- Sixty-four breastfed newborns were randomized to four groups: 1) control; 2) L-aspartic acid; 3) enzymatically hydrolyzed casein (EHC); or 4) whey/casein (W/C). Each of the intervention supplements were given as six doses per day (5 mL per dose) for the first
week. L-Aspartic acid and EHC inhibit ß-glucuronidase.1
- The L-aspartic acid, EHC, and W/C groups had significantly lower transcutaneous bilirubin levels on days 3 to 7. At the bilirubin peak (day 4), treatment group levels were 75.8%, 69.6%, and 69.2% of control values (control mean: 8.53 mg/dL) for the L-aspartic acid, EHC, and W/C groups, respectively.
- Overall fecal bile pigment excretion was significantly higher than control values in the L-aspartic acid (P < .001) and W/C (P = .0014) groups; the L-aspartic acid group excreted more fecal bile pigments than did the control group on days 4 to 6, and the W/C group excreted more bile pigments than did the control group on days 2 to 4. Bile pigment fecal excretion did not differ significantly between the L-aspartic acid and EHC groups.
- Seventeen of the subjects were in a risk zone above the low-risk zone within the first 48 hours after birth (6 in the control group, 5 in the L-aspartic acid group, 1 in the EHC group, and 5 in the W/C group). The combined inhibitor groups had a significantly shorter decline time than the combined no-inhibitor groups. Only 1 subject in the entire study was in the highest (>95th percentile) risk zone (age: 22.7 hours).