Liu, Haoyu
- Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences
Abstract
The mechanism underlying the dose effect of probiotics on ameliorating diarrhea has not been fully elucidated. Here, low (1 x 10(9) CFU/ml) or high (1 x 10(11) CFU/ml) doses of Lactobacillus rhamnosus ATCC 7469 were administered orally to piglets for 1 week before F4 (K88)-positive enterotoxigenic Escherichia coli (F4(+) ETEC) challenge. Administration of a low, but not a high, dose of L. rhamnosus decreased the percentage of CD3(+)CD4(+)CD8(-) T cells in the peripheral blood. Notably, transiently increased serum concentrations of interleukin-17A (IL-17A) were observed after F4(+) ETEC challenge in pigs pretreated with a high dose of L. rhamnosus. Administration of L. rhamnosus increased the percentage of the small intestinal lamina propria CD3(+)CD4(+)CD8(-) cells and Peyer's patch CD3(+)CD4(-)CD8(-) and CD3(-)CD4(-)CD8(+) cells. The percentage of ileal intraepithelial CD3(+)CD4(-)CD8(+) cells increased only in the high-dose piglets. Administration of L. rhamnosus downregulated expression of ileal IL-17A after F4(+) ETEC challenge but had no effect on expression of gamma interferon (IFN-gamma), IL-12, IL-4, and FOXP3 mRNA in the small intestine. Expression of jejunal IL-2, ileal transforming growth factor beta 1 (TGF-beta 1), and ileal IL-10 was upregulated in the low-dose piglets after F4(+) ETEC challenge. Our findings suggest that amelioration of infectious diarrhea in piglets by L. rhamnosus is associated with the generation of lamina propria CD3(+)CD4(+)CD8(-) T cells, the expansion of Peyer's patch CD3(+)CD4(-)CD8(-) and CD3(-)CD4(-)CD8(+) cells, and the attenuation of F4(+) ETEC-induced increase in CD3(+)CD4(+)CD8(+) T cells in the small intestine. However, consumption of high doses of L. rhamnosus may increase levels of serum IL-17A after F4(+) ETEC challenge, thus eliciting a strong proinflammatory response.
Published in
Applied and Environmental Microbiology
2014, volume: 80, number: 5, pages: 1787-1798
Publisher: AMER SOC MICROBIOLOGY
SLU Authors
UKÄ Subject classification
Microbiology
Publication identifier
- DOI: https://doi.org/10.1128/AEM.03668-13
Permanent link to this page (URI)
https://res.slu.se/id/publ/67673