Indole Concentrations Research Articles

GC-MS quantification of fecal short-chain fatty acids and spectrophotometric detection of indole: Do rectal swabs produce comparable results as stool samples? - A pilot study.

The exploration of the gut microbiome and related metabolites holds an exciting future in health science. The challenges associated with fecal sample testing are proper sample collection, sterile transportation, optimal transport conditions, and processing as all these factors could potentially change the microbiome composition, further exacerbated by the patient's customary discomfort regarding feces samples. The study aimed to compare the usage of rectal swabs and stool samples for short-chain fatty acid estimation using gas chromatography-mass spectrometry (GC-MS) and indole estimation using spectrophotometry. From May 2022 to June 2022, three women were recruited from the Department of Obstetrics and Gynecology (OBG) in a secondary care hospital in coastal Karnataka. During their clinical visit, a rectal swab was collected, and the stool sample was transported to the hospital from the patient's home in sterile containers provided. After the extraction, short-chain fatty acids (acetate, propionate, and butyrate) were quantified using GC-MS. The fecal indole concentration was determined using a hydroxylamine-based assay. The GC-MS analysis failed to detect the concentrations of short-chain fatty acids in rectal swab samples. Indole concentrations in stool and swab samples were significantly different. The study's findings do not support the use of rectal swabs to analyze gut metabolites.

Influence of rooting media and indole butyric acid concentrations on growth and development of dragon fruit (Hylocereus polyrhizus L.) cuttings

Influence of rooting media and indole butyric acid concentrations on growth and development of dragon fruit (Hylocereus polyrhizus L.) cuttings

Organic rearing of non-castrated male pigs: welfare indicators, carcass traits, pork quality and boar taint in Duroc and Pietrain crossbreds

The main principles of organic farming as presented by the European organisation for organic food and farming are health, ecology, fairness and care, but the intrinsic quality of products is also important for consumers. Pig genotype was tested as a lever to improve animal welfare and pork quality (meat tenderness, processing ability) of organic, non-castrated males while controlling the risk for boar taint. Non-castrated Large White × Duroc (D, n = 47) or Large White × Pietrain NN (P, n = 34) males were involved in two batches, each including one group of pigs per genotype. Each group was reared in a pen from the same building on deep straw bedding (1.3 m2/pig), with a feeding zone (0.2 m2/pig) and an outdoor area (1.0 m2/pig), from 28 kg BW until slaughter at ca. 125 kg BW. All pigs received ad libitum the same growing and finishing diets, and hay. Overall, health and welfare indicators showed few problems, but the proportions of pigs with skin scratches, and tail lesions at the end of the finishing period, were lower in D than in P pigs (P < 0.05). Growth rate and final BW did not differ between genotypes. The D pigs had lower carcass lean meat content (P < 0.001) and relative proportions of ham and loin (P ≤ 0.01), and higher proportions of belly and backfat (P ≤ 0.001) than P pigs. Compared to P, loin (Longissimus muscle) of D pigs was less light and exudative and had higher chroma (P < 0.05), but pH 24 h and glycolytic potential did not differ. Loin meat of D pigs had higher intramuscular fat content (P < 0.001) and tended to have a lower shear force (P = 0.09), but cooking loss did not differ. In the ham muscles, D pigs had higher chroma than P pigs in the Gluteus medius, whereas pH 24 h did not differ in the Gluteus medius and Semimembranosus. D pigs had higher backfat concentrations of androstenone (P < 0.001), and skatole and indole (P < 0.05) than P pigs, suggesting a higher risk of rejection by consumers due to boar taint. However, only one D carcass was detected as tainted by human nose test. Altogether, organic farming of non-castrated Duroc crossbred males appears to be favourable for animal welfare, technological and several sensory pork properties provided that the risk of undesirable odours is limited through management practices.

Deep Learning Used with a Colorimetric Sensor Array to Detect Indole for Nondestructive Monitoring of Shrimp Freshness.

Intelligent colorimetric freshness indicator is a low-cost way to intuitively monitor the freshness of fresh food. A colorimetric strip sensor array was prepared by p-dimethylaminocinnamaldehyde (PDL)-doped poly(vinyl alcohol) (PVA) and chitosan (Chit) for the quantitative analysis of indole, which is an indicator of shrimp freshness. As a result of indole simulation, the array strip turned from faint yellow to pink or mulberry color with the increasing indole concentration, like a progress bar. The indicator film exhibited excellent permeability, mechanical and thermal stability, and color responsiveness to indole, which was attributed to the interactions between PDL and Chit/PVA. Furthermore, the colorimetric strip sensor array provided a good relationship between the indole concentration and the color intensity within a range of 50-350 ppb. The pathogens and spoilage bacteria of shrimp possessed the ability to produce indole, which caused the color changes of the strip sensor array. In the shrimp freshness monitoring experiment, the color-changing progress of the strip sensor array was in agreement with the simulation and could distinguish the shrimp freshness levels. The image classification system based on deep learning were developed, the accuracies of four DCNN algorithms are above 90%, with VGG16 achieving the highest accuracy at 97.89%. Consequently, a "progress bar" strip sensor array has the potential to realize nondestructive, more precise, and commercially available food freshness monitoring using simple visual inspection and intelligent equipment identification.

In vitro digestion and fermentation of animal-derived fermentable substrates using canine and feline faecal inoculum

Abstract There is increasing interest in understanding the fermentative benefits of animal-derived fermentable substrates (ADFS) in pet foods. While previous research has assessed various ADFS using faecal inoculum derived from the cat, there is no published literature available for the dog. Additionally, very little is understood of the fermentation profiles of ADFS, such as skin and bone. Therefore, faeces were collected from a cohort of cats and dogs fed a complete and balanced high-protein diet and a selection of substrates were analysed in this study. Individual ADFS (tendon, bone cake, mechanically deboned meat (MDM), corium and hydrolysed collagen (a positive control)) were digested in vitro, followed by fermentation using either canine or feline faecal inoculum. Concentrations of butyrate, indole and ammonia were determined after 24 h of fermentation. Regardless of whether cat or dog faecal inoculum was used, fermentation of hydrolysed collagen produced the highest (P &lt; 0.01) concentrations of butyrate and ammonia and the lowest concentrations of indole. For the other substrates, there were differences in the fermentation profiles between the canine and feline inocula. During the feline faecal fermentations, in comparison to the other substrates bone cake produced high (P &lt; 0.05) butyrate concentrations, whereas in the dog faecal fermentations, MDM resulted in high (P &lt; 0.05) butyrate concentrations. In conclusion, ADFS from different alternative co-products lead to different fermentation products, providing valuable information which may be considered in canine and feline dietary formulations.

PSII-13 Effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urine pH, slurry pH, and manure odorous compounds in pigs

Abstract The objective of the present study was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen barrows with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-d adaptation period and a 24-h collection period for slurry, followed by a 4-d collection period for feces and urine. On d 5, feces and urine were collected for 24 h, and the feces and urine were mixed in a ratio of fecal weight to urine weight at the end of the collection to obtain slurry samples. The fecal nitrogen (N) output was greatest (P &amp;lt; 0.05) in pigs fed the diet supplemented with humic substances. The apparent total tract digestibility of N in pigs fed the humic substance diet was less (P &amp;lt; 0.05) than other groups. The urinary pH in pigs fed the adipic acid diet was less (P &amp;lt; 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (P = 0.074) with the least value in pigs fed the adipic acid diet. The concentrations of indole in slurry (P = 0.084) and isovalerate in feces (P = 0.062) tended to differ among the groups with the least values in the pigs fed the humic substance diet. In conclusion, benzoic acid supplemented has the potential to increase N utilization in pigs, and adipic acid supplemented to pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have potential to reduce some odorous compounds.

In Vitro Fermentation Shows Polyphenol and Fiber Blends Have an Additive Beneficial Effect on Gut Microbiota States.

Polyphenols and fermentable fibers have shown favorable effects on gut microbiota composition and metabolic function. However, few studies have investigated whether combining multiple fermentable fibers or polyphenols may have additive beneficial effects on gut microbial states. Here, an in vitro fermentation model, seeded with human stool combined from 30 healthy volunteers, was supplemented with blends of polyphenols (PP), dietary fibers (FB), or their combination (PPFB) to determine influence on gut bacteria growth dynamics and select metabolite changes. PP and FB blends independently led to significant increases in the absolute abundance of select beneficial taxa, namely Ruminococcus bromii, Bifidobacterium spp., Lactobacillus spp., and Dorea spp. Total short-chain fatty acid concentrations, relative to non-supplemented control (F), increased significantly with PPFB and FB supplementation but not PP. Indole and ammonia concentrations decreased with FB and PPFB supplementation but not PP alone while increased antioxidant capacity was only evident with both PP and PPFB supplementation. These findings demonstrated that, while the independent blends displayed selective positive impacts on gut states, the combination of both blends provided an additive effect. The work outlines the potential of mixed substrate blends to elicit a broader positive influence on gut microbial composition and function to build resiliency toward dysbiosis.

Effects of dietary selenized glucose on intestinal microbiota and tryptophan metabolism in rats: Assessing skatole reduction potential

3-Methylindole (Skatole), a degradation product of tryptophan produced by intestinal microbial activity, significantly contributes to odor nuisance. Its adverse effects on animal welfare, human health, and environmental pollution have been noted. However, it is still unclear whether the intestinal microbiota mediates the impact of selenium (Se) on skatole production and what the underlying mechanisms remain elusive. A selenized glucose (SeGlu) derivative is a novel organic selenium compound. In this study, a diverse range of dietary SeGlu-treated levels, including SeGlu-deficient (CK), SeGlu-adequate (0.15 mg Se per L), and SeGlu-supranutritional (0.4 mg Se per L) conditions, were used to investigate the complex interaction of SeGlu on intestinal microbiome and serum metabolome changes in male Sprague-Dawley (SD) rats. The study showed that SeGlu supplementation enhanced the antioxidant ability in rats, significantly manifested in the increases of the activity of catalase (CAT) and glutathione peroxidase (GSH-Px), while no change in the level of malonaldehyde (MDA). Metagenomic sequencing analysis verified that the SeGlu treatment group significantly increased the abundance of beneficial microorganisms such as Clostridium, Ruminococcus, Faecalibacterium, Lactobacillus, and Alloprevotella while reducing the abundance of opportunistic pathogens such as Bacteroides and Alistipes significantly. Further metabolomic analysis revealed phenylalanine, tyrosine, and tryptophan biosynthesis changes in the SeGlu treatment group. Notably, the biosynthesis of indole, a critical pathway, was affected by SeGlu treatment, with several crucial enzymes implicated. Correlation analysis demonstrated strong associations between specific bacterial species - Treponema, Bacteroides, and Ruminococcus, and changes in indole and derivative concentrations. Moreover, the efficacy of SeGlu-treated fecal microbiota was confirmed through fecal microbiota transplantation, leading to a decrease in the concentration of skatole in rats. Collectively, the analysis of microbiota and metabolome response to diverse SeGlu levels suggests that SeGlu is a promising dietary additive in modulating intestinal microbiota and reducing odor nuisance in the livestock and poultry industry.

The neural representations of valence transformation in indole processing.

Indole is often associated with a sweet and floral odor typical of jasmine flowers at low concentrations and an unpleasant, animal-like odor at high concentrations. However, the mechanism whereby the brain processes this opposite valence of indole is not fully understood yet. In this study, we aimed to investigate the neural mechanisms underlying indole valence encoding in conversion and nonconversion groups using the smelling task to arouse pleasantness. For this purpose, 12 conversion individuals and 15 nonconversion individuals participated in an event-related functional magnetic resonance imaging paradigm with low (low-indole) and high (high-indole) indole concentrations in which valence was manipulated independent of intensity. The results of this experiment showed that neural activity in the right amygdala, orbitofrontal cortex and insula was associated with valence independent of intensity. Furthermore, activation in the right orbitofrontal cortex in response to low-indole was positively associated with subjective pleasantness ratings. Conversely, activation in the right insula and amygdala in response to low-indole was positively correlated with anticipatory hedonic traits. Interestingly, while amygdala activation in response to high-indole also showed a positive correlation with these hedonic traits, such correlation was observed solely with right insula activation in response to high-indole. Additionally, activation in the right amygdala in response to low-indole was positively correlated with consummatory pleasure and hedonic traits. Regarding olfactory function, only activation in the right orbitofrontal cortex in response to high-indole was positively correlated with olfactory identification, whereas activation in the insula in response to low-indole was negatively correlated with the level of self-reported olfactory dysfunction. Based on these findings, valence transformation of indole processing in the right orbitofrontal cortex, insula, and amygdala may be associated with individual hedonic traits and perceptual differences.

Unraveling the signaling roles of indole in an opportunistic pathogen Pseudomonas aeruginosa strain Jade-X

Pseudomonas aeruginosa, which can produce several toxins and form biofilm, is listed among the priority pathogens. Indole is a ubiquitous aromatic pollutant and signaling molecule produced by tryptophanase in bacteria. Herein, the impacts of indole on a newly isolated P. aeruginosa strain Jade-X were systematically investigated. Indole (0.5–2.0 mM) enhanced the biofilm production by 1.33–2.31-fold after 24 h incubation at 30 °C. However, the effects indole on biofilm formation were intricate and closely intertwined with factors such as incubation temperature, bacterial growth stage, and indole concentration. The twitching motility was enhanced by 1.15–1.99-fold by indole, potentially facilitating surface exploration and biofilm development. Indole reduced the production of virulence factors (pyocyanin and pyoverdine) as well as altered the surface properties (zeta potential and hydrophobicity). Transcriptional analysis revealed that indole (1.0 mM) significantly downregulated mexGHI-opmD efflux genes (4.73–6.91-fold) and virulence-related genes (pqs, pch, and pvd clusters, and flagella-related genes), while upregulating pili-related genes in strain Jade-X. The quorum sensing related signal regulators, including RhlR, LasR, and MvfR (PqsR), were not altered by indole, while other six transcriptional regulators (AmrZ, BfmR, PchR, QscR, SoxR, and SphR) were significantly affected, implying that indole effects might be regulated in a complex and delicate manner. This study should provide new insights into our understanding of indole signaling roles.

The effect of increasing the level of oat hulls, extent of grinding and their interaction on the performance, gizzard characteristics and gut health of broiler chickens fed oat-based pelleted diets

The effect of ratio of oats with hulls (OWH) to dehulled oats (DO), extent of grinding, and their interaction on the performance, gizzard characteristics and intestinal health of broilers chickens were studied in this experiment. A total of 2860 one-day-old male broilers were allocated to 130 floor pens bedded with wood shavings and fed a starter diet until day 10. On day 11, the birds were randomly distributed among ten dietary treatments (13 replicates each), consisting of five oat-based pelleted diets with different proportion of OWH and DO, and with main ingredients either finely- (2 mm) or coarsely-ground (6 mm). Half of a batch of oats was thoroughly dehulled and half kept as is. The content of hulls (OH) in the DO and OWH was 1 and 224 g/kg, respectively. Using different OWH:DO ratios, the diets were formulated to contain 0, 29.5, 65.0, 96.0 and 114.0 g/kg OH. The ratio of ingredients to DO, and apparent metabolisable energy to protein (AME:CP) were kept constant for all diets. Birds and feed were weighed on day 11 and at termination on day 32. Increasing OH level did not affect weight gain (WG) from 11 to 32 days, but increased FCR linearly (P < 0.001). Although FI was not affected by the extent of grinding, FCR was significantly improved with fine grinding. Birds fed diets with highest OH level had a lower AME:WG compared to those given diets with DO only. Coarse grinding significantly increased gizzard dry matter (DM) weight which also increased linearly (P < 0.001) with increasing OH level. Coarse grinding as well as increasing OH level significantly improved gizzard and pancreas relative weights and decreased gizzard contents pH. Excreta DM contents and litter score were significantly improved with increasing OH level. Coarse grinding tended to (P = 0.069) reduce total eubacteria density in the ileum only at the highest OH level and tended to (P = 0.080) reduce Lactobacillus spp. density compared to fine grinding. Increasing OH level had no impact on caecal short chain fatty acids or lactic acid production, but it decreased indole concentration linearly (P = 0.026). Coarse grinding tended to increase (P = 0.053) caecal propionic acid production. Importantly, broiler chickens were able to handle an OWH-based diet and still maintained a similar WG compared to diets with DO only. A larger gizzard holding capacity and a faster passage of excess OH may explain the ability to increase FI in response to high OH dilution. The positive effect of OH on performance was more obvious when finely ground, but coarse components in the diets induce beneficial effects on intestinal microbiota.

Effects of a Veterinary Gastrointestinal Low-Fat Diet on Fecal Characteristics, Metabolites, and Microbiota Concentrations of Adult Dogs Treated with Metronidazole.

Antibiotics are known to cause loose stools, disrupt the fecal microbiota, and alter fecal bile acid (BA) profiles of dogs. Recovery may be aided by diet, but little research has been conducted. The objective of this study was to determine how a veterinary low-fat diet affected the fecal characteristics, metabolites, BA, and microbiota of dogs receiving antibiotics. Twenty-four healthy adult dogs [7.38 ± 1.95 yr; 7.67 ± 0.76kg body weight (BW)] were used in an 8-wk completely randomized design study. During a 2-wk baseline, all dogs were fed a leading grocery brand dry kibble diet (GBD). Over the next 2wk, dogs were fed GBD and received metronidazole orally (20mg/kg BW twice daily). At wk 4, dogs were randomly allotted to one of two treatments [GBD or Blue Buffalo Natural Veterinary Diet GI Gastrointestinal Support Low-Fat (BB)] and fed for 4wk. Fecal scores were recorded daily and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter content, and metabolite and BA concentrations. Fecal microbiota populations were analyzed by 16S rRNA gene amplicon sequencing and qPCR-based dysbiosis index (DI). All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of treatment, time, and treatment*time and significance set at P<0.05. Metronidazole increased (P<0.0001) fecal scores (looser stools), reduced fecal short-chain fatty acid, branched-chain fatty acid, phenol, and indole concentrations, increased primary BA concentrations, and decreased secondary BA concentrations. Metronidazole also reduced fecal bacterial alpha diversity, altered the abundance of 58 bacterial genera, and increased DI. During antibiotic recovery, change in fecal pH, dry matter percentage, and metabolite and immunoglobulin A concentrations were altered (P<0.05) by diet. Fecal BA concentrations recovered quickly for all dogs. Change in lithocholic acid was affected (P<0.0001) by diet, but other BA were not. Recovery of over 25 bacterial genera was impacted by diet (P<0.05). While many bacterial taxa returned to baseline levels after 4wk, others did not fully recover. DI and bacterial alpha diversity measures recovered quickly for all dogs, but were not impacted by diet. In conclusion, metronidazole drastically altered the fecal microbiota and metabolites of dogs. While most variables returned to baseline by wk 8, diet may be used to aid in recovery.

Effects of a veterinary gastrointestinal diet on fecal characteristics, metabolites, and microbiota concentrations of adult cats treated with metronidazole.

Antibiotics are used to treat gastrointestinal diseases or infections but are known to negatively affect stool quality and gut microbiota in cats and dogs. Therefore, identifying dietary strategies that may aid in antibiotic recovery is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics, microbiota, and metabolite and bile acid (BA) concentrations of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. During a 2-wk baseline, all cats consumed a leading grocery brand diet (GBD). Over the next 2wk, cats consumed GBD and received metronidazole (20mg/kg body weight twice daily). At week 4, cats were randomly allotted to one of 2 treatments [GBD; BLUE Natural Veterinary Diet GI Gastrointestinal Support (BB)] and fed for 4wk. Fecal scores were recorded daily and fresh fecal samples were collected at weeks 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter (DM) %, metabolites, and microbiota. Microbiota was analyzed by 16S rRNA gene sequencing and qPCR, which was used to calculate dysbiosis index. Data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, testing for effects of diet, time and diet*time. Metronidazole had dramatic effects on all outcomes, including increased fecal scores (looser stools), reduced fecal pH and DM%, reduced fecal short-chain fatty acid, branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Metronidazole reduced fecal bacterial alpha diversity, increased dysbiosis index, and altered the relative abundance of 78 bacterial genera. Fecal outcomes partially recovered over the next 4wk, with some being impacted by diet. Fecal acetate concentrations were higher after metronidazole in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4wk, without diet differences. Recovery of 16 bacterial genera was impacted by diet. Fecal BA profiles demonstrated a prolonged impairment of primary to secondary BA conversion, with cholic acid being lower after metronidazole in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. Outcome variables slowly recovered over time, but a gastrointestinal diet may aid in recovery.

Effects of Supplemental Benzoic Acid, Bromelain, Adipic Acid, and Humic Substances on Nitrogen Utilization, Urine pH, Slurry pH, and Manure Odorous Compounds in Pigs.

The objective was to evaluate the effects of benzoic acid, bromelain, adipic acid, and humic substance supplementation on nitrogen balance, urinary pH, slurry pH, and manure odorous compounds in pigs. Fifteen castrated male pigs with an initial body weight of 37.9 kg (standard deviation = 4.1) were individually housed in metabolism crates. The animals were allocated to a triplicated 5 × 2 incomplete Latin square design with 15 animals, 5 experimental diets, and 2 periods. The basal diet mainly consisted of corn, soybean meal, and rapeseed meal. Four experimental diets were prepared by supplementing each additive at a concentration of 10 g/kg at the expense of corn starch to the basal diet. Each period consisted of a 4-day adaptation period, a 24 h collection period for slurry sampling, and a 4-day collection period for feces and urine. The feces and urine collected for 24 h on day 5 were mixed at a ratio of fecal weight and urine weight to obtain slurry samples. The apparent total tract digestibility N in pigs fed the humic substance diet was the least (p < 0.05) compared to the other groups. The daily retained N and N retention as % ingested tended (p < 0.10) to be the lowest in the adipic acid group among the treatments. The urinary pH in pigs fed the adipic acid diet was less (p < 0.05) than that in other groups except the benzoic acid group. The slurry pH tended to differ among the treatment groups (p = 0.074) with the lowest value in the pigs fed the adipic acid diet. The concentrations of indole in slurry (p = 0.084) and isovalerate in feces (p = 0.062) tended to differ among the groups with the lowest values in the pigs fed the humic substance diet. In conclusion, adipic acid supplementation in pig diets can decrease urinary pH and slurry pH. Although benzoic acid and adipic acid have limited effects in reducing odorous compounds, humic substances have the potential to reduce some odorous compounds.

PSIX-3 A Veterinary Gastrointestinal Low-Fat Diet Affects Fecal Characteristics, Metabolites, Bile Acids, and Microbiota Concentrations of Antibiotic-Treated Dogs

Abstract In a recent dog study, the antibiotic metronidazole proved to be an effective disruptor of the fecal microbiota and resulted in looser stools and altered fecal bile acid (BA) profiles. Recovery took several weeks and was aided by a dietary supplement. The objective of this study was to determine how a veterinary gastrointestinal low-fat diet affected the fecal characteristics and metabolite, BA, and microbiota concentrations of dogs recovering from metronidazole administration. Twenty-four healthy adult dogs were used in an 8-wk completely randomized design study. The study began with a 2-wk baseline phase where all dogs consumed a leading grocery brand dry kibble diet (GBD; wk 0 to wk 2). Over the next 2 wk, dogs continued to consume GBD and received metronidazole (20 mg/kg BW; wk 2 to wk 4). At wk 4, dogs were randomly allotted to one of two treatments [GBD; Blue Buffalo Gastrointestinal Support Low-Fat (BB)] for the remaining 4 wk (wk 5 to wk 8). Fecal scores were recorded daily, and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter, and metabolite and bile acid concentrations. Fecal microbiota populations were also analyzed by 16S rRNA sequencing and qPCR, which was used to calculate dysbiosis index. All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, with treatment treated as a fixed effect, dog as a random effect, and significance set at P &amp;lt; 0.05. As anticipated, metronidazole administration increased (P &amp;lt; 0.0001) fecal scores (looser stools) and drastically altered (P &amp;lt; 0.05) fecal metabolite concentrations, reducing fecal short-chain fatty acid (SCFA), branched-chain fatty acid (BCFA), phenol, and indole concentrations, increasing primary BA concentrations, and decreasing secondary bile acid concentrations. Metronidazole dramatically impacted fecal microbiota populations by reducing alpha diversity, altering the abundance of multiple bacterial taxa, and increasing dysbiosis index. Fecal outcome variables recovered over the next 4 wk, with some being impacted by diet. The change in fecal SCFA and immunoglobulin A concentrations were greater (P &amp;lt; 0.01), while the change in fecal BCFA, phenol, and indole concentrations were decreased (P &amp;lt; 0.05) in dogs fed BB. Dysbiosis index and alpha diversity measures recovered quickly for all dogs and without dietary effects. Recovery of over 25 bacterial genera were impacted by diet (P &amp;lt; 0.05). While many bacterial taxa returned to baseline levels after 4 wk, others had still not fully recovered. Fecal BA concentrations recovered quickly for all dogs. The change in lithocholic acid concentration was less (P &amp;lt; 0.0001) in dogs fed BB, but other BA concentrations were not affected by diet. In conclusion, metronidazole drastically alters the fecal microbiota and metabolites of dogs. While most variables return to normal over time, a veterinary gastrointestinal diet may aid in the recovery.

PSIX-4 A Veterinary Gastrointestinal Diet Affects Fecal Characteristics, Metabolites, Bile Acids, and Microbiota Concentrations of Antibiotic-Treated Cats

Abstract Antibiotics are often used to treat animals with gastrointestinal diseases or infections, but their use is known to have negative effects on the intestinal microbiota community. Identifying dietary strategies that may aid in the recovery from antibiotic use is of interest. The objective of this study was to determine how a veterinary gastrointestinal diet affected the fecal characteristics and metabolite, bile acid (BA), and microbiota concentrations of cats recovering from metronidazole administration. Twenty-four healthy adult cats were used in an 8-wk completely randomized design study. The study began with a 2-wk baseline phase where all cats consumed a leading grocery brand dry diet (GBD; wk 0 to wk 2). Over the next 2 wk, cats continued to consume GBD and received metronidazole (20 mg/kg BW; wk 2 to wk 4). At wk 4, cats were randomly allotted to one of two treatments [GBD; Blue Buffalo Gastrointestinal Support (BB)] for the remaining 4 wk (wk 5 to wk 8). Fecal scores were recorded daily, and fresh fecal samples were collected at wk 2, 4, 5, 6, 7, and 8 for measurement of pH, dry matter, and metabolite and BA concentrations. Fecal microbiota were analyzed by 16S rRNA sequencing and qPCR, which was used to calculate dysbiosis index. All data were analyzed as repeated measures using the Mixed Models procedure of SAS 9.4, with treatment treated as a fixed effect, cat as a random effect, and significance set at P&amp;lt; 0.05 and trends at P &amp;lt; 0.10. Metronidazole administration had dramatic effects on the outcomes measured, including increased fecal scores (looser stools), reduced fecal pH and dry matter %, reduced fecal short-chain fatty acid (SCFA), branched-chain fatty acid, ammonia, phenol, and indole concentrations, and altered fecal BA concentrations (increased primary BA; reduced secondary BA). Furthermore, fecal bacterial alpha diversity was reduced, dysbiosis index was increased, and the abundance of several individual bacterial taxa were altered. Fecal outcome variables partially recovered over the next 4 wk, with some being impacted by diet. The change in fecal acetate concentrations were greater and the change in total SCFA concentrations tended to be greater in cats fed BB. Dysbiosis index and alpha diversity measures slowly recovered over 4 wk, without differences due to diet. Recovery of about 20 bacterial genera were impacted by diet. Primary and secondary BA concentrations and ratios demonstrated a prolonged impairment of primary to secondary BA conversion. Most of these changes were an effect of time, but the change of fecal cholic acid concentrations were less in cats fed BB. In conclusion, our data demonstrate that metronidazole is a powerful antibiotic that has long-lasting effects on the fecal microbiota and metabolites of cats. The veterinary gastrointestinal diet tested aided in the recovery of some variables measured.

195 Restricted Feeding and Weight Loss Change Fecal Metabolite Concentrations and Microbiota Populations of Overweight Cats

Abstract Feline obesity negatively influences many metabolic processes, health outcomes, and the individual well-being of cats, but little research evaluates the modification in gastrointestinal microbiota in an overweight state. The use of specially formulated diets and restricted feeding, resulting in subsequent body weight (BW) loss, may be used to improve health and modify gastrointestinal microbiota of overweight cats. This study aimed to identify and determine the effects of restricted feeding and BW loss on fecal metabolite concentrations and microbiota populations of overweight cats. All procedures were approved by the University of Illinois IACUC before experimentation. Twenty-two overweight adult spayed female and neutered male cats [BW = 5.70 ± 1.0 kg; BCS = 7.68±0.6; age = 4 ± 0.4 yr] were used in a 24-wk BW loss study. A control diet (OR) was fed during a 4-wk baseline to identify intake needed to maintain BW. After baseline (wk 0), cats were allotted to OR or a BW loss diet (FT) and fed to lose ~1.0% BW/wk. Fecal samples were collected at baseline (wk 0), and weeks 4, 8, 12, 16, 20, and 24 for microbiota and metabolite analyses. Fecal microbiota data were analyzed and evaluated using QIIME2 and Mixed Models procedure of SAS, with P &amp;lt; 0.05 considered significant. Change from baseline fecal acetate, propionate, butyrate, total short-chain fatty acid, isobutyrate, valerate, phenol, indole, and total phenol and indole concentrations were reduced (P &amp;lt; 0.05) with restricted feeding and BW loss. Change from baseline fecal scores and valerate concentrations were also affected by diet, with greater (P &amp;lt; 0.05) reductions occurring in cats fed OR than those fed FT. Change from baseline fecal pH was also greater (P = 0.05) in cats fed OR than those fed FT. Fecal bacterial alpha diversity was not affected by diet or restricted feeding and BW loss. However, fecal bacterial beta diversity, assessed by weighted and unweighted UniFrac distances and presented as principal coordinate plots, showed separation between dietary groups, with some significant clustering as a result of restricted feeding and weight loss. The relative abundances of a single fecal bacterial phylum and 5 fecal bacterial genera were impacted by restricted feeding and weight loss. Diet had a greater effect, with 3 fecal bacterial phyla and 19 fecal bacterial genera being different (P &amp;lt; 0.05) between dietary treatment groups. Our data demonstrate that restricted feeding of specially formulated diets, and subsequent BW loss, modifies the fecal metabolite profiles and microbiota populations of overweight cats. The mechanisms by which these changes may affect feline gastrointestinal health and metabolism requires further study.

SOME CHARICTERISTIC OF MICROBIAL INDOLE EXTRACTED FROM PATHOGENIC E. COLI IN COMPARABLE WITH STANDARD ONE

Indole molecules as a signal has an important role in bacterial ecosystem, this study was aimed and conducted on the extraction and partial purification of indole from pathogenic E. coli and study several indole characterizations parameters compared with synthetic standard one. A total of 134 urine specimens and other stool 152 specimens were obtained from Al-Ramadi Hospitals, during the period from November / 2018 to March / 2019.The results show the percentage of isolated E. coli from Urinary tract infection was 100 (74.6%)/134, While 152 (100%)/ 152 are isolated from stool. Primary and secondary screening concluded, there are ten isolates are considered as the best in production of indole. The most producible one is selected with indole concentration 165.667 µM/ml. Also, indole production needs several optimal parameters to elevate its production, the study improved that the best pH is 9, temperature is 35 °C, incubation period is 18 hrs. and indole concentration is directly proportional with the amount of tryptophan added. Thin layer chromatography result reveals that no significant difference between extracted indole Rf 0.9 and 0.91 of synthetic standard one. Fourier-Transform-Infrared Spectroscopy, the results show there are some differences in the analysis in some structural positions.

Faecal metabolome responses to an altered dietary protein:carbohydrate ratio in adult dogs

High-protein diets may aid weight loss and weight maintenance programs in both humans and dogs, although the effect of dietary protein levels on gut metabolism and functionality has not been studied in depth. The current study aimed to investigate the effect of an altered dietary protein:carbohydrate ratio on gut function in adult dogs by means of faecal metabolomic fingerprinting. More specifically, functional metabolic differences in dogs fed a high-protein/low-carbohydrate (HPLC) vs. low-protein/high-carbohydrate (LPHC) diet were studied by equally allocating twelve clinically healthy (6 lean and 6 obese) Beagles into two groups in a cross-over design, with each group receiving two isocaloric diets for four weeks. The faecal metabolome revealed that different protein:carbohydrate ratio can influence host and/or gut microbiome metabolism and function, while no effect was observed on the body condition. Targeted analysis demonstrated that the HPLC diet significantly increased the concentration of indole, spermidine, and pipecolinic acid and decreased the concentration of azelaic acid, D-fructose, mannose, and galactose (p < 0.05). Multivariate modelling (OPLS-DA) of the untargeted faecal metabolome revealed distinctly different metabolomic profiles following the HPLC vs. LPHC diet, with 18 altered pathways. The HPLC diet influenced amino acid and lipid metabolism, potentially promoting weight loss and immune function, whereas the LPHC diet affected carbohydrate fermentation and may promote anti-oxidative function.

Association of the AspP298Asn polymorphism in the MC4R gene with fattening productivity of immunologically castrated and uncastrated gilts

The study was aimed at establishing the presence of MC4R (c.1426 A&gt;G) gene polymorphism among the population of immunologically castrated and native gilts (Large White × Landrace) × Maxgro. Asp298Asn polymorphism affects the economic rate of growth and fattening productivity of commercial lines of pigs. Since the polymorphism of the MC4R gene correlates with the concentration of androstenone, skatole, and indole, the possible use of polymorphism as a molecular DNA marker MC4R for genetic selection in order to reduce the level of boar odor in gilts meat and fat. This will establish which alleles and genotypes in general will be determined as desirable in the marker dilution of hybrid pigs. With this in mind, the purpose of the study was to determine the effect of the MC4R genotype on fattening performance indicators and correlation with boar odor in hybrid gilts based on population-genetic variability. Genomic DNA was isolated from the ear hair follicle of native gilts (n=42) and epithelial tissue from the ear of immunologically castrated ones (n=52). Genotyping was performed using polymorphism of the lengths of restrictive fragments (RFLP). Genetic-correlation parameters for native and immunologically castrated gilts were evaluated by ADG/AGE30 and ADG/AGE100. However, the polymorphism of the c.1426 A&gt;G gene did not significantly affect the ADG/AGE100 performance of hybrid gilts. The predominance of the frequency of allele A (0.55) is established above the frequency of the allele G (0.45). Analysis of the frequency distribution of genotypes showed the saturation of micropopulation with heterozygotes AG (0.51) with a small proportion of GG carriers (0.19). Immunologically castrated and uncastrated gilts with an MC4RA allele are characterized by a sufficiently high ADG/AGE100 and are probably characterized by a high level of boar-specific odor compared to gilts with lower ADG/AGE100 with an MC4RG allele. According to the data obtained, the desired genotype for an equilibrium of the concentration of boar odor without compromising physiological development, growth rate, and productivity formation is heterozygous offspring with the MC4RAG genotype.