College of Food and Bioengineering, Xihua University, Chengdu, 610039, China; Food Microbiology Key Laboratory of Sichuan Province, Xihua University, Chengdu, 610039, China.
College of Food and Bioengineering, Xihua University, Chengdu, 610039, China.
J Dairy Sci. 2024 Feb;107(2):742-758. doi: 10.3168/jds.2023-23858. Epub 2023 Sep 13.
Lactic acid bacteria (LAB), a type of microorganism widely used in functional foods, has gained notable research attention in recent years. Certain strains possess the proteolytic ability to release potentially antihypertensive peptides from dairy proteins, which prompted us to explore the LAB strains from an understudied and unique ingredient, Daqu. We screened for 67 strains of LAB strains from traditional Daqu using the calcium dissolution ring method. Sixteen strains exhibiting angiotensin-converting enzyme inhibition (ACE-I) activity exceeding 50% were chosen for 16S rDNA sequencing and safety assessment. It is noteworthy that Enterococcus faecium CP640 and Lacticaseibacillus rhamnosus CP658 exhibited significant ACE-I activity, which was the result of strain fermentation in reconstituted skim milk. These 2 strains did not exhibit hemolytic activity or antibiotic resistance. They also did not produce biogenic amines and showed high survival rates in the gastrointestinal tract. Additionally, Enterococcus faecium CP640 and Lacticaseibacillus rhamnosus CP658 fermented milk exhibited a notable reduction in blood pressure levels in spontaneously hypertensive rats (SHR) compared with negative controls in SHR. Importantly, no adverse effect was observed in normal Wistar-Kyoto rats. Through the analysis of physiological, serum, and urine-related indicators, it was observed that Enterococcus faecium CP640 and Lacticaseibacillus rhamnosus CP658 have the potential to promote weight gain in SHR, alleviate excessive heart rate, improve renal function indicators, and effectively regulate blood sugar and uric acid levels in SHR. These 2 strains showed optimal properties in lowering blood pressure and have the potential to be used in functional dairy products in the future.
乳酸菌（LAB）是一种广泛应用于功能性食品的微生物，近年来受到了广泛关注。某些菌株具有蛋白水解能力，可以从乳制品蛋白中释放出具有潜在降压作用的肽，这促使我们从一种研究较少且独特的原料——大曲中探索 LAB 菌株。我们采用钙溶解环法从传统大曲中筛选了 67 株 LAB 菌株。选择了 16 株具有超过 50%血管紧张素转换酶抑制（ACE-I）活性的菌株进行 16S rDNA 测序和安全性评估。值得注意的是，屎肠球菌 CP640 和鼠李糖乳杆菌 CP658 具有显著的 ACE-I 活性，这是菌株在重组脱脂乳中发酵的结果。这 2 株菌没有溶血活性或抗生素耐药性。它们也不产生生物胺，在胃肠道中具有较高的存活率。此外，与 SHR 的阴性对照相比，屎肠球菌 CP640 和鼠李糖乳杆菌 CP658 发酵乳可显著降低自发性高血压大鼠（SHR）的血压水平。重要的是，在正常 Wistar-Kyoto 大鼠中没有观察到不良反应。通过分析生理、血清和尿液相关指标，观察到屎肠球菌 CP640 和鼠李糖乳杆菌 CP658 有促进 SHR 体重增加的潜力，可减轻心率过快，改善肾功能指标，并有效调节 SHR 的血糖和尿酸水平。这 2 株菌在降低血压方面表现出最佳特性，有望在未来应用于功能性乳制品。
