To determine whether Lactobacillus paracasei NCC2461 (ST11) and its spent culture medium (SCM), devoid of live bacteria, improve Trichinella spiralis (Tsp)-induced gut dysmotility patterns in vivo and explore action mechanisms of metabolites present in the SCM by proteomic analysis.
Mice were gavaged with barium and small intestinal motility examined by fluoroscopy and image analysis before, and on day 21 and 28 after Tsp infection. From day 10 to 21 post infection (PI), mice were gavaged with growth media (MRS), 1010 ST11 /ml SCM (Lpa) or SCM alone. Uninfected mice received MRS. Proteomic analysis was performed in jejunal samples on day 21 PI. RANTES, TGFβ and PGE-2 were measured in intestinal tissue on day 28 PI by ELISA.
Regular peristalsis was observed before Tsp infection. On day 21 PI, Tsp-MRS mice showed decreased frequency of small intestinal contractions and increased retroperistalsis. Lpa or SCM treatment normalized altered motility patterns at 21 PI but only Lpa was effective at 28 PI. Proteomics analysis revealed normalization of NO-associated pathways, re-establishment of cytoskeleton organization and restoration of stress/immune response. One week after treatment, Lpa- but not SCM-treated mice had similar frequency of contraction and PI mediator levels than uninfected mice.
Both Lpa and SCM normalized Tsp-induced dysmotility during active treatment but the presence of live bacteria is required for a long lasting effect. Proteomic analysis suggests that the SCM-mediated normalization of PI muscle dysfunction is achieved through the modulation of multiple proteins involved in filament organization and other components of excitation-contraction coupling.
Administration of live probiotics may confer additional beneficial effects for the restoration of muscle function after gastrointestinal infection than its metabolites alone. Proteomics approach may be useful to identify novel therapeutic targets in PI-IBS.