The Effects of Synbiotics on Dextran-Sodium-Sulfate-Induced Acute Colitis: The Impact of Chitosan Oligosaccharides on Endogenous/Exogenous Lactiplantibacillus plantarum.

In this work, Lactiplantibacillus plantarum (L. plantarum) isolated from mice feces (LP-M) and pickles (LP-P) were chosen as the endogenous and exogenous L. plantarum, respectively, which were separately combined with chitosan oligosaccharides (COS) to be synbiotics. The anti-inflammatory activity of LP-M, LP-P, COS, and the synbiotics was explored using dextran-sodium-sulfate (DSS)-induced acute colitis mice, as well as by comparing the synergistic effects of COS with LP-M or LP-P. The results revealed that L. plantarum, COS, and the synbiotics alleviated the symptoms of mice colitis and inhibited the changes in short-chain fatty acids (SCFAs), tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-6, IL-10, and myeloperoxidase (MPO) caused by DSS. In addition, the intervention of L. plantarum, COS, and the synbiotics increased the relative abundance of beneficial bacteria Muribaculaceae and Lactobacillus and suppressed the pathogenic bacteria Turicibacter and Escherichia-Shigella. There was no statistically difference between LP-M and the endogenous synbiotics on intestinal immunity and metabolism. However, the exogenous synbiotics improved SCFAs, inhibited the changes in cytokines and MPO activity, and restored the gut microbiota more effectively than exogenous L. plantarum LP-P. This indicated that the anti-inflammatory activity of exogenous LP-P can be increased by combining it with COS as a synbiotic.

Structural Characteristics and Immunomodulatory Effects of Melanoidins from Black Garlic.

Melanoidins are considered to have several biological activities. In this study, black garlic melanoidins (MLDs) were collected using ethanol solution extraction; 0%, 20%, and 40% ethanol solutions were used for chromatography. Three kinds of melanoidins were produced by macroporous resin, named MLD-0, MLD-20, and MLD-40. The molecular weight was determined, and the infrared and microscopic structures were studied. In addition, Balb/c mice were induced with cyclophosphamide (CTX) to establish an immune deficiency model to evaluate the immune efficacy of black garlic melanoidins (MLDs). The results showed that MLDs restored the proliferation and phagocytosis ability of macrophages, and the proliferation activity of B lymphocytes in the MD group was 63.32% (♀) and 58.11% (♂) higher than that in the CTX group, respectively. In addition, MLDs alleviated the abnormal expression of serum factors such as IFN-γ, IL-10, and TNF-α. 16SrDNA sequencing of intestinal fecal samples of mice showed that MLDs changed the structure and quantity of intestinal flora, and especially that the relative abundance of Bacteroidaceae was significantly increased. The relative abundance of Staphylococcaceae was significantly reduced. These results showed that MLDs improved the diversity of intestinal flora in mice, and improved the adverse state of immune organs and immune cells. The experiments confirm that black garlic melanoidins have potential value in immune activity, which provides an important basis for the development and utilization of melioidosis.

The effects of live and pasteurized Akkermansia muciniphila on DSS-induced ulcerative colitis, gut microbiota, and metabolomics in mice.

Akkermansia muciniphila (A. muciniphila) plays an important role in intestinal regulation, while it is presently unclear whether live or pasteurized A. muciniphila has different effects on the intestinal health. In the present study, live or pasteurized A. muciniphila was administered to dextran sulfate sodium (DSS)-induced ulcerative colitis mice to investigate its influences on the host intestinal health, gut microbiota, and metabolomic phenotype. The results showed that pasteurized A. muciniphila alleviated the symptoms of colitis in mice more efficiently by encouraging the proliferation of beneficial intestinal bacteria, increasing the production of short-chain fatty acids, and inhibiting intestinal inflammation. Moreover, pasteurized A. muciniphila increased the abundance of Parasutterella and Akkermansia and thus affected the metabolism of lipid and lipid-like molecules associated with lysophosphatidylcholines (LysoPCs). Notably, prophylactic supplementation of pasteurized A. muciniphila increased the relative abundance of the anti-inflammatory microbe Dubosiella, thereby activating intestinal sphingolipid metabolism to alleviate intestinal damage. In conclusion, pasteurized A. muciniphila showed a more effective amelioration of DSS-induced colitis by repairing the dysbiosis of gut microbiota and intestinal metabolism compared to live A. muciniphila, providing a potential strategy to explore the protective effect of A. muciniphila on host intestinal health.

Lactobacillus acidophilus LA85 ameliorates cyclophosphamide-induced immunosuppression by modulating Notch and TLR4/NF-κB signal pathways and remodeling the gut microbiota.

Lactobacillus acidophilus, as the main probiotic in the small intestine, has a role in modulating intestinal immune activity; however, its potential molecular regulatory mechanisms have rarely been investigated. To investigate the effects of Lactobacillus acidophilus LA85 in immunoprophylaxis, LA85 at the dose of 1 × 108 CFU mL-1, 1 × 109 CFU mL-1, and 1 × 1010 CFU mL-1 were orally administered to immunocompromised ICR mice that had been treated intraperitoneally with 80 mg kg-1 cyclophosphamide. The experimental results showed that LA85 could regulate the Notch signaling pathway and promote intestinal mucosal repair. And it could enhance the immune response of the body through the TLR4/NF-κB signaling pathway. 16S rDNA gene sequencing revealed that LA85 reduced the ratio of Firmicutes/Bacteroidetes and reshaped the gut microbiota. Furthermore, we discovered the correlation between Erysipelatoclostridium, Rikenella, and the intestinal Notch signaling pathway, and further discovered the potential mechanism of LA85 in intestinal mucosal repair. Based on the results of the study, we found that the effect of high doses of LA85 was more significant. Therefore, LA85 can be used as a dietary supplement to potentially enhance the immune capacity of patients.