Faculty of Pharmaceutical Sciences, Hokkaido University of Science, 15-4-1, Maeda 7-jo, Teine-ku, Sapporo-shi, Hokkaido, 006-8565, Japan.
Creation Research Institute of Life Science in KITA-no-DAICHI, Hokkaido University of Science, Sapporo-shi, Hokkaido, Japan.
Int Breastfeed J. 2022 Jan 3;17(1):1. doi: 10.1186/s13006-021-00436-7.
Milk-derived microRNAs (miRNAs), including hsa-miR-148a-3p (miR-148a) and hsa-miR-125b-5p (miR-125b), have been shown to be beneficial to the gastrointestinal function in infants. Here, we investigated their expression during lactation in humans and determined whether the infant formulae available in Japan contain these miRNAs.
Healthy Japanese women (n = 16) who gave birth vaginally or by cesarean section at the Teine Keijinkai Hospital between 1 September 2020, and 31 April 2021 were included in this study. Breast milk was collected by nurses on days 4 or 5 after delivery (hereinafter, transition milk) and on day 30 of postpartum (hereinafter, mature milk). The levels of miR-148a and miR-125b in breastmilk and six commercially available infant formulae were compared and evaluated using quantitative reverse transcription-polymerase chain reaction.
In all participants, the miR-148a level in mature breastmilk was significantly lower than that in the transition milk. The changes in miR-125b expression during lactation showed similar trends to the changes in miR-148a expression. The miR-148a and miR-125b levels in all analyzed infant formulae were lower than 1/500th and 1/100th of those in mature breastmilk, respectively.
The levels of both miR-148a and miR-125b in human breast milk decreased on day 30 postpartum compared with those in the transition milk. Additionally, the expression of these miRNAs in infant formulae available in Japan was very low. Further studies with larger populations are required to understand precisely the lactational changes in the expression of miR148a and miR-125b in breast milk.
牛奶来源的 microRNAs（miRNAs），包括 hsa-miR-148a-3p（miR-148a）和 hsa-miR-125b-5p（miR-125b），已被证明对婴儿的胃肠道功能有益。在这里，我们研究了它们在人类哺乳期的表达情况，并确定了在日本销售的婴儿配方奶粉是否含有这些 miRNAs。
本研究纳入了 2020 年 9 月 1 日至 2021 年 4 月 31 日期间在 Teine Keijinkai 医院顺产或剖宫产的 16 名健康日本女性。由护士在产后第 4 或 5 天（以下简称过渡乳）和产后第 30 天（以下简称成熟乳）收集母乳。使用定量逆转录聚合酶链反应比较并评估母乳和六种市售婴儿配方奶粉中 miR-148a 和 miR-125b 的水平。
在所有参与者中，成熟母乳中的 miR-148a 水平明显低于过渡乳。miR-125b 表达在哺乳期的变化趋势与 miR-148a 的变化趋势相似。所有分析的婴儿配方奶粉中的 miR-148a 和 miR-125b 水平分别低于成熟母乳的 1/500 和 1/100。
与过渡乳相比，人乳在产后第 30 天的 miR-148a 和 miR-125b 水平下降。此外，日本市售婴儿配方奶粉中这些 miRNA 的表达水平非常低。需要进行更大规模的研究，以更准确地了解母乳中 miR148a 和 miR-125b 表达的哺乳期变化。
