Bovine Colostrum Supplementation Modulates the Intestinal Microbial Community in Rabbits

Abstract

BC is a nutraceutical that can modulate intestinal microbiota. This study investigates the effects of BC diet supplementation on luminal and mucosa-associated microbiota in the jejunum, caecum, and colon of rabbits. Twenty-one New Zealand White female rabbits were divided into three experimental groups (n = 7) receiving a commercial feed (CTRL group) and the same diet supplemented with 2.5% and 5% BC (2.5% BC and 5% BC groups, respectively), from 35 (weaning) to 90 days of age (slaughtering). At slaughter, the digestive tract was removed from each animal, then both content and mucosa-associated microbiota of jejunum, caecum, and colon were collected and analysed by Next Generation 16SrRNA Gene Sequencing. Significant differences were found in the microbial composition of the three groups (i.e., beta-diversity: p < 0.01), especially in the caecum and colon of the 2.5% BC group. The relative abundance analysis showed that the families most affected by the BC administration were Clostridia UCG-014, Barnesiellaceae, and Eggerthellaceae. A trend was also found for Lachnospiraceae, Akkermansiaceae, and Bacteroidaceae. A functional prediction has revealed several altered pathways in BC groups, with particular reference to amino acids and lactose metabolism. Firmicutes:Bacteroidetes ratio decreased in caecum luminal samples of the 2.5% BC group. These findings suggest that BC supplementation could positively affect the intestinal microbiota. However, further research is needed to establish the optimal administration dose.

Evaluation of the Difference in the Content of Essential and Non-Essential Elements in Wild Boar and Swine Tissues Sampled in the Same Area of Northern Italy

“…Gut bacterial communities are able to influence the absorption of both essential and non-essential elements and, vice versa, the elements are able to modulate the microbiota [ 68 ]. It is widely known for several species, such as rabbits [ 69 ], chickens [ 70 ], cows [ 71 ], that the gut microbiota is largely influenced by the feeding regimen. For example, studies have demonstrated that bacteria such as Lactobacillus johnsonii and Lactobacillus reuteri have the ability to modulate Fe homeostasis [ 72 ]; meanwhile, the effects of Fe supplementation are still little known; in general, Fe is not considered a limiting element in today’s animal production, and some research has found that Fe supplementation increases the presence of beneficial microbiota [ 73 ].…”

Bovine Colostrum Supplementation in Rabbit Diet Modulates Gene Expression of Cytokines, Gut–Vascular Barrier, and Red-Ox-Related Molecules in the Gut Wall

“…At slaughter, the digestive tract was removed from each animal; tissue samples of each section (jejunum, caecum, and colon) and a mesenteric lymph node were collected with the use of a sterile scalpel and stored in 2 mL sterile tubes in RNAlater ® (Sigma-Aldrich, St. Louis, MO, USA). Samples were stored at −80 °C until processing, as previously described [ 35 ]. The content of each intestinal tract was collected in a 2 mL sterile tube and immediately frozen at −20 °C until use.…”

“…Microbial profiles based on 16S rRNA amplicon-based sequencing for all the animals, intestinal tracts, and diets have already been presented elsewhere (Agradi et al, 2023 [ 35 ]). Briefly, the bacterial DNA was extracted using a QIAamp PowerFecal Pro DNA Kit (Qiagen, Hilden, Germany), amplified following the 16S Metagenomic Sequencing Library Preparation Protocol (Illumina, San Diego, CA, USA), and sequenced on a MiSeq (Illumina) instrument with 2 × 250-base paired-end reads run.…”

“…Bacterial composition was evaluated at the genus or family level, according to the lowest level for which a classification was possible; pathway abundances were considered at the L4 level. In order to limit the number of correlations to the most meaningful ones, only families and genera present at >1% on average and L4 pathways reported as differential in Agradi et al, 2023 [ 35 ] were considered. Since the original publication included microbial profiles and functional predictions for both the luminal and mucosal bacteria, in the present paper, only the latter (i.e., mucosa) were considered to be more likely associated with the expression values of inflammatory- or GVB permeability-related genes.…”

Diversity and Co-Occurrence Pattern Analysis of Cecal and Jejunal Microbiota in Two Rabbit Breeds

“…In particular, the large intestine shows the highest richness and diversity in bacterial species, while the small gut has the highest variability in the gastrointestinal tract of rabbits [13]. Several studies have been performed to evaluate the effects of the quality and levels of the diet [16,17], dietary supplementation with nutraceuticals [18][19][20], the temperature of the drinking water [21], age [22], and weaning period [23]. The fecal microbiota and its functional capacity associated with weaning weight in meat rabbits [24], hygiene of the environment [25], season [15], and drug treatments [26,27] have been investigated.…”