Adding a polyphenol-rich fiber bundle to food impacts the gastrointestinal microbiome and metabolome in dogs

Introduction

Pet foods fortified with fermentable fibers are often indicated for dogs with gastrointestinal conditions to improve gut health through the production of beneficial post-biotics by the pet's microbiome.

Methods

To evaluate the therapeutic underpinnings of pre-biotic fiber enrichment, we compared the fecal microbiome, the fecal metabolome, and the serum metabolome of 39 adult dogs with well-managed chronic gastroenteritis/enteritis (CGE) and healthy matched controls. The foods tested included a test food (TF1) containing a novel pre-biotic fiber bundle, a control food (CF) lacking the fiber bundle, and a commercially available therapeutic food (TF2) indicated for managing fiber-responsive conditions. In this crossover study, all dogs consumed CF for a 4-week wash-in period, were randomized to either TF1 or TF2 and fed for 4 weeks, were fed CF for a 4-week washout period, and then received the other test food for 4 weeks.

Results

Meaningful differences were not observed between the healthy and CGE dogs in response to the pre-biotic fiber bundle relative to CF. Both TF1 and TF2 improved stool scores compared to CF. TF1-fed dogs showed reduced body weight and fecal ash content compared to either CF or TF2, while stools of TF2-fed dogs showed higher pH and lower moisture content vs. TF1. TF1 consumption also resulted in unique fecal and systemic metabolic signatures compared to CF and TF2. TF1-fed dogs showed suppressed signals of fecal bacterial putrefactive metabolism compared to either CF or TF2 and increased saccharolytic signatures compared to TF2. A functional analysis of fecal tryptophan metabolism indicated reductions in fecal kynurenine and indole pathway metabolites with TF1. Among the three foods, TF1 uniquely increased fecal polyphenols and the resulting post-biotics. Compared to CF, consumption of TF1 largely reduced fecal levels of endocannabinoid-like metabolites and sphingolipids while increasing both fecal and circulating polyunsaturated fatty acid profiles, suggesting that TF1 may have modulated gastrointestinal inflammation and motility. Stools of TF1-fed dogs showed reductions in phospholipid profiles, suggesting fiber-dependent changes to colonic mucosal structure.

Discussion

These findings indicate that the use of a specific pre-biotic fiber bundle may be beneficial in healthy dogs and in dogs with CGE.

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.

A prospective multicenter study of the efficacy of a fiber-supplemented dietary intervention in dogs with chronic large bowel diarrhea

Background

Chronic large bowel diarrhea is common in dogs and can have a significant impact on their overall health and well being. We evaluated the safety and efficacy of a therapeutic food with select dietary plant fibers known to contain antioxidant and polyphenol compounds on clinical signs in dogs with chronic diarrhea.

Methods

A prospective clinical study was conducted in 31 adult dogs currently experiencing chronic diarrhea from private veterinary practices in the United States. Enrolled dogs were switched to a complete and balanced dry therapeutic food containing whole grains and polyphenol-containing fiber sources for 56 days. Veterinarians evaluated changes from baseline in overall clinical signs, recurrence of clinical signs, and stool parameters at Days 2, 3, 4, 28, and 56. Dog owners evaluated stool consistency daily and nausea/vomiting, quality of life (QoL), and stooling behaviors at Days 1, 14, 28, and 56. Statistical analysis was performed using a mixed-effects model with Day as a fixed-effect.

Results

Assessments of overall clinical response and stool parameters indicated that diarrhea improved significantly within 1 day of initiating the therapeutic food. Veterinarians reported that 68% of dogs had complete resolution of their clinical signs by Day 56 and the remaining 32% experienced improvement (P < 0.05), with no cases of recurrence. Veterinarians also reported improvement in stool consistency (P < 0.001) and reductions of blood and mucus in stool (P < 0.001). Significant improvements in nausea/vomiting, stooling behaviors, and quality of life (QoL) were reported by dog owners after 28 days and were sustained through day 56 (P < 0.05). The therapeutic food was safe and well tolerated.

Conclusions

In dogs with chronic large bowel diarrhea, the therapeutic food rapidly improved stool consistency, resolved clinical signs, and improved stooling behaviors and QoL. Therapeutic foods supplemented with fiber sources rich in antioxidant and anti-inflammatory compounds contribute to rapid resolution of chronic diarrhea without recurrence and may contribute to long term health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03302-8.

Cats with IRIS stage 1 and 2 chronic kidney disease maintain body weight and lean muscle mass when fed food having increased caloric density, and enhanced concentrations of carnitine and essential amino acids

A prospective, randomised, 6-month feeding trial was performed in 28 adult cats with International Renal Interest Society (IRIS) stage 1 and 2 chronic kidney disease (CKD). All cats were assigned to either a control food: Royal Canin Renal Support A Feline, dry or a test food: Hill's Prescription Diet k/d Feline with chicken, dry. Food intake was recorded daily; body weight weekly; and serum, urine, dual-energy x-ray absorptiometry (DEXA) and body condition assessments were performed at 0, 1, 3 and 6 months. Twenty cats (9 control, 11 test group) completed the study according to protocol. Cats consuming control food had significant loss of body weight (n=14; mean, -13.0 per cent, P<0.0001) and lean body mass (LBM; mean, -11.1 per cent, P<0.0001) over the 6-month feeding period, whereas cats consuming test food had a significant increase in body weight (n=14; mean, 5.8 per cent, P=0.003) and no change in LBM (P=0.42). Cats consumed 23 per cent more calories (P=0.05) when fed test food (mean, 207.1 kcal/day) compared with cats fed control food (mean, 168.0 kcal/day). Serum creatinine increased at a faster rate (P=0.0004) in cats consuming control food compared with cats consuming test food. Cats consuming test food had increased caloric and essential amino acid intake, increased body weight, stable biomarkers of kidney function and maintained LBM compared with cats consuming control food.

A longitudinal study on the acceptance and effects of a therapeutic renal food in pet dogs with IRIS-Stage 1 chronic kidney disease

Currently, nutritional management is recommended when serum creatinine (Cr) exceeds 1.4 mg/dl in dogs with IRIS-Stage 2 chronic kidney disease (CKD) to slow progressive loss of kidney function, reduce clinical and biochemical consequences of CKD, and maintain adequate nutrition. It is unknown if dietary interventions benefit non-azotemic dogs at earlier stages. A prospective 12-month feeding trial was performed in client-owned dogs with IRIS-Stage 1 CKD (n = 36; 20 had persistently dilute urine with urine specific gravity (USG) <1.020 without identifiable non-renal cause; six had persistent proteinuria of renal origin with urine protein creatinine (UPC) ratio >0.5; 10 had both). Ease of transition to therapeutic renal food and effects on renal biomarkers and quality of life attributes were assessed. Dogs were transitioned over 1 week from grocery-branded foods to renal food. At 0, 3, 6, 9, and 12-months a questionnaire to assess owner's perception of their pet's acceptance of renal food and quality of life was completed. Renal biomarkers, including serum Cr, blood urea nitrogen (BUN), and symmetric dimethylarginine (SDMA), and USG and UPC ratio were measured. Of 36 dogs initially enrolled, 35 (97%) dogs were transitioned to therapeutic renal food. Dogs moderately or extremely liked the food 88% of the time, ate most or all of the food 84% of the time, and were moderately or extremely enthusiastic while eating 76% of the time. All renal biomarkers (Cr, BUN, and SDMA) were decreased (p ≤ .05) from baseline at 3-months, and remained decreased from baseline at 12-months in dogs completing the study (n = 20). Proteinuria was reduced in 12 of 16 dogs (p = .045) with proteinuria. Owners reported improvement in overall health and quality of life attributes, and hair and coat quality (all p < .01). In summary, dogs with IRIS-Stage 1 CKD readily transition to renal food. Decreasing serum biomarker concentrations and reduction in proteinuria suggest stabilized kidney function.

Acceptance and effects of a therapeutic renal food in pet cats with chronic kidney disease

Introduction

Renal foods are used to manage chronic kidney disease (CKD) in dogs and cats, but their effectiveness may be limited by the ability to transition animals to them.

Material and Methods

In a prospective study, pet cats with previously undiagnosed kidney disease (20 International Renal Interest Society (IRIS) 1, 61 IRIS 2, 14 IRIS 3/4, 33 at risk for CKD) were transitioned to a renal food. Markers of renal function were measured and owners answered questionnaires about their pet over one year.

Results

All but eight cats (120/128; 94 per cent) successfully transitioned to the renal food. Most of the time, cats moderately or extremely liked the food (89 per cent), ate at least half (73 per cent) and were moderately or extremely enthusiastic while eating (68 per cent). Cats rarely disliked the food (2 per cent) or refused to eat it (1 per cent). Markers of renal function were unchanged in IRIS 1 and 2 cats and changed little in IRIS 3/4 cats. In all groups, owner-assessed quality of life improved initially and then remained stable. Mean bodyweight did not change in cats with CKD.

Conclusions

Most cats with CKD successfully transitioned to the renal food. The results also support previous studies that the renal food can help stabilise cats with CKD.