Table 3.

Concentration of metabolites (mM) during the incubation of FOS, inulin and IMMP by faecal inocula from elderly and adults.

Incubation time (h)		Elderly (n = 3)				Adults (n = 3)				Age group × incubation time (P value)
		0	4	10	24	0	4	10	24
FOS	Acetate	0.77 [0.16,1.24]	8.34 [6.21,8.86]	29.38 [23.85,64.55]	33.74 [22.24,51.03]	1.05 [0.86,1.33]	8.31 [7.53,19.11]	54.17 [52.44,57.27]	49.62 [36.91,59.28]	0.469
	Propionate	2.65 [0.61,3.20]	3.83 [2.32,4.47]	6.03 [5.62,7.14]	11.01 [10.03,15.75]*	2.51 [2.31,2.53]	3.93 [3.15,4.70]	6.77 [4.38,7.91]	7.63 [5.06,10.53]	0.171
	Butyrate	0.00 [0.00,0.00]	0.50 [0.12,2.53]	14.29 [5.57,27.58]	41.36 [27.00,43.71]*	0.20 [0.00,0.43]	1.36 [1.00,2.84]	8.96 [5.09,14.09]	8.78 [4.93,26.66]	0.136
	Lactate	0.69 [0.54,0.91]	2.58 [1.72,2.72]	27.40 [7.98,37.34]	0.00 [0.00,13.66]	0.50 [0.27,0.61]	3.54 [3.05,8.60]	32.38 [21.82,34.21]	30.20 [7.12,36.30]	0.255
	Succinate	0.99 [0.71,1.27]	2.01 [1.78,2.59]	6.06 [5.55,8.94]	2.65 [0.99,5.57]	0.60 [0.14,1.30]	3.30 [1.14,4.82]	7.82 [2.19,10.64]	8.33 [2.92,10.13]	0.293
	Isobutyrate	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.45]	0.00 [0.00,0.75]	0.00 [0.00,0.90]	0.00 [0.00,0.50]	0.208
	CH4	0.00 [0.00,0.00]	0.40 [0.09,0.54]	1.31 [0.30,1.45]	1.55 [0.31,7.79]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.208
	H2	0.00 [0.00,0.00]	1.68 [0.79,2.26]	17.92 [7.51,22.45]	8.05 [1.96,13.25]	0.00 [0.00,0.00]	1.76 [1.16,1.93]	5.75 [5.27,14.40]	7.38 [6.55,13.13]	0.32
Inulin	Acetate	0.00 [0.00,0.88]	5.70 [5.38,6.14]	33.81 [29.39,34.34]	37.69 [34.28,55.32]	1.11 [0.89,1.48]	5.64 [5.50,21.88]	53.37 [35.64,57.52]	50.91 [48.09,54.55]	0.293
	Propionate	2.49 [0.58,2.95]	2.69 [2.20,3.89]	8.54 [8.31,9.99]	17.53 [15.05,30.01]	2.33 [2.28,2.65]	4.05 [3.26,4.17]	8.89 [5.47,12.90]	11.56 [6.88,16.43]	0.136
	Butyrate	0.00 [0.00,0.00]	0.50 [0.00,1.25]	30.08 [18.31,30.71]	52.44 [49.71,62.14]	0.00 [0.00,0.00]	1.51 [1.12,3.30]	17.74 [14.13,27.62]	42.21 [39.61,43.39]	0.195
	Lactate	0.67 [0.58,0.76]	1.18 [1.02,1.97]	2.05 [1.66,3.32]	0.00 [0.00,0.00]	0.46 [0.10,0.96]	1.59 [1.18,6.49]	8.11 [3.64,8.91]	0.45 [0.37,1.19]	0.208
	Succinate	0.60 [0.41,1.24]	1.19 [1.09,1.70]	7.64 [7.37,9.73]	6.53 [3.89,9.78]	1.28 [0.32,1.38]	2.45 [0.59,4.51]	6.90 [2.00,10.79]	7.04 [1.60,11.49]	0.439
	Isobutyrate	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.63]	0.00 [0.00,1.01]	0.00 [0.00,0.87]	0.00 [0.00,0.69]	0.317
	CH4	0.00 [0.00,0.00]	0.30 [0.07,0.70]*	1.29 [0.32,3.52]*	6.50 [1.24,9.00] *	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.102
	H2	0.00 [0.00,0.00]	0.83 [0.45,1.74]	20.34 [9.12,25.20]	1.66 [0.09,12.31]	0.00 [0.00,0.00]	1.51 [0.91,1.98]	9.76 [6.07,17.08]	11.12 [9.29,12.62]	0.208
IMMP	Acetate	0.00 [0.00,0.85]	5.38 [5.25,5.97]	32.96 [30.61,37.44]	60.34 [52.14,68.05]	1.10 [0.78,1.23]	6.45 [6.10,7.63]	35.55 [32.04,38.50]	58.93 [57.45,61.55]	0.676
	Propionate	2.49 [0.59,2.94]	4.51 [2.72,5.21]	15.76 [13.67,16.71]	28.53 [24.93,31.53]	2.62 [2.54,2.68]	4.69 [3.69,5.20]	11.90 [8.38,18.93]	18.10 [8.71,34.30]	0.342
	Butyrate	0.00 [0.00,0.00]	0.00 [0.00,1.43]	8.41 [5.87,10.42]	29.37 [26.96,41.61]*	0.00 [0.00,0.38]	1.22 [0.69,2.04]	5.79 [5.59,7.02]	20.84 [15.46,23.72]	0.08
	Lactate	0.73 [0.59,0.82]	1.02 [0.86,1.17]	0.06 [0.00,0.57]	0.00 [0.00,0.00]	0.32 [0.24,0.53]	1.14 [0.52,1.64]	0.00 [0.00,0.16]	0.00 [0.00,0.00]	0.469
	Succinate	1.26 [0.84,1.46]	2.18 [1.28,2.43]	9.20 [8.37,20.06]	10.34 [8.63,21.64]	0.97 [0.69,1.28]	2.84 [1.03,3.50]	22.61 [11.67,24.55]	28.07 [14.28,32.11]	0.317
	Isobutyrate	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,0.00]	0.00 [0.00,1.50]	0.00 [0.00,0.60]	0.00 [0.00,0.00]	0.223
	CH4	0.00 [0.00,0.00]	0.37 [0.15,0.55]*	1.32 [0.29,1.77]*	2.02 [0.56,2.08]*	0.00 [0.00,0.00]	0.02 [0.00,0.07]	0.00 [0.00,0.07]	0.00 [0.00,0.06]	0.08
	H2	0.00 [0.00,0.00]	0.17 [0.11,0.68]	0.17 [0.09,0.24]	0.42 [0.13,1.09]	0.00 [0.00,0.00]	0.67 [0.59,1.93]	0.40 [0.36,1.54]	0.09 [0.05,0.63]	0.08

Data are expressed as median [Q1, Q3] (IQR). Changes in the concentration of each metabolites over time were analyzed using two-way mixed ANOVA, with one between-subjects’ factor (age group) and one within subject factor (incubation time), to uncover the effect of age group (adult vs elderly) over the incubation time period. P-values were corrected for multiple testing by FDR according to Benjamini–Hochberg procedure.

Significant differences between age groups at each time point were highlighted as bold text.

IQR interquatile range.

*Significant between age groups at corresponding time point.