Heat Stress Affects Faecal Microbial and Metabolic Alterations of Rabbits

Abstract

Heat stress can impair the rabbit immune system, induce oxidative stress, and cause many complications. These diseases are characterized by metabolic disorders, but the underlying mechanism is unknown. As a result, the current research determines the effects of HS on intestinal microorganisms in rabbits and the metabolic pathway disorders caused by HS. Twelve rabbits were randomly assigned to one of two groups: CON (22–24°C) and HS (30°C–32°C). Both the groups were treated for 15 days. Blood and fecal samples were collected on day 15. Serum immune oxidation indices were determined using a commercial ELISA kit, and the microbiome of rabbit feces was studied using 16S rRNA gene sequencing. Non-targeted metabolomics was analyzed using ultra-high-performance liquid chromatography-mass spectrometry (UHPC MS/MS). The findings revealed that HS significantly increased IgG and T-AOC levels in serum, whereas it decreased TNF-α and IL-10. NMDS analysis revealed a substantial difference in bacterial community composition between HS and CON groups. At the phylum level, the abundance of Firmicutes, Protobacteria, and Verrucomicrobiota was significantly higher in the HS group, whereas the abundance of Bacteriodota was reduced in the CON group. V9D2013 group, Haloplasma, Comamonas, Clostridium sensu stricto 1, Ruminiclostridium, Syntrophus Lutispora, at the genus level Syntrophorhabdus, Paeniclostridium, Clostridium sensu stricto 6, Candidatus Caldatribacterium, Spirochaeta Synergistaceae, Syner-01, [Eubacterium] xylanophilum group, Cellulosilyticum, ADurb.Bin120, and Devosia were significantly upregulated in the HS group. The metabolism of the HS group was considerably upregulated compared with the metabolism of the CON group, according to principal component analysis (PCA) and least-squares discriminant analysis (PLS-DA). HS increased the concentrations of 4-pyridoxic acid, kynurenine, 20-OH-leukotriene B4, and dopamine and decreased the concentration of pyridoxal. In the rabbit gut, these compounds primarily impact the metabolic pathways of vitamin B6, tryptophan, neutrophil activation, and prolactin. 4-Pyridoxic acid, pyridoxal, kynurenine, 20-OH-leukotriene B4, and dopamine are essential inflammatory response markers and oxidative stress.

Vascular Calcification and the Gut and Blood Microbiome in Chronic Kidney Disease Patients on Peritoneal Dialysis: A Pilot Study

“…An increase in the relative abundance of Devosia genus was found both in CKD-PD patients with VC when compared with CKD-PD patients without VC, as well as in CKD-PD patients with a higher mortality risk. To our knowledge, Devosia has not been reported previously in the blood microbiome but has been found to be increased in the gut microbiota of colorectal cancer patients [ 51 ] and in rabbits with heat stress [ 52 ], suggesting its possible translocation from the gut into the systemic circulation.…”

Effects of Dietary Supplementation of Lactobacillus acidophilus on Blood Parameters and Gut Health of Rabbits

“…In fact, they play an important role in the degradation of vegetable feed components and the production of SCFAs [ 2 ]. Regarding Akkermansia genus, it is part of the Verrucomicrobia phylum and it has been reported to positively regulate the production of antioxidant metabolites, protect the self-healing of the intestinal mucosal protective layer, and enhance the response to inflammatory reaction damage [ 6 ] The most well-known species in this genus is Akkermansia muciniphila , a mucin-degrading bacterium that has been demonstrated to be beneficial in rabbits as its ability to break down mucin is especially important during caecotrophy for optimal nutrient extraction [ 4 ]. Finally, the presence of Muribaculaceae family has not been reported previously in rabbit caeca but in mink gut it seems to be able to degrade complex carbohydrates [ 54 ].…”

“…Indeed, gut health has been defined as the absence, prevention or avoidance of intestinal disease so that the animal is able to perform its physiological functions in order to withstand exogenous and endogenous stressors [ 5 ]. To guarantee a healthy gut, an efficient mucosal barrier function through an adequate gut morphometry and morphology, a stable and diverse microbiota, and an effective intestinal immunity are needed to resist pathogen colonization and to ensure optimal digestion and absorption of nutrients [ 6 ].…”

L‐Theanine alleviates heat stress through modulation of gut microbiota and immunity

“…Studies have indicated that HS can alter the gut microbiota of animals such as mice, rabbits, and chickens. [10][11][12] Dysbiosis of the gut microbiota, characterized by decreased concentrations of beneficial metabolites such as short-chain fatty acids and increased levels of pathogenic metabolites, 13 can trigger excessive activation of the immune system, 14 resulting in intestinal inflammation and discomfort. 15 Secretory immunoglobulin A (sIgA), the primary immunoglobulin in the intestinal mucosa, is produced primarily by B cells and serves as the first line of defense against various endogenous microbial communities and exogenous invasive pathogens.…”

“…HSP70, as the most abundant member of the HSP family, has been shown to alter the composition of the gut microbiota and increase intestinal permeability, 9 leading to the infiltration and translocation of luminal antigens, endotoxins, and pathogenic bacteria. Studies have indicated that HS can alter the gut microbiota of animals such as mice, rabbits, and chickens 10–12 . Dysbiosis of the gut microbiota, characterized by decreased concentrations of beneficial metabolites such as short‐chain fatty acids and increased levels of pathogenic metabolites, 13 can trigger excessive activation of the immune system, 14 resulting in intestinal inflammation and discomfort 15 .…”