Mélanie Pouget

Obesity has reached epidemic proportions worldwide with a substantial burden on both individual health and society. Alterations in gut microbiota are increasingly recognized as a key contributor in disease pathogenesis. However, mechanistic understanding at the ecosystem level remains limited. In line with EU and US regulations, in vitro gut systems can be useful to address these questions, but up to now, there is no validated in vitro model of the obese human colon. To address this gap, we performed dietary surveys and conducted an extensive analysis of 250 articles to set-up and validate a unique in vitro colonic model, based on human in vivo data and reproducing obese-specific nutritional, physicochemical, and lumen vs mucus-associated microbial parameters. Then, in an original experimental set-up, we cross-compared data on gut microbiota structure and activities during fermentations performed with fecal microbiota from healthy (n = 4) or obese (n = 5) donors and operated under healthy or newly designed obese parameters. Interestingly, applying obese parameters on healthy fecal samples resulted in a significant reduction in microbial α-diversity and in taxa associated with health (e.g., Akkermanciaceae, Rikenellaceae, and Archaea), together with a tendency toward increased production of short-chain fatty acids and associated energy, in full agreement with in vivo data. Conversely, applying healthy parameters on obese fecal samples led to gut microbiota resilience. These findings highlight the importance of nutritional and physicochemical environment in shaping colonic bacterial and archaeal populations in obesity. This innovative validated model represents a robust and useful platform for mechanistic investigations on gut microbiome in the absence of the host cells, as well as for preclinical evaluation of food and pharmaceutical strategies aiming to restore microbiota eubiosis in a personalized manner.

Objective: The study objectives were: 1) to detect early signs of low muscle function and assess sarcopenic obesity (SO) prevalence in patients with obesity; and 2) to introduce a new online diagnostic tool for scoring handgrip strength (HGS), adjusted for age and sex.Methods: Patients from the OBESAR cohort (184 men and 499 women) were tested for body composition and functional testing (chair stand test or HGS based on the cutoffs from the European Society for Clinical Nutrition and Metabolism [ESPEN]/European Association for the Study of Obesity [EASO] or adjusted HGS [adHGS] based on reference values), and SO prevalence was calculated accordingly.Results: Among the 683 patients (mean [SD], age 42.6 [12.8] years; BMI 44.4 [6.3] kg/m²), HGS averaged 25.6 (6.8) kg for women and 43.2 (10.4) kg for men. A total of 25.2% of patients had adHGS lower than the 10th percentile, but this was true for only 5.6% using ESPEN/EASO cutoffs of HGS. SO prevalence rates were different according to functional tests: 5.4%, 24.5%, and 3.2% for HGS, adHGS, and the chair stand test, respectively.Conclusions: Using adHGS through a scoring process considering age and sex may help to detect early signs of SO in a primary care setting in order to better prevent SO through a personalized approach in adults with obesity. A free online application, “GRip And Sarcopenia Prediction” (GRASP), is proposed to diagnose probable SO.

Independently of absolute BMI values, the amount, onset date, and duration of early body weight gain may influence cardio-metabolic health later in adulthood. Values of cardiac and metabolic variables from a cohort study of morbidly obese patients were retrospectively analyzed to study the association between early weight history and metabolic syndrome (MetS) occurrence in adults. Of 950 patients with severe morbid obesity (age 44.3 ± 13.8 y, BMI 42.5 ± 7.0 kg/m²), 31.4% had started excess weight gain in childhood (CH), 19.9% in adolescence (ADO), and 48.7% in adulthood (AD). Despite different BMI values, MetS prevalence (57.8%) was not significantly different in the three groups (54.4% CH vs. 57.7% ADO vs. 59.8% AD, p = 0.59). The overweight onset period was not significantly associated with the development of MetS in adults (ADO: OR = 1.14 [0.69–1.92], p = 0.60; AD: OR = 0.99 [0.62–1.56], p = 0.95) despite a higher BMI in the early obesity onset group. Weight gain of more than 50% after age 18 years significantly increased the risk of MetS (OR = 1.75 [1.07–2.88], p = 0.026). In addition to crude BMI values, analysis of body mass trajectories is a relevant clinical tool in the assessment of metabolic risk, suggesting that the magnitude of weight gain may be more important for metabolic syndrome progression than the period of obesity onset.

The COVID-19 pandemic and subsequent lockdowns modified work environments, lifestyles, and food consumption. Eating habits and mood changes in a French population during the first lockdown were examined using an online self-reported questionnaire with REDCap software through the COVISTRESS.ORG website. In 671 French participants, the main changes during lockdown were increased stress levels (64 [23; 86] vs. 3 [0; 18]) and sedentary behavior (7 [4; 9] vs. 5 [3; 8] hours per day), a deterioration in sleep quality (50 [27; 83] vs. 70 [48; 94]) and mood (50 [30; 76] vs. 78 [50; 92]), and less physical activity (2.0 [0.5; 5.0] vs. 3.5 [2.0; 6.0]). Mood was modified, with more anger (56 [39; 76] vs. 31 [16; 50]), more sadness (50 [34; 72] vs. 28 [16; 50]), more agitation (50 [25; 66] vs. 43 [20; 50]), and more boredom (32 [7; 60] vs. 14 [3; 29]). A total of 25% of the participants increased their consumption of alcoholic beverages, 29% their consumption of sugary foods, and 26% their consumption of cocktail snacks. A multiple-correspondence analysis highlights four different profiles according to changes in eating habits, food consumption, lifestyle, and mood. In conclusion, eating habits and lifestyle changes during lockdown periods should be carefully monitored to promote healthy behaviors.