After 3-4 days of anaerobic culture (37°C) the numbers of Selleck GDC-0068 colony forming units (CFU/ml) on the plates were enumerated and were verified as Lactobacillus spp. based on colony morphology and Gram staining. Table 1 Composition of the chemically defined medium (CDM) used to culture the Lactobacilli. Component (g/L) Potassium hydrogen phosphate 3.1 di-ammonium

hydrogen citrate 2.0 Potassium dihydrogen phosphate 1.5 Ascorbic acid 0.5 Potassium acetate 10 Tween 80 – 1.0 Heptahydrated magnesium sulphate 0.5 Hydrated manganese sulphate selleck compound 0.02 Cobalt sulphate 0.5 Calcium Nitrate 1.0 Para-aminobenzoic acid 0.002 Biotin 0.01 Folic acid 0.002 Guanine 0.01 Thymine 0.1 Cytidine 0.1 2′-deoxyadenosine 0.1 2′-deoxyuridine 0.1   (ml/L) Non-Essential Amino Acids Solution1 500 Essential Amino Acids Solution1 63.5 Vitamin Solution1 200 1 Purchased from Invitrogen, Carlsbad, CA Preparation of supernatants from the

Lactobacillus spp. cultures Based on the growth responses and reduced inhibition of glucose accumulation (see the Results section), L. acidophilus were cultured using CDM-fructose. Aliquots (100 ml) of the CDM-fructose medium were collected at the start of the growth phase (32 h), the mid point of the growth phase (48 h), and at the start of the stationary phase (72 h). For the remaining four species of probiotic Lactobacilli, aliquots of the culture medium were collected after KPT-330 order 72 h of cultivation. The culture media were centrifuged (11,180 × g; 15 min; 4°C) to sediment the bacteria. A portion of N-acetylglucosamine-1-phosphate transferase the cell-free supernatant was heated to 100°C in boiling water for 15 min to prepare a heated supernatant. The pH of the heated and unheated supernatants had declined to 4.3-4.5 and was adjusted to 7.4 with NaOH (10 M) to match the pH of the DMEM used to culture the Caco-2 cells. The osmolarity of the supernatants was measured (Wescor, Logan, UT) and was adjusted to 400 mOsm to similarly correspond with the DMEM. The heated and unheated

supernatants were then filter sterilized (0.2 μm) and stored at 4°C until used (<1 week). The sedimented L. acidophilus after removal of the supernatant was suspended in HBSS with 25 mM mannitol to determine if direct interactions between the bacteria and the Caco-2 cells would alter glucose uptake. Glucose Uptake Assay by Caco-2 Cells Caco-2 cells stably transfected to overexpress SGLT1 [35] (graciously provided by Dr. Jerrold R. Turner) were used between passages 22 to 30. Although Caco-2 cells are of colonic origin, they express enterocyte characteristics. Therefore, Caco-2 cells were considered a suitable model for obtaining insights into the non-genomic responses of the intestinal epithelium to bacterial metabolites.