Table 2: H2 and CH4 production by rat colonic rings.

Gas production (ppm)a
1 hour24 hours1 hour24 hours

Without added lactose02,280 ± 1,6950.7 ± 0.31.5 ± 0.4
With added lactose034,280 ± 8,9270.8 ± 0.16.3 ± 0.6

One gram of washed rat colonic rings was incubated as described in Methods. Lactose (1.25 g% final concentration) was added where indicated. H2 and CH4 were determined as described previously [1]. The concentration of the gases is expressed as part per million. The results are the average of three experiments, mean ± SD, with six rats in each experiment.