Protective effect of prebiotic and exercise intervention on knee health in a rat model of diet-induced obesity

Rios JL, Bomhof MR, Reimer RA, Hart DA, Collins KH, Herzog W · Scientific Reports

Prebiotic fibre alone, exercise alone, and the two together each completely prevented the knee joint damage that the high-fat/high-sucrose diet otherwise produced (modified Mankin scores 20.1, 13.6 and 12.3 against 47.9, with chow at 19.1), with matching normalisation of insulin sensitivity, serum endotoxin, triglycerides and leptin. Only the fibre corrected the caecal microbiota: exercise protected the knee without touching it, and the combination was no better than either alone. The damage itself was mostly subchondral bone replaced by fibrotic tissue, in 9 of 12 untreated rats. A rare animal experiment in which a dietary and an exercise intervention are tested head to head and in combination.

Population

Male Sprague-Dawley rats, 12 weeks old, in five groups: 8 chow-fed and 48 on a high-fat/high-sucrose diet split 12 each into sedentary, prebiotic fibre, aerobic exercise, or both, for 12 weeks

Intervention

10% oligofructose in the diet, progressive treadmill running up to 30 minutes five days a week, or both, on a high-fat/high-sucrose diet

Comparator

Chow-fed controls and unsupplemented high-fat/high-sucrose rats

Limitations

Rats, male only, and a diet-induced metabolic OA model rather than a mechanical or age-related one. 'Completely prevented' is against a model whose damage is driven by the diet the prebiotic offsets. Histology scored by two blinded graders; Canadian Institutes of Health Research and Alberta funding, no competing interests.