餵食老鼠乳酸乳球菌cremoris 亞種H61 是否可以延緩聽力之損失(AHL)之發生？

Heat-killed Lactococcus lactis subsp. Cremaris H61 (strain H61) (資料來源：Sci Rep. 2016 Mar 22;6:23556.　 doi: 10.1038/srep23556.)

Dietary intake of heat-killed Lactococcus lactis H61 delays age-related hearing loss in C57BL/6J mice

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.

老化過程中，和年齡有關的聽力損失(Age-related hearing loss (AHL))是常見的現象，本研究目的是想了解餵食老鼠(C57BL/6J mice)吃熱致死的乳酸乳球菌cremoris 亞種H61 (heat-killed Lactococcus lactis subsp. cremoris H61) (strain H61) 是否可以延緩聽力之損失(AHL)之發生？

研究以測量老鼠之聽性腦幹反應(auditory brainstem response (ABR))之數值當指標，研究結果顯示：餵食9個月大的雌鼠吃含0.05%之H61食物6個月，發現其ABR闕值(threshold)會比對照組小，H61可以抑制在耳蝸內和老化有關之神經元或毛細胞之減損，糞便之分析也顯示：餵食H61會增加乳酸桿菌(Lactobacillales) 之數量，而乳酸桿菌的量是和老鼠聽力有正相關。更近一步發現，血漿中脂肪酸和聽力是呈現負相關。整體而言，此研究成果顯示：餵食老鼠含有heat-killed strain H61食物6個月會改變腸道菌、影響血漿之代謝物質量，包括脂肪酸及延緩AHL之發生。