A Double-Blind Controlled Study to Evaluate the Effects of Yogurt Enriched with <i>Lactococcus lactis</i> 11/19-B1 and <i>Bifidobacterium lactis</i> on Serum Low-Density Lipoprotein Level and Antigen-Specific Interferon-γ Releasing Ability

• Main Authors: Kyoko Nishiyama, Takahiro Kobayashi, Yuko Sato, Yoshihisa Watanabe, Riki Kikuchi, Ryoko Kanno, Tetsuo Koshizuka, Nozomu Miyazaki, Ken Ishioka, Tatsuo Suzutani
• Format: Article
• Language: English
• Published: MDPI AG 2018-11-01
• Series: Nutrients
• Subjects: yogurt; <i>Lactococcus lactis</i>; low-density lipoprotein; double-blind controlled study
• Online Access: https://www.mdpi.com/2072-6643/10/11/1778

In order to clarify the effects of the <i>Lactococcus lactis</i> (<i>L. lactis</i>) 11/19-B1 strain, a double-blind controlled study of yogurt fermented with the strain was carried out. For the study, two kinds of yogurt, the control and test yogurt, were prepared; the control yogurt was fermented with <i>Streptococcus thermophiles</i>, <i>Lactobacillus delbrueckii</i> subspecies bulgaricus, and <i>Lactobacillus acidophilus</i>, and the test yogurt was enriched with <i>L. lactis</i> 11/19-B1 and <i>Bifidobacterium lactis</i> (<i>B. lactis</i>) BB-12 strains. Seventy-six volunteers who had not received treatment with pharmaceuticals were randomly divided into two groups with each group ingesting 80 g of either the test or control yogurt every day for 8 weeks. Before and after yogurt intake, fasting blood was taken and blood sugar, blood lipids, and anti-cytomegalovirus cellular immunity were estimated. In the test yogurt group, low-density lipoprotein (LDL) was significantly decreased (159.1 &#177; 25.7 to 149.3 &#177; 24.4; <i>p</i> = 0.02), but this effect was not observed in the control yogurt group. When the test yogurt group was divided into two groups based on LDL levels of over or under 120 mg/dL, this effect was only observed in the high LDL group. No LDL-lowering effect of <i>B. lactis</i> BB-12 strain was previously reported; therefore, the hypocholesterolemic effects observed in this study are thought to be caused by the <i>L. lactis</i> 11/19-B1 strain alone or its combination with the <i>B. lactis</i> BB-12 strain.