Figure 4.

Lactobacillus acidophilus and Bifidobacterium lactis promote F. prausnitzii growth in vitro and in ex vivo. All relative DNA level were calculated by tested value/the 4th h control value. The L. acidophilus and B. lactis were sub-cultured in BHIS broth and incubated until the bacterial density reached OD ≥ 0.5 (5 × 10⁷/μL). Then 100 μL of culture media was added in 5 mL RPMI-1640 (A) or 20 μL in 1 mL cecum fluid (B) and incubated for 24 h. After filtration, 100 μL of supernatant was added in 30 mL YCFA broth with F. prausnitzii (APC 918/95b) co-cultured for 4, 8, and 12 h. (C) F. prausnitzii cultured in YCFA with BHIS or cecum fluid only. (D) The equal-sized cecum tissue was co-cultured with 3 mL RPMI medium with or without L. acidophilus and B. lactis for 24 h. The 100 μL supernatants was added in 30 mL YCFA broth with F. prausnitzii co-cultured for 4, 8, and 12 h. The relative abundance of F. prausnitzii were measured as the percentage of total bacteria DNA copy numbers by real-time PCR. All tests were triplet.