. 2022 Jul 6;9:920362. doi: 10.3389/fnut.2022.920362

TABLE 2.

Fecal pH, total concentration of lactate, and relative proportion of individual short-chain fatty acids at 3 and 6 months of age.

	3 months				6 months

	CG	TG1	TG2	HMG	CG	TG1	TG2	HMG
Fecal pH¹	6.49^a [6.30; 6.68]	6.05^b [5.87; 6.24]	5.82^b [5.63; 6.00]	5.95^b [5.66; 6.24]	6.57^a [6.34; 6.81]	6.14^b [5.90; 6.37]	5.66^c [5.44; 5.88]	5.19^d [4.85; 5.52]
Lactate (umol/g)¹	2.38^a [1.69; 3.35]	4.64^b [3.34; 6.44]	4.73^b [3.41; 6.57]	4.63^b [2.81; 7.63]	0.68^a [0.44; 1.07]	1.98^b [1.29; 3.04]	1.77^b [1.18; 2.66]	4.58^c [2.46; 8.53]
Acetate (%)²	77.1 (12.0)^a 32.6; 98.4	81.8 (9.8)^b 53.7; 99.4	81.2 (10.7)^b 43.9; 99.1	89.2 (9.6)^c 54.7; 99.3	75.3 (10.9)^a 44.4; 94.3	77.4 (12.3)^a,b 8.6; 99.5	79.4 (9.8)^b 41.2; 97.5	86.9 (11.6)^c 44.2; 98.7
Butyrate (%)³	2.76^a [2.20; 3.47]	1.69^b [1.32; 2.17]	1.94^b [1.54; 2.43]	1.41^b [1.00; 1.98]	3.73^a [2.97; 4.70]	2.59^a,b [1.93; 3.47]	2.47^b [1.95; 3.13]	1.43^c [0.94; 2.16]
Isobutyrate (%)³	0.66^a [0.53; 0.83]	0.34^b [0.27; 0.42]	0.32^b [0.26; 0.40]	0.25^b [0.19; 0.34]	0.80^a [0.64; 1.01]	0.60^a [0.47; 0.76]	0.37^b [0.29; 0.47]	0.25^c [0.17; 0.36]
Propionate (%)³	12.6^a [11.0; 14.5]	10.4^a [9.0; 12.0]	10.4^a [8.9; 12.2]	3.7^b [2.6; 5.3]	13.9^a [12.1; 16.1]	12.1^a [10.0; 14.6]	12.6^a [11.1; 14.3]	5.7^b [4.2; 7.7]
Isovalerate (%)³	0.53^a [0.43; 0.66]	0.28^b [0.23; 0.35]	0.28^b [0.23; 0.33]	0.27^b [0.21; 0.36]	0.58^a [0.46; 0.73]	0.43^a [0.34; 0.55]	0.29^b [0.23; 0.36]	0.22^b [0.17; 0.29]
Valerate (%)²	0.33 (0.91)^a 0.02; 6.65	0.21 (0.48)^b 0.02; 3.91	0.23 (0.79)^a,b 0.03; 8.11	0.31 (0.41)^a 0.05; 2.64	0.37 (0.72)^a 0.04; 5.13	0.27 (0.70)^b,c 0.02; 5.96	0.30 (0.60)^a,b 0.03; 3.85	0.23 (0.37)^c 0.04; 1.76

¹Values are adjusted means [95% confidence intervals]. For lactate, absolute concentrations in the feces based on dry matter are reported.

²Values shown are mean (SD); Min, Max for the relative proportion to total short-chain fatty acid concentration.

³Values shown are geometric means [95% confidence intervals] for the relative proportion to total short-chain fatty acid concentration.

Values without a common superscript letter within one timepoint are significantly different from each other (P < 0.05 based on pairwise comparison using ANCOVA models adjusted for baseline value of the measure of interest or Wilcoxon test for valerate). At 3/6 month of age, CG, n = 127/101; TG1, n = 133/102; TG2, n = 135/113; HMG, n = 56/51 for fecal pH; CG, n = 115/89; TG1, n = 125/95; TG2, n = 125/105; HMG, n = 54/45 for lactate; CG, n = 114/81; TG1, n = 122/84; TG2, n = 119/98; HMG, n = 54/46 for acetate, butyrate, isobutyrate, propionate, isovalerate, and valerate. CG, control group; TG1, test group 1 (1.5 g HMOs/L); TG2, test group 2 (1.5 g HMOs/L); HMG, human milk-fed group; HMOs, human milk oligosaccharides.