Gut Microbiota-Polyphenol Interactions in Chicken: A Review

SIMPLE SUMMARY: Gut microbiota play crucial roles in digestion of feed and absorption of nutrients in fast growing chickens. Gut microbiota affects feed conversion ratio, body weight gain, apparent metabolizable energy, residual feed intake, and time taken to attain the desired weight, which have direct influence on the health and productivity of chickens. A normal gut microbiota is therefore very important for optimum health. Factors like the environment, heat stress, and housing conditions can cause detrimental changes in the gut resulting in poor health of birds and decreased production performance. Polyphenols can be used to improve gut health due to their established health benefits and strong antioxidant potential. The interaction between polyphenols and the gut microbiota further generates active metabolites, which can modulate the composition of the chicken gut microbiota. Because of the specificities of the gut microbiota-polyphenols interactions, current knowledge in this area is presented. ABSTRACT: The gastrointestinal tract of the chicken harbors very complex and diverse microbial communities including both beneficial and harmful bacteria. However, a dynamic balance is generally maintained in such a way that beneficial bacteria predominate over harmful ones. Environmental factors can negatively affect this balance, resulting in harmful effects on the gut, declining health, and productivity. This means modulating changes in the chicken gut microbiota is an effective strategy to improve gut health and productivity. One strategy is using modified diets to favor the growth of beneficial bacteria and a key candidate are polyphenols, which have strong antioxidant potential and established health benefits. The gut microbiota-polyphenol interactions are of vital importance in their effects on the gut microbiota modulation because it affects not only the composition of gut bacteria but also improves bioavailability of polyphenols through generation of more bioactive metabolites enhancing their health effects on morphology and composition of the gut microbiota. The object of this review is to improve the understanding of polyphenol interactions with the gut microbiota and highlights their potential role in modulation of the gut microbiota of chicken.