Proteome reference map of Lactobacillus acidophilus NCFM and quantitative proteomics towards understanding the prebiotic action of lactitol

Lactobacillus acidophilus NCFM is a probiotic bacterium adapted to survive in the gastrointestinal tract and with potential health benefits to the host. Lactitol is a synthetic sugar alcohol used as a sugar replacement in low calorie foods and selectively stimulating growth of L. acidophilus NCFM. In the present study the whole‐cell extract proteome of L. acidophilus NCFM grown on glucose until late exponential phase was resolved by 2‐DE (pH 3–7). A total of 275 unique proteins assigned to various physiological processes were identified from 650 spots. Differential 2‐DE (DIGE) (pH 4–7) of L. acidophilus NCFM grown on glucose and lactitol, revealed 68 spots with modified relative intensity. Thirty‐two unique proteins were identified in 41 of these spots changing 1.6–12.7‐fold in relative abundance by adaptation of L. acidophilus NCFM to growth on lactitol. These proteins included β‐galactosidase small subunit, galactokinase, galactose‐1‐phosphate uridylyltransferase and UDP‐glucose‐4‐epimerase, which all are potentially involved in lactitol metabolism. This first comprehensive proteome analysis of L. acidophilus NCFM provides insights into protein abundance changes elicited by the prebiotic lactitol.