Transport of valine across the small intestinal epithelium in pigs fed different valine levels and <italic>Bacillus subtili</italic>s.

Summary: Mutants of <italic>Bacillus subtilis</italic> overproducing valine (<italic>B. subtilis </italic>VAL) could be an approach to supply pigs dietary valine (Val). In the study, 18 gilts were fed: (i) negative diet with a standardized ileal digestible (SID) Val:Lys of 0.63:1 (Neg); (ii) Neg added <italic>B. subtilis </italic>VAL (1.28 × 1011 cfu/kg as‐fed) or; (iii) Neg added L‐Val to a Val:Lys of 0.69:1. Using the Ussing chamber method, the study aimed to investigate whether (i) the diets affect intestinal transport of additions of 0, 5, 10 or 20 mmol Val/L from the mucosal to the serosal side and (ii) the <italic>B. subtilis </italic>VAL contributes to a net transport of Val produced in situ. The results showed that the Isc (ΔIscVal) and release of Val to the serosal side solution (Srel; μmol cm−2 min−1) increased with Val addition (linear and quadratic, <italic>p </italic><<italic> </italic>.0001) but was similar for 5, 10 or 20 mmol Val/L and not affected by diet. No net transport of in situ produced Val by <italic>B. subtilis </italic>VAL was detected. In conclusion, feeding a Val‐deficient diet with or without <italic>B. subtilis </italic>VAL or a Val sufficient diet did not affect the Val transport across intestinal epithelia. No in situ Val production by <italic>B. subtilis </italic>VAL was observed in the Ussing chambers. [ABSTRACT FROM AUTHOR]