Coffee pulp, a by-product of coffee production, modulates gut microbiota and improves metabolic syndrome in high-carbohydrate, high-fat diet-fed rats

Waste from food production can be re‐purposed as raw material for usable products to decrease industrial waste. Coffee pulp is 29% of the dry weight of coffee cherries and contains caf‐feine, chlorogenic acid, trigonelline, diterpenes and fibre. We investigated the attenuation of signs of metabolic syndrome induced by high‐carbohydrate, high‐fat diet in rats by dietary supplementation with 5% freeze‐dried coffee pulp for the final 8 weeks of a 16‐week protocol. Coffee pulp decreased body weight, feed efficiency and abdominal fat; normalised systolic blood pressure, left ventricular diastolic stiffness, and plasma concentrations of triglycerides and non‐esterified fatty acids; and improved glucose tolerance in rats fed high‐carbohydrate, high‐fat diet. Further, the gut microbiota was modulated with high‐carbohydrate, high‐fat diet and coffee pulp supplementation and 14 physiological parameters were correlated with the changes in bacterial community structures. This study suggested that coffee pulp, as a waste from the coffee industry, is useful as a functional food for improving obesity‐associated metabolic, cardiovascular and liver structure and function, and gut microbiota.