TABLE 2.
Intervention studies investigating colonic adaptation in humans after a lactose-feeding period
| Study population | n | Age | Intervention | Result | Reference |
|---|---|---|---|---|---|
| Lactose-malabsorbing African Americans | 22 | 13–39 y | Gradually increased daily lactose intake for 6–12 wk until tolerated dose was reached | Breath H2 concentration <5 ppm in 4 of 22 subjects | (67) |
| Lactose-malabsorbing subjects | 9 | 30 y (mean) | Gradually increased daily lactose intake for 16 d from 0.2 to 1.0 g lactose/kg body weight | Increase in fecal β-galactosidase activity | (68) |
| Lactose-malabsorbing subjects | 20 | 30 y (mean) | Gradually increased daily lactose intake for 10 d from 0.6 g to 1.0 g lactose/kg body weight | Decrease in breath H2 concentrations | (68) |
| Lactose-malabsorbing subjects | 24 | 20–47 y | 17 g lactose 2 times/d for 14 d | Increased fecal β-galactosidase activity and decreased breath H2 concentrations | (69) |
| Lactose-malabsorbing African-Americans girls | 14 | 11–15 y | 33 g lactose/ d for 21 d | Decrease in breath H2 concentrations | (70) |
| Healthy Sicilian man | 1 | 32 y | Decreased daily lactose intake from 28.1 to 1.5 g for 2–3 wk and then increased daily lactose intake to 53 g | Increase in breath H2 concentration followed by a decrease after reintroducing high daily lactose intake | (71) |
| Lactase-deficient subjects | 23 | 32 ± 9 y | 25 g lactose 2 times/d for 14 d | Increased fecal Bifidobacteria counts | (73) |
| Lactase-persistent subjects | 18 | 26 ± 7 y | 25 g lactose 2 times/d for 14 d | No changes in fecal bacterial counts | (73) |