Morphological and Enzymological Studies of the Small Intestine Villi of Rats Receiving Diets Containing Different Levels of Protein

Genome Analysis and Safety Assessment of Achromobacter marplatensis Strain YKS2 Strain Isolated from the Rumen of Yaks in China

Achromobacter marplatensis strain YKS2 isolated from the yak rumen has the feature of producing cellulose. This study aims to analyze the genome and safety of strain YKS2 in vivo, considering its future research and application prospects. The genome of strain YKS2 was sequenced and used for genomic in silico studies. The administration of strain YKS2 in three doses was carried out on mice for 3 days of oral and 7 days of clinical observation tests. The BW, FI, organ indices, gut microbiota, and histological appearances of organs and intestines, along with hematological parameters and serum biochemistry, were measured in mice. The chromosome size of strain YKS2 was 6,588,568 bp, with a GC content of 65.27%. The 6058 coding sequences of strain YKS2 without plasmid were predicted and annotated and have multiple functions. The mice in all groups were alive, with good mental states and functional activities. Compared with the control group, there was no significant difference in the three dose groups on BW, FI, hematological parameters (WBC, LYM, etc.), and serum biochemistry (ALB, ALT, etc.). No abnormalities were observed in the main visceral organs, intestinal tissue, and V/C value in groups. However, the IEL number of duodenum and gut microbiota diversity (Shannon's index) in the high-dose group was significantly higher than in the control group (p < 0.05). Besides, the low dose of strain YKS2 also significantly affected the bacterial abundance of Firmicutes, Actinobacteria, and desulphurizing Bacteroidetes at the phylum level. There was no significant effect at genus levels in groups. In conclusion, the study revealed the genome and potential functional genes of strain YKS2, which is beneficial to understanding the features of the A. marplatensis strain and proved strain YKS2 to be without acute toxicity to mice. However, a long-term feeding toxicity experiment in vivo should be performed to further ensure its potential application value strain in the animal industry.

Intestinal Morphometric Changes Induced by a Western-Style Diet in Wistar Rats and GSPE Counter-Regulatory Effect

Western-style diet is an obesogenic diet for rodents and humans due to its content of saturated fat and refined sugars, mainly sucrose and, in consequence, sucrose-derived fructose. This type of diets relates with intestinal disturbances when consumed regularly. The aim of this work was to analyse the adaptive morphologic and functional changes at intestinal level derived from the unhealthy components of a Cafeteria diet in rats. The effect of grape seed proanthocyanidin extract (GSPE) in the prevention of diet-induced intestinal dysfunction was also analysed. Rats were fed a 17-week cafeteria diet (CAF) without or with oral-GSPE supplementation, either intermittent GSPE administration (SIT-CAF); last 10-day GSPE supplementation at doses of 100 mg/kg and 500 mg/kg day (CORR-100) and (CORR-500) or pre-supplementation with 500 mg/kg GSPE (PRE-CAF). GSPE-CAF supplemented groups showed similar results to CAF diet group regarding morphology and inflammatory score in the duodenum. As an adaptive response to diet, CAF increased intestinal absorptive surface (1.24-fold) all along the intestinal tract and specifically in the small intestine, duodenum, due to increase villus height and a higher villus/crypt ratio, in addition to increase in Goblet cell percentage and inflammatory index. Animals fed GSPE at the current doses and times had higher villus heights and absorptive surface similar to Cafeteria diet group. In the duodenum, villus height correlated with body weight at 17 week and negatively with MLCK gene expression. In the colon, villus height correlated with the percentage of goblet cells. In conclusion, the CAF diet produced adaptive modifications of the intestine by increasing the absorptive area of the small intestine, the percentage of goblet cells and the inflammatory index at the duodenal level. GSPE supplementation can partially reverse the intestinal morphological changes induced by the high fat/sucrose diet when administered intermittently.

Stable Gastric Pentadecapeptide BPC 157 Therapy for Primary Abdominal Compartment Syndrome in Rats

Recently, the stable gastric pentadecapeptide BPC 157 was shown to counteract major vessel occlusion syndromes, i.e., peripheral and/or central occlusion, while activating particular collateral pathways. We induced abdominal compartment syndrome (intra-abdominal pressure in thiopental-anesthetized rats at 25 mmHg (60 min), 30 mmHg (30 min), 40 mmHg (30 min), and 50 mmHg (15 min) and in esketamine-anesthetized rats (25 mmHg for 120 min)) as a model of multiple occlusion syndrome. By improving the function of the venous system with BPC 157, we reversed the chain of harmful events. Rats with intra-abdominal hypertension (grade III, grade IV) received BPC 157 (10 µg or 10 ng/kg sc) or saline (5 ml) after 10 min. BPC 157 administration recovered the azygos vein via the inferior-superior caval vein rescue pathway. Additionally, intracranial (superior sagittal sinus), portal, and caval hypertension and aortal hypotension were reduced, as were the grossly congested stomach and major hemorrhagic lesions, brain swelling, venous and arterial thrombosis, congested inferior caval and superior mesenteric veins, and collapsed azygos vein; thus, the failed collateral pathway was fully recovered. Severe ECG disturbances (i.e., severe bradycardia and ST-elevation until asystole) were also reversed. Microscopically, transmural hyperemia of the gastrointestinal tract, intestinal mucosa villi reduction, crypt reduction with focal denudation of superficial epithelia, and large bowel dilatation were all inhibited. In the liver, BPC 157 reduced congestion and severe sinusoid enlargement. In the lung, a normal presentation was observed, with no alveolar membrane focal thickening and no lung congestion or edema, and severe intra-alveolar hemorrhage was absent. Moreover, severe heart congestion, subendocardial infarction, renal hemorrhage, brain edema, hemorrhage, and neural damage were prevented. In conclusion, BPC 157 cured primary abdominal compartment syndrome.

Probiotic potential and safety assessment of Lactobacillus isolated from yaks

Current problem of antibiotic resistance and the high incidence of bacterial diseases has brought huge losses to the yak breeding industry in Tibet. Therefore, the purpose of this study was to isolate Lactobacillus with safety and beneficial probiotic potential for the prophylaxis of intestinal diseases in yaks. After 16S rDNA sequence, four strains i.e. Lactobacillus sakei (named L4), Enterococcus hirae (named E5), Pediococcus acidilactici (named P7), Weissella confusa (named W8) were isolated from feces of yaks. The results of tolerance to acid, bile salt, enzyme and temperature showed that P7 was highly tolerant to acid, bile salt and digestive enzyme, while E5 was more resistant to temperature. The antibacterial assay showed L4 had a strong inhibitory effect against Staphylococcus aureus (BNCC186335), and E5, P7, W8 had effective antibacterial ability against Escherichia coli (C83902). In addition, L4, E5, P7 and W8 mainly produced organic acids and bacteriocin production to inhibit common intestinal pathogens. The results of antibiotic susceptibility assay indicated that L4, E5, P7 and W8 were highly sensitive to most clinically used antibiotics and didn't contain the VanA and VanB genes on the basis of PCR amplification, and L4, E5, P7 and W8 didn't exhibit hemolytic activity. The animal toxicity experiment results showed that no obvious pathological change was found in intestinal tissue sections, and L4, E5 and W8 strains also promoted the growth performance of mice, consequently, the L4, E5, P7 and W8 had no toxic effect on mice. In conclusion, lactobacillus isolated from feces of yaks not only have potential probiotics and strong antibacterial ability in vitro, but also are safe. Therefore, they have the potential to reduce the occurrence of bacterial diseases as new feed additives.