Phytogenic supplements are developing as an alternative to the use of antibiotics in livestock. Unlike other antibiotic alternatives, where the primary effect is mostly antimicrobial, plant phytogens as synthesised chemicals or natural essential oil products have a range of unexplored beneficial effects, making them popular in alternative medicine for thousands of years. Here we will present a mechanistic evaluation of a phytogen used to supplement layers during the peak of heat stress and Spotty Liver Disease (SLD) outbreak. Phytogenic product improved performance throughout the supplementation period, including during the SLD outbreak, increased the number of ileum goblet cells, reduced microbial functions related to pathogenicity, improved cardiovascular health and altered metabolism towards reduced fat storage.