Blautia producta displays potential probiotic properties against dextran sulfate sodium-induced colitis in mice

Blautia has attracted attention because of its potential efficacy in ameliorating host energy metabolism and inflammation.This study aims to investigate the influences of Blautia producta D4 on colitis induced by dextran sulfate sodium(DSS)and to reveal the underlying mechanisms.Results showed that B.producta D4 intervention significantly relieved body weight loss,and suppressed the elevation of pro-inflammatory cytokines(including interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),and interleukin-1β(IL-1β))and excessive oxidative stress(myeloperoxidease(MPO)activity,superoxide dismutase(SOD)activity,glutathione peroxidase(GSH-Px)activity,and malondialdehyde(MDA)level)in colitis mice.Moreover,the concentrations of tight junction proteins(occludin,claudin-1,and ZO-1)related to the intestinal barrier were obviously elevated,and colitis-related TLR4/NF-κB pathway activation was remarkably inhibited after B.producta D4 intervention.The intestinal microbial disorder was evidently ameliorated by increasing the relative abundance of Clostridium sensu stricto 1,Bifidobacterium,GCA-900066225,Enterorhabdus,and reducing the relative abundance of Lachnospiraceae NK4A136 group.In conclusion,oral administration of B.producta D4 could ameliorate DSS-induced colitis by suppressing inflammatory responses,maintaining the intestinal barrier,inhibiting TLR4/NF-κB pathway,and regulating intestinal microbiota balance.These results are conducive to accelerate the development of B.producta D4 as a functional probiotic for colitis.

Study on Soil Microbiotic Crust and Its Influences on Sand-fixing Vegetation in Arid Desert Region

Based on secular fixed_site data in the artificial sand_fixing vegetation district at the southeast fringe of the Tengger Desert, the formative characteristics of soil microbiotic crusts and its influences on vegetation dynamics were analyzed. Once sand barrier and artificial vegetation have stabilized the surface of the sifting sand, could form aeolian deposition crust and then evolve into algae_dominated crust. Such processes result from the interactions of physical effects of atmospheric dust and silt deposition on sand surface, sinking and raindrop impact, and soil microorganism activities. Under the condition of less than 200 mm precipitation, the presence of microbiotic crust changes the soil hydraulic conductivity, alters the temporal and spatial distribution of the limited precipitation in sand layer and leads to the decline of deep_rooted shrubs. The development of microbiotic crust and subsurface soil affects the plant growth and seed rain distribution, as a result, the diversity of plant species gradually tend to become saturated and finally affects the vegetation stability.

Creep behavior of microbiotic crust

The creep behavior of microbiotic crust at room temperature was revealed by the creep bending tests of cantilever beam under constant-load conditions.The variation in the deflection with time can be depicted well by a standard creep curve.Creep rupture is a fundamental failure mechanism of microbiotic crust due to creep.A simple theory was then applied to describe this new me-chanical behavior.The existence of creep phenomenon brings into question the validity of widely used methods for measuring the strength of microbiotic crust.