Dysbiosis in a canine model of human fistulizing Crohn's disease

Longitudinal evaluation of the cutaneous and rectal microbiota of German shepherd dogs with perianal fistulas undergoing therapy with ciclosporin and ketoconazole

BACKGROUND

Perianal fistulas are painful ulcers or sinus tracts that disproportionately affect German shepherd dogs and are proposed as a spontaneous animal model of fistulising Crohn's disease.

OBJECTIVES

To characterise the rectal and cutaneous microbiota in German shepherd dogs with perianal fistulas and to investigate longitudinal shifts with lesion resolution during immunomodulatory therapy.

ANIMALS

Eleven German shepherd dogs with perianal fistulas and 15 healthy German shepherd dogs.

MATERIALS AND METHODS

Affected dogs were evaluated and swabbed at three visits, 30 days apart, while undergoing treatment with ciclosporin and ketoconazole. Healthy German shepherd dogs were contemporaneously sampled. Sites included the rectum, perianal skin and axilla. The microbiome was evaluated following sequencing of the V4 hypervariable region of the 16S ribosomal RNA (rRNA) gene.

RESULTS

Alpha diversity was not significantly different between healthy and affected dogs at each of the three body sites (p > 0.5), yet rectal and perianal beta diversities from affected dogs differed significantly from those of healthy dogs at Day 0 (p = 0.004). Rectal and perianal relative abundance of Prevotella spp. increased and perianal Staphylococcus spp. relative abundance decreased in affected dogs over time, coincident with lesion resolution.

CONCLUSIONS AND CLINICAL RELEVANCE

Changes in lesional cutaneous and rectal microbiota occur in German shepherd dogs with perianal fistulas and shift over time with lesion resolution during immunomodulatory therapy. Further investigations of the role of cutaneous and enteric microbiota in the pathogenesis of perianal fistulas, and whether manipulation of microbial populations may ameliorate disease, are needed.

Washed microbiota transplantation for Crohn's disease: A metagenomic, metatranscriptomic, and metabolomic-based study

BACKGROUND

Fecal microbiota transplantation (FMT) is a promising therapeutic approach for treating Crohn's disease (CD). The new method of FMT, based on the automatic washing process, was named as washed microbiota transplantation (WMT). Most existing studies have focused on observing the clinical phenomena. However, the mechanism of action of FMT for the effective management of CD-particularly in-depth multi-omics analysis involving the metagenome, metatranscriptome, and metabolome-has not yet been reported.

AIM

To assess the efficacy of WMT for CD and explore alterations in the microbiome and metabolome in response to WMT.

METHODS

We conducted a prospective, open-label, single-center clinical study. Eleven CD patients underwent WMT. Their clinical responses (defined as a decrease in their CD Activity Index score of > 100 points) and their microbiome (metagenome, metatranscriptome) and metabolome profiles were evaluated three months after the procedure.

RESULTS

Seven of the 11 patients (63.6%) showed an optimal clinical response three months post-WMT. Gut microbiome diversity significantly increased after WMT, consistent with improved clinical symptoms. Comparison of the metagenome and metatranscriptome analyses revealed consistent alterations in certain strains, such as Faecalibacterium prausnitzii, Roseburia intestinalis, and Escherichia coli. In addition, metabolomics analyses demonstrated that CD patients had elevated levels of various amino acids before treatment compared to the donors. However, levels of vital amino acids that may be associated with disease progression (e.g., L-glutamic acid, gamma-glutamyl-leucine, and prolyl-glutamine) were reduced after WMT.

CONCLUSION

WMT demonstrated therapeutic efficacy in CD treatment, likely due to the effective reconstruction of the patient's microbiome. Multi-omics techniques can effectively help decipher the potential mechanisms of WMT in treating CD.

Effects of dietary tryptophan supplementation on rectal temperature, humoral immunity, and cecal microflora composition of heat-stressed broilers

This trial aimed to determine the effects of tryptophan (Trp) on the rectal temperature, hormone, humoral immunity, and cecal microflora composition in broiler chickens under heat stress (HS). One hundred and eighty 18 days-old female Arbor Acres broilers were randomly divided into three treatment groups, with six replicates of ten birds in each replicate. The broilers were either raised under thermoneutral conditions (TN, 23 ± 1°C) or subjected to heat stress (34 ± 1°C for 8 h daily). The TN group received a basal diet, and another two heat-stressed groups were fed the basal diet (HS) or the basal diet supplemented with 0.18% Trp (HS + 0.18% Trp) for 21 consecutive days. The basal diet contained 0.18% Trp. Results revealed that HS increased the rectal temperature, serum epinephrine (EPI), and corticotropin-releasing hormone (CRH) concentrations (p < 0.05), reduced the bursal index, the levels of serum immunoglobulin A (IgA), IgG, IgM, and serotonin (5-HT) as well as the relative abundance of Actinobacteria in cecum (p < 0.05) compared with the TN group. Dietary supplementation of Trp decreased the rectal temperature, serum dopamine (DA), EPI, and the levels of CRH and L-kynurenine (p < 0.05), increased the bursal index, the levels of serum IgA, IgM, and 5-HT as well as the relative abundance of Ruminococcus torques group in cecum of heat-stressed broilers (p < 0.05) compared to HS group. In conclusion, dietary Trp supplementation decreased rectal temperature, improved cecal microbiota community and Trp metabolism, and enhanced humoral immunity of heat-stressed broilers.

Effect of Echinacea on gut microbiota of immunosuppressed ducks

Introduction

Immunosuppression puts animals in a susceptible state and disrupts the balance of intestinal flora, which can increase the risk of disease and cause serious harm to the farm. Echinacea can exert its immunomodulatory effect in various ways, but its influence on intestinal flora is unclear.

Methods

Therefore, we investigated the effect of Echinacea extract (EE) on gut microbiota in immunosuppressed ducks by 16s-RNA sequencing in this experiment.

Results

The results showed that EE significantly improved the weight gain of immunosuppressed ducks (p<0.001). It also increased the immune organ index (p<0.01) and upregulated the levels of TNF-α and IFN-γ (p<0.05) as well as IL-2 in the serum. The lesions of the bursa were evident compared to the spleen and thymus. After treatment in the EE group, the lymphocyte count of the bursa returned to healthy levels and the lesions were significantly improved. The diversity analysis showed that neither of the alpha-diversity indices showed a significant difference (p>0.05). However, the EE group had a trend closer to the healthy group compared to the M group. β-diversity analysis revealed a high degree of sample separation between the healthy and immunosuppressed groups. The sequencing result showed a significantly higher relative abundance of Prevotella and Prevotella_UCG_001 in the dexamethasone-treated group, which could be potential biomarkers of dexamethasone-induced immunosuppression. EE increased the relative abundance of Akkermansia, Bacteroides, and Alistipes and significantly decreased the relative abundance of Megamonas, Streptococcus, and Enterococcus (p<0.05).

Conclusion

The results showed that Echinacea extract improves the development of immunosuppressed ducks and modulates intestinal immune function by increasing the abundance of beneficial bacterial genera in the intestine.

The Intersection of Human and Veterinary Medicine-A Possible Direction towards the Improvement of Cell Therapy Protocols in the Treatment of Perianal Fistulas

The effective treatment of perianal fistulizing Crohn's disease is still a challenge. Local administration of mesenchymal stromal cells (MSCs) is becoming a part of accepted treatment options. However, as a fledgling technique, it still can be optimized. A new trend in translational research, which is in line with "One Health" approach, bases on exploiting parallels between naturally occurring diseases affecting humans and companion animals. Canine anal furunculosis (AF) has been indicated as condition analogous to human perianal Crohn's disease (pCD). This narrative review provides the first comprehensive comparative analysis of these two diseases based on the published data. The paper also outlines the molecular mechanisms of action of MSCs which are likely to have a role in modulating the perianal fistula niche in humans, and refers them to the current knowledge on the immunomodulatory properties of canine MSCs. Generally, the pathogenesis of both diseases shares main determinants such as the presence of genetic predispositions, dysregulation of immune response and the relation to intestine microbiota. However, we also identified many aspects which should be further specified, such as determining the frequency of true fistulas formation in AF patients, elucidating the role of TNF and Th17 pathway in the pathogenesis of AF, or clarifying the role of epithelial-to-mesenchymal transition phenomenon in the formation of canine fistulae. Nevertheless, the available data support the hypothesis that the results from testing cell therapies in dogs with anal furunculosis have a significant translational value in optimizing MSC transplants procedures in pCD patients.

Association of anti-TNF-α treatment with gut microbiota of patients with ankylosing spondylitis

OBJECTIVE

Gut dysbiosis contributes to multiple autoimmune diseases, including ankylosing spondylitis, which is commonly treated with tumor necrosis factor (TNF)-α inhibitors (TNFis). Because host TNF-α levels are considered to interact with gut microbiota, we aimed to systematically investigate the microbiota profile of ankylosing spondylitis patients with anti-TNF-α-based treatment and identify potential key bacteria.

METHODS

Fecal samples were collected from 11 healthy controls and 24 ankylosing spondylitis patients before/after anti-TNF-α treatment, the microbiota profiles of which were evaluated by 16S ribosomal DNA amplicon sequencing and subsequent bioinformatic analysis.

RESULTS

Significantly different microbial compositions were observed in samples from ankylosing spondylitis patients compared with healthy controls, characterized by a lower abundance of short-chain fatty acid (SCFA)-producing bacteria. All patients exhibited a positive response after anti-TNF-α treatment, accompanied by a trend of restoration in the microbiota compositions and functional profile of ankylosing spondylitis patients to healthy controls. In particular, the abundance of SCFA-producing bacteria (e.g. Megamonsa and Lachnoclostridium ) was not only significantly lower in ankylosing spondylitis patients than in healthy controls and restored after anti-TNF-α treatment but also negatively correlated with disease severity (e.g. cor  = -0.52, P  = 8 × 10 -5 for Megamonsa ). In contrast, Bacilli and Haemophilus may contribute to ankylosing spondylitis onset and severity.

CONCLUSIONS

Microbiota dysbiosis in ankylosing spondylitis patients can be restored after anti-TNF-α treatment, possibly by impacting SCFA-producing bacteria.

Comprehensive Analysis of Gut Microbiota and Fecal Bile Acid Profiles in Children With Biliary Atresia

Background

Biliary atresia (BA) is the most common cholestatic liver disease in neonates. Herein, we aimed at characterizing the gut microbiota and fecal bile acid profiles of BA patients, defining the correlations between them, and evaluating the relationship between the clinical pathogenesis and changes in the gut microbiota and bile acid profiles.

Methods

A total of 84 fecal samples from BA patients (n = 46) and matched healthy controls (HCs, n = 38) were subjected to sequencing by 16S rRNA gene amplification, and fecal bile acid were analyzed by targeted metabolomics.

Findings

Compared with the controls, a structural separation of the intestinal flora of BA patients was uncovered, which was accompanied by changes in the composition of fecal bile acids. In the BA group, Actinobacillus, Monoglobus, and Agathobacter were enriched in patients without cholangitis (p &lt; 0.05). Selenomonadaceae and Megamonas were more abundant in patients without recurrent cholangitis episodes (p &lt; 0.05), while Lachnospiraceae and Ruminococcaceae were enriched in patients with multiple recurrences of cholangitis (p &lt; 0.05). Postoperative jaundice clearance was associated with Campylobacter and Rikenellaceae (p &lt; 0.05), and tauroursodeoxycholic acid was associated with jaundice clearance (p &lt; 0.001).

Conclusion

BA patients are characterized by different compositions of gut microbiota and bile acids, and their interaction is involved in the process of liver damage in BA, which may be closely related to the occurrence of postoperative cholangitis and jaundice clearance.

Functional properties of miscanthus fiber and prebiotic blends in extruded canine diets

Dietary fiber has become increasingly recognized as a key factor in maintaining gastrointestinal health. Dietary fiber sources are often comprised of several different fiber fractions, each with unique physicochemical properties. These properties can have varying physiological effects on the gastrointestinal tract that include modulation of microbiota, production of fermentation-derived metabolites, and laxation. The objectives of this study were 1) to determine the effects of a novel dietary fiber source, miscanthus grass fiber (MF), and prebiotic and fiber blends on gastrointestinal tolerance, apparent total tract digestibility, fecal metabolites, and fecal microbiota and 2) to evaluate the palatability of extruded diets containing MF in comparison to traditional dietary fiber sources. All animal procedures were approved by the University of Illinois Institutional Animal Care and Use Committee. Six dietary treatments were formulated to meet or exceed the AAFCO nutrient profile of 2018 and included either cellulose (CO), beet pulp (BP), MF, or a blend of MF and tomato pomace, MF and resistant starch, or MF and fructooligosaccharide. A total of 12 adult neutered female beagles (mean age 5.8 ± 1.1 yr; mean body weight 10.9 ± 1.0 kg; mean body condition score 5.7 ± 0.7) were randomly assigned to one of the six treatment diets in a replicated 6 × 6 Latin square design. Each dog was fed their assigned diet for a treatment period of 21 d with 17 d of diet adaptation followed by 4 d of total and fresh fecal collection. All diets were well accepted and digested by the dogs. Dogs fed BP had greater fecal total short-chain fatty acid concentration than the CO treatment (P < 0.05), while the dogs fed diets containing MF were intermediate. In a two-bowl palatability trial, no significant preference was observed between the extruded diets containing MF and CO (P > 0.05). However, a significant preference for the extruded diet containing BP over the diet containing only MF was observed (P < 0.05). The α-diversity of fecal microbial communities was not impacted by treatment (P > 0.05), but β-diversity indicated that dogs fed the BP diet differed from the other treatment groups (P < 0.05). The data from this study suggest that miscanthus grass can be successfully utilized in fiber blends in extruded diets for adult dogs, with modulatory effects similar to the traditional dietary fiber source, cellulose.

Insight Into the Potential Value of Gut Microbial Signatures for Prediction of Gestational Anemia

The gut microbiota alternations are associated with gestational anemia (GA); however, limited predictive value for the subsequent incidence of anemia in normal gestational women has been obtained. We sought to rigorously characterise gut dysbiosis in subjects with GA and explored the potential predictive value of novel microbial signatures for the risk of developing GA. A prospective cohort of subjects with GA (n = 156) and healthy control (n = 402), all of whom were free of GA in the second trimester, by 16S rRNA gene sequencing was conducted. Microbial signatures altered dramatically in GA compared with healthy control in the second trimester. Megamonas, Veillonella, and Haemophilus were confirmed to show differential abundances in GA after adjusting for covariates. On the contrary, Lachnospiraceae and Blautia were enriched in control. Microbial co-abundance group (CAG) network was constructed. Prospectively, CAG network relatively accurately predicted upcoming GA in normal pregnant women with an AUC of 0.7738 (95%CI: 0.7171, 0.8306) and the performance was further validated in Validation set (0.8223, 95%CI: 0.7573, 0.8874). Overall, our study demonstrated that alterations in the gut microbial community were associated with anemia in pregnancy and microbial signatures could accurately predict the subsequent incidence of anemia in normal pregnant women. Our findings provided new insights into understanding the role of gut microbiota in GA, identifying high-risk individuals, and modulating gut microbiota as a therapeutic target, thus improving quality of life and well-being of women and children.

Supplemental selenium source on gut health: insights on fecal microbiome and fermentation products of growing puppies

Selenium is an essential trace element that can modulate the gut microbiome with an impact on host health. The present study aimed to evaluate the effects of organic (selenium-enriched yeast) vs inorganic (sodium selenite) selenium source on fecal end-fermentation products and gut microbiome of puppies from 20 to 52 weeks of age. Alpha and beta diversity of the gut bacterial community were affected by age but not by gender or selenium source. The relative abundance of taxa was differently affected by age, and the DNA concentration of all selected bacterial groups increased with age, although total volatile fatty acids (VFA), acetate, propionate, caproate and lactate concentrations decreased. Organic selenium was associated with a higher concentration of total VFA, propionate and butyrate, a higher number of DNA copies of Lactobacillus, and a trend to lower DNA copies of Escherichia coli. Effects on fecal microbiome during growth differed with selenium source. Females had higher fecal end-fermentation products related to protein degradation, whereas males had higher DNA concentration of Bifidobacterium. Organic selenium might be beneficial over inorganic for dog food supplementation due to the positive modulation of the gut microbiome observed in puppies.