Partially hydrolysed whey has superior allergy preventive capacity compared to intact whey regardless of amoxicillin administration in Brown Norway rats

Brown Norway rats (n=12/group, 3-7 weeks of age, both sex) received daily gavage of amoxicillin (30 mg in 0.5 mL water) or water only (conventional group) for 28 days (Day 0-28). From Day 7-28, one amoxicillin group and one conventional group were given one out of four different whey protein products in their drinking water (12.5 g protein per litre water) ad libitum, or water alone for control. The whey protein products are ingredients for infant formula, and the different products differentiate on their degree of hydrolysis. One week after discontinuing administration of whey products and/or amoxicillin, all rats were post-immunised by intraperitoneal injections with 100 microgram intact whey in in 0.5 mL PBS once a week for four weeks. This was done to induce whey protein allergy and thereby test the allergy preventive capacity of the whey product interventions. The experiment was terminated one week after the last immunisation on Day 64. Temporal effects on the fecal microbiota community structure were analysed on Days 0, 7, 28 and 64, and in the proximal small intestine on Day 64. Changes in microbiota composition were correlated to various host physiological and immune parameters.