16S rRNA gene pyrosequencing reveals bacterial dysbiosis in the duodenum of dogs with idiopathic inflammatory bowel disease

The Relationship between Canine Behavioral Disorders and Gut Microbiome and Future Therapeutic Perspectives

Canine behavioral disorders have become one of the most common concerns and challenging issues among dog owners. Thus, there is a great demand for knowledge about various factors affecting dogs' emotions and well-being. Among them, the gut-brain axis seems to be particularly interesting, especially since in many instances the standard treatment or behavioral therapies insufficiently improve animal behavior. Therefore, to face this challenge, the search for novel therapeutic methods is highly required. Existing data show that mammals' gut microbiome, immune system, and nervous system are in continuous communication and influence animal physiology and behavior. This review aimed to summarize and discuss the most important scientific evidence on the relationship between mental disorders and gut microbiota in dogs, simultaneously presenting comparable outcomes in humans and rodent models. A comprehensive overview of crucial mechanisms of the gut-brain axis is included. This refers especially to the neurotransmitters crucial for animal behavior, which are regulated by the gut microbiome, and to the main microbial metabolites-short-chain fatty acids (SCFAs). This review presents summarized data on gut dysbiosis in relation to the inflammation process within the organism, as well as the activation of the hypothalamic-pituitary-adrenal (HPA) axis. All of the above mechanisms are presented in this review in strict correlation with brain and/or behavioral changes in the animal. Additionally, according to human and laboratory animal studies, the gut microbiome appears to be altered in individuals with mental disorders; thus, various strategies to manipulate the gut microbiota are implemented. This refers also to the fecal microbiome transplantation (FMT) method, based on transferring the fecal matter from a donor into the gastrointestinal tract of a recipient in order to modulate the gut microbiota. In this review, the possible effects of the FMT procedure on animal behavioral disorders are discussed.

Interactions between intestinal microbiota and metabolites in zebrafish larvae exposed to polystyrene nanoplastics: Implications for intestinal health and glycolipid metabolism

Previous studies have shown the harmful effects of nanoscale particles on the intestinal tracts of organisms. However, the specific mechanisms remain unclear. Our present study focused on examining the uptake and distribution of polystyrene nanoplastics (PS-NPs) in zebrafish larvae, as well as its toxic effects on the intestine. It was found that PS-NPs, marked with red fluorescence, primarily accumulated in the intestine section. Subsequently, zebrafish larvae were exposed to normal PS-NPs (0.2-25 mg/L) over a critical 10-day period for intestinal development. Histopathological analysis demonstrated that PS-NPs caused structural changes in the intestine, resulting in inflammation and oxidative stress. Additionally, PS-NPs disrupted the composition of the intestinal microbiota, leading to alterations in the abundance of bacterial genera such as Pseudomonas and Aeromonas, which are associated with intestinal inflammation. Metabolomics analysis showed alterations in metabolites that are primarily involved in glycolipid metabolism. Furthermore, MetOrigin analysis showed a significant correlation between bacterial flora (Pedobacter and Bacillus) and metabolites (D-Glycerate 2-phosphate and D-Glyceraldehyde 3-phosphate), which are related to the glycolysis/gluconeogenesis pathways. These findings were further validated through alterations in multiple biomarkers at various levels. Collectively, our data suggest that PS-NPs may impair the intestinal health, disrupt the intestinal microbiota, and subsequently cause metabolic disorders.

Safety profile and effects on the peripheral immune response of fecal microbiota transplantation in clinically healthy dogs

BACKGROUND

Fecal microbiota transplantation (FMT) is increasingly used for gastrointestinal and extra-gastrointestinal diseases in veterinary medicine. However, its effects on immune responses and possible adverse events have not been systematically investigated.

HYPOTHESIS/OBJECTIVES

Determine the short-term safety profile and changes in the peripheral immune system after a single FMT administration in healthy dogs.

ANIMALS

Ten client-owned, clinically healthy dogs as FMT recipients, and 2 client-owned clinically healthy dogs as FMT donors.

METHODS

Prospective non-randomized clinical trial. A single rectal enema of 5 g/kg was given to clinically healthy canine recipients. During the 28 days after FMT administration, owners self-reported adverse events and fecal scores. On Days 0 (baseline), 1, 4, 10, and 28 after FMT, fecal and blood samples were collected. The canine fecal dysbiosis index (DI) was calculated using qPCR.

RESULTS

No significant changes were found in the following variables: CBC, serum biochemistry, C-reactive protein, serum cytokines (interleukins [IL]-2, -6, -8, tumor necrosis factor [TNF]-α), peripheral leukocytes (B cells, T cells, cluster of differentiation [CD]4+ T cells, CD8+ T cells, T regulatory cells), and the canine DI. Mild vomiting (n = 3), diarrhea (n = 4), decreased activity (n = 2), and inappetence (n = 1) were reported, and resolved without intervention.

CONCLUSIONS AND CLINICAL IMPORTANCE

Fecal microbiota transplantation did not significantly alter the evaluated variables and recipients experienced minimal adverse events associated with FMT administration. Fecal microbiota transplantation was not associated with serious adverse events, changes in peripheral immunologic variables, or the canine DI in the short-term.

Fecal microbiome composition and diversity of cryopreserved canine stool at different duration and storage conditions

Fresh-frozen stool banks intended for humans with gastrointestinal and metabolic disorders have been recently established and there are ongoing efforts to establish the first veterinary fresh-frozen stool bank. Fresh frozen stored feces provide an advantage of increased availability and accessibility to high-quality optimal donor fecal material. The stability of frozen canine feces regarding fecal microbiome composition and diversity has not been reported in dogs, providing the basis for this study. We hypothesized that fecal microbial composition and diversity of healthy dogs would remain stable when stored at -20°C and -80°C for up to 12 months compared to baseline samples evaluated before freezing. Stool samples were collected from 20 apparently healthy dogs, manually homogenized, cryopreserved in 20% glycerol and aliquoted, frozen in liquid nitrogen and stored at -20°C or -80°C for 3, 6, 9, and 12 months. At baseline and after period of storage, aliquots were thawed and treated with propidium monoazide before fecal DNA extraction. Following long-read 16S-rRNA amplicon sequencing, bacterial community composition and diversity were compared among treatment groups. We demonstrated that fresh-frozen canine stools collected from 20 apparently healthy dogs could be stored for up to 12 months at -80°C with minimal change in microbial community composition and diversity and that storage at -80°C is superior to storage at -20°C. We also found that differences between dogs had the largest effect on community composition and diversity. Relative abundances of certain bacterial taxa, including those known to be short-chain fatty acid producers, varied significantly with specific storage temperatures and duration. Further work is required to ascertain whether fecal donor material that differs in bacterial community composition and diversity across storage conditions and duration could lead to differences in clinical efficacy for specific clinical indications of fecal microbiota transplantation.

Effects of Increasing Levels of Purified Beta-1,3/1,6-Glucans on the Fecal Microbiome, Digestibility, and Immunity Variables of Healthy Adult Dogs

Yeast-purified beta-1,3/1,6-glucans (BG) can modulate dogs' immune systems and microbiome, but the optimal inclusion dose remains unknown. The aim of the study was to evaluate the effects of 0.0, 0.07, 0.14, and 0.28% inclusion of BG in a dry extruded diet on the digestibility, immunity, and fecal microbiota of healthy adult dogs. Eight male and female border collies [n = 4; body condition score (BCS) = 5] and English cocker spaniels (n = 4; BCS = 5), aged 3.5 ± 0.5 years, were randomly distributed into two 4 × 4 balanced Latin squares. Fecal microbiota (using 16S rRNA sequencing, Illumina®), apparent digestibility coefficients (ADC) of nutrients, fecal concentrations of short-chain fatty acids (SCFA) and branched-chain fatty acids (BCFA), ammoniacal nitrogen, lactic acid, IgA and pH, lymphocyte immunophenotyping, intensity and percentage of phagocytosis and oxidative burst were determined. No differences were observed in Faith (p = 0.1414) and Pielou-evenness (p = 0.1151) between treatments, but beta diversity was different between 0.0% and 0.14% BG groups (p = 0.047). Moreover, the Firmicutes phylum was the most abundant in all groups and exhibited the highest relative abundance after the consumption of 0.14% BG, a finding considered beneficial for the canine microbiome. The Erysipelotrichaceae and Ruminococcaceae families, along with the Faecalibacterium and Prevotella genera, considered favorable for their involvement in butyrate production and other metabolites, showed increased abundance after the consumption of 0.14% BG. The potentially pathogenic Proteobacteria phylum displayed lower abundance after the consumption of 0.14% BG. Fecal concentrations of the evaluated compounds and pH did not differ after consumption of the BG at all percentages. Higher crude protein ADC was found after 0.14 and 0.28% BG consumption (p < 0.0001), but no differences were found for other nutrients. Phagocytosis, oxidative burst, and lymphocyte populations were not modulated by any of the treatments; however, 0.14% BG modulated the lymphocyte T CD4+:CD8+ ratio (p = 0.0368), an important marker of immune system efficiency. The inclusion of 0.14% BG resulted in the best responses and was the best dose evaluated.

Faecal microbiota and fatty acids in feline chronic enteropathy

BACKGROUND

Feline chronic enteropathy is a set of disorders defined as the presence of clinical signs of gastrointestinal disease for at least three weeks. The most common final diagnoses are inflammatory bowel disease and alimentary small cell lymphoma. The etiopathogenesis of these diseases is incompletely understood; however, it is hypothesised that they involve a combination of factors, including altered composition and/or functionality of the intestinal microbiome. An important factor in the interplay of the microbiome and host is the production of short- and branched-chain fatty acids.  The aim of this study was to evaluate the possible differences in faecal microbiota diversity, composition and fatty acid production between cats suffering from chronic enteropathy and healthy cats. Sixteen cats suffering from chronic enteropathy and fourteen healthy control cats were enrolled in the study. The microbiota compositions of faecal samples were analysed by using next-generation amplicon sequencing of the V3V4 fragment of the 16S rRNA gene. Fatty acids were evaluated by high-performance liquid chromatography.

RESULTS

Both the alpha and beta diversities were significantly lower in samples obtained from cats with chronic enteropathy. The relative abundance of the phylum Proteobacteria, orders Lactobacillales and Enterobacterales, family Enteriobacteriaceae and genus Escherichia Shigella were higher in diseased cats, whereas the abundance of the phylum Bacteroidota and order Peptococcales were higher in control cats. The faecal concentrations of short-chain fatty acids were higher in cats with chronic enteropathy, with lower propionate proportions and higher butyrate proportions.

CONCLUSION

The study revealed alterations in microbiota compositions and short-chain fatty acid concentration in cats suffering from chronic enteropathy, which is an important finding both for research on the pathogenesis of the disease and for potential therapeutic interventions in the form of faecal microbiota transplantation and/or probiotic supplementation.

Noninvasive sampling of the small intestinal chyme for microbiome, metabolome and antimicrobial resistance genes in dogs, a proof of concept

BACKGROUND

The gastrointestinal microbiome and metabolome vary greatly throughout the different segments of the gastrointestinal tract, however current knowledge of gastrointestinal microbiome and metabolome in health and disease is limited to fecal samples due to ease of sampling. The engineered Small Intestinal MicroBiome Aspiration (SIMBA™) capsule allows specific sampling of the small intestine in humans. We aimed to determine whether administration of SIMBA™ capsules to healthy beagle dogs could reliably and safely sample the small intestinal microbiome and metabolome when compared to their fecal microbiome and metabolome.

RESULTS

Eleven beagle dogs were used for the study. Median transit time of capsules was 29.93 h (range: 23.83-77.88). Alpha diversity, as measured by the Simpson diversity, was significantly different (P = 0.048). Shannon diversity was not different (P = 0.114). Beta diversity results showed a significant difference between capsule and fecal samples regarding Bray-Curtis, weighted and unweighted unifrac (P = 0.002) and ANOSIM distance metric s (R = 0.59, P = 0.002). In addition to observing a statistically significant difference in the microbial composition of capsules and feces, distinct variation in the metabolite profiles was seen between the sample types. Heat map analysis showed 16 compounds that were significantly different between the 2 sampling modes (adj-P value ranged between 0.004 and 0.036) with 10 metabolites more abundant in the capsule than in the feces and 6 metabolites more abundant in the feces compared to the capsules.

CONCLUSIONS

The engineered Small Intestinal MicroBiome Aspiration (SIMBA™) capsule was easy and safe to administer to dogs. Microbiome and metabolome analysis from the capsule samples were significantly different than that of the fecal samples and were like previously published small intestinal microbiome and metabolome composition.

A comprehensive analysis of gut and skin microbiota in canine atopic dermatitis in Shiba Inu dogs

BACKGROUND

Like its human counterpart, canine atopic dermatitis (cAD) is a chronic relapsing condition; thus, most cAD-affected dogs will require lifelong treatment to maintain an acceptable quality of life. A potential intervention is modulation of the composition of gut microbiota, and in fact, probiotic treatment has been proposed and tried in human atopic dermatitis (AD) patients. Since dogs are currently receiving intensive medical care, this will be the same option for dogs, while evidence of gut dysbiosis in cAD is still missing, although skin microbial profiling in cAD has been conducted in several studies. Therefore, we conducted a comprehensive analysis of both gut and skin microbiota in cAD in one specific cAD-predisposed breed, Shiba Inu. Additionally, we evaluated the impact of commonly used medical management on cAD (Janus kinase; JAK inhibitor, oclacitinib) on the gut and skin microbiota. Furthermore, we genotyped the Shiba Inu dogs according to the mitochondrial DNA haplogroup and assessed its association with the composition of the gut microbiota.

RESULTS

Staphylococcus was the most predominant bacterial genus observed in the skin; Escherichia/Shigella and Clostridium sensu stricto were highly abundant in the gut of cAD-affected dogs. In the gut microbiota, Fusobacteria and Megamonas were highly abundant in healthy dogs but significantly reduced in cAD-affected dogs. The abundance of these bacterial taxa was positively correlated with the effect of the treatment and state of the disease. Oclacitinib treatment on cAD-affected dogs shifted the composition of microbiota towards that in healthy dogs, and the latter brought it much closer to healthy microbiota, particularly in the gut. Additionally, even within the same dog breed, the mtDNA haplogroup varied, and there was an association between the mtDNA haplogroup and microbial composition in the gut and skin.

CONCLUSIONS

Dysbiosis of both the skin and the gut was observed in cAD in Shiba Inu dogs. Our findings provide a basis for the potential treatment of cAD by manipulating the gut microbiota as well as the skin microbiota. Video Abstract.

Intestinal Microbiome in Dogs with Chronic Hepatobiliary Disease: Can We Talk about the Gut-Liver Axis?

The gut-liver axis represents a current topic in human medicine. Extensive research investigates the gut microbiome (GM) modifications in relation to various kinds of chronic hepatobiliary diseases (CHD), with many mechanisms and therapeutical implications recognized. Those aspects in veterinary medicine are still quite unexplored. The aim of the present study was to evaluate GM in dogs diagnosed with CD. Comparison among CHD dogs were made considering some clinical and biochemical variables (lipemia and alanine-aminotransferase activities), presence of cholestasis or endocrine disorders, diet). Sixty-five dogs were prospectively enrolled with clinical and hematobiochemical evaluation and 16S-RNA GM sequencing assessed. Dogs that received antibiotics and/or pre/pro/symbiotics administration were excluded. Deeper GM alteration was observed between dogs with or without ultrasonographic and biochemical cholestatic CHD. Cholestasis was associated with a decrease in several bacterial taxa, including Clostridium hiranonis, Fusobacterium, Megamonas, Ruminococcus faecis, Turicibacter, and higher levels of Escherichia/Shigella and Serratia. Thus, the alteration in bile flow and composition, typical of cholestasis, may directly affect the local intestinal microbial environment. For the management of dogs with CHD and especially cholestatic CHD, clinicians should be aware that gut-liver interaction may lead to dysbiosis.

Composition and evolution of the gut microbiota of growing puppies is impacted by their birth weight

Low birth weight puppies present an increased risk of neonatal mortality, morbidity, and some long-term health issues. Yet it has not been investigated if those alterations could be linked to the gut microbiota composition and evolution. 57 puppies were weighed at birth and rectal swabs were performed at 5 time points from birth to 28 days of age. Puppies were grouped into three groups based on their birth weight: low birth weight (LBW), normal birth weight (NBW) and high birth weight (HBW). 16S rRNA gene sequencing was used to highlight differences in the fecal microbiota. During the first three weeks, the relative abundance of facultative anaerobic bacteria such as E. coli, C. perfringens and Tyzzerella was higher in LBW feces, but they catch back with the other groups afterwards. HBW puppies showed higher abundances of Faecalibacterium and Bacteroides during the neonatal period, suggesting an earlier maturation of their microbiota. The results of this study suggest that birth weight impact the initial establishment of the gut microbiota in puppies. Innovative strategies would be desired to deal with altered gut microbiota in low birth weight puppies aiming to improve their survival and long term health.

The use of metronidazole in acute diarrhea in dogs: a narrative review

Acute diarrhea is a common reason for non-wellness veterinary visits in dogs. Treatment for acute diarrhea usually consists of supportive care with nutritional intervention, fluid therapy, anthelmintics, and often an antibiotic - commonly metronidazole in North America. The empirical use of metronidazole for acute diarrhea in dogs has been a common practice in veterinary medicine for many decades; however, recent studies evaluating its use suggest it may be inappropriately utilized in many cases. Herein, we review the evidence evaluating the use of metronidazole and other antibiotics in acute diarrhea in the human and veterinary literature. Recommendations on the use of metronidazole and other antibiotics as well as other therapeutic considerations in the treatment of acute diarrhea are also provided.

Age-associated changes in intestinal health biomarkers in dogs

The gut microbiome is critical for maintaining host health. In healthy humans, the aging process is one of the main factors modulating the changes in the intestinal microbiota. However, little is known about the relationship between gut health, microbiota, and the aging process in dogs. The present study aims to explore the differences in the intestinal microbiota and intestinal health based on fecal biomarkers in a population of dogs of different ages. The study involved 106 dogs of different breeds aged between 0.2 and 15 years categorized as senior (>7 years; n = 40), adult (2-7 years; n = 50), and junior (< 2 years; n = 16). Fecal samples were collected during the same period at the same facilities. The analysis included the following gut health indicators: 16S rRNA gene sequencing to investigate the differences in the fecal microbiota; qPCR to determine the dysbiosis index; fecal short-chain fatty acid concentrations; fecal calprotectin; and immunoglobulin A. Beta diversity analysis revealed a significant difference with a small effect size (p = 0.003; R = 0.087) among age categories based on the unweighted UniFrac metric, but no significance was observed based on the weighted UniFrac metric or Bray-Curtis distances. There were no significant differences in the alpha diversity measures or the fecal dysbiosis index among age categories. Senior dogs had significantly higher relative abundance proportions in phyla Bacteroidota and Pseudomonadota and the genus Faecalibacterium, but not on qPCR analysis. At the family level, Ruminococcaceae, Uncl. Clostridiales.1, Veillonellaceae, Prevotellaceae, Succinivibrionaceae, and Bacteroidaceae abundances were higher in the senior category than in the adult and/or junior categories. Relative proportions, but not concentrations of fecal acetate, were higher in the senior category, while butyrate, isovaleric acid, and valeric acid were lower. The valeric acid concentration was significantly lower in the senior category than in the adult category. Calprotectin and immunoglobulin A levels did not differ significantly across groups. In conclusion, this study observed multiple minor changes in the fecal microbiota composition and the relative amount of short-chain fatty acids in dogs among different age groups, but studies in larger populations representative of all ages are warranted to refine the present results.

Research Progress of Biological Feed in Beef Cattle

Biological feed is a feed product developed through bioengineering technologies such as fermentation engineering, enzyme engineering, protein engineering, and genetic engineering. It possesses functional characteristics of high nutritional value and good palatability that can improve feed utilization, replace antibiotics, enhance the health level of livestock and poultry, improve the quality of livestock products, and promote a better breeding environment. A comprehensive review is provided on the types of biological feed, their mechanism of action, fermenting strains, fermenting raw material resources, and their current status in animal production to facilitate in-depth research and development of applications.

Isolation, Characterization, and Comparative Genomics of the Novel Potential Probiotics from Canine Feces

Lactic acid bacteria (LAB) are commonly used as probiotics; however, not all LAB strains have the same beneficial effects. To successfully use LAB as probiotics in canines, LAB species should originate from the canine intestinal tract as they display host specificity. The objective of this study was to investigate the phenotypic and genomic traits of potential probiotic LAB isolated from canine fecal samples. Twenty LAB samples were evaluated for their potential probiotic characteristics including resistance to low pH, bile salts, hydrophobicity, auto-aggregation, co-aggregation, adhesion to epithelia or mucosa, and production of inhibitory compounds. Additionally, we evaluated their safety and other beneficial effects on canine health, such as DPPH free radical scavenging, and β-galactosidase. Four strains demonstrated potential probiotic characteristics and were selected: Enterococcus hirae Pom4, Limosilactobacillus fermentum Pom5, Pediococcus pentosaceus Chi8, and Ligilactobacillus animalis FB2. Safety evaluations showed that all strains lacked hemolytic activity, could not produce biogenic amines, and did not carry any pathogenic genes. In addition, L. fermentum Pom5 and P. pentosaceus Chi8 displayed susceptibility to all antibiotics and concordant with the absence of antibiotic resistance genes. Based on their phenotypic and genomic characteristics, L. fermentum Pom5 and P. pentosaceus Chi8 were identified as potential probiotic candidates for canines.

Pilot evaluation of a single oral fecal microbiota transplantation for canine atopic dermatitis

The gut microbiota has been suggested to be involved in the pathogenesis of canine atopic dermatitis (cAD). However, the gut microbiota has not been well characterized in dogs with atopic dermatitis (AD). In addition, the efficacy of fecal microbiota transplantation (FMT) in dogs with AD remains unclear. This research, therefore, aimed to characterize the gut microbiota of dogs with AD and conduct pilot evaluation of the efficacy of a single oral FMT on clinical signs and the gut microbiota of dogs with AD. For these purposes, we used 12 dogs with AD and 20 healthy dogs. The 16S rRNA analysis of the fecal microbiota revealed significant differences between 12 dogs with AD and 20 healthy dogs. Next, a single oral FMT was performed in 12 dogs with AD as a single-arm, open-label clinical trial for 56 days. A single oral FMT significantly decreased Canine Atopic Dermatitis Extent and Severity Index (CADESI)-04 scores from day 0 (median score, 16.5) to day 56 (8) and Pruritus Visual Analog Scale (PVAS) scores from days 0 (median score, 3) to day 56 (1). Furthermore, a single oral FMT changed the composition of the fecal microbiota of dogs with AD at the phylum and genus levels. The number of common amplicon sequence variants in the fecal microbiota between donor dogs and dogs with AD was positively correlated with CADESI-04 and PVAS reduction ratios 56 days after FMT. Our findings suggest that the gut microbiota plays a pivotal role in the pathogenesis of cAD, and that oral FMT could be a new therapeutic approach targeting the gut microbiota in cAD.

Special Issue "Gut Microbiota, Inflammatory Bowel Diseases, and Therapeutic Targets"

The gut microbiota and its overall genetic composition, the microbiome, have been the subject of extensive research over the last decade within the fields of genomics, transcriptomics and metabolomics, and their role in various other targeted approaches and advanced technologies has been explored [...].

Comparison of the Effects of Enzymolysis Seaweed Powder and Saccharomyces boulardii on Intestinal Health and Microbiota Composition in Kittens

Kittens are prone to intestinal health problems as their intestines are not completely developed. Seaweed is rich in plant polysaccharides and bioactive substances that are highly beneficial to gut health. However, the effects of seaweed on cat gut health have not been assessed. This study compared the effects of dietary supplementation with enzymolysis seaweed powder and Saccharomyces boulardii on the intestinal health of kittens. In total, 30 Ragdoll kittens (age: 6 months; weight: 1.50 ± 0.29 kg) were assigned to three treatment groups for a 4-week feeding trial. The dietary treatment given was as follows: (1) basal diet (CON); (2) CON + enzymolysis seaweed powder (20 g/kg of feed) mixed evenly with the diet (SE); and (3) CON + Saccharomyces boulardii (2 × 10¹⁰ CFU/kg of feed) mixed evenly with the diet (SB). Compared with the CON and SB groups, dietary supplementation with the enzymolysis seaweed powder improved the immune and antioxidant capacity and also reduced the intestinal permeability and inflammation levels of kittens. The relative abundance of Bacteroidetes, Lachnospiraceae, Prevotellaceae, and Faecalibacterium in the SE group was higher than those in the CON and SB groups (p ≤ 0.05), while the relative abundance of Desulfobacterota, Sutterellaceae, and Erysipelatoclostridium in the SB group was lower than that in the SE group (p ≤ 0.05). Moreover, enzymolysis seaweed powder did not alter the level of intestinal SCFAs in kittens. Conclusively, supplementing kitten diet with enzymolysis seaweed powder can promote intestinal health by enhancing the gut barrier function and optimizing the microbiota composition. Our findings provide new perspectives on the application of enzymolysis seaweed powder.

The Intestinal Microbiome in Dogs with Chronic Enteropathies and Cobalamin Deficiency or Normocobalaminemia-A Comparative Study

Cobalamin deficiency is a common sequela of chronic enteropathies (CE) in dogs. Studies comparing the intestinal microbiome of CE dogs with cobalamin deficiency to those that are normocobalaminemic are lacking. Therefore, our aim was to describe the fecal microbiome in a prospective, comparative study evaluating 29 dogs with CE and cobalamin deficiency, 18 dogs with CE and normocobalaminemia, and 10 healthy control dogs. Dogs with cobalamin deficiency were also analyzed after oral or parenteral cobalamin supplementation. Overall microbiome composition (beta diversity) at baseline was significantly different in CE dogs with cobalamin deficiency when compared to those with normocobalaminemia (p = 0.001, R = 0.257) and to healthy controls (p = 0.001, R = 0.363). Abundances of Firmicutes and Actinobacteria were significantly increased (q = 0.010 and 0.049), while those of Bacteroidetes and Fusobacteria were significantly decreased (q = 0.002 and 0.014) in CE dogs with cobalamin deficiency when compared to healthy controls. Overall microbiome composition in follow-up samples remained significantly different after 3 months in both dogs receiving parenteral (R = 0.420, p = 0.013) or oral cobalamin supplementation (R = 0.251, p = 0.007). Because cobalamin supplementation, in combination with appropriate therapy, failed to restore the microbiome composition in the dogs in our study, cobalamin is unlikely to be the cause of those microbiome changes but rather an indicator of differences in underlying pathophysiology that do not influence clinical severity but result in a significant aggravation of dysbiosis.

Analysis of fecal microbial profiles in dogs with intestinal lymphangiectasia

Intestinal lymphangiectasia (IL) is a common complication in dogs. This study analyzed intestinal microbiota using 16S rRNA amplicon analysis as candidate factors that strongly influence the small intestinal lymphatic vessels in dogs with and without IL. Twelve dogs were included, of which six were diagnosed with lymphoplasmacytic enteritis, four with small-cell lymphoma, and two with large-cell lymphoma. Seven of these dogs had IL, whereas five did not. First, the microbial diversity analyzed by Faith pd index was significantly decreased in dogs with IL compared to dogs without IL. Then, the relative amounts of each bacterial taxa were compared between dogs with and without IL using Linear discriminant analysis effect size analysis. At the genus level, the Ruminococcus gnavus group significantly increased in dogs with IL compared to dogs without IL. A total of four genera, including Ruminococcus torques group and Faecalibacterium, which produce butyrate, significantly decreased in dogs with IL. This study showed decreased intestinal bacterial diversity and several alterations of intestinal microbiota, including a decrease in butyrate-producing bacteria in dogs with IL, compared to dogs without IL.

Characterization of the Fecal and Mucosa-Associated Microbiota in Dogs with Chronic Inflammatory Enteropathy

Canine chronic inflammatory enteropathy implicates multifactorial pathogenesis where immunological dysregulation and gut microbiota changes have a central role. Most sequencing-based taxonomic studies have been focused on the fecal microbiota. However, the analysis of these samples does not provide complete information regarding the composition of the small intestine affected by this canine disease. Therefore, in this study, we aimed to characterize the intestinal bacterial microbiota in dogs with inflammatory bowel disease (IBD) (n = 34) by means of duodenal biopsies and fecal samples collected at the time of the diagnosis and to compare those to a group of healthy dogs (n = 12) using the 16S ribosomal RNA (16S rRNA) gene-targeted sequencing (Illumina MiSeq platform). Our study showed that IBD dogs presented differences in the fecal bacterial communities when compared with healthy dogs, with a lower relative abundance of Prevotellaceae (p = 0.005), Prevotella (p = 0.002), and Prevotellaceae Ga6A1 group (0.006); Erysipelotrichales (p = 0.019), Candidatus Stoquefichus (p < 0.001), Erysipelotrichaceae (p = 0.011), and Allobaculum (p = 0.003); Lachnospiraceae NK4A136 group (p = 0.015), Sellimonas (p = 0.042), Oscillospirales (p = 0.037), Oscillospiraceae UCG-005 (p < 0.001), Faecalibacterium (p = 0.028), and Fournierella (p = 0.034); Acidaminococcales, Acidaminococcaceae, and Phascolarctobacterium (p = 0.001); Aeromonadales (p = 0.026), Succinivibrionaceae (p = 0.037), and Succinivibrio (p = 0.031). On the other hand, a higher relative abundance of Enterococcaceae (Enterococcus; p = 0.003), Streptococcaceae (Streptococcus, p = 0.021), Enterobacterales (p = 0.027), Enterobacteriaceae (p = 0.008), and Escherichia-Shigella (p = 0.011) was detected. Moreover, when evaluating α-diversity, the dogs with IBD showed lower diversity in terms of richness and abundance of species (observed species [p = 0.031] and Shannon index [p = 0.039]). Furthermore, fecal microbiota in dogs with IBD was significantly different from healthy dogs (p = 0.006). However, only a few taxa relative abundance shifts (lower Rubrobacteria, Rubrobacterales, Rubrobacteriaceae, and Rubrobacter [p = 0.002]; Cyanobacteria [p = 0.010], Vampirivibrionia, Obscuribacterales, and Obscuribacteraceae [p = 0.005]; Neisseriaceae [p = 0.004] and Conchiformibius [p = 0.003]) were observed when assessing duodenal-associated microbiota of dogs with IBD. Thus, even if the bowel inflammation mainly affects the small intestine in the IBD-affected dogs of the study, fecal specimens may constitute a better sample due not only to their easy availability but also in terms of searching for bacterial taxa as biomarkers for canine IBD. The use of different diets in the study can also have a partial influence on the microbiota composition. Future studies encompassing multi-omics approaches should evaluate the functionality in both levels to unravel the pathophysiology of canine IBD.

Responses of roots and rhizosphere of female papaya to the exogenous application of GA3

Exogenous GAs have an indeterminate effect on root development. Our current study used female papaya to reveal how the roots and rhizosphere respond to the exogenous application of GA₃ by investigating the transcriptome profile in roots, metabolic profile and microbial community in both roots and rhizosphere of GA₃-treated and control female papaya. The results demonstrated that exogenous GA₃ treatment enhanced female papaya lateral root development, which gave plants physical advantages of water and nutrient uptake. In addition, it was likely that GA₃ spraying in papaya shoot apices increased the level of auxin, which was transported to roots by CpPIN1, where auxin upregulated CpLBD16 and repressed CpBP to promote the lateral root initiation and development. In papaya roots, corresponding transporters (CpTMT3, CpNRT1:2, CpPHT1;4, CpINT2, CpCOPT2, CpABCB11, CpNIP4;1) were upregulated and excretion transporters were downregulated such as CpNAXT1 for water and nutrients uptake with exogenous GA₃ application. Moreover, in GA₃-treated papaya roots, CpALS3 and CpMYB62 were downregulated, indicating a stronger abiotic resistance to aluminum toxic and phosphate starvation. On the other hand, BRs and JAs, which involve in defense responses, were enriched in the roots and rhizosphere of GA₃-treated papayas. The upregulation of the two hormones might result in the reduction of pathogens in roots and rhizosphere such as Colletotrichum and Verticillium. GA₃-treated female papaya increased the abundance of beneficial bacteria species including Mycobacterium, Mitsuaria, and Actinophytocola, but decreased that of the genera Candidatus and Bryobacter for that it required less nitrate. Overall, the roots and rhizosphere of female papaya positively respond to exogenous application of GA₃ to promote development and stress tolerance. Treatment of female papaya with GA3 might result in the promotion of lateral root formation and development by upregulating CpLBD16 and downregulating CpBP. GA₃-treated papaya roots exhibited feedback control of brassinolide and jasmonate signaling in root development and defense. These findings revealed complex response to a growth hormone treatment in papaya roots and rhizosphere and will lead to investigations on the impact of other plant hormones on belowground development in papaya.

Effects of a milk oligosaccharide biosimilar on fecal characteristics, microbiota, and bile acid, calprotectin, and immunoglobulin concentrations of healthy adult dogs treated with metronidazole

In recent dog and cat experiments, a novel milk oligosaccharide biosimilar (GNU100) positively modulated fecal microbiota and metabolite profiles, suggesting benefits to gastrointestinal health. The objective of this study was to investigate the effects of GNU100 on the fecal characteristics, microbiota, and bile acid (BA) concentrations of healthy adult dogs treated with antibiotics. Twelve healthy adult female dogs (mean age: 3.74 ± 2.4 yr) were used in an 8-wk crossover design study (dogs underwent both treatments). All dogs were fed a control diet during a 2-wk baseline, then randomly allotted to 1 of 2 treatments (diet only or diet + 1% GNU100) for another 6 wk. From weeks 2 to 4, dogs were orally administered metronidazole (20 mg/kg BW) twice daily. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, and 8 for measurement of pH, dry matter, microbiota populations, and BA, immunoglobulin A, and calprotectin concentrations. On weeks 0, 4, and 8, blood samples were collected for serum chemistry and hematology analysis. All data were analyzed as repeated measures using the Mixed Models procedure of SAS version 9.4, with significance considered P < 0.05. Metronidazole increased (P < 0.0001) fecal scores (looser stools) and modified (P < 0.05) fecal microbiota and BA profiles. Using qPCR, metronidazole reduced fecal Blautia, Fusobacterium, Turicibacter, Clostridium hiranonis, and Faecalibacterium abundances, and increased fecal Streptococcus and Escherichia coli abundances. DNA sequencing analysis demonstrated that metronidazole reduced microbial alpha diversity and influenced the relative abundance of 20 bacterial genera and families. Metronidazole also increased primary BA and reduced secondary BA concentrations. Most antibiotic-induced changes returned to baseline by week 8. Fecal scores were more stable (P = 0.01) in GNU100-fed dogs than controls after antibiotic administration. GNU100 also influenced fecal microbiota and BA profiles, reducing (P < 0.05) the influence of metronidazole on microbial alpha diversity and returning some fecal microbiota and secondary BA to baseline levels at a quicker (P < 0.05) rate than controls. In conclusion, our results suggest that GNU100 supplementation provides benefits to dogs treated with antibiotics, providing more stable fecal scores, maintaining microbial diversity, and allowing for quicker recovery of microbiota and secondary BA profiles which play an essential role in gut health.

Synbiotic-IgY Therapy Modulates the Mucosal Microbiome and Inflammatory Indices in Dogs with Chronic Inflammatory Enteropathy: A Randomized, Double-Blind, Placebo-Controlled Study

Chronic inflammatory enteropathy (CE) is a common cause of persistent gastrointestinal signs and intestinal inflammation in dogs. Since evidence links dysbiosis to mucosal inflammation, probiotics, prebiotics, or their combination (synbiotics) may reduce intestinal inflammation and ameliorate dysbiosis in affected dogs. This study's aim was to investigate the effects of the synbiotic-IgY supplement on clinical signs, inflammatory indices, and mucosal microbiota in dogs with CE. Dogs with CE were enrolled in a randomized prospective trial. Twenty-four client-owned dogs were fed a hydrolyzed diet and administered supplement or placebo (diet) for 6 weeks. Dogs were evaluated at diagnosis and 2- and 6-week post-treatment. Outcome measures included clinical activity, endoscopic and histologic scores, inflammatory markers (fecal calprotectin, C-reactive protein), and composition of the mucosal microbiota via FISH. Eleven supplement- and nine placebo-treated dogs completed the trial. After 6 weeks of therapy, clinical activity and endoscopic scores decreased in both groups. Compared to placebo-treated dogs, dogs administered supplement showed decreased calprotectin at 2-week post-treatment, decreased CRP at 2- and 6-week post-treatment increased mucosal Clostridia and Bacteroides and decreased Enterobacteriaceae in colonic biopsies at trial completion. Results suggest a beneficial effect of diet and supplements on host responses and mucosal microbiota in dogs with CE.

Gut microbiota and transcriptome profiling revealed the protective effect of aqueous extract of Tetrastigma hemsleyanum leaves on ulcerative colitis in mice

Tetrastigma hemsleyanum, a traditional Chinese medicinal plant, possesses various biological activities, including anti-inflammatory and immunomodulatory functions. The purpose of this study was to determine the alleviating effect of the water extract of Tetrastigma hemsleyanum leaves (THLW) on ulcerative colitis (UC) and its relationship with gut microbiota. The administration of THLW significantly decreased the severity of dextran sulfate sodium (DSS)-induced intestinal damage, as demonstrated by the stabilization of body weight and colon length, and decreased disease activity index (DAI) and histological scores. THLW also decreased NF-κB protein expression in colon tissues and reduced the serum levels of IL-6, IL-1β, and TNF-α. Further co-housing experiment confirmed that the anti-UC effect of THLW was possibly by regulating the structure and composition of gut microbiota, including increasing the abundance of Oscillospiraceae, Prevotellaceae and Corynebacterium. Additionally, the expression of genes related to inflammation and immunity was also regulated by THLW treatment as evidenced by transcriptome analysis. These results suggested that the protective effect of THLW on DSS-induced colitis was mediated by alleviating inflammation and modulating the microbiota composition. This work proved the potent protective effects of THLW treatment on colitis and may have potential for UC relief.

Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

Many dogs and cats are affected by chronic diseases that significantly impact their health and welfare and relationships with humans. Some of these diseases can be challenging to treat, and a better understanding of early-life risk factors for diseases occurring in adulthood is key to improving preventive veterinary care and husbandry practices. This article reviews early-life risk factors for obesity and chronic enteropathy, and for chronic behavioral problems, which can also be intractable with life-changing consequences. Aspects of early life in puppies and kittens that can impact the risk of adult disorders include maternal nutrition, establishment of the gut microbiome, maternal behavior, weaning, nutrition during growth, growth rate, socialization with conspecifics and humans, rehoming and neutering. Despite evidence in some species that the disorders reviewed here reflect the developmental origins of health and disease (DOHaD), developmental programming has rarely been studied in dogs and cats. Priorities and strategies to increase knowledge of early-life risk factors and DOHaD in dogs and cats are discussed. Critical windows of development are proposed: preconception, gestation, the suckling period, early growth pre-neutering or pre-puberty, and growth post-neutering or post-puberty to adult size, the durations of which depend upon species and breed. Challenges to DOHaD research in these species include a large number of breeds with wide genetic and phenotypic variability, and the existence of many mixed-breed individuals. Moreover, difficulties in conducting prospective lifelong cohort studies are exacerbated by discontinuity in pet husbandry between breeders and subsequent owners, and by the dispersed nature of pet ownership.

Sex-based metabolic and microbiota differences in roots and rhizosphere soils of dioecious papaya (Carica papaya L.)

Dioecious plant species have a high genetic variation that is important for coping with or adapting to environmental stress through natural selection. Intensive studies have reported dimorphism morphism in morphology, physiology, as well as biotic and abiotic stress responses in dioecious plants. Here, we demonstrated the dimorphism of metabolic profile and the preference of some microorganisms in the roots and rhizosphere soils of male and female papaya. The metabolic composition of roots were significantly different between the males and females. Some sex hormones occurred in the differential metabolites in roots and rhizosphere soils. For example, testosterone was up-regulated in male papaya roots and rhizosphere soils, whereas norgestrel was up-regulated in the female papaya roots, indicating a possible balance in papaya roots to control the sexual differentiation. Plant hormones such as BRs, JAs, SA and GAs were also detected among the differential metabolites in the roots and rhizosphere soils of dioecious papaya. In addition, some metabolites that have medicinal values, such as ecliptasaponin A, crocin, berberine and sapindoside A were also expressed differentially between the two sexes. Numerous differential metabolites from the papaya roots were secreted in the soil, resulting in the differences in microbial community structure in the roots and rhizosphere soils. Some nitrogen-fixing bacteria such as Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Brevundimonas and Microvirga were enriched in the male papaya roots or rhizosphere soils. While Candidatus Solibacter and Tumebacillus, which utilize organic matters, were enriched in the roots or rhizosphere soils of the female papaya. Some differences in the fungi abundance were also observed in both male and female papaya roots. These findings uncovered the effect of sex types on the metabolic and microbiota differences in roots and rhizosphere soils in papaya and will lead to investigations of underlining genomic and molecular mechanisms.

Canine chronic enteropathy—Current state-of-the-art and emerging concepts

Over the last decade, chronic inflammatory enteropathies (CIE) in dogs have received great attention in the basic and clinical research arena. The 2010 ACVIM Consensus Statement, including guidelines for the diagnostic criteria for canine and feline CIE, was an important milestone to a more standardized approach to patients suspected of a CIE diagnosis. Great strides have been made since understanding the pathogenesis and classification of CIE in dogs, and novel diagnostic and treatment options have evolved. New concepts in the microbiome-host-interaction, metabolic pathways, crosstalk within the mucosal immune system, and extension to the gut-brain axis have emerged. Novel diagnostics have been developed, the clinical utility of which remains to be critically evaluated in the next coming years. New directions are also expected to lead to a larger spectrum of treatment options tailored to the individual patient. This review offers insights into emerging concepts and future directions proposed for further CIE research in dogs for the next decade to come.

Gut microbiota development in the growing dog: A dynamic process influenced by maternal, environmental and host factors

Microorganisms of the gastrointestinal tract play a crucial role in the health, metabolism and development of their host by modulating vital functions such as digestion, production of key metabolites or stimulation of the immune system. This review aims to provide an overview on the current knowledge of factors shaping the gut microbiota of young dogs. The composition of the gut microbiota is modulated by many intrinsic (i.e., age, physiology, pathology) and extrinsic factors (i.e., nutrition, environment, medication) which can cause both beneficial and harmful effects depending on the nature of the changes. The composition of the gut microbiota is quickly evolving during the early development of the dog, and some crucial bacteria, mostly anaerobic, progressively colonize the gut before the puppy reaches adulthood. Those bacterial communities are of paramount importance for the host health, with disturbance in their composition potentially leading to altered metabolic states such as acute diarrhea or inflammatory bowel disease. While many studies focused on the microbiota of young children, there is still a lack of knowledge concerning the development of gut microbiota in puppies. Understanding this early evolution is becoming a key aspect to improve dogs' short and long-term health and wellbeing.

Phenotypic correlates of the working dog microbiome

Dogs have a key role in law enforcement and military work, and research with the goal of improving working dog performance is ongoing. While there have been intriguing studies from lab animal models showing a potential connection between the gut microbiome and behavior or mental health there is a dearth of studies investigating the microbiome-behavior relationship in working dogs. The overall objective of this study was to characterize the microbiota of working dogs and to determine if the composition of the microbiota is associated with behavioral and performance outcomes. Freshly passed stools from each working canine (Total n = 134) were collected and subject to shotgun metagenomic sequencing using Illumina technology. Behavior, performance, and demographic metadata were collected. Descriptive statistics and prediction models of behavioral/phenotypic outcomes using gradient boosting classification based on Xgboost were used to study associations between the microbiome and outcomes. Regarding machine learning methodology, only microbiome features were used for training and predictors were estimated in cross-validation. Microbiome markers were statistically associated with motivation, aggression, cowardice/hesitation, sociability, obedience to one trainer vs many, and body condition score (BCS). When prediction models were developed based on machine learning, moderate predictive power was observed for motivation, sociability, and gastrointestinal issues. Findings from this study suggest potential gut microbiome markers of performance and could potentially advance care for working canines.

Microbiome Profile of Dogs with Stage IV Multicentric Lymphoma: A Pilot Study

Simple Summary

Lymphoma is a common type of hematopoietic cancer encountered in small animal practices. Canine multicentric lymphoma represents 80% of lymphoma cases and is characterized by a spread of the disease in multiple lymph nodes and organs as well. A causal role of the gut microbiota in disease spread has been shown in different diseases. In this study, the gut microbiome of dogs diagnosed with stage IV multicentric lymphoma has been analyzed and compared with that of healthy dogs to evaluate potential changes linked to lymphoma and disease spread.

Abstract

Changes in the gut microbiome can be associated with diseases and affect the overall health of an individual. In the current study, the gut microbiome profile of dogs diagnosed with advanced stages of multicentric lymphoma was compared with that of healthy dogs and analyzed. For this purpose, dogs from veterinary hospitals diagnosed with lymphoma were selected and were further narrowed down to cases of stage IV multicentric lymphoma. Fecal samples from the selected sick and healthy dogs were collected and analyzed using MiSeq sequencing. The gut microbiota in the two groups of dogs was statistically analyzed and compared. The results revealed significant differences in the microbial populations present in sick and healthy dogs. Phylum Actinobacteria and two species (Corynebacterium amycolatum and Streptococcus lutetiensis) were found in high proportions in sick dogs and may be considered as potential biomarkers for canine stage IV multicentric lymphoma. Further investigations need to be conducted to understand the mechanisms they might be involved in.

Gut Microbiota and Lymphocyte Subsets in Canine Leishmaniasis

Gut microbiota seems to interact with immune system. Canine leishmaniasis pathogenesis and severity of disease lean on the host immunity, but there is no information in literature about gut microbiota in infected animals. Thus, this study aims to compare the microbiota composition and leukocyte subset of healthy dogs with those of asymptomatic dogs exposed to Leishmania spp. and dogs with clinical leishmaniasis. Thirty-nine dogs were enrolled and grouped into three groups: healthy, exposed asymptomatic and infected symptomatic for Leishmania spp. Flow cytometry on whole blood evaluated the prevalence of CD4, CD5, CD8, CD11b, CD14, and CD21 positive cells. Gut microbiota was investigated using a next generation sequencing (NGS) technique. Firmicutes resulted significantly more abundant in the healthy dogs compared with the other two groups. Conversely, Proteobacteria were more abundant in symptomatic dogs. Even in rarest phyla comparison some significant differences were found, as well as in comparison at classes, order, family and genus levels. The symptomatic group had lower concentration of all the lymphocyte classes (CD5, CD21, CD4, CD8) compared to the other groups. A lower abundance of Firmicutes is reported in literature in diseased animals compared to the healthy ones and this is in agreement with the results of this study. Increased Proteobacteria in sick animals could suggest a dysbiosis status, even without distinct gastrointestinal signs. The leukocyte classes results indicate a decreased Th1 response in symptomatic dogs. Studies also investigating the cytokine response could deepen the knowledge on the pathogenesis of canine leishmaniasis.

Effect of Dietary Methylsulfonylmethane Supplementation on Growth Performance, Hair Quality, Fecal Microbiota, and Metabolome in Ragdoll Kittens

Methylsulfonylmethane (MSM) is a natural sulfur-containing organic substance that has many biological functions, such as antioxidant, anti-inflammatory, skin nourishing, and hair growth-promoting effects. This study was conducted to determine the effect of MSM supplementation on growth performance, antioxidant capacity, and hair quality in kittens. A total of 21 Ragdoll kittens were assigned to three diets by initial body weight and gender: basal diet supplemented with 0%, 0.2%, and 0.4% MSM (CON, LMSM, and HMSM groups) for 65 days. During the whole period, the food intake of kittens in the MSM-treated groups tended to be higher (P < 0.10) compared with the CON group, and the average daily gain (ADG) had no significant difference when compared to the kittens in the CON group (P > 0.05). Antioxidant capacity had no significant difference (P > 0.05) among the groups. The scale thickness of hair tended to be smaller in the LMSM group compared to the CON group (P < 0.10) and decreased significantly (P < 0.05) over time from d 0 to d 65 in the LMSM group, indicating the improvement of hair quality. Besides, supplementation with LMSM increased bacterial diversity. Kittens fed MSM had no significant differences in fecal genus at the end of the study. No significant differences in fecal short-chain fatty acids were observed among groups. Fecal metabolomics analysis further revealed that MSM hardly affected the metabolites. Overall, dietary supplementation with 0.2% MSM can improve the hair quality of kittens. Furthermore, 0.2∼0.4% of MSM had no detrimental effects on serum biochemistry, growth performance, gut microbiota, and metabolome, which supports the safety inclusion of MSM to a certain degree in feline diets. To the best of our knowledge, this is the first study to investigate the effects of MSM supplementation in cats.

Microbiome function underpins the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea

Background

Chronic large bowel diarrhea is a common occurrence in pet dogs. While nutritional intervention is considered the primary therapy, the metabolic and gut microfloral effects of fiber and polyphenol-enriched therapeutic foods are poorly understood.

Methods

This prospective clinical study enrolled 31 adult dogs from private veterinary practices with chronic, active large bowel diarrhea. Enrolled dogs received a complete and balanced dry therapeutic food containing a proprietary fiber bundle for 56 days. Metagenomic and metabolomic profiling were performed on fecal samples at Days 1, 2, 3, 14, 28, and 56; metabolomic analysis was conducted on serum samples taken at Days 1, 2, 3, 28, and 56.

Results

The dietary intervention improved clinical signs and had a clear effect on the gut microfloral metabolic output of canines with chronic diarrhea, shifting gut metabolism from a predominantly proteolytic to saccharolytic fermentative state. Microbial metabolism of tryptophan to beneficial indole postbiotics and the conversion of plant-derived phenolics into bioavailable postbiotics were observed. The intervention altered the endocannabinoid, polyunsaturated fatty acid, and sphingolipid profiles, suggesting a modulation in gastrointestinal inflammation. Changes in membrane phospholipid and collagen signatures were indicative of improved gut function and possible alleviation of the pathophysiology related to chronic diarrhea.

Conclusions

In dogs with chronic diarrhea, feeding specific dietary fibers increased gut saccharolysis and bioavailable phenolic and indole-related compounds, while suppressing putrefaction. These changes were associated with improved markers of gut inflammation and stool quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03315-3.

Effect of antimicrobial administration on fecal microbiota of critically ill dogs: dynamics of antimicrobial resistance over time

Background

Multidrug resistance in companion animals poses significant risks to animal and human health. Prolonged antimicrobial drug (AMD) treatment in animals is a potential source of selection pressure for antimicrobial resistance (AMR) including in the gastrointestinal microbiota. We performed a prospective study of dogs treated for septic peritonitis, pyometra, or bacterial pneumonia and collected repeated fecal samples over 60 days. Bacterial cultures and direct molecular analyses of fecal samples were performed including targeted resistance gene profiling.

Results

Resistant Escherichia coli increased after 1 week of treatment (D1:21.4% vs. D7:67.9% P < 0.001) and returned to baseline proportions by D60 (D7:67.9% vs D60:42.9%, P = 0.04). Dogs with septic peritonitis were hospitalized significantly longer than those with pneumonia or pyometra. Based on genetic analysis, Simpson’s diversity index significantly decreased after 1 week of treatment (D1 to D7, P = 0.008), followed by a gradual increase to day 60 (D1 and D60, P = 0.4). Detection of CTX-M was associated with phenotypic resistance to third-generation cephalosporins in E. coli (OR 12.1, 3.3–68.0, P < 0.001). Lincosamide and macrolide-resistance genes were more frequently recovered on days 14 and 28 compared to day 1 (P = 0.002 and P = 0.004 respectively).

Conclusion

AMR was associated with prescribed drugs but also developed against AMDs not administered during the study. Companion animals may be reservoirs of zoonotic multidrug resistant pathogens, suggesting that veterinary AMD stewardship and surveillance efforts should be prioritized.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-022-00178-9.

Any Future for Faecal Microbiota Transplantation as a Novel Strategy for Gut Microbiota Modulation in Human and Veterinary Medicine?

Alterations in the composition of the intestinal microbiome, also known as dysbiosis, are the result of many factors such as diet, antibiotics, stress, diseases, etc. There are currently several ways to modulate intestinal microbiome such as dietary modulation, the use of antimicrobials, prebiotics, probiotics, postbiotics, and synbiotics. Faecal microbiota transplantation (FMT) represents one new method of gut microbiota modulation in humans with the aim of reconstructing the intestinal microbiome of the recipient. In human medicine, this form of bacteriotherapy is successfully used in cases of recurrent Clostridium difficile infection (CDI). FMT has been known in large animal medicine for several years. In small animal medicine, the use of FMT is not part of normal practice.

Mutual Links between the Endocannabinoidome and the Gut Microbiome, with Special Reference to Companion Animals: A Nutritional Viewpoint

There is growing evidence that perturbation of the gut microbiome, known as “dysbiosis”, is associated with the pathogenesis of human and veterinary diseases that are not restricted to the gastrointestinal tract. In this regard, recent studies have demonstrated that dysbiosis is linked to the pathogenesis of central neuroinflammatory disorders, supporting the existence of the so-called microbiome-gut-brain axis. The endocannabinoid system is a recently recognized lipid signaling system and termed endocannabinoidome monitoring a variety of body responses. Accumulating evidence demonstrates that a profound link exists between the gut microbiome and the endocannabinoidome, with mutual interactions controlling intestinal homeostasis, energy metabolism and neuroinflammatory responses during physiological conditions. In the present review, we summarize the latest data on the microbiome-endocannabinoidome mutual link in health and disease, focalizing the attention on gut dysbiosis and/or altered endocannabinoidome tone that may distort the bidirectional crosstalk between these two complex systems, thus leading to gastrointestinal and metabolic diseases (e.g., idiopathic inflammation, chronic enteropathies and obesity) as well as neuroinflammatory disorders (e.g., neuropathic pain and depression). We also briefly discuss the novel possible dietary interventions based not only on probiotics and/or prebiotics, but also, and most importantly, on endocannabinoid-like modulators (e.g., palmitoylethanolamide) for intestinal health and beyond.

Nonpharmacological Treatment Strategies for the Management of Canine Chronic Inflammatory Enteropathy—A Narrative Review

Chronic inflammatory enteropathy (CIE) refers to a heterogeneous group of idiopathic diseases of the dog characterised by persistent gastrointestinal (GI) clinical signs. If conventional dietary treatment alone would be unsuccessful, management of CIE is traditionally attained by the use of pharmaceuticals, such as antibiotics and immunosuppressive drugs. While being rather effective, however, these drugs are endowed with side effects, which may impact negatively on the animal’s quality of life. Therefore, novel, safe and effective therapies for CIE are highly sought after. As gut microbiota imbalances are often associated with GI disorders, a compelling rationale exists for the use of nonpharmacological methods of microbial manipulation in CIE, such as faecal microbiota transplantation and administration of pre-, pro-, syn- and postbiotics. In addition to providing direct health benefits to the host via a gentle modulation of the intestinal microbiota composition and function, these treatments may also possess immunomodulatory and epithelial barrier-enhancing actions. Likewise, intestinal barrier integrity, along with mucosal inflammation, are deemed to be two chief therapeutic targets of mesenchymal stem cells and selected vegetable-derived bioactive compounds. Although pioneering studies have revealed encouraging findings regarding the use of novel treatment agents in CIE, a larger body of research is needed to address fully their mode of action, efficacy and safety.

Dysbiotic microbiota interactions in Crohn's disease

Crohn's disease (CD) is a major form of inflammatory bowel disease characterized by transmural inflammation along the alimentary tract. Changes in the microbial composition and reduction in species diversity are recognized as pivotal hallmarks in disease dynamics, challenging the gut barrier function and shaping a pathological immune response in genetically influenced subjects. The purpose of this review is to delve into the modification of the gut microbiota cluster network during CD progression and to discuss how this shift compromises the gut barrier integrity, granting the translocation of microbes and their products. We then complete the scope of the review by retracing gut microbiota dysbiosis interactions with the main pathophysiologic factors of CD, starting from the host's genetic background to the immune inflammatory and fibrotic processes, providing a standpoint on the lifestyle/exogenous factors and the potential benefits of targeting a specific gut microbiota.

Short- and long-term effects of amoxicillin/clavulanic acid or doxycycline on the gastrointestinal microbiome of growing cats

Antibiotic treatment in early life influences gastrointestinal (GI) microbial composition and function. In humans, the resultant intestinal dysbiosis is associated with an increased risk for certain diseases later in life. The objective of this study was to determine the temporal effects of antibiotic treatment on the GI microbiome of young cats. Fecal samples were collected from cats randomly allocated to receive either amoxicillin/clavulanic acid (20 mg/kg q12h) for 20 days (AMC group; 15 cats) or doxycycline (10 mg/kg q24h) for 28 days (DOX group;15 cats) as part of the standard treatment of upper respiratory tract infection. In addition, feces were collected from healthy control cats (CON group;15 cats). All cats were approximately two months of age at enrolment. Samples were collected on days 0 (baseline), 20 or 28 (AMC and DOX, respectively; last day of treatment), 60, 120, and 300. DNA was extracted and sequencing of the 16S rRNA gene and qPCR assays were performed. Fecal microbial composition was different on the last day of treatment for AMC cats, and 1 month after the end of antibiotic treatment for DOX cats, compared to CON cats. Species richness was significantly greater in DOX cats compared to CON cats on the last day of treatment. Abundance of Enterobacteriales was increased, and that of Erysipelotrichi was decreased in cats of the AMC group on the last day of treatment compared to CON cats. The abundance of the phylum Proteobacteria was increased in cats of the DOX group on days 60 and 120 compared to cats of the CON group. Only minor differences in abundances between the treatment groups and the control group were present on day 300. Both antibiotics appear to delay the developmental progression of the microbiome, and this effect is more profound during treatment with amoxicillin/clavulanic acid and one month after treatment with doxycycline. Future studies are required to determine if these changes influence microbiome function and whether they have possible effects on disease susceptibility in cats.

Effects of graded inclusion levels of raw garbanzo beans on apparent total tract digestibility, fecal quality, and fecal fermentative end-products and microbiota in extruded feline diets

Garbanzo beans (GB; Cicer arietinum) are a readily available pulse crop that have gained popularity as a plant-based protein source in the pet food industry. However, raw GB contain anti-nutritional factors that can reduce digestibility and cause digestive upsets in pets that are undesirable to owners. The objective of this study was to determine the effects of the inclusion of raw or cooked GB in extruded feline diets on macronutrient digestibility, gastrointestinal tolerance, and fermentative end-products in cats. Five diets were formulated to contain raw GB at 0%, 7.5%, 15%, or 30% or cooked GB at 30%. Ten adult, male cats (mean age: 1.0 ± 0.0 yr, mean BW: 4.7 ± 0.4 kg) were used in a replicated 5 × 5 Latin square design. Each period consisted of 14 d, with 10 d of diet adaptation followed by 4 d of total fecal and urine collection. At the end of each period, 4 mL of blood were collected and analyzed for a serum chemistry and complete blood count to ensure all animals remained healthy throughout the study. Cats were fed twice daily and food intake was calculated to maintain body weight. Food intake was highest (P < 0.05) for cats fed 0% raw GB (72.2 g/d, dry matter basis [DMB]) compared with GB inclusions of 7.5% or greater (average 70.3 g/d, DMB). Dry matter and organic matter apparent total tract digestibility (ATTD) were lowest (P < 0.05) for cats consuming the 30% cooked GB diet (77.3% and 81.7%, respectively). Cats fed 7.5% raw GB had greater (P < 0.05) crude protein ATTD (86.2%) than cats fed 15% raw GB (82.3%) or 30% cooked GB (81.6%). Total short-chain fatty acid concentrations were highest (P < 0.05) for 30% cooked GB at 682 μmol/g but not different (P > 0.05) than 15% GB (528 μmol/g) or 30% raw GB (591 μmol/g) diets. In terms of fecal microbial abundance, the predominant phyla were Firmicutes, Bacteroidota, and Actinobacteria. Cats fed the 0% GB diet had a greater relative abundance of Firmicutes (62.1%) and Fusobacteria (4.0%) than the remaining diets (average 54% and 1.6%, respectively). In conclusion, all inclusion levels of raw GB resulted in high digestibility (average > 80%) and ideal fecal scores (average 2.9), demonstrating their adequacy as a protein source in feline diets up to a 30% inclusion level.

Altered fecal microbiota, IgA, and fermentative end-products in adult dogs fed prebiotics and a nonviable Lactobacillus acidophilus

A study investigating the use of a nonviable Lactobacillus acidophilus (NVL: Culbac; TransAgra, Storm Lake, IA) and a mixed prebiotic (MP) blend (beet pulp, fructooligosaccharide (FOS), mannanoligosaccharide (MOS), inulin, and kelp) was done to evaluate changes in fecal microbiota, fermentative end products, and gut immune health in healthy female and male adult Beagle dogs (n = 24; 5.74 ± 2.18 yr; 9.30 ± 1.32 kg). The study protocol was first approved by the facility's Institutional Animal Care and Use Committee (Summit Ridge Farms; Susquehanna, PA) and followed throughout. Each of four test diets (control, NVL, MP, and MP + NVL [formulated to crude protein 25%, crude fat 14%, crude fiber 10% as-fed]) was fed once daily to maintain body weight for 21 d in a randomized-crossover design (four treatment periods and four washout periods). Fecal samples were collected on days 0 and 21 only for immunoglobulin A (IgA) and microbiota evaluation (16S rRNA V4 region and qPCR for Escherichia coli and Bifidobacterium), and fecal fermentative end-products and fecal pH were assessed only on day 21. Over the test periods, apparent total tract nutrient digestibility and stool quality were assessed. Data were analyzed by ANOVA (SAS v9.4, Cary, NC) or Kruskal-Wallis for between-diet effects, and paired t-test or Wilcoxon for time effects. Statistical significance was set at P ≤ 0.05. Apparent total tract nutrient digestibility revealed feeding MP-containing diets resulted in lower (P < 0.05) crude protein and fat digestibility vs. control and NVL diets. When dogs were fed MP, they had lower (P < 0.05) fecal pH compared with control and NVL diets, whereas fecal pH was lower in (P < 0.05) MP + NVL- vs. NVL-fed dogs. Fecal E. coli was (P < 0.05) lower at day 21 vs. day 0 when dogs were fed MP. Fecal Fusobacterium spp. was lower (P < 0.05) in both MP diets vs. control. Fecal Lactobacillus spp. increased (P < 0.05) from baseline with MP. Both diets with MP elicited greater (P < 0.05) fecal acetate and propionate concentration vs. control diet. At day 21, fecal IgA was greater (P < 0.05) in MP and MP + NVL compared with NVL diet. Only when dogs were fed MP did they have increased (P < 0.05) fecal IgA from day 21 vs. day 0. The MP + NVL diet decreased (P < 0.05) fecal isovalerate, isobutyrate, phenol, and indole vs. control. Overall, the MP elicited the most changes on microbiota, fermentative end-products, and IgA. Further investigation into NVL's gut health benefits is warranted.

Continuous Sugarcane Planting Negatively Impacts Soil Microbial Community Structure, Soil Fertility, and Sugarcane Agronomic Parameters

Continuous planting has a negative impact on sugarcane plant growth and reduces global sugarcane crop production, including in China. The response of soil bacteria, fungal, and arbuscular mycorrhizae (AM) fungal communities to continuous sugarcane cultivation has not been thoroughly documented. Using MiSeq sequencing technology, we analyzed soil samples from sugarcane fields with 1, 10, and 30 years of continuous cropping to see how monoculture time affected sugarcane yield, its rhizosphere soil characteristics and microbiota. The results showed that continuous sugarcane planting reduced sugarcane quality and yield. Continuous sugarcane planting for 30 years resulted in soil acidification, as well as C/N, alkali hydrolyzable nitrogen, organic matter, and total sulfur content significantly lower than in newly planted fields. Continuous sugarcane planting affected soil bacterial, fungal, and AM fungal communities, according to PCoA and ANOSIM analysis. Redundancy analysis (RDA) results showed that bacterial, fungal, and AM fungal community composition were strongly associated with soil properties and attributes, e.g., soil AN, OM, and TS were critical environmental factors in transforming the bacterial community. The LEfSe analysis revealed bacterial families (e.g., Gaiellaceae, Pseudomonadaceae, Micromonosporaceae, Nitrosomonadaceae, and Methyloligellaceae) were more prevalent in the newly planted field than in continuously cultivated fields (10 and 30 years), whereas Sphingomonadaceae, Coleofasciculaceae, and Oxyphotobacteria were depleted. Concerning fungal families, the newly planted field was more dominated than the continuously planted field (30 years) with Mrakiaceae and Ceratocystidaceae, whereas Piskurozymaceae, Trimorphomycetaceae, Lachnocladiaceae, and Stigmatodisc were significantly enriched in the continuously planted fields (10 and 30 years). Regarding AMF families, Diversisporaceae was considerably depleted in continuously planted fields (10 and 30 years) compared to the newly planted field. These changes in microbial composition may ultimately lead to a decrease in sugarcane yield and quality in the monoculture system, which provides a theoretical basis for the obstruction mechanism of the continuous sugarcane planting system. However, continuous planting obstacles remain uncertain and further need to be coupled with root exudates, soil metabolomics, proteomics, nematodes, and other exploratory methods.

Analysis of the gut microbiome in dogs and cats

The gut microbiome is an important immune and metabolic organ. Intestinal bacteria produce various metabolites that influence the health of the intestine and other organ systems, including kidney, brain, and heart. Changes in the microbiome in diseased states are termed dysbiosis. The concept of dysbiosis is constantly evolving and includes changes in microbiome diversity and/or structure and functional changes (eg, altered production of bacterial metabolites). Molecular tools are now the standard for microbiome analysis. Sequencing of microbial genes provides information about the bacteria present and their functional potential but lacks standardization and analytical validation of methods and consistency in the reporting of results. This makes it difficult to compare results across studies or for individual clinical patients. The Dysbiosis Index (DI) is a validated quantitative PCR assay for canine fecal samples that measures the abundance of seven important bacterial taxa and summarizes the results as one single number. Reference intervals are established for dogs, and the DI can be used to assess the microbiome in clinical patients over time and in response to therapy (eg, fecal microbiota transplantation). In situ hybridization or immunohistochemistry allows the identification of mucosa‐adherent and intracellular bacteria in animals with intestinal disease, especially granulomatous colitis. Future directions include the measurement of bacterial metabolites in feces or serum as markers for the appropriate function of the microbiome. This article summarizes different approaches to the analysis of gut microbiota and how they might be applicable to research studies and clinical practice in dogs and cats.

Rules of Engagement: Epithelial-Microbe Interactions and Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are complex, multifactorial disorders that lead to chronic and relapsing intestinal inflammation. The exact etiology remains unknown, however multiple factors including the environment, genetic, dietary, mucosal immunity, and altered microbiome structure and function play important roles in disease onset and progression. Supporting this notion that the gut microbiota plays a pivotal role in IBD pathogenesis, studies in gnotobiotic mice have shown that mouse models of intestinal inflammation require a microbial community to develop colitis. Additionally, antimicrobial therapy in some IBD patients will temporarily induce remission further demonstrating an association between gut microbes and intestinal inflammation. Finally, a dysfunctional intestinal epithelial barrier is also recognized as a key pathogenic factor in IBD. The intestinal epithelium serves as a barrier between the luminal environment and the mucosal immune system and guards against harmful molecules and microorganisms while being permeable to essential nutrients and solutes. Beneficial (i.e., mutualists) bacteria promote mucosal health by strengthening barrier integrity, increasing local defenses (mucin and IgA production) and inhibiting pro-inflammatory immune responses and apoptosis to promote mucosal homeostasis. In contrast, pathogenic bacteria and pathobionts suppress expression and localization of tight junction proteins, cause dysregulation of apoptosis/proliferation and increase pro-inflammatory signaling that directly damages the intestinal mucosa. This review article will focus on the role of intestinal epithelial cells (IECs) and the luminal environment acting as mediators of barrier function in IBD. We will also share some of our translational observations of interactions between IECs, immune cells, and environmental factors contributing to maintenance of mucosal homeostasis, as it relates to GI inflammation and IBD in different animal models.

Long-Term Recovery of the Fecal Microbiome and Metabolome of Dogs with Steroid-Responsive Enteropathy

The long-term impact of treatment of dogs with steroid-responsive enteropathy (SRE) on the fecal microbiome and metabolome has not been investigated. Therefore, this study aimed to evaluate the fecal microbiome and metabolome of dogs with SRE before, during, and following treatment with standard immunosuppressive therapy and an elimination diet. We retrospectively selected samples from 9 dogs with SRE enrolled in a previous clinical trial, which received treatment for 8 weeks, and had achieved remission as indicated by the post-treatment clinical scores. Long-term (1 year) samples were obtained from a subset (5/9) of dogs. Samples from 13 healthy dogs were included as controls (HC). We evaluated the microbiome using 16S rRNA sequencing and qPCR. To evaluate the recovery of gut function, we measured fecal metabolites using an untargeted approach. While improvement was observed for some bacterial taxa after 8 weeks of treatment, several bacterial taxa remained significantly different from HC. Seventy-five metabolites were altered in dogs with SRE, including increased fecal amino acids and vitamins, suggesting malabsorption as a component of SRE. One year after treatment, however, all bacterial species were evaluated by qPCR and 16S rRNA gene sequencing, and all but thirteen metabolites were no longer different from healthy controls.

Hierarchical modelling of immunoglobulin coated bacteria in dogs with chronic enteropathy shows reduction in coating with disease remission but marked inter-individual and treatment-response variability

Chronic enteropathies are a common problem in dogs, but many aspects of the pathogenesis remain unknown, making the therapeutic approach challenging in some cases. Environmental factors are intimately related to the development and perpetuation of gastrointestinal disease and the gut microbiome has been identified as a contributing factor. Previous studies have identified dysbiosis and reduced bacterial diversity in the gastrointestinal microbiota of dogs with chronic enteropathies. In this case-controlled study, we use flow cytometry and 16S rRNA sequencing to characterise bacteria highly coated with IgA or IgG in faecal samples from dogs with chronic enteropathy and evaluated their correlation with disease and resolution of the clinical signs. IgA and IgG-coated faecal bacterial counts were significantly higher during active disease compared to healthy dogs and decreased with the resolution of the clinical signs. Characterisation of taxa-specific coating of the intestinal microbiota with IgA and IgG showed marked variation between dogs and disease states, and different patterns of immunoglobulin enrichment were observed in dogs with chronic enteropathy, particularly for Erysipelotrichaceae, Clostridicaceae, Enterobacteriaceae, Prevotellaceae and Bacteroidaceae, families. Although, members of these bacterial groups have been associated with strong immunogenic properties and could potentially constitute important biomarkers of disease, their significance and role need to be further investigated.

Gut Health in Veterinary Medicine: A Bibliometric Analysis of the Literature

Gut health is a recent relevant research topic in veterinary medicine and it has been shown to be associated with better zootechnical performances and animal welfare. A bibliometric analysis was performed to explore publication trends, dynamics and possible knowledge gaps in this field in the last twenty years (2000-2020). The database Web of Science was searched and the results were analyzed by the R package Bibliometrix. A total of 1696 documents were retrieved in the evaluated period, showing a constant annual growth in the number of publications of 22.4%. These articles focused mainly on pigs (34.8%), poultry (chicken, duck, turkey and quail-33.9%) and aquaculture (fishes, crustaceans and frog-15.0%) while a scarce number was found on felines, cows, horses, rodents, goats and sheep. China was the most productive country (24.7%) followed by the USA (17.2%) and Canada (5.7%). Keyword's analysis showed that the main research lines aimed to explore animal nutrition, prevention of inflammatory diseases and microbiota composition. This study shows a comprehensive bibliometric analysis of the evolution of veterinary gut health research that will help to drive future investigations on this topic.

Longitudinal Survey of Fecal Microbiota in Healthy Dogs Administered a Commercial Probiotic

The aim of this longitudinal microbiome study was to investigate the effects of a commercially available veterinary synbiotic product (Blackmore's® Paw DigestiCare 60™) on the fecal microbiome of healthy dogs using 16S rRNA gene microbial profiling. Fifteen healthy, privately-owned dogs participated in a 2-week trial administration of the product. Fecal samples were collected at different time points, including baseline (prior to treatment), during administration and after discontinuation of product. Large intra- and inter-individual variation was observed throughout the study, but microbiome composition at higher phylogenetic levels, alpha and beta diversity were not significantly altered after 2 weeks of probiotic administration, suggesting an absence of probiotic impact on microbial diversity. Administration of the synbiotic preparation did, however, result in transient increases in probiotic species from Enterococacceae and Streptococacceae families as well as an increase in Fusobacteria; with the fecal microbiota partially reverting to its baseline state 3-weeks after cessation of probiotic administration.

Faecal Microbiome Transplantation as a Solution to Chronic Enteropathies in Dogs: A Case Study of Beneficial Microbial Evolution

Chronic enteropathies (CE) are gastrointestinal diseases that afflict about one in five dogs in Europe. Conventional therapeutic approaches include dietary intervention, pharmacological treatment and probiotic supplements. The patient response can be highly variable and the interventions are often not resolutive. Moreover, the therapeutic strategy is usually planned (and gradually corrected) based on the patient's response to empirical treatment, with few indirect gut health indicators useful to drive clinicians' decisions. The ever-diminishing cost of high-throughput sequencing (HTS) allows clinicians to directly follow and characterise the evolution of the whole gut microbial community in order to highlight possible weaknesses. In this framework, faecal microbiome transplantation (FMT) is emerging as a feasible solution to CE, based on the implant of a balanced, eubiotic microbial community from a healthy donor to a dysbiotic patient. In this study, we report the promising results of FMT carried out in a 9-year-old dog suffering from CE for the last 3 years. The patient underwent a two-cycle oral treatment of FMT and the microbiota evolution was monitored by 16S rRNA gene sequencing both prior to FMT and after the two administrations. We evaluated the variation of microbial composition by calculating three different alpha diversity indices and compared the patient and donor data to a healthy control population of 94 dogs. After FMT, the patient's microbiome and clinical parameters gradually shifted to values similar to those observed in healthy dogs. Symptoms disappeared during a follow-up period of six months after the second FMT. We believe that this study opens the door for potential applications of FMT in clinical veterinary practice and highlights the need to improve our knowledge on this relevant topic.

Successful outcome after a single endoscopic fecal microbiota transplantation in a Shiba dog with non-responsive enteropathy during the treatment with chlorambucil

A 7-year 6-month-old, castrated male Shiba dog presented with a 1-month history of lethargy, anorexia, vomiting, and frequent watery diarrhea. Weight loss, hypoalbuminemia, anemia, and leukocytosis were detected at the first visit. The dog was diagnosed with non-responsive enteropathy (NRE) based on clinical and histopathological examinations. Since the dog did not respond to the immunosuppressive drugs, fecal microbiota transplantation (FMT) was performed during the treatment with chlorambucil. A single endoscopic FMT into the cecum and colon drastically recovered clinical signs and clinicopathological abnormalities and corrected dysbiosis in the dog. No recurrence or adverse events were observed. The present case report suggests that FMT, possibly together with chlorambucil, might be a treatment option for NRE in Shiba dogs that have poorer prognosis compared with other dog breeds.