Randomised, double-blind and placebo-controlled study of the effect of a synbiotic dairy product on orocecal transit time in healthy adult women.

OBJECTIVE To evaluate oro-cecal intestinal transit time (ITT) before and after administration of a dairy product containing Bifidobacterium BB12, Lactobacillus casei CRL 431 and fiber in healthy women. METHODS A prospective, randomised, double-blind and cross-over study with a 4-phase design (run-in: time 0 [T0], two intervention periods: time 1 [T1] and time 3 [T3] and a wash-out: time 2, [T2]) was performed. Participants were asked about bowel movement and fiber consumption. ITT was assessed by the carmine red dye method. RESULTS Mean age was 40.7 years (n = 102 healthy women; 83 completed the study). In women with initial ITT (IITT) ≥ 48 h consuming the synbiotic product, mean IITT and final ITT (FITT) was 86.9 ± 38.5 h and 51.2 ± 29.8 h (-40.9%), as compared to women consuming the control yoghurt (IITT, 80.8 ± 31.7 h; FITT, 69.5 ± 31.5 h; -13.8%) (p = 0.001). IITT in women with functional constipation consuming the control yoghurt was 57.0 ± 30.0 h; such figure increased 2.8 h after yoghurt consumption (FITT, 59.8 ± 3 0.2 h; +4.9%). Conversely, IITT in women who received the synbiotic yoghurt was 69.0 ± 49.6 h, with a -27.5% decrease 19 h later (FITT, 50.0 ± 27.5 h; p = 0.023). Enteric lactic flora stabilization was significantly higher in women who initially consumed the synbiotic product (p < 0.1). CONCLUSION ITT decreased significantly after consumption of the synbiotic product. Such beneficial effect was more evident in women with IITT ≥ 48 h and with functional constipation.