A Multiomic Approach to Investigate the Effects of a Weight Loss Program on the Intestinal Health of Overweight Horses

Abstract

Obesity is endemic in human populations in the western society, and with mounting evidence that the intestinal ecological environment plays a major role in its pathogenesis, identification of therapies based on intestinal microbiota modulation are gaining attention. Obesity in companion animals is also a common clinical problem. We set out using a multidimensional approach, to determine the effectiveness and safety of a weight loss program for horses incorporating diet restriction and exercise. In addition, we aimed to investigate the effect of this program on the overall intestinal health of overweight sedentary horses. The investigation comprised of a randomized, controlled, 6-week study of 14 overweight sedentary horses and ponies who were blocked for age, gender, and breed (controls n = 7, treatment n = 7). The treatment group were fed a restricted diet (1.4% of body weight dry matter intake) and the control group a maintenance diet (2% of body weight as dry matter intake) over the study period. The treatment group were subjected to a prescribed exercise regime, while the control group were exercised to mimic foraging conditions. Several clinical measurements were taken at the start and end of the study, including morphological parameters, ultrasound measurements of subcutaneous fat, and blood pressure. Fecal microbiota analysis was performed using 16S rRNA gene sequence analysis, and fecal metabolome was analyzed using NMR spectroscopy, on samples taken at weeks 1, 3, and 6 of the study. All horses completed the study period successfully. However, two of the treatment group had to have modified exercise regimes. The treatment group showed significant weight loss (p < 0.00001) and an associated decrease in waste circumference (p < 0.0001) when compared with the control group. The alpha-diversity of the fecal microbiota in the treatment group showed a significant increase from the start to the end of the study period (p < 0.05); however, there was no significant difference between groups at any sampling point. There were significant changes (p < 0.05) in the metabolome in both groups between the start and end of the study, but not between groups at any sampling point. Finally, the resting blood pressure of all horses was significantly lower by the end of the study.

Variations in the fecal microbiota and their functions of Thoroughbred, Mongolian, and Hybrid horses

“…Meanwhile, some beneficial microbes in the gut can also specifically bind to the mucosal epithelium to enhance the gut immune protection barrier, thus preventing the invasion of pathogenic microorganisms ( 3 ). In addition to nutritional and immune barrier roles, the composition of the gut microbiota and their stability also play an important role in the host behavior ( 4 ), metabolism ( 5 ), obesity ( 6 ), disease ( 7 ), and more.…”

A Systematic Review on the Effects of Exercise on Gut Microbial Diversity, Taxonomic Composition, and Microbial Metabolites: Identifying Research Gaps and Future Directions

“…Thirteen studies conducted in various animal models met the inclusion criteria for this review ( Table 2 ). Of these 13, 5 were conducted in mice (Lamoureux et al, 2017; Houghton et al, 2018; Ribeiro et al, 2019; Chen et al, 2021; Yang et al, 2021a), 4 were in rats (Mika et al, 2015; Giacco et al, 2020; Meng et al, 2020; Castro et al, 2021), and 4 in horses (De Almeida et al, 2016; Janabis et al, 2016; Janabi et al, 2017; Walshe et al, 2021). All but one (Castro et al, 2021) of these studies examined the effects of either aerobic exercise or interventions with aerobic exercise as an important component.…”

“…All but one (Castro et al, 2021) of these studies examined the effects of either aerobic exercise or interventions with aerobic exercise as an important component. Twelve studies were trials with a parallel design (2–8 arms) (Mika et al, 2015; De Almeida et al, 2016; Janabis et al, 2016; Lamoureux et al, 2017; Houghton et al, 2018; Ribeiro et al, 2019; Giacco et al, 2020; Meng et al, 2020; Castro et al, 2021; Chen et al, 2021; Walshe et al, 2021; Yang et al, 2021b), of which the longest trial had a duration of 7 mon (Houghton et al, 2018) and the shortest trials had a duration of 3 days (Giacco et al, 2020). One study followed a crossover design in which horses were exposed to a graded exercise test and a standing control (Janabi et al, 2017).…”

“…In another study, aerobic exercise resulted in differential Jaccard diversity at 6 wk in comparison to control (De Almeida et al, 2016). In a weight-loss intervention, aerobic exercise for 6 wk increased Fisher alpha index, richness index, and Simpson index (Walshe et al, 2021).…”

Equine Fecal Microbiota Transplantation: Possible Mechanisms and Future Perspectives

“…Obesity is a growing health issue in horses, as it is linked to metabolic disorders like insulin imbalances, high lipid levels, and laminitis [113][114][115]. Studies have shown that gut microbiota can change in overweight horses after weight loss [116], leading to a significant increase in the alpha-diversity of their fecal microbiota. Given these findings and the impact gut microbiomes have on fitness, using lean horse feces, selected based on Body Condition Score (BCS), as a treatment option for weight loss in overweight horses may be a safe and cost-effective approach.…”