No abstract

Butyric acid (BA), one of the short chain fatty acids (SCFAs), has positive actions on the metabolism, inflammation, etc. However, whether it influences the reproductive physiology and if so the detail mechanism involved has not yet been determined. In this study, the porcine granulosa cells (PGCs) were treated with gradient concentrations of BA. After 24h culture, 0.05mM BA significantly stimulated the progesterone (P) secretion (P<0.05), 5mM and 10mM BA significantly inhibited the P secretion (P<0.05). Simultaneously, BA up-regulated the estradiol (E) secretion in a dose dependent manner, 5mM and 10mM BA significantly promoted the E level (P<0.05). In addition, 10mM BA significantly promoted the G-protein-coupled receptor 41/43 mRNA (P<0.05). Interestingly, 5mM BA treatment significantly down-regulated cyclic adenosine monophosphate (cAMP) content (P<0.05), steroidogenic acute regulatory (StAR), steroidogenic factor 1 (SF1), P450scc in the mRNA and/or protein level (P<0.05), and these actions were reversed by cAMP activator forskolin (FK). Moreover, the co-treatment of 5mM BA and bupivacaine (BPC, the cAMP inhibitor) significantly accumulated the inhibition action of BPC on cAMP, the secretion of P, and the abundance of StAR mRNA (P<0.05), inhibited the up-regulation of 5mM BA on the E secretion (P<0.05). Further, the Global Proteome and KEGG pathway analysis found that 5mM BA significantly up-regulated the I3LM80 proteins (P<0.05), which is involved in the steroid biosynthesis signaling pathway. 5mM BA significantly decreased the F2Z5G3 protein level (P<0.05), and the cAMP signaling pathway. In conclusion, present findings for the first time demonstrated that BA could regulate the P and E hormone synthesis in PGCs via the cAMP signaling pathway.

Pyrodextrin (PD) is prepared from starch by heat treatment and is resistant to amylase. We hypothesized that PD might have prebiotic potential affecting the microbiota composition, because it contains a non-digestible portion that may behave as dietary fiber. This study investigated the effects of PD supplementation on growth performance, gut morphology, short-chain fatty acids (SCFAs), and the bacterial community in weaned piglets receiving dietary supplementation of 0.5% PD. The piglets in the PD (treated) groups showed greater antioxidant capacity and feed efficiency (P < 0.05), as well as improved intestinal morphology in comparison with the piglets in the weaned (control) group. Gut microbiota profiles were assessed through 16S rRNA sequencing on the ileum contents and feces of early weaned piglets. Several genus-level enrichments and depletions were observed in response to PD treatment. Of note, PD supplementation decreased the relative abundance of pathogenic organisms, including Defluviicoccus and Gardnerella, while markedly increasing that of commensal bacteria (genera Psychrobacter and Prevotella), which have important roles in nutrient absorption and immune response regulation. The most notable effect in the PD treatment groups was increased production of SCFAs in the feces of PD-treated weaned piglets. Correlation analysis revealed that the improvement in SCFAs was positively correlated with the increase in SCFA-producing bacteria. Overall, this study provides a more comprehensive understanding of the effects of PD supplementation on the fecal microbial community and the modulation of SCFA production in early weaned piglets, thus indicating that PD can be used to alleviate weaning stress in piglets.