To study why flaxseed supplementation causes adverse effects on the performance of poultry, we investigated the gut microbiota of Peking ducks after consumption of a flaxseed diet. A total of 792, 12-day-old white Peking ducks were divided into four groups. In the control group, birds were provided with a basal diet. In the three experimental groups, the birds were fed flaxseed containing diet (10% flaxseed and 90% basal diet) for 30, 20 and 10 d, respectively. On day 42, ceca were collected to evaluate the bacterial diversity of the gut microbiota using microbial 16S rDNA gene profiling; serums were obtained to determine the levels of inflammatory mediators. The flaxseed diet decreased the alpha diversity and shifted the predominant genera of the gut microbiota. Flaxseed-fed groups had higher abundances of Escherichia/Shigella (p < 0.1) and Campylobacter (p < 0.05) than the control group. The abundance of pro-inflammatory bacteria such as Veillonellaceae increased (p < 0.05) at first and then decreased (p < 0.05) with prolonged flaxseed supplementation. The levels of prostaglandin E2 and Leukotriene B4 in serum showed the same pattern as that of the pro-inflammatory bacteria. In conclusion, flaxseed diets are associated with inflammation by altering the cecal microbiota dynamics.
Keywords: Duck; flaxseed; inflammation; microbiota.