Skip to main content

Advertisement

Table 1 Free amino acid content (μmol/dL) 1 of human milk collected during three stages of lactation

From: Free amino acid content in breast milk of adolescent and adult mothers in Ecuador

  Stage of lactation:  
  Colostrum Transition Mature Statistical analyses: effect of maternal age (p value)
Essential FAAs2:
  Histidine 1.45 ± 0.15a,3 2.31 ± 0.16b 2.00 ± 0.16b p = 0.85
  Isoleucine 0.54 ± 0.06a 0.62 ± 0.07a,b 0.71 ± 0.07b p = 0.89
  Leucine 1.31 ± 0.19a 1.69 ± 0.20a 2.86 ± 0.20b p = 0.21
  Lysine 2.72 ± 0.27a 1.40 ± 0.29b 1.28 ± 0.29b p = 0.54
  Methionine 0.27 ± 0.03a 0.35 ± 0.04a 0.48 ± 0.04b p = 0.17
  Phenylalanine 0.51 ± 0.08a 0.89 ± 0.08b 1.04 ± 0.08b p = 0.69
  Threonine 4.77 ± 0.49a 6.11 ± 0.53b 7.33 ± 0.53b p = 0.08
  Tryptophan nd4 nd nd ---
  Valine 2.36 ± 0.23a 3.76 ± 0.25b 4.57 ± 0.25c p = 0.44
Non-essential FAAs:
  Alanine 12.54 ± 1.56a 21.33 ± 1.69b 27.27 ± 1.69c p = 0.46
  Arginine 1.56 ± 0.18a 1.05 ± 0.19b 0.95 ± 0.19b p = 0.87
  Aspartic acid 2.41 ± 0.48a 3.78 ± 0.52b 5.56 ± 0.52c p = 0.31
  Asparagine nd nd nd ---
  Cysteine 0.65 ± 0.15a 1.28 ± 0.16b 2.24 ± 0.16c p = 0.58
  Glutamic acid 44.44 ± 5.96a 91.25 ± 6.45b 120.33 ± 6.45c p = 0.19
  Glutamine 10.70 ± 2.64a 33.40 ± 2.86b 61.15 ± 2.86c p = 0.48
  Glycine 4.94 ± 0.73a 9.74 ± 0.78b 13.23 ± 0.78c p = 0.76
  Proline 3.70 ± 0.35a 2.68 ± 0.38b 2.61 ± 0.38b p = 0.89
  Serine 4.12 ± 0.61a 8.43 ± 0.66b 12.55 ± 0.66c p = 0.69
  Taurine 51.24 ± 2.39a 42.49 ± 2.58b 35.72 ± 2.58c p = 1.00
  Tyrosine 0.68 ± 0.09a 0.95 ± 0.10b 1.02 ± 0.10b p = 0.43
Totals
Essential 13.93 ± 1.09a 17.14 ± 1.17b 20.27 ± 1.17c p = 0.13
Non-essential 136.98 ± 11.35a 216.31 ± 12.26b 282.54 ± 12.26c p = 0.67
All FAAs 150.91 ± 12.00a 233.44 ± 12.97b 302.82 ± 12.97c p = 0.79
  1. 1Data are expressed as Least Squared Means (LSM) ± SEM. Estimates created from Mixed effects model.
  2. 2Classification of FAA based on Dietary Reference Intakes13.
  3. 3Different letters are statistically different from each other.
  4. 4nd = not detectable; below the limit of detection.