Composition of mucus- and digesta-associated bacteria in growing pigs with and without diarrhea differed according to the presence of colonic inflammation

C16 peptide and angiopoietin-1 alleviate the side effects of glucocorticoids in a rat multiple sclerosis model

BACKGROUND

Natural glucocorticoids (GCs) have been widely used to treat acute multiple sclerosis (MS) attacks. However, they also cause significant side effects related to immunosuppression. Our previous study found that C16 peptide combined with angiopoietin-1 (Ang-1) inhibited inflammatory cell infiltration and protected blood vessels in animal models of inflammatory neurodegenerative diseases.

METHODS

An acute experimental autoimmune encephalomyelitis model was established in Lewis rats to explore the effects of these drugs on MS. One hundred rats were equally and randomly assigned into five groups: normal control, vehicle, low-dose methylprednisolone (MP), high-dose MP, and C16 + Ang-1 (C+A). Histological examinations, behavioral tests, and high-throughput 16S rRNA gene sequencing were conducted to determine inflammation levels in the central nervous system, neuronal survival, functional recovery and gut microbiota.

RESULTS

The results illustrated that C+A exerted a neuroprotective effect in MS rats, with fewer side effects observed in the C+A group than in the high-dose MP group. The abundance of Campylobacter was increased in vehicle-treated rats, indicating an imbalance of the gut microbiota after MS. The abundance of probiotic Lactobacillus plantarum was increased in the C+A group. Low-dose MP failed to reverse the gut microbiota imbalance, whereas both the C+A and high-dose MP groups exhibited gut microbiota profiles more similar to those of the normal controls, with C+A displaying superior efficacy.

CONCLUSIONS

C16 plus Ang-1 might serve as a complement to GCs for the treatment of MS. Changes in the abundance of Campylobacter and L. plantarum suggest their essential roles in the pathogenesis of MS.

Microbiota governs host chenodeoxycholic acid glucuronidation to ameliorate bile acid disorder induced diarrhea

BACKGROUND

Disorder in bile acid (BA) metabolism is known to be an important factor contributing to diarrhea. However, the pathogenesis of BA disorder-induced diarrhea remains unclear.

METHODS

The colonic BA pool and microbiota between health piglets and BA disorder-induced diarrheal piglets were compared. Fecal microbiota transplantation and various cell experiments further indicated that chenodeoxycholic acid (CDCA) metabolic disorder produced CDCA-3β-glucuronide, which is the main cause of BA disorder diarrhea. Non-targeted metabolomics uncovered the inhibition of the BA glucuronidation by Lactobacillus reuteri (L. reuteri) is through deriving indole-3-carbinol (I3C). In vitro, important gene involved in the reduction of BA disorder induced-diarrhea were screened by RNA transcriptomics sequencing, and activation pathway of FXR-SIRT1-LKB1 to alleviate BA disorder diarrhea and P53-mediated apoptosis were proposed in vitro by multifarious siRNA interference, CO-IP, immunofluorescence, and so on, which mechanism was also verified in a variety of mouse models.

RESULTS

Here, we reveal for the first time that core microbiota derived I3C represses gut epithelium glucuronidation, particularly 3β-glucuronic CDCA production, which reaction is mediated by host UDP glucuronosyltransferase family 1 member A4 (UGT1A4) and necessary of BA disorder induced diarrhea. Mechanistically, L. reuteri derived I3C activates aryl hydrocarbon receptor to decrease UGT1A4 transcription and CDCA-3β-glucuronide content, thereby upregulating FXR-SIRT1-LKB1 signal. LKB1 binds with P53 based on protein interaction, ultimately resists to apoptosis and diarrhea. Moreover, I3C assists CDCA to attain the ameliorative effects of FXR activation in BA disorder diarrhea, through reversion of abnormal metabolism pathway, improving the outcomes of CDCA supplement.

CONCLUSION

These findings uncover the crucial interplay between gut epithelial cells and microbes, highlighting UGT1A4-mediated conversion of CDCA-3β-glucuronide as a key target for ameliorating BA disorder-induced diarrhea. Video Abstract.

Comparative analysis of fecal microbiota between diarrhea and non-diarrhea piglets reveals biomarkers of gut microbiota associated with diarrhea

Diarrhea poses a significant threat to the health and well-being of weaned piglets, leading to substantial morbidity and mortality and economic loss in the pig industry. However, the structural characteristics of the gut microbiota and the key genera associated with early diarrhea in piglets within large-scale production systems are poorly understood. This study aimed to investigate the differences in the microbial community structure and the specific genera alteration between the healthy piglets and diarrhea piglets, and to identify the biomarkers of gut microbiota associated with diarrhea in piglets. A total of 250 fecal samples, including 130 healthy piglets (Duroc × Landrace × Large Yorkshire) in the Control group and 120 from diarrhea piglets in Diarrhea group, were collected from three large-scale farms as discovery cohorts and were used for 16S rRNA gene sequencing. Additionally, 150 fecal samples from another large-scale pig farm were collected for the validation trail. The Chao1 and ACE indices were obviously lower (P < 0.01) in the diarrhea piglets compared to the healthy ones. Principal coordinate analysis showed significant differences in the distance matrix of gut microbiota between the healthy and diarrhea piglets (Bray-Curtis: P = 0.001, Jaccard: P = 0.001). Eighty-five genera were differentially enriched (P < 0.001) between healthy and diarrhea piglets. Notably, Treponema, Sphaerochaeta, Escherichia-Shigella, Slackia, and Staphylococcus were identified as potential biomarkers of diarrhea susceptibility; Clostridium sensu stricto 1, Prevotella_9, Olsenella, Dorea, and Lachnospiraceae NK4A136 group were found to be beneficial for maintaining intestinal homeostasis. These differentially enriched genera of healthy and diarrhea piglets were further confirmed in the validation cohort. In conclusion, this study identified the diarrhea-associated and beneficial genera in the faces of piglet, providing a theoretical basis for the diagnosis and intervention of diarrhea in weaned piglets.

Phenolic acids from Chicory roots ameliorate dextran sulfate sodium-induced colitis in mice by targeting TRP signaling pathways and the gut microbiota

BACKGROUND

Inflammatory bowel disease (IBD) is a type of immune-mediated condition associated with intestinal homeostasis. Our preliminary studies disclosed that Cichorium intybus L., a traditional medicinal plant, also known as Chicory in Western countries, contained substantial phenolic acids displaying significant anti-inflammatory activities. We recognized the potential of harnessing Chicory for the treatment of IBD, prompting a need for in-depth investigation into the underlying mechanisms.

METHODS

On the third day, mice were given 100, 200 mg/kg of total phenolic acids (PA) from Chicory and 200 mg/kg of sulfasalazine (SASP) via gavage, while dextran sodium sulfate (DSS) concentration was 2.5 % for one week. The study measured and evaluated various health markers including body weight, disease activity index (DAI), colon length, spleen index, histological score, serum concentrations of myeloperoxidase (MPO), nitric oxide (NO), superoxide dismutase (SOD), lipid oxidation (MDA), and inflammatory factors. We evaluated the TRP family and the NLRP3 inflammatory signaling pathways by Western blot, while 16S rDNA sequencing was used to track the effects of PA on gut microbes.

RESULTS

It was shown that PA ameliorated the weight loss trend, attenuated inflammatory damage, regulated oxidative stress levels, and repaired the intestinal barrier in DSS mice. Analyses of Western blots demonstrated that PA suppressed what was expressed of transient receptor potential family TRPV4, TRPA1, and the expression of NLRP3 inflammatory signaling pathway, NLRP3 and GSDMD. In addition, PA exerted therapeutic effects on IBD by regulating gut microbiota richness and diversity. Meanwhile, the result of the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis showed that gut microbiota was mainly related to Membrane Transport, Replication and Repair, Carbohydrate Metabolism and Amino Acid Metabolism.

CONCLUSION

PA derived from Chicory may have therapeutic effects on IBD by regulating the TRPV4/NLRP3 signaling pathway and gut microbiome. This study provides new insights into the effects of phenolic acids from Chicory on TRP ion channels and gut microbiota, revealing previously unexplored modes of action.

Purine Metabolism and Hexosamine Biosynthetic Pathway Abnormalities in Diarrheal Weaned Piglets Identified Using Metabolomics

Post-weaning diarrhea significantly contributes to the high mortality in pig production, but the metabolic changes in weaned piglets with diarrhea remain unclear. This study aimed to identify the differential metabolites in the urine of diarrheal weaned piglets and those of healthy weaned piglets to reveal the metabolic changes associated with diarrhea in weaned piglets. Nine 25-day-old piglets with diarrhea scores above 16 and an average body weight of 5.41 ± 0.18 kg were selected for the diarrhea group. Corresponding to the body weight and sex of the diarrhea group, nine 25-month-old healthy piglets with similar sex and body weights of 5.49 ± 0.21 kg were selected as the control group. Results showed that the serum C-reactive protein and cortisol of piglets in the diarrhea group were higher than those in the control group (p < 0.05). The mRNA expression of TNF-α, IFN-γ in the jejunum and colon, and IL-1β in the jejunum were increased in diarrhea piglets (p < 0.05), accompanied by a reduction in the mRNA expression of ZO-1, ZO-2, and CLDN1 in the jejunum and colon (p < 0.05); mRNA expression of OCLN in the colon also occurred (p < 0.05). Metabolomic analysis of urine revealed increased levels of inosine, hypoxanthine, guanosine, deoxyinosin, glucosamine, glucosamine-1-p, N-Acetylmannosamine, chitobiose, and uric acid, identified as differential metabolites in diarrhea piglets compared to the controls. In summary, elevated weaning stress and inflammatory disease were associated with the abnormalities of purine metabolism and the hexosamine biosynthetic pathway of weaned piglets. This study additionally indicated the presence of energy metabolism-related diseases in diarrheal weaned piglets.