Research Article: Astragalus affects fecal microbial composition of young hens as determined by 16S rRNA sequencing

Date Published: April 30, 2018

Publisher: Springer Berlin Heidelberg

Author(s): Hongxing Qiao, Liheng Zhang, Hongtao Shi, Yuzhen Song, Chuanzhou Bian.


The gut microbiota play important roles in the degradation of chemical compounds of herbal medicines (HMs). However, little information regarding the interplay between HMs and the gut microbiota is available. Thus, the aim of this study was to investigate the composition of the fecal microbiota of young (age, 11 weeks) hens fed a conventional diet containing a crude Astragalus (0.5%) additive for 21 days (group A) vs. controls (group B) that were fed only conventional feed. The fecal contents of 14-week-old hens were collected for DNA extraction, and then the V3 and V4 hyper-variable regions of the 16S rRNA gene were amplified and analyzed using high-throughput sequencing technology. A distinctive difference in microbial diversity was observed between the two groups. The microbial composition of hens fed a diet supplemented with Astragalus was greater than that of the control group. At the genus level, Lactobacillus was more abundant in group A than group B (p < 0.05). Importantly, this study is the first to report the observation of a novel Romboutsia sp. in the feces of hens. However, Romboutsia was less abundant in group A than group B (17.94 vs. 33.98%, respectively, p < 0.05). The microbial community differed significantly between the two groups at the genus level, suggesting that Astragalus modulates the composition of the fecal microbiota. Based on these differences, these findings provide fresh insights into the application of Astragalus in the poultry industry, as well as a better understanding of the interplay between HMs and the gut microbiota.

Partial Text

Poultry meat and eggs are common nutritious and healthy sources of animal protein for human consumption. However, the accumulation of antibiotic residues in chickens and eggs, and the subsequent prevalence of drug-resistant pathogens have received attention worldwide (Wang et al. 2017b). The use of antibiotics can result in gut dysbiosis, diarrhea, and host immune dysregulation (Willing et al. 2011), which results in reduced growth and production (Gao et al. 2017). Recent studies have shown that the composition of the gut microbiota affects various physiological functions of the host, such as nutrient utilization, gut epithelium nourishment, and the development and activity of the gut immune system (Ismail et al. 2009 and Hill et al. 2010).

Although many studies have investigated the gut microbiota composition of poultry, very few have assessed the interactions between HMs and gut microbes. In recent years, the potential application of HMs in aquatic animals and rat models has been increasingly explored. A recent study showed that Yu-Ping-Feng (Jade screen) powder (Chinese parsnip root, Astragalus membranaceus and Atractylodes macrocephala Koidz) can regulate the intestinal microbiota of fish (Wu et al. 2018), the combination of Gancao-Gansui impacted the gut microbiota diversity of the rat (Yu et al. 2018), and Salvia miltiorrhiza Bge. modulated the microbiota imbalance in diabetic mice (Gu et al. 2017). Previous studies have shown that fermented Ginkgo leaves contributed to the microbial ecology in the gut of broiler chicks (Zhang et al. 2015), while fermented pine needles (Pinus ponderosa) improved antioxidant status and growth performance in broilers (Wu et al. 2015) and improved meat quality and lipid metabolism in broilers (Cao et al. 2012). The principle of HMs supplementation of feed lies in maintaining or restoring the balance or enhancing the ability of immune defenses (Guo et al. 2004). Therefore, the aim of the present study was to compare the gut microbiota composition of young laying hens fed a diet supplemented with or without Astragalus supplement.




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