TY - JOUR A1 - Sieksmeyer, T. A1 - He, S. A1 - Esparza-Mora, M. A. A1 - Jiang, S. A1 - Petrasiunaite, V. A1 - Kuropka, B. A1 - Banasiak, Robert A1 - Julseth, M. J. A1 - Weise, C. A1 - Johnston, P. R. A1 - Rodriguez-Rojas, A. A1 - McMahon, Dino Peter T1 - Eating in a losing cause: Limited benefit of modifed macronutrient consumption following infection in the oriental cockroach Blatta orientalis N2 - Background: Host–pathogen interactions can lead to dramatic changes in host feeding behaviour. One aspect of this includes self-medication, where infected individuals consume substances such as toxins or alter their macronutrient consumption to enhance immune competence. Another widely adopted animal response to infection is illness-induced anorexia, which is thought to assist host immunity directly or by limiting the nutritional resources available to pathogens. Here, we recorded macronutrient preferences of the global pest cockroach, Blatta orientalis to investigate how shifts in host macronutrient dietary preference and quantity of carbohydrate (C) and protein (P) interact with immunity following bacterial infection. Results: We fnd that B. orientalis avoids diets enriched for P under normal conditions, and that high P diets reduce cockroach survival in the long term. However, following bacterial challenge, cockroaches signifcantly reduced their overall nutrient intake, particularly of carbohydrates, and increased the relative ratio of protein (P:C) consumed. Surprisingly, these behavioural shifts had a limited efect on cockroach immunity and survival, with minor changes to immune protein abundance and antimicrobial activity between individuals placed on diferent diets, regardless of infection status. Conclusions: We show that cockroach feeding behaviour can be modulated by a pathogen, resulting in an illness-induced anorexia-like feeding response and a shift from a C-enriched to a more P:C equal diet. However, our results also indicate that such responses do not provide signifcant immune protection in B. orientalis, suggesting that the host’s dietary shift might also result from random rather than directed behaviour. The lack of an apparent beneft of the shift in feeding behaviour highlights a possible reduced importance of diet in immune regulation in these invasive animals, although further investigations employing pathogens with alternative infection strategies are warranted. KW - Animal immune system KW - A key interface KW - Host and symbiont ecology KW - Behavioural mechanisms KW - Biotic environment PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-550022 SN - 2730-7182 VL - 22 IS - 1 SP - 1 EP - 14 PB - Springer Nature CY - London, UK AN - OPUS4-55002 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -