Feeding Mode, but Not Prebiotics, Affects Colonic Microbiota Composition and Volatile Fatty Acid Concentrations in Sow-Reared, Formula-Fed, and Combination-Fed Piglets

Background: Many infants consume both human milk and infant formula (combination-fed); however, little is known about how combination-feeding affects the gut microbiota or prebiotic fermentation compared to formula feeding.

Objectives: We investigated the impact of feeding mode and prebiotics on bacterial colonization and volatile fatty acid (VFA) concentrations.

Methods: Newborn piglets (Large White and Landrace) were randomly assigned to 5 groups (n = 6/group): formula-fed (FF), formula-fed with prebiotics (FP), sow-reared (SR), combination-fed (CF), and combination-fed with prebiotics (CP). SR piglets remained with the sows 24 h/d. FF and FP were fed formula or formula with galactooligosaccharide and inulin (4 g/L in a 4:1 ratio). CF and CP were sow-reared for 5 d and then rotated between the sow and formula-feeding every 12 h. Ascending colon contents were collected at day 21. The microbiota was analyzed by pyrosequencing and denaturing gradient gel electrophoresis (DGGE). VFAs were determined by gas chromatography.

Results: Distance-based redundancy analysis of DGGE and pyrosequencing data separated microbiota of FF from CF and SR. CF differed from SR by DGGE, but only a trend (P = 0.09) by pyrosequencing. Bacterial composition of CF was more similar to SR than FF. No bacterial genera in CF significantly differed from SR; however, 9 genera differed between CF and FF, including Lactobacillus, Clostridium XIVa, and Fusobacterium. VFA concentrations were similar between CF and SR, while isovalerate and isobutyrate were 2-fold greater (P < 0.05) in CF than FF. Neither microbiota nor VFA profile was affected by prebiotic supplementation.

Conclusions: Microbial colonization patterns and VFA profiles of CF piglets were more similar to SR piglets than FF piglets. Prebiotics did not affect piglet bacterial composition and/or VFA concentrations relative to the main feeding modes (FF and CF). Thus, partial exposure to breast milk can be beneficial for microbiota development of FF neonates.