scholarly journals The rumen epithelial microbiota: gatekeepers of the rumen epithelium and its potential contributions to epithelial barrier function and animal health and performance

2021 ◽  
Author(s):  
Stephan Schmitz-Esser
2021 ◽  
Vol 8 ◽  
Author(s):  
Yi Ma ◽  
Ying Zhang ◽  
Hao Zhang ◽  
Hongrong Wang

High-concentrate diets are continually used in ruminants to meet the needs of milk yield, which can lead to the occurrence of subacute rumen acidosis in ruminants. This study investigated the protective effects of dietary thiamine supplementation on the damage of the ruminal epithelium barrier function in goats fed a high-concentrate diet. Twenty-four healthy Boer goats (live weight of 35.62 ± 2.4 kg; age, 1 year) were randomly assigned into three treatments, with eight goats in each treatment, consuming one of three diets: a low-concentrate diet (CON; concentrate/forage, 30:70), a high-concentrate diet (HC; concentrate/forage, 70:30), or a high-concentrate diet with 200 mg of thiamine/kg of dry matter intake (HCT; concentrate/forage, 70:30) for 12 weeks. The additional dose of thiamine was based on our previous study wherein thiamine ameliorates inflammation. Compared with HC treatment, the HCT treatment had markedly higher concentrations of glutathione, superoxide dismutase, and glutathione peroxidase and total antioxidant capacity (P < 0.05) in plasma and rumen epithelium. The results showed that the apoptosis index was lower (P < 0.05) in the HCT treatment than in that of the HC treatment. Compared with the HC treatment, permeability and the electrophysiology parameter short circuit current for ruminal epithelial tissue were significantly decreased (P < 0.05) in the HCT treatment. The immunohistochemical results showed that the expression distribution of tight junctions including claudin-1, claudin-4, occludin, and zonula occludin-1 (ZO-1) was greater (P < 0.05) in the HCT treatments than in the HC treatment. The mRNA expression in the rumen epithelium of ZO-1, occludin, claudin-1, B-cell lymphoma/leukemia 2, nuclear factor erythroid-2 related factor 2 (Nrf2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1, and the phase II metabolizing enzymes quinone oxidoreductase and heme oxygenase in the HCT group was significantly increased in comparison with the HC diet treatment (P < 0.05), whereas the mRNA expression of caspase 3, caspase 8, caspase 9, bcl-2 associated X protein, lipopolysaccharide binding protein, toll-like receptor 4, nuclear factor kappa-B (NFκB), tumor necrosis factor alpha, interleukin-1β, interleukin, and tumor necrosis factor receptor-associated factor 6 decreased significantly in the HCT treatment (P < 0.05). Compared with the HC treatment, the HCT diet significantly increased the protein expression of ZO-1, occludin, claudin-1, NQO1, HO-1, SOD2, serine/threonine kinase, p-Akt, Nrf2, and p-Nrf2; conversely, the expression of NFκB-related proteins p65 and pp65 was significantly decreased (P < 0.05). In addition, thiamine relieved the damage on the ruminal epithelium caused by the HC diet. The results show that dietary thiamine supplementation improves the rumen epithelial barrier function by regulating Nrf2–NFκB signaling pathways during high-concentrate-diet feeding.


2020 ◽  
Author(s):  
Hao Wu ◽  
Yan Li ◽  
Qingxiang Meng ◽  
Zhenming Zhou

Abstract Background: Sulfur is essential for maintaining animal health and functional processing, but high sulfur in the diet can be toxic. The underlying mechanism for this toxicity is not clear in ruminants. Thus, we conducted experiments to evaluate the effect of excessive sulfur on rumen fermentation, microflora, and epithelial barrier function in steers through in vitro gas production and animal feeding trials.Results: The results showed that increasing the level of sulfur in substrates, decreased the total gas and methane production linearly while increasing the hydrogen sulfide gas (P<0.01). Though the high sulfur diet did not affect the rumen fermentation parameters (P>0.05), the volatile fatty acid concentration, especially the butyric acid, was increased by extra sulfur (P<0.01). Sulfur content in the diet had no significant effect (P>0.05) on most of the rumen microbes, expect Desulfovibrio, one of the major sulfate-reducing bacteria (SRB) in the rumen, whose population increased by adding extra sulfur (P<0.001). Changes in the morphology of rumen epithelium and thickening of the total epithelial layer were mainly attributed to the increase in the acanthosis cell layer and stratum basale (P<0.05). Also, the relative expression of two tight junction protein regulating genes, CLDN-1 and TJP1, were reduced with an increase in sulfur level in the diet (P<0.05).Conclusion: These results indicate that excessive sulfur in the diet can change the type of rumen fermentation, sulfate metabolism and SRB population, and the rumen epithelial barrier function.


Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2545
Author(s):  
Hao Wu ◽  
Yan Li ◽  
Qingxiang Meng ◽  
Zhenming Zhou

These experiments were conducted to evaluate the effect of excessive sulfur on rumen fermentation, microflora, and epithelial barrier function in steers through in vitro gas production and animal feeding experiments. Nine and four levels of sulfur addition were evaluated in in vitro ruminal fermentation and animal feeding experiment, respectively. The results showed that increasing the level of sulfur in substrates decreased the total gas and methane production linearly, while increasing the production of hydrogen sulfide gas (p < 0.01). Volatile fatty acid concentrations, especially that of butyric acid, were increased by extra sulfur (p < 0.01). Sulfur content in the diet had no significant effect (p > 0.05) on most of the rumen microbes, except for Desulfovibrio, one of the major sulfate-reducing bacteria (SRB) in the rumen, whose population increased by adding extra sulfur (p < 0.001). The changes in the morphology of rumen epithelium and thickening of the total epithelial layer were mainly attributed to the increase in the acanthosis cell layer and stratum basale (p < 0.05). Further, the relative expressions of two tight junction protein regulating genes, CLDN-1 and TJP1, were reduced (p < 0.05). Excessive sulfur in the diet can change the type of rumen fermentation, sulfate metabolism and SRB population, and the rumen epithelial barrier function. The results of this study demonstrated that sulfur can be used as a methane inhibitor with the mechanism that SRB competitively used protons to produce hydrogen sulfide. However, a higher level of sulfur in the diet could increase the inflammatory reaction of the rumen epithelium which may affect nutrient absorption.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aubrey N. Michi ◽  
Bryan G. Yipp ◽  
Antoine Dufour ◽  
Fernando Lopes ◽  
David Proud

AbstractHuman rhinoviruses (HRV) are common cold viruses associated with exacerbations of lower airways diseases. Although viral induced epithelial damage mediates inflammation, the molecular mechanisms responsible for airway epithelial damage and dysfunction remain undefined. Using experimental HRV infection studies in highly differentiated human bronchial epithelial cells grown at air-liquid interface (ALI), we examine the links between viral host defense, cellular metabolism, and epithelial barrier function. We observe that early HRV-C15 infection induces a transitory barrier-protective metabolic state characterized by glycolysis that ultimately becomes exhausted as the infection progresses and leads to cellular damage. Pharmacological promotion of glycolysis induces ROS-dependent upregulation of the mitochondrial metabolic regulator, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), thereby restoring epithelial barrier function, improving viral defense, and attenuating disease pathology. Therefore, PGC-1α regulates a metabolic pathway essential to host defense that can be therapeutically targeted to rescue airway epithelial barrier dysfunction and potentially prevent severe respiratory complications or secondary bacterial infections.


2010 ◽  
Vol 4 (5) ◽  
pp. 637-651 ◽  
Author(s):  
Susanne A Snoek ◽  
Marleen I Verstege ◽  
Guy E Boeckxstaens ◽  
René M van den Wijngaard ◽  
Wouter J de Jonge

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