Salinity is one of the most important stresses that reduces plant growth and productivity in several parts of the world. Nine Tunisian durum wheat genotypes grown under hydroponic conditions were subjected to two levels of salt stress (100 and 170 mM NaCl) for 21 days. An integrative analysis revealing the impact of salinity on key phenotypic and physiological marker traits was then conducted. Principal component analysis grouped these traits into three different clusters corresponding to the absence of salt stress and the two levels of salt stress. This analysis also allowed the identification of genotypes exhibiting various levels of tolerance to NaCl. Among the nine genotypes of Triticum durum Desf., cultivar Om Rabiaa was the most tolerant whereas cultivar Mahmoudi genotype was the most sensitive. Following the multivariate analysis of the examined phenotypic and physiological traits, we found that shoot length, shoot fresh weight, leaf area, the whole-plant stable isotope ratios of nitrogen (δ¹⁵N), shoot ammonium and proline contents, and shoot glutamine synthetase activity could be used as markers for the selection of salt-tolerant wheat genotypes.

Background: Obesity is a complex multifactorial disease associated with chronic low grade inflammation, gut microbiota dysbiosis, and impaired gut-brain communication. Oligomeric procyanidins from grape seed extracts (GSE) are promising prebiotic candidates, capable of modulating host metabolism through interactions with the gut microbiota. Methods: C57Bl/6J male mice were rendered obese by feeding them a high fat, high sucrose diet and were orally administered GSE at a dose of 1or 2 g/kg/day for 12 weeks. We assessed body weight, adiposity, glucose tolerance, insulin sensitivity, circulating hormones, brain homeostasis markers, colonic and liver gene expression, 16S rRNA gene sequencing of the gut microbiota profiles, and untargeted cecal metabolomics. Results: GSE reduced body weight gain, visceral adiposity, adipocyte hypertrophy, and improved oral glucose tolerance and insulin sensitivity. It normalized circulating lipid and glucose levels and lowered fasting insulin and leptin while increasing endogenous GLP-1. Hepatic gene expression analysis revealed a dose-dependent restoration of antioxidant defenses (SOD, CAT) and lipogenic transcription factors (SREBP, ChREBP). In the colon, GSE attenuated pro-inflammatory IL6 cytokine expression and strikingly upregulated GLP-1 and GLP-1 receptor expression. Microbiota analysis revealed a profound, dose-dependent remodeling of gut microbiota composition and diversity, with an expansion of health-associated taxa, such as Akkermansia muciniphila . Brain analyses revealed restoration of NAA and BDNF levels together with markers consistent with improved mitochondrial function. Cecal metabolomics revealed normalization of secondary bile acid metabolism, restoration of arginine bioavailability, and reduction in the accumulation of L-DOPA and spermidine. Conclusions: An oligomeric procyanidin-rich grape seed extract acts as a multitarget prebiotic that alleviates diet-induced obesity and is associated with coordinated restoration of gut microbiota composition, GLP-1 signaling, and gut–brain and gut-liver communication pathways. Convergent dose-dependent effects on Akkermansia muciniphila abundance, GLP-1, NAA, and BDNF identify key mechanisms underlying its metabolic benefits.