Prof. dr. Myriam Hesta, PhD Vet Sci, Dip ECVCN

Prof. Hesta is responsible for research, education and services regarding nutrition of companion animals (esp. dogs, cats and horses). Besides the research done on the diet of domesticated carnivores, research studies are also conducted in wild carnivores -including the cheetah. In this way, it is expected to understand the nutrition of this endangered species, but also to obtain more insight in the nutritional evolution that domesticated carnivores have gone through.

The study area includes two predominant lines of research.

Nutritional control of gastrointestinal and general health

The gastrointestinal (GI) microbiota plays an important role in maintaining the health of humans and animals, even in species that naturally have a poorly developed colon as carnivores. An unbalanced composition of the GI microbiota can have many negative consequences. In humans, it was shown that an excessive intake of red meat can lead to an increased concentration of putrefaction products and even to an increased risk of colon cancer. However, carnivores have a much higher dietary protein requirement and therefore take up more proteins than humans. Naturally, there will be more protein fermented in the large intestine of carnivores. We are currently investigating the effect of the quantity and quality of protein on the fecal microbiota and markers for GI health in healthy dogs (Jia Xu). The effect of the heme that is present in red meat, on the faecal microbiota of cats may have interesting implications for the feeding "natural" diets (Sandra Debevere) for example. We also assess the effect of feeding prey (including skin, tendons, bones etc.) versus pure meat on the fecal microbiota (Anne Becker) and fecal markers (cfr. PhD Sarah De Pauw) in wild carnivores such as cheetahs, and in dogs (Annelies De Cuyper). Moreover, research also focuses whether any detrimental effects of heme can be reduced by supplementing the diet with animal fibers in domestic cats (Sandra Debevere). Furthermore we will investigate the role that the GI microbiota plays in the onset and development of inflammatory bowel disease (IBD) (Jia Xu) and how dietary changes can be used (adding pre-, pro-, syn- or postbiotica or by adjusting the quantity and quality of the protein) preventively and curatively.

Moreover, research in this lab showed (cfr. PhD Adronie Verbrugghe Kristel Rochus) that the GI fermentation can also influence general host metabolism and possibly the amino acid (AA) gut metabolism can affect host metabolism. The saving mechanism of AA in pure carnivores like the cat can be very interesting when for example the protein intake should be limited because of kidney or liver pathology or when a loss of lean mass should be limited as far as possible (intensive care or obese patients undergoing a weight loss plan). Also in herbivores the GI flora and fermentation play an important role. In horses it will be determined whether addition of a postbioticum has a positive effect on gastrointestinal function (Wendy Wambacq).

Investigating these aspects in both healthy and diseased animals and across species will improve the understanding of these problems and the underlying mechanisms can be unraveled. This can then, in turn, lead to an adjusted preventive and / or curative treatment diet.

Nutritional control of immunity in general and of inflammation in particular

Obesity leads to an increased risk of a variety of other disorders, such as bladder stones, joint problems, heat intolerance, constipation, skin, heart problems etc. When obese animals suddenly stop eating, it can lead to hepatic lipidosis (cat) or hyperlipemia (horse) and these may be fatal.

It is suggested that a chronic ‘low grade’ inflammation is the basis for the increased prevalence of a lot of diseases in obese animals and humans. The effect of gaining and of losing weight on inflammation and immunity in general has already been examined in both the dog and the cat (cfr. PhD Hannelore Van De Velde). In humans, obesity is a risk factor for vascular dysfunction, and kidney disease. In dogs, the effect is not yet known and will therefore be investigated with an innovative technique (CEUS) (Daisy Liu). Obesity may also cause insulin resistance and diet and loss of weight play an important role in the treatment of diabetes. The latter will be examined in the cat (Veerle Vandendriessche).

More and more the importance of the GI microbiota in obese animals is demonstrated and this is where the two lines of research come together. The effect of gaining and losing weight on the fecal microbiota and energy metabolism will be examined in dogs (Daisy Liu) and horses (Wendy Wambacq). In horses and ponies is obesity, in addition to insulin resistance (IR), an important factor in the equine metabolic syndrome (EMS). Ponies with EMS have an increased risk of laminitis. Both general and regional fat deposits play an important role. It has been shown that different degrees of energy constraints may affect several of these aspects (cfr. PhD Lien Bruynsteen).

Since weight loss programs do not always provide the optimum effect, an attempt to develop an ideal weight loss diet is ongoing by investigating the underlying mechanisms in different species. Research also focuses on how to overcome and prevent the negative effects of obesity through dietary changes or use of dietary supplements and indirectly reduce the comorbidity.