Cecal Microbial Succession and Its Apparent Association with Nutrient Metabolism in Broiler Chickens.

The chicken gut microbiota plays an influential role in nutrient absorption and metabolism. A clear picture of microbiota succession can enhance host nutrition and disease resistance. This study investigated the cecal microbiota succession of broilers between 3 and 42 days after hatching using 16S rRNA gene sequencing and analyzed its potential association with intestinal nutrient metabolism. Microbiota structure differed significantly at different time points depending on the microbiota alpha-diversity or beta-diversity. Proteobacteria and Bacteroidetes promoted succession on days 3 to 7 and days 28 to 35, respectively. Firmicutes and Tenericutes maintained homeostasis on days 7 to 28 and days 35 to 42. Shigella , [ Ruminococcus ], Erysipelotrichaceae&#95;Clostridium , and Coprobacillus promoted succession on days 3 to 7; Faecalibacterium modified microbial composition on days 7 to 14; Faecalibacterium and Bacteroides regulated microbial structure from days 21 to 28. The microbiota structure was relatively stable on days 14 to 21 and days 28 to 35. Spearman's correlation analysis indicated a positive correlation between Lactobacillus and villus height and crypt depth ( P <  0.01). Faecalibacterium and Shigella were correlated with propionate, butyrate, and valerate concentrations ( P <  0.01). Ruminococcus was correlated with sodium-glucose cotransporters 1 and cationic amino acid transporter 1 expression ( P <  0.05). Erysipelotrichaceae&#95;Clostridium and Shigella were positively correlated with serum levels of total cholesterol, tryglucerides, and high- and low-density lipoprotein cholesterol ( P <  0.01). Bacteroides , Parabacteroides , Lactobacillus , and Shigella were correlated with serum VB6 levels ( P <  0.01). Bacteroides , Erysipelotrichaceae&#95;Clostridium , and Coprobacillus were correlated with the moisture content of cecal contents ( P <  0.05). The identification of the microbiota in correlation with nutrient metabolism will promote microbial nutrition through microbiota intervention or nutritional regulation. IMPORTANCE The poultry industry has become a global leader in livestock farming over the past few decades. Poultry production has a large consumer market as an integrated industry producing high-protein foods. Establishing the association between microbiota and nutrient metabolism processes provides fresh insights for precise nutrient regulation. This study aimed to describe the development of cecal microbiota in broiler chickens throughout the production cycle and to assess the correlation of nutrient metabolism phenotypes with temporal changes in the microbiota. The results suggested that changes in cecal microbes with age partly explain changes in gut nutrient metabolic processes, and numerous microbes were significantly associated with the processes. Therefore, this study attempts to further find efficient ways of improving poultry production. One is to promote nutrient metabolism by identifying potential candidates for probiotics, and another is to foster the dominant colonization of the microbiota by regulating nutrient metabolism.
Competing Interests: The authors declare no conflict of interest.