Diet Supplementation with a Bioactive Pomace Extract from Olea europaea Partially Mitigates Negative Effects on Gut Health Arising from a Short-Term Fasting Period in Broiler Chickens

SIMPLE SUMMARY: Plant-derived feed additives have been gaining interest as a means to maintain gut health in poultry. Recent studies have shown that fasting broilers up to 24 h triggers intestinal permeability increase and might be used as an experimental model to challenge gut health. The present study has demonstrated that feeding broiler chickens with an olive pomace extract rich in bioactive anti-inflammatory compounds do not negatively affect growth performance. Moreover, the olive pomace extract reduced some of the negative effects that a short-term fasting period induced in the intestine of broiler chickens. ABSTRACT: The effects of supplementing chicken diets with an olive pomace extract (OE) from Olea europaea on performance and gut health after a challenge of intestinal permeability (IP) increase were studied. Treatments included a control diet with no additives (CF), and diets supplemented with 100 ppm of monensin (MF) or with 500 (OE500F) and 1500 ppm (OE1500F) of an OE. At 14 d, all birds, except those allocated in a control group (CNF), were submitted to a 15.5 h short-term fasting period to induce IP increase. Fasting increased (p < 0.05) lactulose/mannitol ratio and Alpha 1 Acid Glycoprotein concentration, and reduced (p < 0.001) villus/crypt ratio. Moreover, a down-regulation of Claudin-1 (p < 0.05), an up-regulation of TLR4 and IL-8 (p < 0.05) ileal gene expression was observed in CF birds compared to CNF. OE500F treatment reduced duodenal crypt depth compared to CF (p < 0.05; OE linear effect). Mannitol concentration and ileal IL-8 expression were reduced in OE500F compared to CF and OE1500F (p = 0.05). Fasting challenge induced an increase in IP triggering an inflammatory response. Supplementation of OE up to 1500 ppm did not affect growth performance and alleviated some of the negative effects of the fasting challenge.