Original ResearchPsyllium Lowers Blood Glucose and Insulin Concentrations in Horses
Introduction
Psyllium is a commercially marketed plant product that is readily available to horse owners; however, there is no evidence of the metabolic effects of daily psyllium supplementation on horses. Human research [1], [2] reported that oral psyllium supplementation reduced the blood glucose and insulin response after a meal in equine patients. Animal and human studies have revealed that psyllium, that is, the seed husk of Plantago ovata, primarily consists of unique, physiologically active, gel-forming, non-nutrient polysaccharides that resist digestion by the intestinal microflora [3]. Recent research regarding metabolic syndrome in human beings and studies on rodents support the emerging theory that gastrointestinal microflora influence insulin sensitivity by virtue of interactions with endocrine and epithelial cells [4], [5], [6]. Insulin resistance, obesity, and laminitis are important components of metabolic syndrome described in equids [7].
Diet, obesity, insulin sensitivity, and laminitis are interrelated; recent research [8], [9], [10], [11], [12] suggests that hyperinsulinemia in horses may be involved in the pathogenesis of laminitis. Hyperinsulinemia is caused by insulin insensitivity which is a result of ongoing insulin resistance and obesity. A 2007 report [13] indicated that nearly 10% of horses in the United States suffered from hyperinsulinemia. Insulin resistance, the resultant hyperinsulinemia, and obesity are strongly inter-linked, each exacerbating the other, and ultimately have the potential to cause laminitis [14], [15], [16].
Laminitis is a painful and potentially career-ending condition in horses that weakens the dermal–epidermal union within the hoof. To avoid endocrinopathic laminitis, it is essential to prevent obesity and insulin resistance, which can be accomplished in part by lowering blood glucose and insulin concentrations in the horse.
The objectives of experiment 1 were as follows: (1) to determine whether 60 days of psyllium treatment would suppress postprandial blood glucose and insulin concentrations in normal horses, and (2) to determine what dose of psyllium would elicit the greatest metabolic response, if any. The objectives of experiment 2 were as follows: (1) to determine whether the psyllium fed for 60 days before an intravenous glucose infusion would affect blood glucose and insulin concentrations after infusion, and (2) what dose of psyllium would elicit the greatest metabolic response, if any.
Section snippets
Materials and Methods
All procedures were approved by Montana State University’s Animal Care and Use Committee. The study was conducted between June 11, 2009 and August 12, 2009. A total of 16 mature healthy light breed stock horses (eight geldings, eight mares; body weight: 515.3 ± 37 kg [mean ± SD]; age range: 7-16 years; mean: 11.6 ± 3.2 years) were used. Body condition score [17] was recorded as the mean of four scores assigned by trained observers; individual horse scores ranged from 4.5 to 5.5 for the 16
Experiment 1
Horses fed with psyllium for 60 days had lower (P < .01) mean postprandial blood glucose (88.6 ± 13.5 vs. 95.0 ± 18.9 mg/dL) concentrations as compared with horses that were fed with an isocaloric control supplement, and peak glucose concentrations were lower (P = .05) for horses treated with psyllium as compared with untreated horses. There were no differences in AUC glucose response or time to peak glucose response for untreated versus treated horses (Table 1). A treatment by time effect (P
Discussion
Horses can be challenging to feed. The ideal situation for the physical, mental, and digestive state of a horse is to graze moderate quality of mature pasture grass ad libitum throughout the day. Human intervention, space availability, and the risk of becoming obese inhibit most horses from living in that ideal environment. Obesity is a major concern because it predisposes horses to insulin resistance and alters metabolic pathways that could ultimately result in laminitis [13], [14], [15], [16]
Conclusion
Results from experiment 1 are similar to results from studies on psyllium supplementation in human beings. Postprandial blood glucose was lower in horses fed with 90, 180, and 270 g psyllium for 60 days and insulin concentrations were lower in horses that were fed with 270 g of psyllium for 60 days.
Psyllium could be especially beneficial to obese, insulin-resistant horses, or horses that are predisposed to developing laminitis because of metabolic syndrome. Psyllium is commercially marketed and
Acknowledgments
The authors thank Dr. Jim Berardinelli for his guidance in the physiology laboratory, and Kyla Hendry and the many volunteers for their assistance in the field throughout the study.
Funding for this study was provided by the Montana State University Department of Agriculture and the Montana Agricultural Experiment Station. Vetri-Science Laboratories (Essex Junction, Vermont) provided psyllium pellets in bulk for a discount off the market price, but had no involvement in the experimental design,
References (28)
- et al.
The gel-forming polysaccharide of psyllium husk (Plantago ovata Forsk)
Carbohydr Res
(2004) The role of insulin in endocrinopathic laminits
J Equine Vet Sci
(2008)- et al.
Induction of laminitis by prolonged hyperinsulinemia in clinically normal ponies
Vet J
(2007) Metabolic predispositions to laminitis in horses and ponies: obesity, insulin resistance and metabolic syndromes
J Equine Vet Sci
(2008)Equine metabolic syndrome
J Equine Vet Sci
(2009)- et al.
Body condition during pregnancy and lactation and reproductive efficiency of mares
Theriogenology
(1984) The nutritional significance of “dietary fibre” analysis
Anim Feed Sci Technol
(2001)- et al.
The effects of feed form on consumption time and glucose and insulin response to a concentrate meal in equine
J Equine Vet Sci
(2008) - et al.
Effects of ispaghula husk and guar gum on post prandial glucose and insulin concentrations in healthy subjects
Euro J Clin Nutr
(2001) - et al.
Farmafibra Group. Therapeutic effects of psyllium in type 2 diabetic patients
Euro J Clin Nutr
(2002)
Obesity and the human microbiome
Curr Opin Gastroenterol
Metabolic cross talk between the colon and the periphery: implications for insulin sensitivity
Proc Nutr Soc
Metabolic syndrome and altered gut microbiota in mice lacking toll-like receptor 5
Science
Equine metabolic syndrome (ACVIM consensus statement)
J Vet Int Med
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