Obesity, a major public health problem, is the consequence of an excess of body fat and biological alterations in the adipose tissue. Our aim was to determine whether high-intensity interval training (HIIT) and/or α-linolenic acid supplementation (to equilibrate the n-6/n-3 polyunsaturated fatty acids (PUFA) ratio) might prevent obesity disorders, particularly by modulating the mucosa-associated microbiota. Wistar rats received a low fat diet (LFD; control) or high fat diet (HFD) for 16 weeks to induce obesity. Then, animals in the HFD group were divided in four groups: HFD (control), HFD + linseed oil (LO), HFD + HIIT, HFD + HIIT + LO. In the HIIT groups, rats ran on a treadmill, 4 days.week⁻¹. Erythrocyte n-3 PUFA content, body composition, inflammation, and intestinal mucosa-associated microbiota composition were assessed after 12 weeks. LO supplementation enhanced α-linolenic acid (ALA) to docosahexaenoic acid (DHA) conversion in erythrocytes, and HIIT potentiated this conversion. Compared with HFD, HIIT limited weight gain, fat mass accumulation, and adipocyte size, whereas LO reduced systemic inflammation. HIIT had the main effect on gut microbiota β-diversity, but the HIIT + LO association significantly increased Oscillospira relative abundance. In our conditions, HIIT had a major effect on body fat mass, whereas HIIT + LO improved ALA conversion to DHA and increased the abundance of Oscillospira bacteria in the microbiota.

Obesity and prediabetes are the two strongest risk factors of type 2 diabetes. It has been reported that TOTUM-63, a polyphenol-rich plant extract, has beneficial effects on body weight (BW) and insulin resistance in mice fed a high fat diet (HFD). The study aim was to determine whether high-intensity interval training (HIIT) and/or TOTUM-63 supplementation improved body composition and glycemic control and gut microbiota composition in a Western diet-induced obesity rat model. Wistar rats received a standard diet (CTRL; control; n = 12) or HFD (HFD; n = 48) for 16 weeks. Then, HFD rats were divided in four groups: HFD, HFD + TOTUM-63 (T63), HFD + HIIT (HIIT), and HFD + HIIT +T63 (HIIT + T63). Training was performed 4 days/week for 12 weeks. TOTUM-63 was included in diet composition (2%). The HIIT + T63 combination significantly limited BW gain, without any energy intake modulation, and improved glycemic control. BW variation was correlated with increased α-diversity of the colon mucosa microbiota in the HIIT + T63 group. Moreover, the relative abundance of Anaeroplasma, Christensenellaceae and Oscillospira was higher in the HIIT + T63 group. Altogether, these results suggest that the HIIT and TOTUM-63 combination could be proposed for the management of obesity and prediabetes.

The Western diet, rich in lipids and in n-6 polyunsaturated fatty acids (PUFAs), favors gut dysbiosis observed in Crohn’s disease (CD). The aim of this study was to assess the effects of rebalancing the n-6/n-3 PUFA ratio in CEABAC10 transgenic mice that mimic CD. Mice in individual cages with running wheels were randomized in three diet groups for 12 weeks: high-fat diet (HFD), HFD + linseed oil (HFD-LS-O) and HFD + extruded linseed (HFD-LS-E). Then, they were orally challenged once with the Adherent-Invasive Escherichia coli (AIEC) LF82 pathobiont. After 12 weeks of diet, total energy intake, body composition, and intestinal permeability were not different between groups. After the AIEC-induced intestinal inflammation, fecal lipocalin-2 concentration was lower at day 6 in n-3 PUFAs supplementation groups (HFD-LS-O and HFD-LS-E) compared to HFD. Analysis of the mucosa-associated microbiota showed that the abundance of Prevotella, Paraprevotella, Ruminococcus, and Clostridiales was higher in the HFD-LS-E group. Butyrate levels were higher in the HFD-LS-E group and correlated with the Firmicutes/Proteobacteria ratio. This study demonstrates that extruded linseed supplementation had a beneficial health effect in a physically active mouse model of CD susceptibility. Additional studies are required to better decipher the matrix influence in the linseed supplementation effect.

High-intensity interval training (HIIT) and linseed oil (LO) supplementation are effective strategies to reduce obesity-induced oxidative stress. Our aim was to determine whether the HIIT + LO combination prevents obesity-induced oxidative stress in high fat diet (HFD)-fed rats. HFD-fed 8-week-old, male, Wistar rats were subdivided in four groups: HFD, LO (2% of sunflower oil replaced with 2% of LO in the HFD), HIIT (4 days/week for 12 weeks), and HIIT + LO. Wistar rats fed a low-fat diet (LFD) were used as controls. Epididymal and subcutaneous adipose tissue, gastrocnemius muscle, liver, and plasma samples were collected to measure oxidative stress markers (AOPP, oxLDL), antioxidant (SOD, CAT, and GPx activities) and pro-oxidant (NOx and XO) enzyme activities. Compared with the LFD, the HFD altered the pro/antioxidant status in different tissues (increase of AOPP, oxLDL, SOD and catalase activities in plasma, and SOD activity increase in liver and decrease in adipose tissues) but not in gastrocnemius. LO upregulated CAT activity and decreased NOx in liver. HIIT alleviated HFD negative effects in liver by reducing SOD and NOx activities. Moreover, the HIIT + LO combination potentiated SOD activity upregulation in subcutaneous tissue. HIIT and LO supplementation have independent beneficial effects on the pro/antioxidant balance. Their association promotes SOD activity in subcutaneous adipose tissue.

The excessive accumulation of adipose tissue in obesity appears to result in adipose tissue dysfunction perpetuating the onset of obesity-related diseases, including type 2 diabetes (T2DM). In humans, adipose tissue is stored in several depots including subcutaneous and visceral. These depots contribute to the pathology of obesity differently owing to differences in the tissue microenvironment, a main one being preadipocyte function. In examining adipocyte and preadipocyte characteristics, many have used the 3T3-L1 murine cell lines. Though these cell lines provide valuable mechanistic data, the results remain to be translated to humans. Experiments using primary human preadipocytes has shown that obesity and T2DM impact preadipocyte phenotypes. The objective of this review is to describe the differences in regional characteristics of primary preadipocytes collected from humans with obesity and to discuss how these characteristics might be affected in type 2 diabetes mellitus. In doing so, we will show that the characteristics of regional primary preadipocytes in humans are differentially affected by obesity and the development of T2DM.

Transwell co‐culture systems are models for examining cellular crosstalk, but the impact of porous membrane material on myogenic outcomes remains uncharacterized. We investigated the influence of transwell membrane material on myoblast differentiation in co‐culture with human primary adipocytes and in varying concentrations of insulin‐transferrin‐selenium (ITS). Primary human myoblasts were differentiated on 0.4 μm polycarbonate or polyester membranes, either alone (Myo‐Only) or with adipocytes (Myo + Adipo) in two different ITS concentrations ([ITS]; 0.5× or 1×). Myogenesis was evaluated by immunofluorescence, using fusion index (%) and myotube thickness (μm), and adipokine levels were measured in each co‐culture compartment. Polycarbonate membranes supported a greater fusion index and myotube thickness than polyester at both 1× ( p < 0.001) and 0.5× ITS ( p = 0.002). Across [ITS] (1× p = 0.035; 0.5× p = 0.006), the fusion index was higher in Myo + Adipo co‐cultures than in Myo‐Only conditions. Leptin diffusion was reduced across polyester compared to polycarbonate membranes (0.5× p = 0.036; 1× p = 0.091), whereas adiponectin diffusion was similar between materials. These findings underscore that membrane material and medium composition are critical variables in transwell adipocyte‐myoblast co‐culture systems. This study highlights the importance in the selection and reporting of these parameters to improve reproducibility across future studies.