Effect of dietary α‐ketoglutarate and allicin supplementation on the composition and diversity of the cecal microbial community in growing pigs

The search for substitutes for antibiotics has recently become urgent. In our previous work, dietary α-ketoglutarate (AKG) combined with allicin improved growth performance and enhanced immunity in growing pigs, whereas the effects on them of intestinal microbiota were unclear. Here, we further investigate the effects of dietary AKG and allicin supplementation on the composition and diversity of intestinal microbiota in growing pigs.Treatment with a combination of AKG and allicin enhanced cecal bacteria richness and diversity, as evidenced by changes in Chao 1, ACE, Shannon, and Simpson values when compared to the control group and antibiotics group. At the phylum level, Bacteroidetes and Firmicutes were the two most abundant phyla. Treatment with a combination of AKG and allicin increased the numbers of Firmicutes and reduced the numbers of Bacteroidetes. Prevotella was the most abundant genus; it was increased by treatment with a combination of AKG and allicin. Furthermore, compared with the antibiotic group, the level of acetate was increased in the AKG group with or without allicin. Treatment with a combination of AKG and allicin increased the levels of cecal butyrate and total volatile fatty acids (VFA) when compared with the control group in growing pigs.Dietary 1.0% AKG combined with 0.5% allicin improved cecal microbial composition and diversity, which might further promote VFA metabolism in growing pigs. © 2018 Society of Chemical Industry.