Bifidobacterium animalis ssp. lactis Bb12 induces IL-10 through cell membrane-associated components via TLR2 in swine

Development of Alginate Composite Microparticles for Encapsulation of Bifidobacterium animalis subsp. lactis

The probiotic bacterium Bifidobacterium animalis subsp. lactis BB-12 (BB-12) was encapsulated in two composites, alginate/agar and alginate/agar/casein. The network structure and physicochemical properties of these composites are influenced by complex interactions, including hydrogen bonding, electrostatic forces between biopolymers, calcium ions, and the encapsulated bacteria. The composites demonstrated a granular surface, with the granules being spatially oriented on the alginate/agar/BB-12 surface and linearly oriented on the alginate/agar/casein/BB-12 surface. They possess a highly organized microparticle structure and exhibit viscoelastic solid-like behavior. The alginate/agar/BB-12 composite showed higher storage modulus, shear stress, and shear strain values, indicating enhanced stability in various physical environments. Both composites displayed good thermal stability, aligning with their rheological properties, confirming their well-ordered structures. Despite differences in composite structures, the release mechanism of bacteria is governed by Fickian diffusion through the composite matrix. Based on physicochemical properties, the alginate/agar/casein composite is recommended for dairy product fermentation, while the alginate/agar composite seems more suitable for oral use. These findings provide new insights into the interactions between bacterial cultures and alginate composite ingredients.

Effects of Bifidobacterium animalis subsp. lactis IU100 on Immunomodulation and Gut Microbiota in Immunosuppressed Mice

Probiotics are live microorganisms with immunomodulatory effects in a strain-specific and dose-dependent manner. Bifidobacterium animalis subsp. lactis IU100 is a new probiotic strain isolated from healthy adults. This study aimed to evaluate the effects of IU100 on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that IU100 significantly ameliorated CTX-induced decreases in body weight and immune organ indices. The promoted delayed-type hypersensitivity, serum hemolysins and immunoglobulin (IgA, IgG and IgM) levels after IU100 treatment indicated its enhancing role in cellular and humoral immunity. In addition, oral administration of IU100 increased serum cytokine (IL-1β, IL-2, IL-4, IL-6, IFN-γ, TNF-α) levels dose-dependently, which are associated with CTX-induced shifts in the Th1/Th2 balance. The probiotic IU100 also modulated the composition of gut microbiota by reducing the Firmicutes/Bacteroidetes ratio; increasing beneficial Muribaculaceae and the Lachnospiraceae NK4A136 group; and inhibiting harmful Clostridium sensu stricto 1, Faecalibaculum and Staphylococcus at the genus level. The above genera were found to be correlated with serum cytokines and antibody levels. These findings suggest that IU100 effectively enhances the immune function of immunosuppressed mice, induced by CTX, by regulating gut microbiota.

Effects of Bifidobacterium animalis subsp. lactis IU100 on Immunomodulation and Gut Microbiota in Immunosuppressed Mice

Probiotics are live microorganisms with immunomodulatory effects in a strain-specific and dose-dependent manner. Bifidobacterium animalis subsp. lactis IU100 is a new probiotic strain isolated from healthy adults. This study aimed to evaluate the effects of IU100 on cyclophosphamide (CTX)-induced immunosuppression in mice. The results showed that IU100 significantly ameliorated CTX-induced decreases in body weight and immune organ indices. The promoted delayed-type hypersensitivity, serum hemolysins and immunoglobulin (IgA, IgG and IgM) levels after IU100 treatment indicated its enhancing role in cellular and humoral immunity. In addition, oral administration of IU100 increased serum cytokine (IL-1β, IL-2, IL-4, IL-6, IFN-γ, TNF-α) levels dose-dependently, which are associated with CTX-induced shifts in the Th1/Th2 balance. The probiotic IU100 also modulated the composition of gut microbiota by reducing the Firmicutes/Bacteroidetes ratio; increasing beneficial Muribaculaceae and the Lachnospiraceae NK4A136 group; and inhibiting harmful Clostridium sensu stricto 1, Faecalibaculum and Staphylococcus at the genus level. The above genera were found to be correlated with serum cytokines and antibody levels. These findings suggest that IU100 effectively enhances the immune function of immunosuppressed mice, induced by CTX, by regulating gut microbiota.

IFN-γ and IL-10: seric and placental profile during pig gestation Seric and placental cytokines in pig gestation

Concentration of interferon-gamma and interleukin-10 in maternal serum and in maternal and fetal porcine placental extracts from different gestation periods was determined. Crossbred pigs' placental samples of 17, 30, 60, 70, and 114 days gestation and non-pregnant uteri were used. Interferon-gamma concentration was increased at the placental interface at 17 days, in maternal and fetal placenta, and decreased significantly in the remaining gestation periods. Interferon-gamma showed a peak in serum at 60 days. Regarding interleukin-10, placental tissue concentrations were unaltered, there were no significant differences with non-gestating uteri samples. In serum interleukin-10 increased at 17, 60, and 114 days gestation. At 17 days there are uterus structural and molecular changes that allow the embryos implantation and placenta development. The presence of interferon-gamma found at this moment in the interface would favor that placental growth. Moreover, its significant increase in serum at 60 days, would generate a proinflammatory cytokine pattern that facility the placental remodeling characteristic of this moment of porcine gestation. On the other hand, a significant interleukin-10 increase in serum at 17, 60 and 114 days could indicate its immunoregulatory role at a systemic level during pig gestation.

Downregulation of miR-671-5p promotes IL-10 mRNA increase in porcine moDCs stimulated with the probiotic BB12

BACKGROUND

Previous work showed that the microRNA (miRNA) miR-671-5p was upregulated in monocyte-derived dendritic cells (moDCs) stimulated with Bifidobacterium animalis subsp. lactis BB12 (BB12) with no increase in IL-10 after six hours of stimulation. In this work, we performed an in silico prediction of genes targeted by miR-671-5p and which are the terms and pathways involved with it. Also, miR-671-5p was transiently downregulated to assess its effect on IL-10 regulation.

METHODS AND RESULTS

First, we performed a Gene Ontology enrichment analysis to predict immune response terms and pathways involved with miR-671-5p. Some of the terms and pathways found were related to the immune response promoted by the probiotic, as the terms "negative regulation of the inflammatory response to an antigenic stimulus" and "cancer" were highlighted. Then, to assess the role of miR-671-5p in IL-10 regulation, moDCs were derived from porcine peripheral blood and later transfected with miR-671-5p antisense oligonucleotide (ASO). Flow cytometry was employed to evaluate the transfection efficiency. Then, the moDCs were stimulated with BB12, and the expression of IL-10 was assessed by RT-qPCR and ELISA. An increase in IL-10 transcript in miR-671-5p-ASO-transfected moDCs stimulated with BB12 was observed compared with moDCs stimulated with BB12 but not transfected. These results suggest the participation of miR-671-5p as a negative regulator of IL-10.

CONCLUSION

These findings suggest that miR-671-5p participates in the downregulation of IL-10, as previously predicted in silico by our work group. miR-671-5p could play an essential role in the immunomodulation promoted by the probiotic BB12.

Bifidobacterium animalis Promotes the Growth of Weaning Piglets by Improving Intestinal Development, Enhancing Antioxidant Capacity, and Modulating Gut Microbiota

In the modern swine industry, weaning is a critical period in the pig’s life cycle. Sudden dietary, social, and environmental changes can easily lead to gut microbiota dysbiosis, diarrhea, and a decrease in growth performance.

Probiotics and gut microbiota: mechanistic insights into gut immune homeostasis through TLR pathway regulation

Consumption of probiotics as a useful functional food improves the host's wellbeing, and, when paired with prebiotics (indigestible dietary fibre/carbohydrate), often benefits the host through anaerobic fermentation.

Immunomodulation by Bifidobacterium animalis subsp. lactis Bb12: Integrative Analysis of miRNA Expression and TLR2 Pathway-Related Target Proteins in Swine Monocytes

Bifidobacterium animalis subsp. lactis Bb12 is a widely used probiotic that provides numerous health benefits to its host, many due to its immunomodulatory properties. Although the precise mechanism of modulation is still under investigation, several reports associate the interaction of TLR2 with components of the bacterial cell wall inducing a signaling cascade that culminates with the production of cytokines and co-stimulatory molecules. MicroRNAs (miRNAs) have emerged as important post-transcriptional regulators of immune responses, including those toward probiotics. In this study, we analyzed the miRNA expression profile in swine monocytes exposed to Bb12 by using an anti-TLR2 blocking strategy and Bb12 involvement in the regulation of the TLR2 pathway. As a result, the expression of 40 miRNAs was influenced by the treatments (p < 0.01), and 15 differentially expressed miRNAs with validated miRNA–mRNA interactions with around 26 proteins related to the TLR2 pathway were identified. The miRNAs upregulated in response to Bb12 included miR-15a-5p, miR-16-5p, miR-26a-5p, miR-29b-3p, and miR-30d-5p, and the following showed downregulation: miR-181a-5p, miR-19b-3p, miR-21-5p, miR-23a-5p, and miR-221-3p. The expression of let-7c-5p, let-7f-5p, miR-146b-5p, miR-150-5p, and miR-155-5p was increased by Bb12 only when TLR2 was blocked. The identified miRNA common targets were downstream proteins from bacterial recognition via TLR2, such as MyD88, TRAF6, and MAPK members; transcription factors such as NF-κB and AP-1; and cytokines such as IL-6, IL-10, and TNF-α. TLR2 participation was abrogated by anti-TLR2 antibody and suggests that bacterial recognition is complemented by other receptors since there were still changes in the microtranscriptome.

Hematobiochemical and Immunological Responses of Rats Treated with Multi-strain Probiotics and Infected with Trypanosoma brucei

The effects of treatment with probiotics on the immunological and hematobiochemical changes in Trypanosoma brucei infection were investigated. Probiotic strains used are Bifidobacterium BB-12, Lactobacillus acidophilus LA-5, Lactobacillus delbrueckii LBY-27, Lactobacillus paracasei LC-01, and Streptococcus thermophilus STY-31. Thirty rats randomly assigned to five groups were used in the experiment. Groups A to C received 1 × 10⁹ CFU, 5 × 10⁹ CFU, and 10 × 10⁹ CFU of the multi-strain probiotics daily and respectively from day 0 post-supplementation (PS) to termination. Group D and E were the infected and uninfected controls respectively. On day seven PS, groups A to D were challenged intraperitoneally with approximately 1 × 10⁶ trypanosomes. Parasitemia, nitric oxide level, hematobiochemical parameters, and antibody titer to heterologous antigen stimulation were monitored post-infection. By days 7 and 16 PS, probiotics-treated groups had significantly lower (p < 0.05) mean creatinine concentration than the controls; however, on day 7 PS, there were no significant variations in the leukocyte counts (LC), total erythrocyte counts (TEC), and the packed cell volume (PCV) in all experimental groups. Following infection, by day 16 PS, the pre-patent period, parasitemia levels, and antibody titer were similar in all infected groups. Furthermore, the probiotics-treated groups and the infected control had significantly lower PCV, TEC, and LC values when compared to the uninfected control, and probiotics treated groups (A and C) had only marginally lower nitric oxide levels than the infected control. Treatment with the probiotic strains gave a creatinine-lowering effect, was innocuous to the hematopoietic system, but was not sufficiently immunostimulatory in trypanosomosis.

The Probiotic BB12 Induces MicroRNAs Involved in Antigen Processing and Presentation in Porcine Monocyte-Derived Dendritic Cells

MicroRNAs (miRNAs) mediate the regulation of gene expression. Several reports indicate that probiotics induce miRNA-mediated immunomodulation at different levels, such as cytokine production and the up-regulation of several markers related to antigen presentation in antigen-presenting cells. The objective of this work was to identify target genes of miRNAs that are involved in the processing and presentation of antigens in monocyte-derived dendritic cells (moDCs) stimulated with the probiotic Bifidobacterium animalis ssp. lactis BB12 (BB12). First, an in silico prediction analysis for a putative miRNA binding site within a given mRNA target was performed using RNAHybrid software with mature sequences of differentially expressed miRNAs retrieved from a Genbank data set that included BB12-stimulated and unstimulated porcine monocytes. From them, 23 genes resulted in targets of 19 miRNAs, highlighting miR-30b-3p, miR-671-5p, and miR-9858-5p, whose targets were costimulatory molecules, and were overexpressed (p < 0.05) in BB12-stimulated moDCs. The analysis of moDCs showed that the percentage of cells expressing SLA-DR⁺CD80⁺ decreased significantly (p = 0.0081) in BB12-stimulated moDCs; interleukin (IL)-10 production was unchanged at 6 h but increased after 24 h of culture in the presence of BB12 (p < 0.001). In summary, our results suggest that SLA-DR and CD80 can be down-regulated by miRNAs miR-30b-3p, miR-671-5p, and miR-9858-5p, while miR-671-5p targets IL-10.

Bifidobacterium lactis BB-12 Attenuates Macrophage Aging Induced by D-Galactose and Promotes M2 Macrophage Polarization

Immunosenescence comprises a set of dynamic changes occurring in innate and adaptive immune systems, and macrophage aging plays an important role in innate and adaptive immunosenescence. However, function and polarization changes in aging macrophages have not been fully evaluated, and no effective method for delaying macrophage senescence is currently available. The results of this study reveal that D-galactose (D-gal) can promote J774A.1 macrophage senescence and induce macrophage M1 polarization differentiation. Bifidobacterium lactis BB-12 can significantly inhibit J774A.1 macrophage senescence induced by D-gal. IL-6 and IL-12 levels in the BB-12 groups remarkably decreased compared with that in the D-gal group, and the M2 marker, IL-10, and Arg-1 mRNA levels increased in the BB-12 group. BB-12 inhibited the expression of p-signal transducer and activator of transcription 1 (STAT1) and promoted p-STAT6 expression. In summary, the present study indicates that BB-12 can attenuate the J774A.1 macrophage senescence and induce M2 macrophage polarization, thereby indicating the potential of BB-12 to slow down immunosenescence and inflamm-aging.

Alterations to the Gut Microbiota and Their Correlation With Inflammatory Factors in Chronic Kidney Disease

Alterations to the gut microbiota have been previously suggested to be tightly linked to chronic systemic inflammation, which is a major contributing factor to complications and disease progression in chronic kidney disease (CKD). Nevertheless, the effect of gut dysbiosis on the pathogenesis and/or production of inflammatory factors in CKD has not been extensively studied to date. In the present study, we conducted 16S ribosomal DNA pyrosequencing using fecal microbiota samples and analyzed the production of serum inflammatory factors in 50 patients with CKD and 22 healthy control (HC) subjects. The results revealed that compared to the HC subjects, patients with CKD exhibited a significant reduction in the richness and structure of their fecal microbiota. At the phylum level, compared to the HC group, patients with CKD also presented reduced abundance of Actinobacteria but increased abundance of Verrucomicrobia. Moreover, the genera Lactobacillus, Clostridium IV, Paraprevotella, Clostridium sensu stricto, Desulfovibrio, and Alloprevotella were enriched in the fecal samples of patients with CKD, while Akkermansia and Parasutterella were enriched in those of the HC subjects. The abundance of Akkermansia in the CKD group was significantly lower than that in the HC group (3.08 vs. 0.67%); this decrease in the abundance of Akkermansia, an important probiotic, in patients with CKD is a striking discovery as it has not been previously reported. Finally, we analyzed whether these changes to the fecal microbiota correlated with CKD clinical characteristics and/or the production of known inflammatory factors. Altered levels of the microbiota genera Parasutterella, Lactobacillus, Paraprevotella, Clostridium sensu stricto, and Desulfovibrio were shown to be correlated with CKD disease-severity indicators, including the estimated glomerular filtration rate. Most notably, Akkermansia was significantly negatively correlated with the production of interleukin-10. The results of the present study suggest that microbiota dysbiosis may promote chronic systemic inflammation in CKD. Furthermore, they support that modifying the gut microbiota, especially Akkermansia, may be a promising potential therapeutic strategy to attenuate the progression of, and/or systemic inflammation in, CKD.