A multi-omic assessment of the mechanisms of intestinal microbes used to treat diarrhea in early-weaned lambs.

Transplant of donor microbiota can significantly alter the structure of the host's intestinal microbiota and alleviate early weaning stress. Screening for alternative-resistant products by transplanting fecal bacteria from healthy lambs is a current research trend in the livestock industry. In the present study, fecal microbiota transplantation was performed in lambs with diarrhea during early weaning. The transplanted fecal microbiota greatly reduced the diarrhea and serum inflammatory factor levels caused by early weaning. Transcriptome sequencing revealed that fecal microbiota transplantation alleviated colonic inflammation and increased the expression of colonic ion transport proteins. In addition, the levels of Streptococcus, Enterococcus, and Escherichia Shigella decreased in the jejunum, cecum, and colon of the lambs; meanwhile, the levels of Bifidobacterium and multiple secondary bile acids, such as ursodeoxycholic acid, increased in the colon. Furthermore, the abundance of Bifidobacterium was significantly negatively correlated with the diarrhea index. The fecal microbiota transplantation reshaped the intestinal microbiota of early-weaned lambs, protected the intestinal physiology and immune barrier, and reduced weaning stress. In addition to making available bacteriological products for controlling intestinal inflammation in young lambs, this study offers a theoretical framework and technical system for the mechanisms by which microbiota transplantation regulates intestinal health in young lambs.IMPORTANCEBefore weaning, the digestive system of lambs is not well developed; hence, its resistance to infectious diseases is weak. Under intensive feeding systems, lambs can easily be stressed and the risk of bacterial infection is high, which causes diarrhea, which in turn may cause mortality and significant economic losses to the livestock industry. With the elimination of antibiotics in animal feed, the incidence of mortality due to intestinal illnesses in lambs has gradually increased. There are several types of probiotics routinely used in young animals, but the effects and processes of their usage have only been assessed in monogastric animals. The lack of data on ruminants, particularly sheep, has severely hampered the process of efficient and healthy sheep breeding. Therefore, there is an urgent need to identify effective and safe functional supplements for lambs.

Dietary Nutritional Level Affects Intestinal Microbiota and Health of Goats.

The intestine is a complex micro-ecosystem, and its stability determines the health of animals. Different dietary nutritional levels affect the intestinal microbiota and health. In this study, the nutritional levels of energy and protein in the diet of goats were changed, and the body weight was measured every 15 days. In the late feeding period, 16 S rRNA sequencing technology was used to detect the content of microorganisms. A meteorological chromatograph was used to detect volatile fatty acids in the cecum and colon of goats. In the feeding stage, reducing the nutritional level of the diet significantly reduced the weight of the lamb (p < 0.05). In the cecum, the abundance of potentially harmful bacteria, such as Sphingomonas, Marvinbryantia, and Eisenbergiella, were significantly enriched in goats fed with the standard nutritional level diets (p < 0.05). Additionally, the contents of acetate (p = 0.037) and total VFAs (p = 0.041) increased. In the colon, the abundance of SCFAs-producing bacteria, such as Ruminococcaceae, Christensenellaceae, and Papillibacter, decreased as the nutritional level in the diet increased (p < 0.05). In conclusion, the increase in nutritional level could affect the growth performance and composition of intestinal microbiota.

Changes in Rumen Microbiota Affect Metabolites, Immune Responses and Antioxidant Enzyme Activities of Sheep under Cold Stimulation.

Low-temperature environments can strongly affect the normal growth and health of livestock. In winter, cold weather can be accompanied by strong winds that aggravate the effects of cold on livestock. In this study, two experiments were conducted to investigate the effect of low temperature and/or wind speed on physiological indices, rumen microbiota, immune responses and oxidative stress in sheep. When sheep were exposed to cold temperature and/or stronger wind speeds, the average daily gain (ADG) decreased (p < 0.05), and the abundance of Lachnospiraceae was significantly higher (p < 0.05). The acetate and propionate contents and the proportion of propionate in the rumen also significantly reduced (p < 0.05). The immunoglobulin G (IgG) and TH1-related cytokines in the blood were significantly lower (p < 0.05). However, antioxidant enzyme contents were significantly increased and the concentration of malondialdehyde (MDA) was reduced (p < 0.05). In a cold environment, the abundance of Lachnospiraceae in the rumen of sheep was highly enriched, and the decreasing of propionate might be one of the factors affecting the immunity of the animals, the sheep did not suffer from oxidative damage during the experiment.

Construction of a Three-Dimensional Interpenetrating Network Sponge for High-Efficiency and Cavity-Enhanced Solar-Driven Wastewater Treatment.

It is well known that the photothermal conversion performance of solar-driven interfacial water evaporation systems is known to have a stronger photothermal conversion performance than suspended water evaporation systems due to their relatively strong ability to suppress overall heat loss. Natural polymer chitosan and gelatin can form a three-dimensional interpenetrating network (IPN) sponge to provide an interface for water evaporation due to strong hydrogen bonding and electrostatic attraction interaction. However, the lack of effective light absorption, the intrinsic short lifetime, and the poor photothermal conversion greatly compromise their steam generation performance. Here, we fabricated a chitosan/gelatin-based IPN sponge incorporated with melanin-coated titania hollow nanospheres (CG@MPT-h) as a solar thermal converter, which is designed to exhibit a unique cavity structure and vertical channels. The cavity structure of melanin-coated titania acts as a solar thermal transducer, while the chitosan/gelatin-based IPN sponge acts as a single-pass water pump. A water hyacinth-inspired evaporation system shows outstanding steam generation performance, and the highest steam generation rate was 3.17 kg m-2 h-1 under a 2.5 sun illumination because of the cavity enhancement effect, far above TiO2 particles and reported photo-thermal conversion materials. More importantly, the embedding of MPT-h nanoparticles in the IPN sponge effectively inhibits the growth of bacteria in the vertical channels, resulting in an antibacterial solar-driven water evaporator. This advanced sponge provides a cost-effective and practical sustainable energy technique for solar-driven wastewater treatment.

MiR-184 Combined with STC2 Promotes Endometrial Epithelial Cell Apoptosis in Dairy Goats via RAS/RAF/MEK/ERK Pathway.

The endometrium undergoes a series of complex changes to form a receptive endometrium (RE) that allows the embryo to be implanted. The inability to establish endometrial receptivity of livestock causes embryo implantation failure and considerable losses to animal husbandry. MicroRNAs (miRNAs) are a class of noncoding RNAs. Studies have found that miRNAs can regulate many critical physiological processes, including the establishment of RE during embryo implantation. miR-184 is highly expressed in the endometrial receptive period of dairy goats. This study aimed to explore the effect of miR-184 on endometrial epithelial cell (EEC) apoptosis and RE establishment. Stanniocalcin2 (STC2) is a direct target of miR-184, and miR-184 decreases the expression of STC2 in dairy goat EECs. miR-184 can activate EECs apoptosis through the RAS/RAF/MEK/ERK pathway. Additionally, miR-184 increases the expression levels of RE marker genes, such as forkhead box M1 (FOXM1) and vascular endothelial growth factor (VEGF). These findings indicate that miR-184 promotes the apoptosis of endometrial epithelial cells in dairy goats by downregulating STC2 via the RAS/RAF/MEK/ERK pathway, and that it may also regulate the establishment of RE in dairy goats.

A highly sensitive electrochemical biosensor for protein based on a tetrahedral DNA probe, N- and P-co-doped graphene, and rolling circle amplification.

A tetrahedral DNA probe can effectively overcome the steric effects of a single-stranded probe to obtain well-controlled density and minimize nonspecific adsorption. Herein, a highly sensitive electrochemical biosensor is fabricated for determination of protein using a tetrahedral DNA probe and rolling circle amplification (RCA). N- and P-co-doped graphene (NP-rGO) is prepared, and AuNPs are then electrodeposited on it for DNA probe immobilization. Benefitting from the synergistic effects of the excellent electrical conductivity of NP-rGO, the stability of the tetrahedral DNA probe and the signal amplification of RCA, the biosensor achieves a low limit of 3.53 × 10-14 M for thrombin and a wide linear range from 1 × 10-13 to 1 × 10-7 M. This study provides a sensitive and effective method for the detection of protein in peripheral biofluids, and paves the way for future clinical diagnostics and treatment of disease. Graphical abstract.

Temperature and humidity index (THI)-induced rumen bacterial community changes in goats.

The rumen microbiome is thought to play an important role in maintaining normal gastrointestinal metabolism and nutrient absorption in ruminants. The present study was designed to investigate the effect of heat stress on the rumen microbiome of goats using 16S rRNA sequencing technology. Six female goats were randomly allocated into two control metabolic chambers: A and B (in which the temperature and humidity could be precisely controlled with a precision deviation of ± 0.5 °C and ± 5%, with three goats/chamber). Dynamic changes in the rumen bacterial community were detected under 16 gradually increasing temperature and humidity indexes (THIs). Heat stress had no significant effect on alpha diversity but affected the main phyla and genera of the goat rumen microbiota. With a deeper level of heat stress, the TH groups formed a distinct cluster that differed from that of the control check (CK) group. The dominant phylum transitioned from Firmicutes to Bacteroidetes, and co-exclusion occurred between these two phyla. With the increase in THI, the content of probiotics in the Lachnospiraceae_ND3007_group (P < 0.05) decreased, and the abundance of pathogenic bacteria, such as Erysipelotrichaceae_UCG-004 and Treponema_2, increased; however, the difference between the groups was not significant (P > 0.05). Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was used to predict bacterial function, and we found that the ambient environment significantly affected the balance between carbohydrate and energy metabolism (P < 0.05). In conclusion, heat stress changed the composition of rumen microbes and affected metabolic function. This experiment provides a theoretical basis for exploring the effects of environmental factors on the rumen of goats.