Effects of prebiotics on the stability of the microbiota of the pig

Prebiotics are non-digestible food ingredients that selectively stimulate the growth and activity of beneficial bacteria in the large intestine, thereby improving host’s health (Gibson et al., 2004). Several questions that can be raised are the following: ‘what happens with the intestinal microbiota when the supplementation of a prebiotic stops, and do the beneficial effects on the host remain? Or what happens when the prebiotic is used during early life, when the colonization of the intestinal microbiota is in full development? Or can the positive effects of a prebiotic, supplied to the mother sow, be transmitted to the offspring? Can we shape the microbiota of piglets by the modulation of the microbiota of the sow, as contact with sow’s feces contributes to the microbial colonization in their offspring (Everaert et al., 2017)?’
Inulin is an example of a prebiotic, which has been found to enhance the abundance of Bifidobacterium and Lactobacillus in pigs (Tako et al., 2008; Patterson et al., 2010). Interestingly, when neonatal piglets were supplemented orally with an inulin solution for 4 weeks, this effect was not observed at weaning (end of supplementation), nor three weeks after supplementation stopped. However, positive effects on the host (body weight, gut morphology, short-chain fatty acids, gene expression of genes related to inflammation) were observed during the inulin supplementation, fading out when supplementation stopped.
Recently, we conducted two experiments on sows to modify their microbiota: in one experiment, we supplemented the diet with a high inclusion level of wheat bran (WB) during gestation (24% WB) and lactation (14% WB), and in the second animal experiment, we used resistant starch (RS) (33%) as a modulator of the intestinal microbiota. Results on their fecal microbiota indicated that wheat bran and resistant starch had the ability to alter sows’ microbiota during gestation but not anymore during lactation. A limited (WB-experiment) or no (RS-experiment) modulation of the piglet’s intestinal microbiota was observed. These results are in line with experiments on the supplementation of probiotics to sow’s diet, showing modification on microbial profiles in suckling piglets, with effects diminishing after weaning (Starke et al., 2013).
In conclusion, positive effects of prebiotics are well established, they shape the intestinal microbiota and have beneficial health effects on the host. Several studies suggest that the effects on the microbiota are mainly direct: only during the supplementation, when no other factors interfere, with maternal nutrition as a limited ‘environmental factor’ for the modulation of the microbiota of the piglet.