Expression profiles of hsa-miR-148a-3p and hsa-miR-125b-5p in human breast milk and infant formulae

Background 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. Methods 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. Results 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. Conclusions 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.

Measurement of Cellular Immune Function of Breast Milk and Health Education of Pregnant and Lying in Women

Breast milk is different from any nutritional substitutes. Breast milk has biological specificity. The most irreplaceable nutrient for newborns is breast milk. In order to determine the immunoprotective effect of breast milk on newborns, 30 primiparas were selected to obtain a little milk before feeding in three different periods, which were divided into colostrum, transitional milk and mature milk. The contents of CD3, CD4, CD8, SlgA, IgG and IgM positive cells in nuclear cells were observed by inverted fluorescence microscope. The contents of IL-8, IFN - γ, and potassium, sodium, chlorine, calcium, magnesium and phosphorus in different time periods were compared between six groups. The results showed that the content of IFN - γ cells in colostrum was 1.61 and that of IL-8 cells was 0.83. However, the contents of IFN - γ cells and IL-8 cells in colostrum decreased to 0.31 and 0.36 at the time of transition milk. Therefore, breastfeeding from the third to the fifth day after delivery can give more immune cells to the newborn, which is conducive to the establishment of their own immune system. Therefore, in the teaching of health-related knowledge to pregnant women, we should advocate more maternal breastfeeding newborns, for the health of the newborn.

Colostro como fonte imunológica e nutricional na criação de bezerras de aptidão leiteira

Facing the absence of transplacental transfer of immunoglobulins to the bovine newborn, the primary objective of this review was to address the colostrum relevance as an immunological source and care needed to perform an adequate colostrum intake. Aiming at the maximum absorption of maternal immunoglobulins, we highlight the maintenance of a colostrum bank in dairy farms, focusing in providing high quality colostrum, in adequate quantity and at the right time after birth. Also, the use of surplus colostrum and transition milk in the form of silage is discussed, being it a restricted nutritional alternative for dairy calves, compared to others, such as whole milk and milk replacers.

Temporal kinetics of bovine mammary IgG secretion into colostrum and transition milk

Neonatal calf survival and health is predominantly dependent on sufficient consumption of immunoglobulin G (IgG) and the resulting transfer of passive immunity (TPI). In this study we investigate the potential for continued IgG secretion and temporal kinetics of mammary IgG output in sequential milkings performed at 0, 4, 16, 28, 40 and 52 hours post-calving in Holstein dairy cows. For colostrum (0 hour), we also scrutinize the relationships between IgG concentration, volume, refractometer readings (˚Bx values, Brix ®) and concentration of sugars (lactose and glucose). Mammary transcripts postpartum (0 hour) indicated that active IgG secretion continues beyond the first milking (colostrum; n=4-5). IgG measurements at the different timepoints indicated that colostrum represents only 25.1% of the total IgG produced across the six sequential milking timepoints, with a substantial 48.9% being secreted into transition milk over the next three timepoints (4-, 6- and 28-hour) combined. The differences on the basis of IgG concentrations across 0-, 4- and 16-hour milking timepoints were not statistically significant (p=0.1522; n=9). For colostrum, volume remained highly variable, even with induced let-down prior to milking (n=27). Nonetheless, colostrum IgG secretion was significantly co-regulated with volume (R 2=0.915; p<0.001; n=18), an association that was stronger than that measured for lactose (R 2=0.803; p<0.001; n=18) and glucose (R 2=0.467; p=0.002; n=17). Comparing colostrum ˚Bx values to absolute IgG concentrations showed no correlation (R 2=0.127; p=0.07; n=27); biochemical separation of colostrum components indicated that both proteins and non-protein solutes could affect ˚Bx values (p<0.0001 for both; n=5). This suggests that ˚Bx values do not reasonably indicate IgG concentration to serve as a measure of “colostrum quality.” Additionally, our finding that early transition milk (4-, 6- and 28-hour) can contribute substantially more IgG than colostrum forces a rethink of existing feeding paradigms and means to maximize TPI in calves. Collectively, our results reveal the remarkable value of early transition milk and caveats to colostrum assessments that could advance application in enhancing neonatal calf health.

Influence of Dry Period Length of Swedish Dairy Cows on the Proteome of Colostrum

The aim of this study was to evaluate the influence of applying a 4-week instead of an 8-week dry period to dairy cows on the proteome of colostrum (first sample) and of transition milk (the fifth postpartum milk sample). Individual milk serum samples of colostrum and transition milk were analysed from 12 Swedish Holstein (SH) and 12 Swedish Red (SR) cows. Samples were prepared by filter-aided sample preparation and dimethyl labelling and analysed by liquid chromatography tandem mass spectrometry. Shortening the dry period resulted in upregulation of 18 proteins in colostrum and transition milk of SR, whereas no statistical differences were found for SH colostrum and transition milk. These upregulated proteins may reflect a specific immune response in the SR samples that was reflected in colostrum as well as in transition milk. Upregulated proteins in colostrum seemed to reflect increased mammary epithelial cell proliferation in the periparturient period when a 4-week dry period was applied. The proteome data indicate that a dry period of 4 weeks to SR cows may not be sufficient for complete regeneration of the mammary epithelium.