Table 1

TER across HT29-MTX monolayers depends on temporal and environmental factors including SCFAs in reactor effluents

Experimental period


Stab

Sal

Ecol I

Ecol II

Bif

Inulin


R1


TER

1-3 h

247 ± 24a

144 ± 24bc

143 ± 22bc

114 ± 14c

167 ± 34b

121 ± 13bc


24 h

127 ± 23a

69 ± 20b

55 ± 11b

36 ± 4b

130 ± 47a

65 ± 14b


SCFAs* (A:P:

    B
)

138 ± 6a

(54:11:

    34
)

179 ± 6a

(44:7:

    50
)


R2


TER

1-3 h

266 ± 19a

135 ± 29b

144 ± 17b

96 ± 4c

158 ± 8b

142 ± 29b


24 h

205 ± 34a

74 ± 17c

52 ± 4cd

34 ± 8d

115 ± 19b

87 ± 11bc


SCFAs* (A:P:

    B
)

172 ± 6b

(54:14:

    32
)

245 ± 6b

(45:12:

    43
)


R3


TER

1-3 h

240 ± 24a

124 ± 30bc

141 ± 16b

91 ± 6c

145 ± 8b

121 ± 30bc


24 h

190 ± 37a

75 ± 17cd

77 ± 13c

32 ± 11d

119 ± 30b

91 ± 25bc


SCFAs* (A:P:

    B
)

180 ± 13b

(55:14:

    31
)

234 ± 11b

(46:11:

    4
3)


Mean transepithelial electrical resistance (TER; expressed in Ω cm2) ± SD were measured after incubation of HT29-MTX cell monolayers for 1-3 h (N = 18) and 24 h (N = 6) with effluents retained from (R1) proximal, (R2) transverse and (R3) distal colon reactors of F1 and F2 during the last three days of each experimental period. Values with different letters in a row of the same reactor are significantly different according to the Tukey-Kramer-HSD test (P < 0.05). *No treatment effects (except for inulin addition) were detected on total short chain fatty acid (SCFA) concentrations (expressed in mM). Mean SCFA concentrations ± SD and (A) acetate: (P) propionate: (

    B
) butyrate ratios measured during the last three days of non-inulin (N = 33) and inulin (N = 3) periods are therefore presented. Values with different letters in the same column of different reactors are significantly different with the Tukey-Kramer-HSD test (P < 0.05). (Stab) initial system stabilization periods, (Sal) Salmonella infection periods, (Ecol) E. coli L1000 treatments, (Bif) B. thermophilum RBL67 treatments, (Inulin) prebiotic inulin treatment.

Zihler et al. BMC Microbiology 2011 11:264   doi:10.1186/1471-2180-11-264

Open Data