Influence of xylan and microcrystalline cellulose on the American cockroach gut microbiome

The gut microbiota of the American cockroach, Periplaneta americana, is diverse and normally resistant to diet-related shifts when fed whole foods. However, chemically defined artificial diets may perturb the gut community. This experiment examines a variety of synthetic diets previously produced in the Ottesen lab that feature xylan and microcrystalline cellulose as the primary carbohydrate source. The standard artificial diet contains lab-grade ingredients that make up, as percent of dry mass, 70.5% variable carbohydrate, 17% casein, 8% peptone, 0.5% Vanderzant vitamin mixture, 3% Wesson salt mixture, and 1% cholesterol. Variations of this standard artificial diet are used to understand what conditions are associated with the alterations seen following ingestion of xylan: diets without casein/peptone, diets without vitamins/cholesterol, diets with tuna in lieu of casein/peptone, diets with mixtures of xylan/microcrystalline cellulose in set ratios, and diets with simple sugar forms of the complex carbohydrates (xylose, glucose, and cellobiose).