# Sequential Galacto- and Xylo-Oligosaccharide Feeding Transiently Modulates Gut Microbiota and Upregulates Intestinal Alkaline Phosphatase in Weaning Piglets

## TL;DR

Feeding piglets galacto- and xylo-oligosaccharides briefly changed gut bacteria and boosted gut health markers, but did not improve growth or feed efficiency.

## Contribution

The study introduces a sequential prebiotic feeding strategy and highlights the importance of timing in modulating gut microbiota during weaning.

## Key findings

- Sequential GOS and XOS feeding increased gut microbiota diversity and short-chain fatty acid-producing bacteria temporarily.
- Intestinal alkaline phosphatase was upregulated in GXOS and XOS groups, indicating improved gut health.
- The prebiotic strategy did not enhance growth or feed efficiency, likely due to timing issues.

## Abstract

Neonatal piglets reared for human consumption are weaned from the sow at an early age, well before their gastrointestinal tract has fully developed. During weaning, piglets must adapt to a sudden dietary shift from highly digestible, liquid sow’s milk to a more complex, solid, cereal-based feed. The abrupt diet change, combined with other stressors and an immature gut, disrupts the gut microbiota, predisposing piglets to post-weaning diarrhoea and growth checks. These cause both economic loss for producers and welfare concerns for the animals. Historically, antibiotics were added to livestock feeds to reduce post-weaning diarrhoea and improve feed efficiency. However, the use of antibiotics as growth promoters has been banned in many territories, creating a need for alternative strategies to support piglet health during weaning. In this study, we tested whether two prebiotic dietary fibres could ease the weaning transition by stimulating beneficial bacteria in the gut, with the aim of improving gut health and growth. Our results show that these prebiotics briefly altered the gut microbiota and enhanced markers of gut health but did not improve feed efficiency or growth.

Improving growth and health at weaning remains a priority in pig production. This study investigates whether supplementation with galacto-oligosaccharides (GOSs) followed by xylo-oligosaccharides (XOSs) improves performance and gut health of healthy 28-day old weaning piglets. Pigs received either a control basal (CON) diet, the CON diet containing 1% GOS for 7 days followed by the CON diet containing 0.017% XOS for 47 days (GXOS), or the CON diet for 7 days followed by the CON diet containing 0.017% XOS for 47 days (XOS). Body weight, average daily gain, average daily feed intake, and feed conversion ratio did not differ between diets from day 1 of weaning (d1) to d54. At d7, GXOS pigs showed increased jejunal and caecal α-diversity (Shannon, inverse Simpson), distinct ileal β-diversity (Yu and Clayton, Bray–Curtis, Jaccard), and greater short-chain fatty acid-producing Lactobacillus and Veillonella; no taxa remained differentially abundant by d22, and the XOS group showed no microbiota shifts throughout the study. Jejunal goblet cell density was lower in GXOS pigs at d7. Jejunal and caecal IL-1β, IL-6, IL-8, and IL-10 gene expression was transiently greater at d7 in GXOS pigs, whereas by d22 cytokine/chemokine differences resolved, whilst intestinal alkaline phosphatase was upregulated in the ileum and caecum (XOS) and colon (GXOS and XOS). Sequential prebiotic switching and delayed XOS onset likely missed the immediate post-weaning window, during which the gut microbiota is most receptive to dietary modulation, consequently limiting potential performance gains; therefore, prebiotic timing, sequence, and duration are critical to achieving functional benefits at weaning.