Oxalobacter sp. reduces urinary oxalate excretion by promoting enteric oxalate secretion  M. Hatch, J. Cornelius, M. Allison, H. Sidhu, A. Peck, R.W. Freel  Kidney International  Volume 69, Issue 4, Pages 691-698 (February 2006) DOI: 10.1038/sj.ki.5000162 Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 1 Unidirectional and net transepithelial fluxes of oxalate across isolated, short-circuited segments of the distal colon from rats non-colonized (n=10) and artificially colonized rats (n=6) fed a diet containing 1.5% oxalate/0.5% calcium for a period of 9 days. An asterisk indicates a significant difference between the groups. Isc and transepithelial conductance (GT) were not affected by colonization (Isc=4.0±0.3 μEq/cm2/h and GT=13.7±0.8/mS/cm2 in non-colonized rats). For comparison, fluxes across the distal colon of non-colonized rats (n=7) fed the standard Purina 5001 chow (contemporary controls) are presented. Isc and GT measured in the distal colon of the latter group was 5.0±0.5 μEq/cm2/h and 11.3±0.8 mS/cm2. Kidney International 2006 69, 691-698DOI: (10.1038/sj.ki.5000162) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 2 Unidirectional and net transepithelial fluxes of oxalate across isolated, short-circuited segments of the distal colon from non-colonized rats (n=8) and naturally colonized rats (n=13) fed a diet containing 0.5% oxalate/0.5% calcium for a period of 9 days. An asterisk indicates a significant difference between the groups. Isc and GT were not affected by colonization (Isc=3.8±0.3 μEq/cm2/h and GT=9.8±0.6 mS/cm2 in NC rats) or by the diet (compared with results of controls in Figure 1). Kidney International 2006 69, 691-698DOI: (10.1038/sj.ki.5000162) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 3 Unidirectional and net transepithelial fluxes of oxalate across isolated, short-circuited segments of the distal colon from artificially colonized rats fed a diet containing 0.5% oxalate/0.01% calcium (n=7) or a diet containing 0.5% oxalate/1.2% calcium (n=7) for a period of 30 days. An asterisk indicates a significant difference between the group fed 1.2% calcium and a group of non-colonized rats fed the standard chow (comparison with results in Figure 1 for non-colonized rats fed the standard chow which contains 0.95% calcium). Isc and GT were not affected by colonization (Isc=4.5±0.3 μEq/cm2/h and GT=11.0±0.4 mS/cm2 in colonized rats fed 0.01% calcium) or by the calcium content of the diet (compared with results of controls in Figure 1). Kidney International 2006 69, 691-698DOI: (10.1038/sj.ki.5000162) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 4 Unidirectional and net transepithelial fluxes of oxalate across isolated, short-circuited segments of the distal colon from artificially colonized rats with a unilateral nephrectomy given different three treatment regimens for 14 days. (1) Diet containing 0.5% oxalate/0.5% calcium only (Ox, n=6). (2) Diet containing no oxalate/0.5% calcium and 0.75% ethylene glycol in the drinking water (EG, n=6). (3) Diet containing 0.5% oxalate/0.5% calcium and 0.75% ethylene glycol in the drinking water (Ox+EG, n=6). There are no significant differences among the groups in fluxes or electrical characteristics. An asterisk indicates a significant difference when comparisons are made between each group and the appropriate group of non-colonized rats fed the standard chow (data provided for distal colon in Figure 1). Kidney International 2006 69, 691-698DOI: (10.1038/sj.ki.5000162) Copyright © 2006 International Society of Nephrology Terms and Conditions

Figure 5 Unidirectional and net transepithelial fluxes of oxalate across isolated, short-circuited segments of the distal colon from unilaterally nephrectomized rats (not colonized) fed standard chow and provided 0.75% ethylene glycol for 5 days. Capsules containing Oxalobacter lysate (n=6), or placebo capsules (n=9) were administered twice on each day. An asterisk indicates a significant difference between the groups. Isc was higher in the lysate-treated group (4.3±0.6 μEq/cm2/h) compared to placebo (3.0±0.2 μEq/cm2/h). GT in the experimental groups was not significantly different from each other or from control rats fed standard chow (data provided in Figure 1). Kidney International 2006 69, 691-698DOI: (10.1038/sj.ki.5000162) Copyright © 2006 International Society of Nephrology Terms and Conditions