The Lactic Acid Bacteria from Fermented Milk: Survival during Gastric Transit and Duodenal Delivery Rate

Park, Min Jung; Ko, Byung Sung; Kim, Joo Sung; Jung, Hyun Chae; Song, In Sung; Lee, Jung Hee; Baek, Young Jin

Abstract

BACKGROUND/AIMS: The gastric acidity has been known as a powerful inhibitor of ingested lactic acid bacteria (LAB), but the evidences are largely based on in vitro studies. We intended to evaluate the LABs' survival during gastric transit and their duodenal delivery rate in human.
METHODS
Twenty-eight volunteers (age range, 24-31 years; M:F=14:14) were enrolled and allocated into two groups. One group ingested fermented milk only (without-meal group) and the other group consumed fermented milk with a test meal (with-meal group) via nasogastric tube. The pH and concentration of LAB in gastric aspirates of the two groups were measured every 30 min for 3 hr after ingestion. Additionally, gastric emptying time of fermented milk was determined and it was used to calculate the duodenal delivery rate of LAB.
RESULTS
The basal and post-ingestion pH profiles showed no significant difference. The two groups didn't show any significant difference in their LAB concentrations. The mean duodenal delivery rates of B. longum, L. acidophilus, S. thermophilus were 39%, 59%, 48% in the without-meal group and 47%, 59%, 49% in the with-meal group, respectively.
CONCLUSIONS
Although the concentrations of LAB in the human stomach decreases with exposure time, a considerable amount of LAB can be delivered to duodenum. Moreover, the doudenal delivery rates of LAB are not related with the ingestion of meal.