Dynamics of key gut microbiome taxa in piglets under the influence of an isotonic protein mixture

Early weaning of piglets causes significant changes in intestinal microbiota, digestion, and immune response of the organism, induces substantial disruptions in intestinal morphology and barrier function that manifest as villus atrophy, decreased crypt height, impaired intercellular junctions, and increased mucosal permeability due to abrupt dietary changes, stress, and microbial imbalance disruption, which impairs nutrient absorption and overall organism resistance. Considering this, the study aims to examine the dynamics of microbiota composition in different intestinal segments of early-age piglets during the weaning period and to evaluate how isotonic-protein mixture affects the abundance of key bacterial groups (Escherichia coli, Staphylococcus spp., Enterococcus spp.). We conducted the experiment on early postnatal piglets and divided them into control and experimental groups. We determined bacterial counts in the duodenum, jejunum, ileum, cecum, colon, and rectum at 9, 21, and 35 days of age by quantifying colony-forming units (CFU) per 1 cm³ of intestinal content. Weaning significantly reduced E. coli levels across all intestinal segments in both groups (by 80.0–99.1 %; P < 0.001). Tonisity Px application amplified this effect, particularly in the cecum (-73.3 %; P < 0.01) and duodenum (-45.2 %; P < 0.01). Staphylococcus spp. abundance surged by day 21 (30–44-fold; P < 0.001) but decreased post-weaning (by 84.7–99.6 %; P < 0.001), with the experimental group showing higher levels in specific intestinal segments at later stages. Enterococcus spp. showed the most pronounced changes: in the control group, their abundance declined with age (by 97.4–98.7 %; P < 0.001), whereas the experimental group recorded significant increases: 6.7-fold in the jejunum (P < 0.01), 139.4-fold in the cecum (P < 0.001), and 477-fold in the colon (P < 0.001). These findings indicate that isotonic protein mixture stimulates beneficial microbiota. Thus, weaning represents a critical period for shaping piglet gut microbiota, characterized by substantial shifts in bacterial composition. Isotonic protein mixture promotes microbial balance, reduces pathogenic bacterial colonization, and enhances beneficial microbiota development, potentially improving piglet resistance to infections and supporting optimal postnatal growth.