Effects of purified fibre-mixture supplementation of gestation diet on gut microbiota, immunity and reproductive performance of sows.

This experiment was conducted to investigate the effects of a purified fibre-mixture (FM, 50% guar gum, 50% cellulose) supplementation of gestation diet on the immunity, faecal microbial composition and reproductive performance of sows. A day after breeding, 68 multiparous sows were randomly allocated to receive treatment with a control (CON) diet or a diet containing 3% FM (FM diet). Results showed the FM diet to be associated with a significant increase in the number of live-born piglets relative to CON (13.65 vs. 12.47, p < .05). In addition, this FM diet coincided with significantly increased faecal concentrations of butyrate on day 30 and propionate on day 100 (p < .05), with trends towards increased propionate on day 30 and increased short-chain fatty acids (SCFAs) on days 30 and 110 (p < .1). Meanwhile, FM addition markedly increased the abundance of representative SCFAs producing-related genera as Roseburia on days 30 and 110 (p < .05), Eubacterium-hallii-group on days 30 and 110 (p < .05), and Bacteroides on day 110 of gestation (p < .05). The serotonin concentration on day 110 of gestation had increased (p < .05) and that on day 30 of gestation (p < .1) exhibited a tendency to increase with the FM-supplemented diet in comparison with the CON. Besides, FM supplementation caused an increase in serum interleukin-10 concentrations on days 30 (p < .05) and 110 of gestation (p < .1), and a decrease in interferon-γ concentration on day 30 of gestation (p < .05). Together these results indicated that purified FM was able to improve sow reproductive performance through a mechanism potentially linked with a bias towards type-2 helper T-cell differentiation that supported embryonic survival and thereby improve reproductive yields. Changes in metabolites produced by the intestinal microbiome may thus have an impact on host immunity and reproductive performance.