High numbers of red deer (Cervus elaphus) pose a challenge for natural forests because of their high browsing intensities, especially during winter months. To mitigate this human–wildlife conflict, conservation management in Central Europe involves luring red deer into fenced winter-feeding sites. The supplementary diet provided in these so-called winter enclosures strongly differs from the natural diet of red deer. Dietary shifts, however, can lead to an imbalance of the gut microbiota, which could promote bacterial...