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Previous studies have shown that dietary resveratrol (RES) reduces diarrhea and attenuates oxidative stress in piglets challenged with diquat. However, the effect of dietary resveratrol on the gut microbiota of these piglets, as well as the potential relationships between intestinal microflora and metabolites, remain unclear. Here, 16S ribosomal DNA sequencing and metabolome analyses were performed to investigate the effect of RES on the gut microbiota and metabolome of diquat-challenged piglets. A total of 18 weaned piglets (aged 28 ± 2 days) were divided into the control group (basal diet), diquat group (basal diet + diquat challenge), and RES group (basal diet containing 90 mg/kg RES + diquat challenge). Compared with the control group, piglets in the diquat group showed enriched relative abundance of the phyla Firmicutes and Actinobacteria, the genus Ruminococcaceae UCG-005, and members of the Eubacterium coprostanoligenes group. Noteworthy, RES supplementation significantly reduced the levels of these microorganisms. In contrast, the relative abundance of some beneficial bacterial species in the RES group, such as the genera Clostridium sensu stricto 1 and Lachnospiraceae unclassified were significantly higher than in the diquat and control groups. Metabolomic analysis indicated that some metabolites, including indole-3-carbinol, 5-hydroxyindole-3-acetic acid, and uridine, were significantly upregulated upon RES supplementation. In particular, the relative abundance of uridine, indole, and alpha- and beta-dihydroresveratrol was significantly higher in the RES group than in the control group. Moreover, most gut bacterial genera were found to be highly correlated with altered gut microbiota-related metabolites. These findings suggest that dietary supplementation with resveratrol may alter the composition and metabolites of colonic microbiota in diquat-challenged piglets, which provides important insights into the use of resveratrol as a feed additive for gut microbial regulation in piglets with inflammatory and oxidative stress-associated disorders.

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Two 2,2':6',2''-terpyridine-based Schiff bases (TPySSB and TPySB) have been 10 synthesized. The TPySSB shows remarkable selective 'off-on' fluorescence for Al 3+ by 11 photoinduced electron transfer (PET) mechanism of sensing. Chemosensor TPySSB binds Al 3+ in a 12 1:2 ratio with an association constant 6.8×10 5 (R 2 =0.98) and this 1:2 stoichiometric model is 13 established on Job's plot and 1 H NMR. Compared TPySSB and TPySB, it is of great importance of 14 the existence of salicylidene unit due to its strong binding abilities of both phenol and C=N 15 structure to the Al 3+ .16 Al 3+ ions exists in natural waters and most plants, which can enter the human body through 20 food and water[1]. Since Al 3+ is closely related to human health, much attention have been paid to 21 developing new fluorescent chemosensors with high selectivity and sensitivity to detect Al 3+ [2-7]. 22 At present, fluorescent chemosensors have been widely used to detect different metal ions because 23 of their high sensitivity, selectivity and fast response time[8-12]. Typically, metal ion chemosensors 24 are composed of a metal binding unit and signaling unit, which enable the fluorescent chemosensors 25 to coordinate with metal ions. Later on, fluorescent sensors based on a large group of structurally 26 different metal binding units, including pyrazoline[13], peptide[14], salicylimine[15], tetrazole[16], 27 triazole[17], 4,5-diazafluorene[7,8] and 2,2':6',2''-terpyridine (TPy)[18-20] have been developed. 28Among these receptors, 2,2':6',2''-terpyridine moiety is an ideal model for the construction of 29 fluorescence sensors because of its excellent coordination ability with various metal ions[21]. Indeed, 30 it has become one of the most important chemical sensors in supramolecular chemistry. There are 31 reports about the detection of anion and cation by 2,2':6',2''-terpyridine based fluorescent 32 chemosensor [22-25]. However, there is still no report about fluorescent sensing of Al 3+ by 33 2,2':6',2''-terpyridine derivatives. Therefore, the design and preparation of 2,2':6',2''-terpyridine 34 based fluorescent chemosensors are necessary for the construction and development of sensors for 35 detecting Al 3+ with high selectivity and sensitivity.36 Salicylidene Schiff bases (SSB) has attracted increasing attention because they enable simple 37 and inexpensive determinations of various metal ions. Over the past decades, it has been 38 demonstrated that the presence of phenolic OH and the nitrogen atom of azomethine C=N double 39 bond in Schiff base exhibits a strong affinity for transition metal ions[26,27]. Due to the formation of40the chelatogenic cycle (metal-oxygen-nitrogen chain), the intramolecular charge transfer (ICT) was 41 highly improved between the π-conjugated rings. Mostly, these kinds of molecules display unique 42 emission enhancement due to strong binding abilities of both phenol and C=N structure to the metal 43 ions. Therefore, combination of 2,2':6',2''-terpyridine and salicylidene Schiff base into a unique entity ...