RESUMEN
Salmonella enterica serovar Infantis (S. Infantis) is an intracellular bacterial pathogen. It is prevalent but resistant to antibiotics. Therefore, the therapeutic effect of antibiotics on Salmonella infection is limited. In this study, we used the piglet diarrhea model and the Caco2 cell model to explore the mechanism of probiotic Lactobacillus johnsonii L531 (L. johnsonii L531) against S. Infantis infection. L. johnsonii L531 attenuated S. Infantis-induced intestinal structural and cellular ultrastructural damage. The expression of NOD pathway-related proteins (NOD1/2, RIP2), autophagy-related key proteins (ATG16L1, IRGM), and endoplasmic reticulum (ER) stress markers (GRP78, IRE1) were increased after S. Infantis infection. Notably, L. johnsonii L531 pretreatment not only inhibited the activation of the above signaling pathways but also played an anti-S. Infantis infection role in accelerating autophagic degradation. However, RIP2 knockdown did not interfere with ER stress and the activation of autophagy induced by S. Infantis in Caco2 cells. Our data suggest that L. johnsonii L531 pretreatment alleviates the intestinal damage caused by S. Infantis by inhibiting NOD activation and regulating ER stress, as well as promoting autophagic degradation.
Asunto(s)
Estrés del Retículo Endoplásmico , Salmonella enterica , Animales , Antibacterianos , Autofagia , Proteínas Relacionadas con la Autofagia , Células CACO-2 , Humanos , Proteínas Serina-Treonina Quinasas , PorcinosRESUMEN
Probiotic pretreatment is an effective non-antibiotic strategy for preventing or controlling Salmonella infections. We found that Lactobacillus johnsonii L531, isolated from the colon of a clinically healthy weaned piglet, effectively prevented infection with Salmonella enterica serovar Infantis in a pig model. Newly weaned piglets were intragastrically administered Lactobacillus johnsonii L531 at 1.0 × 1010 CFU/day for 1 week before S. Infantis challenge. Pretreatment with L. johnsonii L531 lessened the severity of diarrhea and ileal inflammation in S. Infantis-infected piglets. Lactobacilli were more abundant in the ileum than jejunum after L. johnsonii L531 pretreatment. Treatment with L. johnsonii L531 reduced the abundance of total bacteria in the ileal mucosa and the production of lipocalin 2 in the jejunum of piglets challenged with Salmonella. Both intestinal morphology and transmission electron microscopy results indicated that L. johnsonii L531 alleviated intestinal tissue damage following S. Infantis challenge, especially in the villus and endoplasmic reticulum (ER). ER stress induced by S. Infantis was attenuated by L. johnsonii L531 treatment. The number of CD4- CCR6+ T cells decreased following S. Infantis challenge, but the percentage of CCR6- IFNγ+ T cells in peripheral blood increased. In intestinal mesenteric lymph nodes, S. Infantis increased the proportion of CCR6+ IFNγ+ T cells, whereas L. johnsonii L531 induced an increase in the proportion of CD4+ CCR6+ T cells in response to S. Infantis infection. Our data thus suggest that L. johnsonii L531 contributes to the maintenance of intestinal homeostasis by modulating T-cell responses and ER stress.
Asunto(s)
Antiinflamatorios/farmacología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Lactobacillus johnsonii/química , Probióticos/farmacología , Salmonelosis Animal/prevención & control , Enfermedades de los Porcinos/prevención & control , Linfocitos T/inmunología , Animales , Salmonelosis Animal/inmunología , Porcinos , Enfermedades de los Porcinos/inmunologíaRESUMEN
Efficient strategies for treating enteritis caused by F4(+) enterotoxigenic Escherichia coli (ETEC)/verocytotoxigenic Escherichia coli (VTEC)/enteropathogenic E. coli (EPEC) in mucin 4 resistant (MUC4 RR; supposed to be F4ab/ac receptor-negative [F4ab/acR(-)]) pigs remain elusive. A low (3.9 × 10(8) CFU/day) or high (7.8 × 10(8) CFU/day) dose of Bacillus licheniformis and Bacillus subtilis spore mixture (BLS-mix) was orally administered to MUC4 RR piglets for 1 week before F4(+) ETEC/VTEC/EPEC challenge. Orally fed BLS-mix upregulated the expression of TLR4, NOD2, iNOS, IL-8, and IL-22 mRNAs in the small intestine of pigs challenged with E. coli. Expression of chemokine CCL28 and its receptor CCR10 mRNAs was upregulated in the jejunum of pigs pretreated with high-dose BLS-mix. Low-dose BLS-mix pretreatment induced an increase in the proportion of peripheral blood CD4(-)CD8(-) T-cell subpopulations and high-dose BLS-mix induced the expansion of CD4(-)CD8(-) T cells in the inflamed intestine. Immunostaining revealed that considerable IL-7Rα-expressing cells accumulated at the lamina propria of the inflamed intestines after E. coli challenge, even in pigs pretreated with either low- or high-dose BLS-mix, although Western blot analysis of IL-7Rα expression in the intestinal mucosa did not show any change. Our data indicate that oral administration of the probiotic BLS-mix partially ameliorates E. coli-induced enteritis through facilitating upregulation of intestinal IL-22 and IκBα expression, and preventing loss of intestinal epithelial barrier integrity via elevating ZO-1 expression. However, IL-22 also elicits an inflammatory response in inflamed intestines as a result of infection with enteropathogenic bacteria.
Asunto(s)
Bacillus/inmunología , Infecciones por Escherichia coli/veterinaria , Intestinos/inmunología , Probióticos/uso terapéutico , Enfermedades de los Porcinos/inmunología , Linfocitos T/inmunología , Animales , Recuento de Linfocito CD4/veterinaria , Linfocitos T CD8-positivos/inmunología , Resistencia a la Enfermedad/inmunología , Escherichia coli Enterotoxigénica/inmunología , Infecciones por Escherichia coli/inmunología , Infecciones por Escherichia coli/prevención & control , Femenino , Interleucinas/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/microbiología , Masculino , Inhibidor NF-kappaB alfa/metabolismo , Porcinos , Enfermedades de los Porcinos/microbiologíaRESUMEN
Although breeding of F4 receptor - negative (F4R(-)) pigs may prevent post-weaning diarrhea, the underlying immunity is poorly understood. Here, various doses of a Bacillus licheniformis and Bacillus subtilis mixture (BLS-mix) were orally administered to F4ab/acR(-) pigs for 1 week before F4 (K88) - positive ETEC/VTEC/EPEC challenge. Administration of BLS-mix increased the percentage of Foxp3(-)IL-10(+) T cells but not of Foxp3(+)IL-10(+) regulatory T (Treg) cells among peripheral blood CD4(+) T cells. A low dose of BLS-mix feeding resulted in increased the expression of IL-6, TNF-α, IL-10, and the transcription factors Foxp3 and T-bet mRNAs in the jejunum. Administration of either a low or high dose BLS-mix also led to an increase in the percentage of CD4(+)Foxp3(+) Treg cells among intraepithelial lymphocytes and CD4(+)IL-10(+) T cells in the small intestinal Peyer's patches and the lamina propria of F4ab/acR(-) pigs following F4(+) ETEC/VTEC/EPEC challenge. The increased number of IL-10-producing CD4(+) T cells was attributed to an increase in the proportion of Foxp3(-)IL-10(+) Treg cells rather than Foxp3(+)IL-10(+) Treg cells. Our data indicate that oral administration of BLS-mix to newly weaned F4ab/acR(-) pigs ameliorates enteritis in an F4(+) ETEC/VTEC/EPEC model; however, induction of IL-10-producing Foxp3(-) Treg cells by BLS-mix administration cannot account for the protection of newly weaned F4ab/acR(-) pigs from F4(+) ETEC/VTEC/EPEC infection, and that excessive generation of CD4(+)IL-10(+) T cells following consumption of BLS-mix during episodes of intestinal inflammation that is caused by enteric pathogens might prohibit clearance of the pathogen. Select probiotic mixtures may allow for tailoring strategies to prevent infectious diseases.
Asunto(s)
Bacillus/química , Infecciones por Escherichia coli/veterinaria , Escherichia coli/fisiología , Probióticos/administración & dosificación , Enfermedades de los Porcinos/terapia , Linfocitos T Reguladores/inmunología , Administración Oral , Animales , Escherichia coli Enteropatógena/fisiología , Escherichia coli Enterotoxigénica/fisiología , Infecciones por Escherichia coli/inmunología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/terapia , Femenino , Intestino Delgado/inmunología , Masculino , Escherichia coli Shiga-Toxigénica/fisiología , Porcinos , Enfermedades de los Porcinos/inmunología , Enfermedades de los Porcinos/microbiología , Linfocitos T Reguladores/metabolismo , DesteteRESUMEN
OBJECTIVE: To investigate the effects of oral contraceptive pretreatment (OCP) in patients with polycystic ovarian syndrome (PCOS) undergoing controlled ovarian hyperstimulation for IVF-ET. METHODS: We randomly divided 85 patients with P-COS undergoing IVF-ET into an OCP (n = 53) and a control group (n = 32), the former received OCP, while the latter did not before the cycle. We retrospectively analyzed the data of the patients for the ovulation promoting effect of OCP and its influence on the incidence of ovarian hyperstimulation syndrome (OHSS) and outcomes of IVF-ET. RESULTS: Compared with the control group, OCP significantly reduced the formation of ovarian cyst (P < 0.05), remarkably increased the duration of gonadotropin stimulation and consumption (P < 0.01) , and markedly raised the percentage of mature ova (87.92% vs 92.85%, P < 0.05). But no significant differences were observed between the two groups in the incidences of moderate and severe OHSS, number of retrieved oocytes, and rates of fertilization, miscarriage and clinical pregnancy. CONCLUSION: OCP for patients with PCOS can help to control the time of ovarian stimulation, improve the synchronism of follicular development, and increase the duration of gonadotropin stimulation and consumption, but cannot change the incidences of moderate and severe OHSS.
Asunto(s)
Anticonceptivos Orales/uso terapéutico , Transferencia de Embrión/métodos , Fertilización In Vitro/métodos , Infertilidad Femenina/terapia , Inducción de la Ovulación , Adulto , Femenino , Humanos , Infertilidad Femenina/etiología , Ovulación , Síndrome del Ovario Poliquístico/complicaciones , Embarazo , Resultado del Embarazo , Estudios RetrospectivosRESUMEN
OBJECTIVE: To explore the postoperative effect of auricular acupuncture on primipara with cesarean in order to promote postpartum rehabilitation. METHODS: A total of 120 primiparas with cesarean were randomly divided into an observation group and a control group, 60 cases in each group. The routine treatment and care after surgery were given in the two groups. On the basis treatment, auricular acupuncture was applied at penqiang (TF5), shenmen (TF4), jiaogan (AH6a), pizhixia (AT4), neishengzhiqi(TF2), pi(CO13), wei(CO4) in the observation group, even-needling technique at all points. The needles were retained for 30 min, 3 times a day, the acupuncture was alternately every other day for 5 days continuously. The postpartum pain, anus exhaust time, incidence of postpartum hemorrhage, urinary retention and constipation, and postpartum average hospitalization day were recorded and compared between the two groups. RESULTS: Twenty-seven cases of postpartum uterine contraction pain (45.0%), 25 cases of wound pain (41.7%), 19 cases of breast distending pain (31.7%) and 11 cases of muscle soreness (18.3%) in the observation group, which was significantly lower than 38 cases (63.3%), 36 cases (60.0%), 30 cases (50.0%) and 21 cases (35.0%) respectively in the control group (P<0.05). The anus exhaust time in the observation group was earlier than that in the control group (P<0.05), and the average hospitalization time was shorter than that in the control group (P<0.05). The incidence of postpartum hemorrhage, urinary retention and constipation in the observation group was lower than that in the control group (P<0.05). CONCLUSION: Auricular acupuncture can effectively relieve postpartum pain in primipara with cesarean, promote postpartum exhaust and shorten hospitalization days, and reduce the incidence of postpartum complications such as postpartum hemorrhage, urinary retention and constipation, it is conducive to postpartum rehabilitation.
Asunto(s)
Acupuntura Auricular , Puntos de Acupuntura , Femenino , Humanos , Paridad , Periodo Posparto , EmbarazoRESUMEN
OBJECTIVE: To explore the effect of auricula-point pressure combined with personalized music therapy on perioperative stress response in primipara. METHODS: A total of 1000 primiparas who were elective for cesarean section were randomly divided into an observation group and a control group, 500 cases in each one. 1 h before surgery and 3 h, 6 h, 12 h and 24 h after surgery, individualized music relaxation intervention was given for 1 h in the two groups. On the basis of the treatment, auricular-point pressure was added at Pizhixia (AT4), Shenmen (TF4), Xin (CO15), Zigong (uterus), Luanchao (ovary), Neishengzhiqi (TF2) in the observation group. Each point was pressed for 1 min each time, repeated once every 15 min, the force is from light to heavy, and it is better to have a feeling of distension, sourness and radiation in the auricle. The scores of anxiety self-rating scale, visual analog scale (VAS), heart rate, systolic blood pressure, thyroid stimulating hormone, cortisol and blood glucose levels were observed in the two groups. RESULTS: A total of 973 primiparas completed the clinical study in the end, including 488 patients in the observation group and 485 patients in the control group. Compared to enrollment, the scores of anxiety self-rating scale before entering the operating room in the two groups were significantly improved (P<0.05), and the observation group was superior to the control group (P<0.05). Entering the operating room and tracheal extubation, the heart rate and systolic blood pressure of the primiparas in the observation group were more stable than those in the control group, and the differences were statistically significant (P<0.05). Entering the operating room, 1 h into the surgery and 3 h after surgery, the thyroid stimulating hormone, cortisol and blood glucose levels of the primiparas in the observation group were significantly better than those in the control group (P<0.05). The VAS scores in the observation group at 6 h, 12 h and 24 h after surgery were lower than those in the control group (P<0.05). CONCLUSION: Auricular-point pressure combined with personalized music therapy can reduce the perioperative stress response in primipara and promote the improvement of psychological, physiological and emotional.
Asunto(s)
Terapia por Acupuntura , Musicoterapia , Atención Perioperativa , Puntos de Acupuntura , Acupuntura Auricular , Cesárea , Femenino , Humanos , Música , Paridad , EmbarazoRESUMEN
Intestinal pathogenic Escherichia coli (InPEC) is a leading cause of postweaning diarrhea (PWD) in pigs. Here, a total of 455 E. coli strains were isolated from small intestinal content or feces from pigs with PWD in 56 large-scale (>500 sows; 10,000 animals per year) swine farms between 2014 and 2016. The frequency of occurrence of selected virulence factors for InPEC pathotypes was detected in 455 isolates by real-time PCR. Sequence types (STs), pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility profiles of 171 E. coli isolates from 56 swine farms were further determined. The heat-labile enterotoxin (LT) was the most common (61.76%), followed by heat-stable enterotoxin (STb) (33.19%), stx2e (21.54%), STa (15.00%), eae (8.98%), cnf2 (5.71%), stx2 (5.71%), F18 (3.25%), and F4 (2.25%) with rates varying by geographic area and year of isolation. Notably, hybrids of E. coli isolates were potentially more virulent, as some InPEC hybrids (virotype F18:LT:eae:stx2e) can rapidly cause cell death in vitro. Genotypic analysis revealed that the most prominent genotype was ST10 (12.87%). The PFGE patterns were heterogeneous but were not ST or virotype related. A total of 94.15% of isolates were multidrug-resistant, with average resistance rates ranging from 90.05% for nalidixic acid to 2.34% for meropenem. Our investigation contributes to establishing the etiology of diarrhea and developing intervention strategies against E. coli-associated diarrheal disease in the future.
RESUMEN
In the current study, we screened Lactobacillus strains isolated from the colon of clinically healthy weaned piglets for potential probiotic properties and isolated Lactobacillus. johnsonii L531, which produced high levels of beneficial metabolites (butyric, acetic, and lactic acid) in vitro. We also evaluated the efficacy of this metabolites-producing probiotic in treating Salmonella. Infantis infection. Oral administration of L. johnsonii L531 to newly weaned piglets significantly decreased levels of Salmonella colonization in colonic and jejunal contents, accelerated the clearance of Salmonella in feces after infection, and reduced S. Infantis translocation to the spleen. Pretreatment with SCFAs-promoting probiotic L. johnsonii L531 significantly ameliorated the depletion of SCFAs induced by S. Infantis infection and led to significantly greater weight gain and better feed conversion ratios compared to piglets challenged only with S. Infantis. These data provide further evidence that SCFAs-promoting probiotic L. johnsonii L531 treatment could be a suitable nonantibiotic alternative for controlling Salmonella infection and maintaining metabolic homeostasis, thereby enhancing the gut health of piglets during the critical weaning period.
Asunto(s)
Ácidos Grasos Volátiles/análisis , Intestinos/química , Lactobacillus johnsonii/fisiología , Interacciones Microbianas , Probióticos/uso terapéutico , Salmonella enterica/patogenicidad , Administración Oral , Animales , Carga Bacteriana , Traslocación Bacteriana , Heces/microbiología , Intestinos/microbiología , Lactobacillus johnsonii/aislamiento & purificación , Probióticos/administración & dosificación , Salmonelosis Animal/microbiología , Bazo/microbiología , Porcinos/microbiología , Destete , Aumento de PesoRESUMEN
Salmonella can cause enteric diseases in humans and a wide range of animals, and even outbreaks of foodborne illness. The aim of this study was to investigate the frequency and distribution of serovars, and antimicrobial resistance in Salmonella isolates from pigs with diarrhea in 26 provinces in China from 2014 to 2016. A total of 104 Salmonella isolates were identified and the dominant serovar was S. 4,[5],12:i:- (53.9%). All Salmonella isolates were resistant to trimethoprim-sulfamethoxazole, and many were resistant to ampicillin (80.8%) and tetracycline (76.9%). Among 104 Salmonella isolates, aac(6')-Ib-cr was the dominant plasmid-mediated quinolone resistance gene (80.8%), followed by qnrS (47.1%). The pulsed-field gel electrophoresis results suggest that the Salmonella isolates from different regions were genetically diverse, and ST34 was the most prevalent. S. 4,[5],12:i:- isolates is the widespread presence of heavy metal tolerance genes. The fact that the same sequence types were found in different regions and the high similarity coefficient of S. 4,[5],12:i:- isolates from different regions indicate the clonal expansion of the isolates, and the isolates carried various antimicrobial resistance genes. The multidrug resistant Salmonella can be widely detected in pigs, which will present a challenge for farm husbandry.
RESUMEN
The high rate of Salmonella enterica serovar Infantis (S. Infantis) infection poses significant risk for the development of non-typhoidal Salmonella gastroenteritis. However, efficient strategies to prevent or treat the infection remain elusive. Here, we explored the effect of the probiotic Lactobacillus rhamnosus GG (LGG) administration in preventing S. Infantis infection in a pig model. Probiotic LGG (1.0 × 1010 CFU/day) was orally administered to newly weaned piglets for 1 week before S. Infantis challenge. LGG pretreatment reduced the severity of diarrhea and alleviated intestinal inflammation caused by S. Infantis. Pre-administration of LGG excluded Salmonella from colonization of the jejunal mucosa but increased the abundance of Bifidobacterium in the feces. LGG promoted the expansion of CD4+ T-bet+ IFNγ+ T cells but attenuated S. Infantis-induced increases in the percentage of CD4+ IFNγ+ T cells and serum interleukin (IL)-22 levels in peripheral blood after S. Infantis challenge. In the small intestine, LGG pretreatment upregulated expression of the transcription factor T-bet but downregulated the S. Infantis-induced increase of CD4+ IFNγ+ T cells in Peyer's patches and IL-7Rα expression in the jejunum. Notably, LGG-treated pigs had enhanced expression of IL-22 and activated STAT3 in the ileum in response to S. Infantis infection. Pretreatment of pigs with LGG also elevated intestinal IL-22-binding protein production in response to S. Infantis challenge. In contrast, LGG consumption reduced the S. Infantis-induced increase in the number of CCL20-expressing cells in the jejunum. Our results suggest that the mechanism by which LGG ameliorates the intestinal inflammation caused by S. Infantis involves the upregulation of T-bet, activation of STAT3, and downregulation of CCL20.
Asunto(s)
Gastroenteritis/prevención & control , Interleucinas/metabolismo , Lacticaseibacillus rhamnosus/inmunología , Probióticos/administración & dosificación , Receptores de Interleucina/metabolismo , Factor de Transcripción STAT3/metabolismo , Salmonelosis Animal/prevención & control , Administración Oral , Animales , Modelos Animales de Enfermedad , Heces/microbiología , Gastroenteritis/patología , Gastroenteritis/terapia , Íleon/microbiología , Mucosa Intestinal/microbiología , Salmonelosis Animal/patología , Salmonelosis Animal/terapia , Porcinos , Interleucina-22RESUMEN
In this study, we investigated the effect of Lactobacillus rhamnosus GG strain (LGG) in ameliorating enteritis in newly weaned pigs following challenge with a monophasic variant of Salmonella enterica serovar Typhimurium (serotyped as 4,[5],12:i:-), which has been linked to disease in humans and livestocks over the past 10 years. In weaned pigs, S. enterica serovar 4,[5],12:i:- induced the mRNA expression of toll like receptor (TLR) 5 and TLR4, while increasing interleukin (IL)-8 and IL-6 mRNA expression in the jejunum. The monophasic variant Salmonella stimulated the expression of nucleotide-binding oligomerization domain-containing protein 1/2 (NOD1/2) mRNA in the ileum, which was accompanied by phosphorylation of IκB-α, an inhibitor of NF-κB, activating the NF-κB pathway and promoting the release of inflammatory cytokines. Oral administration of LGG attenuated the Salmonella-induced increases in the expression of NOD1 mRNA of jejunal and ileal tissues. LGG promoted the secretion of immunoglobulin A in different intestinal segments but did not induce expression of polymeric immunoglobulin receptor. LGG also impeded the activation of the Nod-like receptor protein (NLRP) 6/apoptosis-associated speck-like protein/caspase-1 inflammasome and decreased the production of IL-18 in the ileum during Salmonella infection. In contrast, activation of the NLRP3 inflammasome was not altered. Our data indicate that LGG accelerated the clearance of Salmonella in the early phase of infection and prevented the excessive inflammatory responses in S. enterica serovar 4,[5],12:i:- model. LGG ameliorates inflammation induced by infection with the monophasic variant Salmonella via inhibition of the canonical NF-κB pathway and attenuation of the NLRP6-mediated inflammasome in the intestine.
Asunto(s)
Antiinflamatorios/inmunología , Péptidos y Proteínas de Señalización Intracelular/inmunología , Lacticaseibacillus rhamnosus/inmunología , Salmonelosis Animal/prevención & control , Salmonella typhimurium/inmunología , Animales , Citocinas/inmunología , Intestinos/inmunología , Intestinos/microbiología , Lacticaseibacillus rhamnosus/fisiología , Salmonelosis Animal/inmunología , Salmonelosis Animal/microbiología , PorcinosRESUMEN
Salmonella enterica serovar Infantis (S. Infantis) is a common source of foodborne gastroenteritis worldwide. Here, Lactobacillus rhamnosus GG (LGG) was administrated to weaned piglets for 1 week before S. Infantis challenge. S. Infantis caused decreased ileal mucosal microbiota diversity, a dramatic Lactobacillus amylovorus bloom, and decreased abundance of Arsenicicoccus, Janibacter, Kocuria, Nocardioides, Devosia, Paracoccus, Psychrobacter, and Weissella. The beneficial effect of LGG correlated with the moderate expansion of L. amylovorus, L. agilis, and several members of the phyla Proteobacteria, Firmicutes, and Bacteroidetes. S. Infantis translocation to the liver was decreased in the LGG-pretreated piglets. An in vitro model of LGG and S. Infantis co-incubation (involving the porcine intestinal epithelial cell line IPEC-J2) was established, and nalidixic acid was used to kill the extracellular S. Infantis. LGG suppressed the initial S. Infantis invasion in the IPEC-J2 cells and deceased the rate of cell death. LGG inhibited S. Infantis-induced autophagy and promoted epidermal growth factor receptor (EGFR) and Akt phosphorylation in both the ileum and IPEC-J2 cells. Our findings suggest that LGG inhibited S. Infantis-induced autophagy by promoting EGFR-mediated activation of the negative mediator Akt, which, in turn, suppressed intestinal epithelial cell death and thus restricted systemic S. Infantis infection. LGG can restore the gut microbiota balance and preserve the autophagy-related intestinal epithelial barrier, thereby controlling infections.
RESUMEN
Enterotoxigenic Escherichia coli (ETEC) are important intestinal pathogens that cause diarrhea in humans and animals. Although probiotic bacteria may protect against ETEC-induced enteric infections, the underlying mechanisms are unknown. In this study, porcine intestinal epithelial J2 cells (IPEC-J2) were pre-incubated with and without Lactobacillus rhamnosus ATCC 7469 and then exposed to F4+ ETEC. Increases in TLR4 and NOD2 mRNA expression were observed at 3 h after F4+ ETEC challenge, but these increases were attenuated by L. rhamnosus treatment. Expression of TLR2 and NOD1 mRNA was up-regulated in cells pre-treated with L. rhamnosus. Pre-treatment with L. rhamnosus counteracted F4+ ETEC-induced increases in TNF-α concentration. Increased PGE2. concentrations were observed in cells infected with F4+ ETEC and in cells treated with L. rhamnosus only. A decrease in phosphorylated epidermal growth factor receptor (EGFR) was observed at 3 h after F4+ ETEC challenge in cells treated with L. rhamnosus. Pre-treatment with L. rhamnosus enhanced Akt phosphorylation and increased ZO-1 and occludin protein expression. Our findings suggest that L. rhamnosus protects intestinal epithelial cells from F4+ ETEC-induced damage, partly through the anti-inflammatory response involving synergism between TLR2 and NOD1. In addition, L. rhamnosus promotes EGFR-independent Akt activation, which may activate intestinal epithelial cells in response to bacterial infection, in turn increasing tight junction integrity and thus enhancing the barrier function and restricting pathogen invasion. Pre-incubation with L. rhamnosus was superior to co-incubation in reducing the adhesion of F4+ ETEC to IPEC-J2 cells and subsequently attenuating F4+ ETEC-induced mucin layer destruction and suppressing apoptosis. Our data indicate that a selected L. rhamnosus strain interacts with porcine intestinal epithelial cells to maintain the epithelial barrier and promote intestinal epithelial cell activation in response to bacterial infection, thus protecting cells from the deleterious effects of F4+ ETEC.