Table 2 Baseline characteristics for the mothers and their infants selected for breast milk metabolomics

  Maternal Age (years), median (IQR)

34

32 (28, 35)

31 (26, 33)

32 (31, 37)

0.1239^W

  Employed,n(%)

34

30 (88.2)

15 (88.2)

15 (88.2)

1^F

  Education,n(%)

34

0.0005^F

   Primary/junior secondary

9 (26.5)

1 (5.9)

8 (47.1)

   Senior secondary

10 (29.4)

3 (17.6)

7 (41.2)

   Tertiary

15 (44.1)

13 (76.5)

2 (11.7)

  Married,n(%)

34

22 (64.7)

15 (88.2)

7 (41.2)

0.0104^F

  Parity,n(%)

34

0.4132^F

   Primip

8 (23.5)

6 (35.3)

2 (11.8)

   2–4

23 (67.7)

10 (58.8)

13 (76.4)

   > 4

3 (8.8)

1 (5.9)

2 (11.8)

  CD4 count (cells/mm³), median (IQR)

17

377 (242, 497)

  Baby

  Gender, female,n(%)

34

13 (38.2)

7 (41.2)

6 (35.3)

1^F

  Delivery type,n(%)

34

1^F

   Vaginal

28 (82.4)

28 (82.4)

28 (82.4)

   Cesarean section

6 (17.6)

3 (17.6)

3 (17.6)

  Premature delivery,n(%)

34

5 (15.2)

1 (6.3)

4 (23.5)

0.3353^F

  Birth weight (Kg), median (IQR)

34

2.88 (2.5, 3.3)

3.25 (2.7, 3.5)

2.7 (2.5, 3.0)

0.0364^W

  Birth weight <2.5 Kg,n(%)

34

6 (17.6)

2 (11.8)

4 (23.5)

0.6562^F

   Weight-for-age

34

− 1.05 (1.34)

− 0.57 (1.41)

− 1.53 (1.12)

0.0356^T

  Meconium microbiome Shannon diversity, median (IQR)

26

1.66 (1.27, 2.18)

1.89 (1.33, 2.179)

1.32 (1.01, 2.26)

0.1134^W

  Exclusive breastfeeding (6 months),n(%)

34

30 (88.2)

15 (88.2)

15 (88.2)

1^F

  Breastfeeding duration (months), median (IQR)

34

9 (6, 10)

10 (9, 15)

6 (6, 9)

< .0001^W

  Trimethoprim-sulfamethoxazole use (6 months), n(%)

34

19 (55.9)

3 (17.7)

16 (94.1)

< .0001^F

  Antibiotic use (6 months),n(%)

34

25 (73.5)

8 (47.1)

17 (100)

0.0009^F