title: Dietary intake of heat-killed Lactococcus lactis H61 delays age-related hearing loss in C57BL/6J mice.
abstract: Age-related hearing loss (AHL) is a common disorder associated with aging. In this study, we investigated the effect of the intake of heat-killed Lactococcus lactis subsp. cremoris H61 (strain H61) on AHL in C57BL/6J mice. Measurement of the auditory brainstem response (ABR) demonstrated that female mice at 9 months of age fed a diet containing 0.05% strain H61 for 6 months maintained a significantly lower ABR threshold than control mice. The age-related loss of neurons and hair cells in the cochlea was suppressed by the intake of strain H61. Faecal analysis of bacterial flora revealed that the intake of strain H61 increased the prevalence of Lactobacillales, which is positively correlated with hearing ability in mice. Furthermore, plasma fatty acid levels were negatively correlated with hearing ability. Overall, the results supported that the intake of heat-killed strain H61 for 6 months altered the intestinal flora, affected plasma metabolite levels, including fatty acid levels, and retarded AHL in mice.
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Oike
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, JAPAN.|Graduate school of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, JAPAN.
authors.forename: Ayako
authors.initials: A
authors.lastname: Aoki-Yoshida
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, JAPAN.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kimoto-Nira
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, JAPAN.
authors.forename: Naoko
authors.initials: N
authors.lastname: Yamagishi
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Satoru
authors.initials: S
authors.lastname: Tomita
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Sekiyama
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Manabu
authors.initials: M
authors.lastname: Wakagi
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Sakurai
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Katsunari
authors.initials: K
authors.lastname: Ippoushi
authors.affiliation: NARO Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, 2 Ikenodai, Tsukuba, Ibaraki 305-0901, JAPAN.
authors.forename: Chise
authors.initials: C
authors.lastname: Suzuki
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, JAPAN.
authors.forename: Masuko
authors.initials: M
authors.lastname: Kobori
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D004032:Diet; D034381:Hearing Loss; D013294:Lactococcus lactis; D051379:Mice; D008810:Mice, Inbred C57BL; D019936:Probiotics