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The probiotic Bifidobacterium breve is known for its efficient conjugated linoleic acid (CLA) conversion, yet their CLA conversion pathway remains underexplored. This study investigated B. breve JKL2022 for its CLA conversion in actively growing cells, washed cell states, and in crude protein extracts. Moreover, the study aimed to confirm the CLA-converting enzyme in strain JKL2022 and optimize its purification through heterologous expression of fusion proteins (LAI_sGFP and MBP_LAI). JKL2022 exhibited superior CLA conversion compared to genetically similar B. breve strains (JCM7017, JCM7019, JCM1192, and JCM1273), particularly the observed CLA conversion in washed cells (60.14 ± 7.60%) and crude protein fractions (96.11 ± 6.63%). The multipass transmembrane linoleic acid isomerase (LAI) was cloned into the E. coli BL21(DE3) as free LAI or modified with superfolder-GFP or MBP tags and expressed with 0.01 mM IPTG at 37 °C, resulting in highly active protein fractions. LAI was characterized by predictive modeling, molecular docking, and phylogenetic analyses. Moreover, reverse transcription-quantitative PCR analysis revealed upregulation (20-140× higher expression) of lai in JKL2022 compared with that in the JCM strains. Nevertheless, upscaling the production and purification of LAI for downstream applications remains a challenge, primarily because of their membrane-spanning configuration.

This study used bifidobacterial exopolysaccharides (EPSs) from the selected strains of Bifidobacterium bifidum WBBI01 and WBIN03, Bifidobacterium breve WBBR04, Bifidobacterium infantis WBAN07 and Bifidobacterium longum WBLO01 to explore the EPSs regulatory effect on anaphylaxis in mice. First of all, allergy mouse models were established via subcutaneous injection followed by OVA gavage, and then the EPSs from the five Bifidobacteria were fed into the mice via continuous gavage. Samples were taken from the mice periodically to determine the changes of cytokine levels in serum, including those of IgE, IgG, IL-4, IL-5, IL-13 and INF-γ. The test revealed that the EPSs from B. breve WBBR04 could considerably relieve food allergy in the mouse models, but the effect of B. infantis WBAN07 was unsatisfactory. Based on the above conclusions, the EPSs of B. bifidum WBBR04 and WBIN03, B. breve WBBR04, and B. longum WBLO01 were respectively incubated with the small intestine tissue sections of an allergic mouse model. The resulting culture supernatants were then tested. Based on the above, it can be concluded that EPS of B. breve WBBR04 can enhance the intestinal barrier integrity by attaching themselves onto the inner walls of the small intestine, hence effectively isolating the allergens and preventing food allergy., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2020. Published by Elsevier B.V.)

Background: Studies of probiotics have suggested they have a positive effect on anxiety and depressive symptoms in humans. This study investigated the effect of consuming the probiotic Bifidobacterium breve A-1 on anxiety and depressive symptoms in patients with schizophrenia and explored its effect on immune products such as cytokines and chemokines., Methods: In this open-label single-arm study, all participants received B. breve strain A-1 (10 11 cfu/day) for 4 weeks followed by 4 weeks of observation. The primary outcome was the Hospital Anxiety and Depression Scale (HADS) score. Secondary outcomes were anxiety and depressive symptoms on the Positive and Negative Syndrome Scale (PANSS), blood test findings, and fecal microbiome composition., Results: Twenty-nine outpatients completed the study. HADS total score and PANSS anxiety/depression score were significantly improved at 4 weeks. Based on the criterion of a greater than 25% reduction in HADS total score at 4 weeks from baseline, there were 12 responders and 17 non-responders. Responders were found to have fewer negative symptoms, reduced intake of dairy products, and higher relative abundance of Parabacteroides in the gut microbiome than non-responders. Moreover, IL-22 and TRANCE expression was significantly increased at 4 weeks from baseline in responders but not in non-responders., Limitations: This open-label, single-arm study cannot exclude a placebo effect., Conclusions: The results suggest the potential effect of B. breve A-1 in improving anxiety and depressive symptoms in patients with schizophrenia. Further studies should investigate this effect in patients with other psychiatric conditions and assess dietary habits and the gut microbiome., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Three strains of Bifidobacterium breve (JCM 7017, JCM 7019 and JCM 2258) and two strains of Bifidobacterium animalis subsp. lactis (AD011 and A1dOxR) were grown in broth cultures or on plates, and a standard exopolysaccharide extraction method was used in an attempt to recover exocellular polysaccharides. When the extracted materials were analysed by NMR it was clear that mixtures of polysaccharides were being isolated including exopolysaccharides (EPS) cell wall polysaccharides and intracellular polysaccharides. Treatment of the cell biomass from the B. breve strains, or the B. animalis subsp. lactis AD011 strain, with aqueous sodium hydroxide provided a very similar mixture of polysaccharides but without the EPS. The different polysaccharides were partially fractionated by selective precipitation from an aqueous solution upon the addition of increasing percentages of ethanol. The polysaccharides extracted from B. breve JCM 7017 grown in HBM media supplemented with glucose (or isotopically labelled D-glucose-1- 13 C) were characterised using 1D and 2D-NMR spectroscopy. Addition of one volume of ethanol generated a medium molecular weight glycogen (Mw=1×10 5 Da, yield 200 mg/l). The addition of two volumes of ethanol precipitated an intimate mixture of a low molecular weight β-(1→6)-glucan and a low molecular weight β-(1→6)-galactofuranan which could not be separated (combined yield 46 mg/l). When labelled D-glucose-1- 13 C was used as a carbon supplement, the label was incorporated into >95% of the anomeric carbons of each polysaccharide confirming they were being synthesised in situ. Similar 1 H NMR profiles were obtained for polysaccharides recovered from the cells of B. animalis subsp. lactis AD011and A1dOxR (in combination with an EPS), B. breve JCM 7017, B. breve JCM 7019, B. breve JCM 2258 and from an EPS (-ve) mutant of B. breve 7017 (a non-EPS producer).