The purpose of the present investigation was to study the in vivo survival of the probiotic strain Lactobacillus plantarum 2035 during passage through the gastrointestinal tract and potential adhesion in intestinal mucosa using Wistar rats as an experimental model. Thus, the study was divided in two experiments. At experiment 1, 15 rats were randomly assigned into 3 groups of 5 animals each. XA Ringer’s solution containing free L. plantarum 2035 cells (9-10 logCFU/ml) was administered at a dose of lml/rat/day for 1, 3, or 7 days by intragastric gavage using a blunt-ended needle. Feces were collected at various timepoints (at 12h, 24h, 36h, 48h, 72h, 96h, and 120h) and the lactobacilli levels were monitored using serial dilutions and microbiological analysis. Subsequently, L. plantarum 2035 strain was identified by strain- specific multiplex PCR assay. Similarly, at experiment 2, 36 rats were randomly assigned into 4 groups of 9 animals each and the above probiotic formulation (9-10 logCFU/ml) was administered orally at a dose of 1ml/rat/day for 1, or 7 days. 24 and 48h post administration, intestinal content and tissue samples from distinctive parts (duodenum, jejunum, ileum, cecum, and colon), were collected and subjected to microbiological and molecular analysis, as described above. The results showed that L. plantarum 2035 was detected in rat feces 48h post administration at levels > 6 logCFU/g (minimum levels for conferring a probiotic effect). Moreover, L. plantarum 2035 was detected in both cecum and colon contents at levels > 7 logCFU/g at 24h post administration. Finally, L. plantarum 2035 was detected at cecum and colon intestinal tissues at levels > 6 logCFU/g and > 5 logCFU/g, respectively, after single-dose of probiotic formulation at 24h post administration and at levels 5 logCFU/g and > 6 logCFU/g, respectively, after daily administration for 7 days of probiotic formulation at 24h post administration. To conclude, L. plantarum 2035 survived during passage through the gastrointestinal tract but the ability to adhere to intestinal mucosa is relatively poor because adhesion lasts no longer than 24h post administration. Therefore, daily consumption of the probiotic culture is necessary in order to maintain cell levels above the minimum concentration (> 6 logCFU/g) for a beneficial effect.
107 σ.
Βιβλιογραφία: σ. 82-107
Democritus University of Thrace
