Differential effects of probiotics, prebiotics, and synbiotics on gut microbiota and gene expression in rats

• Probiotics, prebiotics, and synbiotics differed in their effects on the biomarkers of large bowel health.
• Rats fed L. rhamnosus HN001 gained less weight and had higher numbers of caecal Bifidobacterium spp. and Lachnospiraceae.
• L. rhamnosus HN001, fructo-oligosaccharide, and all the synbiotic combinations enhanced mucin 4 gene expression.

The effects of probiotics (Bifidobacterium animalis subsp. lactis HN019 and Lactobacillus rhamnosus HN001) and prebiotics (fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), and inulin) individually and in synbiotic combinations (B. lactis HN019+FOS, B. lactis HN019+GOS, B. lactis HN019+inulin, L. rhamnosus HN001+FOS, L. rhamnosus HN001+GOS, and L. rhamnosus HN001+inulin) on large bowel health were investigated in rats fed the respective diets for 21 days. All experimental treatments led to significantly lower body weight gains and decreased caecal acetic acid concentrations compared to the control diet (no pro-, pre-, and synbiotics). Caecal Bifidobacterium spp. or Lachnospiraceae were increased in L. rhamnosus HN001, FOS or inulin treatments. Rats fed L. rhamnosus HN001 had enhanced colonic β-defensin 1 and mucin (MUC)-4 gene expression. All synbiotic combinations increased the MUC4 gene expression. The pro-, pre-, and synbiotics had beneficial effects on the biomarkers of large bowel health in rats. A selective inclusion of pro-, pre-, and synbiotics in the diet will be required to achieve desired health benefits.