Relative Effects of Dietary Administration of a Competitive Exclusion Culture and a Synbiotic Product, Age and Sampling Site on Intestinal Microbiota Maturation in Broiler Chickens

Abstract

In this research, the effects of early post-hatch inoculation of a competitive exclusion product (Br) and the continuous feeding of a synbiotic supplement (Sy) containing probiotic bacteria, yeast, and inulin on the production traits and composition of ileal chymus (IC), ileal mucosa (IM), and caecal chymus (CC) microbiota of broiler chickens were evaluated. The dietary treatments had no significant effects on the pattern of intestinal microbiota or production traits. The digestive tract bacteriota composition was affected mostly by the sampling place and age of birds. The dominant family of IC was Lactobacillaceae, without change with the age. The abundance of the two other major families, Enterococcaceae and Lachnospiraceae decreased with the age of birds. In the IM, Clostridiaceae was the main family in the first three weeks. Its ratio decreased later and Lactobacillaceae became the dominant family. In the CC, Ruminococcaceae and Lachnospiraceae were the main families with decreasing tendency in the age. In IC, Br treatment decreased the abundance of genus Lactobacillus, and both Br and Sy increased the ratio of Enterococcus at day 7. In all gut segments, a negative correlation was found between the IBD antibody titer levels and the ratio of genus Leuconostoc in the first three weeks, and a positive correlation was found in the case of Bifidobacterium, Rombutsia, and Turicibacter between day 21 and 40.

Gut Microbiome Studies in Livestock: Achievements, Challenges, and Perspectives

“…Shotgun metagenomics has also recently been employed to assess the role of dietary supplementation in improving the health status—and hence the productive performances—in broiler chickens by fostering the diversity of their cecum microbiome [ 134 ], also in the form of in ovo supplementation [ 92 ], as well as to characterize new bacterial, archaeal, and bacteriophage taxa of the chicken gut microbiome [ 135 ], thus shedding light on their biological function [ 136 ]. However, 16S rRNA metabarcoding alone is still widely used to compare the microbiome composition of healthy versus unhealthy individuals as a consequence of viral, e.g., [ 137 ], or bacterial [ 138 ] infections, of individuals subjected to different dietary treatments [ 139 ], as well as across different indigenous breeds [ 140 ], GIT locations [ 141 ], rearing systems [ 142 ] and individual lifetimes [ 143 ], with a special focus on improving growth performance by transplanting cecal [ 144 ] or fecal [ 92 ] material between individuals of different age groups. However, compared to other livestock species, the non-bacterial component of the gut microbiome has been given more attention and most of the studies focus on possible pathogens such as Cryptosporidium [ 145 ].…”

“…Similar to what occurs in the GIT of other livestock species, the most abundant microbial phyla in chicken are Bacteroidetes and Firmicutes [ 136 , 146 ], even though sometimes Proteobacteria are more abundant than the former [ 135 , 138 , 145 ], while Bacilli, Clostridia, and Gammaproteobacteria are the dominant classes [ 134 ]. At the order level, Bacillales, Enterobacteriales, Lactobacillales, and Campylobacterales are the most common groups ( Figure 2 ), while the most prevalent families include Enterobacteriaceae and Lactobacillaceae [ 139 ]. As far as the dominant genera are concerned, Alistipes , Bacteroides , Clostridium , Helicobacter , Lactobacillus , and Ruminococcus [ 133 , 143 , 144 , 146 , 147 , 148 , 149 ] stand out as well as Flavobacterium [ 139 ], Campylobacter, and Veillonella [ 150 ].…”

“…At the order level, Bacillales, Enterobacteriales, Lactobacillales, and Campylobacterales are the most common groups ( Figure 2 ), while the most prevalent families include Enterobacteriaceae and Lactobacillaceae [ 139 ]. As far as the dominant genera are concerned, Alistipes , Bacteroides , Clostridium , Helicobacter , Lactobacillus , and Ruminococcus [ 133 , 143 , 144 , 146 , 147 , 148 , 149 ] stand out as well as Flavobacterium [ 139 ], Campylobacter, and Veillonella [ 150 ]. A detailed list of the GIT-associated bacterial taxa and the related bibliographic references in pig is reported in Table S2 .…”

“…In this respect, it is pertinent to mention their contribution to the development of non-antibiotic microbial therapies based on probiotics [ 175 ] as well as in pinpointing biomarkers of feed efficiency to deploy strategies that can notably improve livestock production performances [ 67 , 68 , 76 , 84 , 85 , 98 , 126 , 134 , 148 , 176 ] and growth [ 69 , 93 , 115 ]. Additionally, gut microbial profiling is paramount to monitor livestock health status and set up treatments to boost it, e.g., [ 113 , 125 , 139 , 144 , 165 , 177 ] as well as to prevent the establishment or aggravation of pathologic states [ 64 , 137 , 138 , 150 ] and evidence peculiar adaptations of local breeds to harsh environments [ 80 ].…”

Comparison of Cecal Microbiota and Performance Indices Between Lean-Type and Fatty-Type Pekin Ducks

“…The caeca microbial communities of broiler chicken were more diverse in comparison to ilea. Distinction in functions and roles of gut microbiota such as gene pathways related to nutrient absorption (e.g., sugar and amino acid metabolism), and bacterial proliferation and colonization (e.g., bacterial motility proteins, two-component system, and bacterial secretion system) were observed in caeca, respectively ( Barnes et al, 1972 ; Such et al, 2021 ; Xiao et al, 2021 ).…”