Coumarin derivatives ameliorate the intestinal inflammation and pathogenic gut microbiome changes in the model of infectious colitis through antibacterial activity.

Coumarin, a phenolic compound, is a secondary metabolite produced by plants such as Tanga and Lime. Coumarin derivatives were prepared via Pechmann condensation. In this study, we performed in vitro and in vivo experiments to determine the antimicrobial and gut immune-regulatory functions of coumarin derivatives. For the in vitro antimicrobial activity assay, coumarin derivatives C1 and C2 were selected based on their pathogen-killing activity against various pathogenic microbes. We further demonstrated that the selected coumarin derivatives disrupted bacterial cell membranes. Next, we examined the regulatory function of the coumarin derivatives in gut inflammation using an infectious colitis model. In an in vivo infectious colitis model, administration of selected C1 coumarin derivatives reduced pathogen loads, the number of inflammatory immune cells (Th1 cells and Th17 cells), and inflammatory cytokine levels (IL-6 and IL-1b) in the intestinal tissue after pathogen infection. In addition, we found that the administration of C1 coumarin derivatives minimized abnormal gut microbiome shift-driven pathogen infection. Potential pathogenic gut microbes, such as Enterobacteriaceae and Staphylococcaceae, were increased by pathogen infection. However, this pathogenic microbial expansion was minimized and beneficial bacteria, such as Ligilactobacillus and Limosilactobacillus, increased with C1 coumarin derivative treatment. Functional gene enrichment assessment revealed that the relative abundance of genes associated with lipid and nucleotide metabolism was reduced by pathogen infection; however, this phenomenon was not observed in C1 coumarin derivative-treated animals. Collectively, our data suggest that C1 coumarin derivative is effective antibacterial agents that minimize pathogen-induced gut inflammation and abnormal gut microbiome modulation through their antibacterial activity.

Inclusion of Lacticaseibacillus paracasei NSMJ15 in broiler diets induces changes in jejunal immune cell population and cecal microbiota.

Objective: The objective was to investigate growth performance, antioxidant enzyme activity, intestinal morphology, immune cell distribution, short chain fatty acid (SCFA) profile, and microbiota in broiler chickens fed a diet containing Lacticaseibacillus paracasei NSMJ15. Methods: A total of 120-day-old Ross 308 male broilers were allocated to 2 dietary treatments in a randomized complete block design. A control group was fed a corn-soybean meal control diet, and an NSMJ15-supplemented group was fed a control diet supplemented with 1 g/kg L. paracasei NSMJ15 at the expense of cornstarch. Each dietary treatment had 6 replicates with 10 birds per cage. Growth performance was recorded on day 9. On day 10, one bird representing median body weight was selected to collect serum for antioxidant enzyme activity, jejunal tissue for immune cell isolation and morphometric analysis, and cecal digesta for 16S rRNA gene sequencing and SCFA analysis. Results: Supplementation of L. paracasei NSMJ15 did not affect growth performance, serum antioxidant enzyme activity, and jejunal histomorphology compared to the control group. In the NSMJ15-supplemented group, the population of CD3+CD4+CD8- T cells increased (p=0.010), while the population of CD3+CD8+TCRγδ+ T cells decreased (p=0.022) compared to the control group. The L. paracasei NSMJ15 supplementation decreased (p=0.022) acetate concentration in the cecal digesta compared to the control group. The 16S rRNA gene sequencing analysis showed that NSMJ15-supplemented group differentially expressed (p<0.05) 10 more amplicon sequence variants compared to control group without affecting alpha and beta diversity indices of the cecal microbiota. Genera Mediterraneibacter and Negativibacillus were positively (p<0.05) correlated with CD4+ T cells, while genera Gemmiger, Coprococcus, Sellimonas, Massilimicrobiota, and Blautia were negatively (p<0.05) correlated with SCFA concentration. Conclusion: The results of the present study suggest dietary L. paracasei NSMJ15 supplementation may increase percentage of CD4+ T cells and decrease acetate concentration in broiler chickens by increasing the differential expression of specific microbial genera.

Dietary probiotic Lacticaseibacillus paracasei NSMJ56 modulates gut immunity and microbiota in laying hens.

This study was performed to investigate supplementary effects of probiotic Lacticaseibacillus paracasei NSMJ56 strain on laying performance, egg quality, intestinal histology, antioxidant status, gut immunity and microbiota in laying hens. A total of ninety-six 21-wk-old Hy-Line Brown laying hens were randomly subjected to one of 2 dietary treatments: a control group fed a non-supplemented diet, or a probiotic group fed with a diet supplemented with 1 g of Lacticaseibacillus paracasei NSMJ56 (5 × 108 CFU/kg of diet). The trial lasted for 4 wk. Egg weight was increased (P < 0.05) in laying hens fed probiotic-fed diet compared with the control group. Dietary probiotics did not affect egg quality except for Haugh unit, which was improved (P < 0.05) in the probiotic-fed group. Neither jejunal histology nor cecal short-chain fatty acids were affected by dietary treatments. Dietary probiotics increased the activity of catalase compared with the control group. Flow cytometry analysis revealed that dietary probiotics elevated the CD4+ T cells, but not CD8+ T cells, in jejunal lamina propria. Based on the LEfSe analysis at the phylum and genus levels, Erysipelotrichales, Erysipelotrichia, Flintibater, Dielma, Hespellia, Coprobacter, Roseburia, Anaerotignum, and Coprococcus were enriched in the probiotic group compared with the control group. Taken together, our study showed that dietary probiotics could be used to improve some parameters associated with egg freshness and antioxidant capacity, and to partially alter T cell population and microbial community in laying hens.