Persistence of Lactobacillus Reuteri DSM17938 in the Human Intestinal Tract: Response to Consecutive and Alternate-Day Consumption with Varying Storage Conditions

Abstract : Probiotic-containing foods are consumed to enhance gastrointestinal (GI) health and immune function. How storage of probiotic-containing foods affects colonization and persistence of probiotics in the GI tract after the stored foods are consumed is undefined. Similarly, the amount or dose of probiotics that must be consumed to achieve colonization and persistence of probiotics in the GI tract is not known. Volunteers ate fresh pudding with Lactobacillus reuteri DSM17938 (L. reuteri; BioGaia AB, Stockholm, Sweden; 10(8) CFU/serving; room temperature less than 1 week followed by freezer) daily (n = 9) or on alternate days (n = 9) over 7 days; or, stored pudding with L. reuteri (10(9) CFU/serving; 37 deg C for 7 days followed by freezer) daily over 7 days (n = 10). Fecal samples were collected daily during probiotic consumption (D1-7) and after dosing ended (D13-15 and D20-22), and analyzed for the presence of L. reuteri. All volunteers who consumed fresh probiotic-containing pudding, and one volunteer who consumed stored probiotic-containing pudding, had detectable L. reuteri during consumption (D1-7). L. reuteri count significantly rose in response to daily consumption and alternate-day consumption of fresh probiotic-containing pudding, and significantly fell in both groups one week after dosing ended. In contrast, L. reuteri count did not rise in response to stored probiotic-containing pudding. The total number of volunteers with detectable L. reuteri one and two weeks after dosing ended was similar in response to daily feeding and alternate-day feeding of fresh probiotic-containing pudding; however, L. reuteri was not detected after dosing ended in response to stored probiotic-containing pudding. Alternate-day probiotic intake achieves equivalent colonization to daily intake, but colonization declines rapidly once dosing stops. Colonization of L. reuteri is achievable with daily or alternate day intake of fresh, but not stored L. reuteri-containing pudding.