1 Possible nitric oxide (NO)-mediated eects on lipolysis were investigated in vivo in human subcutaneous adipose tissue using microdialysis, as well as in vitro on isolated fat cells of non-obese, healthy volunteers. NO donors were added to the ingoing dialysate solvents. 2 Changes in lipolysis and local blood¯ow were investigated by measuring glycerol levels and ethanol ratios, respectively, in the microdialysates. 4 Nitric oxide gas as well as the NO donor, nitroglycerine, reduced glycerol release from isolated adipocytes in vitro. 5 Expression of inducible nitric oxide synthase (iNOS) in human adipose tissue was shown by Western blot analysis. Biologically active NOS was demonstrated by measuring total enzymatic activity. 6 In conclusion, the data demonstrate that inhibition of NO release in subcutaneous adipose tissue results in an increased lipolysis in vivo. These eects, which were also observed in vitro, are independent of local blood¯ow changes. Furthermore, the demonstration of enzymatic NOS activity and the expression of inducible nitric oxide synthase (iNOS) in adipose tissue indicate that locally synthesized NO may play a role in the physiological control of lipolysis in human adipose tissue.

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Background & aims: Ageing is associated with an increased risk of frailty, intestinal microbiota perturbations, immunosenescence and oxidative stress. Prebiotics such as galacto-oligosaccharides (GOS) may ameliorate these ageing-related alterations. We aimed to compare the faecal microbiota composition, metabolite production, immune and oxidative stress markers in prefrail elderly and younger adults, and investigate the effects of GOS supplementation in both groups. Methods: In a randomised controlled cross-over study, 20 prefrail elderly and 24 healthy adults received 21.6 g/day Biotis™ GOS (containing 15.0 g/day GOS) or placebo. Faecal 16S rRNA gene-based microbiota and short-chain fatty acids were analysed at 0, 1 and 4 weeks of intervention.Volatile organic compounds were analysed in breath, and stimulated cytokine production, CRP, malondialdehyde, trolox equivalent antioxidant capacity (TEAC) and uric acid (UA) in blood at 0 and 4 weeks. Results: Principle coordinate analysis showed differences in microbial composition between elderly and adults (P 0.05), with elderly having lower bifidobacteria (P 0.033) at baseline. In both groups, GOS affected microbiota composition (P 0.05), accompanied by increases in bifidobacteria (P<0.001) and decreased microbial diversity (P 0.023). Faecal and breath metabolites, immune and oxidative stress markers neither differed between groups (P ! 0.125) nor were affected by GOS (P ! 0.236). TEAC values corrected for UA were higher in elderly versus adults (P<0.001), but not different between interventions (P ! 0.455). Conclusions: Elderly showed lower faecal bifidobacterial (relative) abundance than adults, which increased after GOS intake in both groups. Faecal and breath metabolites, parameters of immune function and oxidative stress were not different at baseline, and not impacted by GOS supplementation. Clinicaltrials.gov with study id number: NCT03077529.

Intestinal epithelial barrier is affected by multiple factors, such as tumour necrosis factor-α (TNF-α). Plasma concentration of TNF-α is higher in patients with Crohn’s disease (CD) than healthy controls (HC) and correlates positively with disease activity. This study aimed to determine the effect of plasma from active, inactive CD patients on intestinal barrier function and to investigate the underlying mechanism. Plasma samples were collected from CD patients and HC. 3D Caco-2 cysts were treated with plasma or TNF-α, with or without pre-incubation of adalimumab (a monoclonal antibody that antagonizes TNF-α) or JNK inhibitor SP600125. The results demonstrated that exposure of the cysts to plasma from CD patients resulted in enhanced paracellular permeability in a disease activity-dependent manner. Compared to HC, active CD plasma decreased ZO-1 and OCCLUDIN expression on mRNA and protein levels, and led to an increased JNK phosphorylation. Pre-incubation with adalimumab or SP600125 ameliorated TJ disruption and barrier dysfunction induced by plasma from CD patients. These results indicate that plasma from CD patients is able to induce epithelial barrier disruption, in part through TNF-α induced TJs modulation. The data also demonstrate an involvement of MAPK pathway, in particular the JNK isoform, in CD patient plasma-induced barrier dysfunction.