Comparison of Diet versus Exercise on Metabolic Function and Gut Microbiota in Obese Rats

Abstract

Cardiometabolic impairments that begin early in life are particularly critical, as they often predict metabolic dysfunction into adulthood. Obesity, high-fat diet (HFD), and inactivity are all associated with adipose tissue (AT) inflammation and insulin resistance (IR), major predictors of metabolic dysfunction. Recent evidence also has associated the gut microbiome with cardiometabolic health. PURPOSE Compare equal energy deficits induced by exercise and caloric reduction on cardiometabolic disease risk parameters including AT inflammation, IR and gut microbiota changes during HFD consumption. METHODS Obesity-prone rats fed HFD were exercise trained (Ex, n=10) or weight-matched to Ex via caloric reduction while kept sedentary (WM, n=10), and compared to ad libitum HFD-fed (Sed, n=10) rats for IR, systemic energetics and spontaneous physical activity (SPA), adiposity, and fasting metabolic parameters. Visceral, subcutaneous, periaortic, and brown AT, liver, aorta, and cecal digesta were examined. RESULTS Despite identical reductions in adiposity, Ex, but not WM, improved IR, increased SPA by ~26% (p<0.05 compared to WM and Sed), and reduced LDL cholesterol (p<0.05 compared to Sed). WM and Ex both reduced inflammatory markers in all AT depots and aorta, while only Ex increased indicators of mitochondrial function in brown AT. Ex significantly increased the relative abundance of cecal Streptococcaceae and decreased S24-7 and one undefined genus in Rikenellacea; WM induced similar changes that did not reach statistical significance. CONCLUSIONS Both Ex and WM reduced AT inflammation across depots, while Ex caused more robust changes to gut microbial communities, improved IR, increased fat oxidation, increased SPA, and increased indices of brown AT mitochondrial function. Our findings add to the growing body of literature indicating that there are weight-loss independent metabolic benefits of exercise.

Habitual physical activity protects against lipopolysaccharide-induced inflammation in mouse adipose tissue

“…15,17 In this regard, a recent study from Welly and colleagues demonstrated that caloric restriction as a means to match the reduction in adiposity induced by VWR, led to similar effects on inflammatory gene expression when rats were fed a high fat diet. 16 The results from our current study support and add to these previous studies, as we observed that VWR attenuated the LPSmediated induction of TNF-a and MCP-1 mRNA expression in iWAT providing some evidence that the effects of VWR go beyond the attenuation of weight gain. Intriguingly, the effects of physical activity are The potential mechanistic basis for the protective effects of VWR against LPS induced adipose tissue inflammation are likely multifaceted.…”

“…Physical activity and exercise training increase indices of mitochondrial biogenesis in adipose tissue [9][10][11][12] and induce a thermogenic gene program that is characterized by increases in uncoupling protein 1 (UCP-1) mRNA expression and/or protein content in some 9,13,14 but not all studies. 15,16 While physical activity can protect against adipose tissue inflammation induced by obesity, 15,17 this beneficial anti-inflammatory effect is likely mediated, at least in part, through reducing the accretion of adipose tissue. 18 Thus, as the inflammatory cascade induced by sepsis manifests without significant changes in the accretion of adipose tissue, it is important to determine if physical activity or exercise protect against sepsis induced inflammation in adipose tissue.…”

Homage to the ‘H’ in developmental origins of health and disease

“…89,90 In adult rodents, exercise changes the gut microbial populations. [140][141][142][143] In turn, the composition of the gut microbiota may influence exercise performance of mice through anti-oxidant enzyme production. 144 In mice, exercise attenuates gut dysbiosis due to exposure to polychlorinated biphenyls.…”

Anti-inflammatory effects of exercise training in adipose tissue do not require FGF21

“…Adipose tissue is an active endocrine organ that is profoundly affected by exercise. Exercise lessens WAT inflammation and improves systemic metabolic health, even in settings of obesity (Vieira, et al 2009a; Welly, et al 2016a), although the mechanisms are not fully understood. Less is known about the effect of exercise on BAT inflammation.…”

“…Less is known about the effect of exercise on BAT inflammation. In this regard, we recently showed that exercise training also reduces obesity-induced BAT inflammation in rodents (Wainright, et al 2015; Welly et al 2016a). In addition, evidence suggests that exercise increases WAT mitochondrial content and function (Lee, et al 2014; Stallknecht, et al 1991; Stanford and Goodyear 2016; Wainright et al 2015), which is associated with metabolically healthier WAT.…”