Strong tight junctions and curtailed inflammatory responses under stressful conditions are key for optimal digestive health. Bacillus-based probiotics are increasingly being used to maintain broilers' health, but their mode of action is often not well-defined. In the present study we used Caco-2 cells as a model for intestinal epithelia and assessed the effect of three Bacillus-based probiotics on intestinal barrier function and intestinal inflammation. Experimental results showed that one of the three tested strains, Bs 29784, significantly reinforced intestinal barrier integrity under basal conditions through an up-regulation of the expression of tight junction's proteins, whereas the others had no or detrimental effects. When Caco-2 cells were pre-treated with Bacillus subtilis strains, the subsequent IL-8 release to various pro-inflammatory signals (IL-1β, deoxynivalenol, or flagellin) was blunted compared to cells that had not been pretreated, but to a different extent depending on the strain of Bacillus used. Bs 29784, was able to significantly decrease IL-8 production in all stressed conditions tested. Mechanistically, Bs 29784 appeared to limit nuclear translocation of NF-κB during IL-1β exposure by preventing IκB degradation. The effects of Bs 29784 were observed independently with supernatant and cells but in a lesser extent than with the combination, indicating that they can thus likely be attributed to both secreted metabolites and cell-associated compounds. Moreover, under inflammatory conditions, Bs 29784 significantly reduced the upregulation of iNOS protein levels further underlining its intestinal anti-inflammatory potential. Our data show that Bacillus-based probiotics may indeed improve digestive health by strengthening intestinal barrier and limiting inflammatory responses and that these properties are strain-dependent.

Patients with multiple cholesterol gallstones are at increased risk of recurrence after nonsurgical therapy, possibly because of fast biliary cholesterol crystallization. Serum apolipoprotein E4 (apo E4) is a risk factor for primary cholesterol gallstone formation as well as recurrence. We examined potential effects of stone number and apolipoprotein E genotype on crystallization and on various crystallization-influencing factors in gallbladder biles of 36 cholesterol stone patients (25 multiple stones: 10 carrying the ε4 allele). Biliary cholesterol saturation, bile salt composition or concentrations of total protein, immunoglobulin (Ig)A, IgG, α₁-acid glycoprotein, haptoglobin, or mucin—all crystallization promoters—did not differ between multiple and solitary stone patients, apparently not explaining different speed of crystallization (crystal observation time 3.5 ± 0.6 days vs. 12.7 ± 2.4 days, respectively; P = .0003). In contrast, biliary aminopeptidase-N activities (2,607 ± 592 mU/mL vs. 947 ± 185 mU/mL; P = .04) were higher and IgM levels (179 ± 39 vs. 65 ± 8 mg/L; P = .09) tended to be higher in the case of multiple stones. Although patients carrying the ε4 allele had similar stone numbers and crystallization as patients without the ε4 allele, their cholesterol saturation index (CSI) was lower (1.08 ± 0.09 vs. 1.54 ± 0.13; P = .01), whereas total protein and bile salt concentrations tended to be higher with preferential taurine-conjugation. In conclusion, fast cholesterol crystallization is associated with multiple stones but not with apolipoprotein E4. Whereas fast crystallization may contribute to high recurrence rates after nonsurgical therapy in case of multiple gallstones, the mechanism for increased risk of gallstone formation in patients carrying the ε4 allele remains unknown.

Background: Lentinan (LNT) may regulate many important physiological functions of human and animals. This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus (RV)-challenged weaned pigs. Methods: Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d (n = 14). RV infection was executed on d 15. After extracting polysaccharides from LNT product, its major monosaccharides were analyzed. Then, LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells. Results: Dietary LNT supplementation supported normal function of piglets even when infected with RV, as reflected by reduced growth performance loss and diarrhea prevalence, and maintained gut immunity (P < 0.05). The polysaccharide was isolated from LNT product, which molecular weight was 5303 Da, and major monosaccharides included glucose, arabinose and galactose. In RV-infected IPEC-J2 cells, this polysaccharide significantly increased cell viability (P < 0.05), and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides (P < 0.05). Conclusion: Those results suggest that LNT administration increases the piglets’ resistance to RV-induced stress, likely by supporting intestinal immunity.

Postbiotics may help strengthen intestinal barrier function. This study assessed the effects of a postbiotic derived from Limosilactobacillus fermentum and Lactobacillus delbrueckii subsp. lactis on epithelial barrier and cytokine production. Human-derived colon tubules were cultured on chips for 15 days. On day 8, the epithelial barrier was disrupted with 0.7 μM afatinib. Postbiotic doses of 5, 10, or 20 mg/mL were added on days 6, 8, 11, and 13. Trans-epithelial electrical resistance (TEER) was measured on days 6, 8, 11, 13, and 15, along with phase contrast imaging. Cytokine levels were measured on day 13. All three postbiotic concentrations resulted in better TEER recovery on day 15 vs. the control (p < 0.001). On day 13, 10 and 20 mg/mL increased TEER (p < 0.001), but only 20 mg/mL did on day 11 (p < 0.05). Phase imaging confirmed the dose-dependent effect. The 20 mg/mL dose more effectively reduced CCL2, CX3CL1, CXCL1, CXCL5, IL-8, IL-11, and IL-4 than the other doses (p < 0.01), and 10 mg/mL more effectively reduced CCL2, CXCL1, CXCL10, IL-10, IL-11, and IL-23 than 5 mg/mL (p < 0.01). In a colonic organoid model, the Lactobacillaceae-derived postbiotic prevented drug-induced epithelial damage, enhanced recovery, and modulated cytokine secretion towards a more anti-inflammatory profile in a dose-dependent manner.