Interspecific differences and mechanisms of Lactobacillus-derived anti-inflammatory exopolysaccharides

Characterization of a postbiotic exopolysaccharide produced by Lacticaseibacillus paracasei ET-22 with antioxidant and anti-inflammatory efficacy

Exopolysaccharides (EPSs) produced by lactic acid bacteria have been extensively studied, but the EPSs as postbiotics are much less investigated. In this study, the EPS, designated as ET22-EPS, was extracted and purified from the culture broth of Lacticaseibacillus paracasei ET-22 previously characterized with strong postbiotic activities. ET22-EPS was determined with a molecular weight of 5.12 × 105 Da, and a monosaccharide composition of mannose, galactose, glucose, and N-acetylglucosamine in a molar ratio of 0.662:0.103:0.095:0.026. ET22-EPS exhibited a sheet-like and fibrous stacking morphology with a networked structure. ET22-EPS also showed high thermal stability with a degradation temperature of 295.33 °C. ET22-EPS was identified to consist of an octasaccharide repeating unit with a backbone structure of four consecutively linked →2)-α-D-Manp (1 → together with →2,6)-α-D-Manp(1 → 2)-α-D-Glcp(1→, and a branch chain of α-D-Galp(1 → 6)-α-D-Manp(1→. The in vitro bioassay indicated that ET22-EPS effectively scavenged the free radicals of diammonium 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate), 1,1-diphenyl-2-picrylhydrazyl, hydroxyls, and superoxide anion. ET22-EPS showed strong anti-inflammatory effects by reducing cell phagocytosis, nitric oxide production, pro-inflammatory cytokine secretion, and the TNF-α/IL-10 ratio in a RAW264.7 cell model. Therefore, ET-22-EPS shows good prospects as potential postbiotics in the development of health foods.

Isolation, structural characterization and multiple activity of a novel exopolysaccharide produced by Gelidibacter sp. PG-2

Microbial exopolysaccharides have been extensively explored due to their distinctive structural features and physiological activities, making them suitable for diverse applications in the food and environmental applications. Current studies mainly focus on the structural and functional characterization of exopolysaccharides from known strains, with limited exploration of novel strains. In this study, a novel exopolysaccharide was produced by Gelidibacter sp. PG-2 with a yield of 874 mg·L-1. The purified exopolysaccharides, termed as ZPS, had a molecular weight of 45,514 Da and contained numerous hydroxyl and carbonyl groups. ZPS was a heteropolysaccharide composed of mannose, glucosamine, glucuronic acid, galactonic acid, galactosamine, glucose, galactose, and fucose, with a molar ratio of 54.98: 4.05: 6.69: 1.00: 1.46: 2.95: 2.92: 1.55. ZPS linkage comprised Glcp-(1→, Manp-(1→, →2)-Manp-(1→, →4)-Galp-(1→, and →4)-Manp-(1→. The morphology of ZPS presented the smooth surface, spherical nanoparticle, and irregular network structure. ZPS demonstrated thermal stability and emulsification activity. ZPS potently stimulated macrophage phagocytic function and effectively inhibited the migration of cancer cells, thereby enhancing overall immunomodulatory activity. Additionally, ZPS featured cryoprotective activity and flocculation property. Overall, the multiple activity of ZPS hold tremendous potential in the food and pharmaceutical industries, offering new dimensions for novel microbial exopolysaccharides.

Impact of Ligilactobacillus salivarius Li01 on benzo[a]pyrene-induced colitis, based on host-microbiome interactions in Mongolian gerbils

Background

Probiotics supplementations have been regarded as an effective strategy for colitis treatment. However, the effect of Ligilactobacillus salivarius Li01 on benzo[a]pyrene (BaP)-induced colitis in Mongolian gerbils remains unclear. In this study, we leverage a BaP-induced model of colitis that exhibits significant remission following Ligilactobacillus salivarius Li01 intervention, to conduct an animal experiment that integrates histopathological assessment, inflammatory cytokines, 16S rRNA sequencing, targeted metabolomic profiling to investigate the relationship between Ligilactobacillus salivarius Li01, gut microbiota, and colitis.

Results

We demonstrated that the improvements in colon histopathological assessment and inflammatory cytokines by Ligilactobacillus salivarius Li01 supplementation are accompanied by alterations in gut microbiota structure marked by increased abundance of strains with probiotic potential belonging to Bifidobacterium and Eubacterium_coprostanoligenes. Targeted metabolomic profiling analysis showed that Ligilactobacillus salivarius Li01 supplementation increases the concentration of acetic, propionic, butyric, and valeric acid. Correlation analysis showed that the alteration in the indicators associated with colitis is closely correlated to the changed microbial taxa and short-chain fatty acids (SCFAs).

Conclusion

These data highlighted that Ligilactobacillus salivarius Li01 supplementation ameliorated the BaP-induced colitis, probably via modulating the structure of gut microbiota and promoting the production of SCFAs. Our findings provide preliminary evidence for a possible therapeutic strategy for the treatment of colitis based on host-microbiome interactions.

Accumulation of Water-Soluble Polysaccharides during Lychee Pulp Fermentation with Lactiplantibacillus plantarum Involves Endoglucanase Expression

In the current work, lychee pulp was subjected to Lactiplantibacillus plantarum ATCC 14917 fermentation, leading to a substantial increase (2.32-2.67-fold) in water-soluble polysaccharides (WSP). Concurrently, a significant degradation occurred in water-insoluble polysaccharides (WISP) composed of glucose (28.73%), arabinose (28.25%), galacturonic acid (25.07%), and galactose (11.00%). To clarify polysaccharide conversion and its relevant mechanism, carbohydrate-active enzyme encoding sequences in the L. plantarum ATCC 14917 genome and structural alterations of two polysaccharide fractions were dissected. By integrating the transcriptional assay, prokaryotic expression, and enzymic hydrolysis, three endoglucanases were demonstrated to catalyze WISP degradation, leading to WSP accumulation during lychee pulp fermentation with L. plantarum ATCC 14917. Reductions in proportions of galactose and galacturonic acid in WSPs were partly attributed to the actions of multiple galactosidases. These findings provide an enzyme-based explanation for WSP accumulation during Lactobacillus fermentation and serve as a practical foundation for directional polysaccharide conversion.

Comparison of the effects of three sourdough postbiotics on high-fat diet-induced intestinal damage

There is significant interest in using postbiotics as an intervention strategy to address obesity. This study assesses the efficacy of postbiotics derived from different sourdough strains (Lactiplantibacillus plantarum LP1, LP25, and Pediococcus pentosaceus PP18) in mitigating intestinal injury in zebrafish fed on a high-fat diet. We screened postbiotics for their anti-colon cancer cell effects and compared various preparation methods applied to live bacterial strains, including heat-killing at different temperatures, pH adjustments, and ultraviolet radiation exposure. Heat-killing at 120 °C proved to be the most effective preparation method. A marked variation in health effects was observed in the heat-killed microbial cells, as evidenced by their hydrophobicity and self-aggregation ability. A five-week high-fat dietary intervention study in zebrafish demonstrated that diets supplemented with 108 CFU g-1 K-LP25 significantly attenuated weight gain and body fat, along with reductions in FASN, Leptin, and SREBF1 mRNA expression. However, diets supplemented with 107 CFU g-1 K-PP18 only reduced Leptin and SREBF1 mRNA expression. K-PP18 was more effective at mitigating gut barrier damage, promoting colonic Occludin, ZO-1, and Claudin-1 levels. Additionally, K-LP25 supplementation markedly downregulated the pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, reducing intestinal inflammation. Supplementation with K-LP1 and K-PP18 increased the abundance of Acinetobacter spp., whereas K-LP25 increased the abundance of Cetobacterium and Plesiomonas. Collectively, these findings suggest that inactivated strains confer protective effects against high-fat diet-induced intestinal damage in zebrafish, with variation observed across different species. Studying the effects of sourdough-derived postbiotics on gut health may open new avenues for dietary interventions to manage gut-related diseases.

Microbial exopolysaccharides: Unveiling the pharmacological aspects for therapeutic advancements

Microbial exopolysaccharides (EPSs) have emerged as a fascinating area of research in the field of pharmacology due to their diverse and potent biological activities. This review paper aims to provide a comprehensive overview of the pharmacological properties exhibited by EPSs, shedding light on their potential applications in various therapeutic areas. The review begins by introducing EPSs, exploring their various sources, significance in microbial growth and survival, and their applications across different industries. Subsequently, a thorough examination of the pharmaceutical properties of microbial EPSs unveils their antioxidant, immunomodulatory, antimicrobial, antidepressant, antidiabetic, antiviral, antihyperlipidemic, hepatoprotective, anti-inflammatory, and anticancer activities. Mechanistic insights into how different EPSs exert these therapeutic effects have also been discussed in this review. The review also provides comprehensive information about the monosaccharide composition, backbone, branches, glycosidic bonds, and molecular weight of pharmacologically active EPSs from various microbial sources. Furthermore, the factors that can affect the pharmacological activities of EPSs and approaches to improve the EPSs' pharmacological activity have also been discussed. In conclusion, this review illuminates the immense pharmaceutical promise of microbial EPS as versatile bioactive compounds with wide-ranging therapeutic applications. By elucidating their structural features, biological activities, and potential applications, this review aims to catalyze further research and development efforts in leveraging the pharmaceutical potential of microbial EPS for the advancement of human health and well-being, while also contributing to sustainable and environmentally friendly practices in the pharmaceutical industry.

Effect of Composite Probiotics on Antioxidant Capacity, Gut Barrier Functions, and Fecal Microbiome of Weaned Piglets and Sows

This study investigated the efficacy of a composite probiotics composed of lactobacillus plantarum, lactobacillus reuteri, and bifidobacterium longum in alleviating oxidative stress in weaned piglets and pregnant sows. Evaluations of growth, oxidative stress, inflammation, intestinal barrier, and fecal microbiota were conducted. Results showed that the composite probiotic significantly promoted average daily gain in piglets (p < 0.05). It effectively attenuated inflammatory responses (p < 0.05) and oxidative stress (p < 0.05) while enhancing intestinal barrier function in piglets (p < 0.01). Fecal microbiota analysis revealed an increase in the abundance of beneficial bacteria such as faecalibacterium, parabacteroides, clostridium, blautia, and phascolarctobacterium in piglet feces and lactobacillus, parabacteroides, fibrobacter, and phascolarctobacterium in sow feces, with a decrease in harmful bacteria such as bacteroides and desulfovibrio in sow feces upon probiotic supplementation. Correlation analysis indicated significant negative associations of blautia with inflammation and oxidative stress in piglet feces, while treponema and coprococcus showed significant positive associations. In sow feces, lactobacillus, prevotella, treponema, and CF231 exhibited significant negative associations, while turicibacter showed a significant positive association. Therefore, the composite probiotic alleviated oxidative stress in weaned piglets and pregnant sows by modulating fecal microbiota composition.