal lactobacilli using B. subtilis BN.
本研究的目的是确定枯草芽孢杆菌BN（一种形成芽孢的细菌，也被称为“纳豆激酶”，用于制作日本发酵食品纳豆）的益生菌和益生元样特性。我们使用了该菌株的芽孢和营养细胞，并比较了它们对乳酸菌生长的影响。将枯草芽孢杆菌BN的培养上清液添加到用于培养乳酸菌的无葡萄糖MRS培养基中。当在含有上清液的培养基中培养乳酸菌时，其生长得到改善。这种效果是由枯草芽孢杆菌分泌的淀粉酶对淀粉的消化作用导致的。此外，还观察到了与淀粉酶无关的生长改善。与枯草芽孢杆菌共培养可改善乳酸菌的生长，且这种效果仅在营养细胞中观察到；芽孢不能改善乳酸菌的生长。对营养细胞进行热处理后，这种对生长的影响就消失了。这些结果表明，枯草芽孢杆菌BN营养细胞的表面蛋白参与了乳酸菌生长改善作用。枯草芽孢杆菌BN有可能改善肠道菌群。此外，枯草芽孢杆菌BN抑制了肠炎沙门氏菌的生长。因此，结果表明枯草芽孢杆菌BN具有益生菌和益生元的潜力。这是第一项证明使用枯草芽孢杆菌BN对肠道内源性乳酸菌有选择性生长促进作用的研究。
