Effect of caloric intake and macronutrient composition on intestinal cholesterol absorption and bile acids in patients with obesity

Obesity is associated with alterations in cholesterol and bile acid (BA) metabolism. However, the interaction among dietary intake, cholesterol absorption, and BA metabolism in patients with obesity remains unclear. We conducted a 4-wk nutritional intervention nonrandomized clinical trial with three different sequential diets for a week in the following order: regular diet (RD); high calorie, high-fat diet (HCHF), washout period on RD; and low-calorie, low-fat diet (LCLF). We provided participants with meal replacements during HCHF and LCLF diets. A total of 16 participants completed the study [n = 8 normal weight (NW); n = 8 with obesity (OB)]. Overall, there was a significant increase in intestinal cholesterol uptake when changing from RD to HCHF and a reduction in intestinal cholesterol uptake from HCHF to LCLF. When analyzing by BMI groups, these findings were similar in patients with NW (RD to HCHF: P < 0.007; HCHF to LCLF: P = 0.02); however, in patients with obesity, the change in intestinal cholesterol uptake was only observed when changing from RD to HCHF (P = 0.006). There was no correlation between cholesterol absorption and fecal bile acids or other markers of BA metabolism in all patients or the subgroups. Dietary caloric content had a significant effect on cholesterol absorption, however, this effect is blunted in patients with obesity. These data are consistent with the impaired effect of a low-fat diet on cholesterol absorption in obesity.NEW & NOTEWORTHY We show how switching from a regular diet to an HCHF increases cholesterol absorption in patients with normal weight and obesity. The decrease in cholesterol absorption from an HCHF to an LCLF, on the other hand, was only seen in normal-weight controls, underlining the importance of body weight in this regulation. In addition, changes in caloric and fat content had an immediate and direct effect on hepatic bile acid production.

Association Between Food Intake and Gastrointestinal Symptoms in Patients With Obesity

BACKGROUND AND AIMS

Hunger, satiation, postprandial satiety, and hedonic eating constitute key food intake parameters. We aim to study whether these symptoms are associated with gastrointestinal symptoms (GIS) in patients with obesity.

METHODS

This is a cross-sectional study of patients with obesity. Patients completed the following validated biomarkers and questionnaires: hunger was measured via visual analog scale (100 mm) following a standard meal, satiation was measured via ad libitum meal (calories to fullness; kcal), postprandial satiety was measured via gastric emptying scintigraphy (T_1/2; mins), and hedonic eating was measured via the Hospital Anxiety and Depression Scale questionnaire. Participants completed the abridged Bowel Disease Questionnaire to evaluate their GIS. We calculated the odds ratios (ORs) adjusted for sex, weight, and age between food intake parameters <25^th or >75^th percentile observed in a prior cohort of 450 participants with obesity and GIS.

RESULTS

A total of 274 participants (41 ± 10 [SD] years, 75% females, body mass index 39 ± 8 kg/m²) were included in the analysis. Increased hunger was associated with a lower prevalence of lumpy stools (OR = 0.18, P = .02). Satiation was associated with abdominal pain/discomfort (relieved by defecation [OR = 2.4, P = .02] or associated with change in stool consistency [OR = 2.92, P < .01]), loose/watery stools (OR = 2.09, P = .02), and bloating (OR = 2.49, P < .01). Abnormal postprandial satiety was associated with bloating (OR = 2.26, P < .01) and loose/watery stools (OR = 1.84, P = .04). Hedonic eating was associated with abdominal pain/discomfort with stool frequency change (OR = 2.4, P = .02), >3 bowel movements per day (OR = 1.93, P = .048), bloating (OR = 2.49, P = .01), abdominal pain after meals >1 per month (OR = 4.24, P < .01), and nausea >1 per week (OR = 4.51, P < .01).

CONCLUSION

Alterations in hunger, satiation, postprandial satiety, and hedonic eating are associated with GIS in patients with obesity.

Association between CYP metabolizer phenotypes and selective serotonin reuptake inhibitors induced weight gain: a retrospective cohort study

BACKGROUND

Prescription medications such as selective serotonin reuptake inhibitors (SSRIs), commonly used to treat depression, are associated with weight gain. The role of pharmacogenomics in predicting SSRI-induced weight gain is unclear.

METHODS

In this retrospective cohort study from participants in the Mayo Clinic RIGHT study who were prescribed citalopram, paroxetine, sertraline, or fluoxetine, our aim was to evaluate the association of metabolizer phenotype and total body weight after 6 months of SSRIs initiation. We evaluated the metabolizer phenotypes (poor/intermediate, normal, and rapid/ultra-rapid) of the cytochromes P450 enzymes genes: CYP2C9, CYP2C19, and CYP2D6 known to influence the metabolism of SSRI medications: CYP2C19 for citalopram, CYP2D6 for paroxetine, CYP2D6 and CYP2C19 for sertraline, and CYP2D6 and CYP2C9 fluoxetine. In addition, we assessed the association of metabolizer phenotype and total body weight change at six months following SSRI prescription using parametric analysis of covariance adjusted for baseline body weight and multivariate regression models.

RESULTS

CYP2C19 poor/intermediate metabolizers prescribed citalopram gained significantly more weight than normal or rapid/ultra-rapid metabolizers at 6 months (TBWG %: 2.6 [95% CI 1.3-4.1] vs. 0.4 [95% CI -0.5 - 1.3] vs. -0.1 [-95% CI -1.5-1.1]; p = 0.001). No significant differences in weight outcomes at six months of treatment with paroxetine, sertraline, or fluoxetine were observed by metabolizer status.

CONCLUSIONS

Weight gain observed with citalopram may be mediated by CYP2C19 metabolizer status.

A Protocol for the Cryopreservation of Human Intestinal Mucosal Biopsies Compatible With Single-Cell Transcriptomics and Ex Vivo Studies

The heterogeneity of the human intestinal epithelium has hindered the understanding of the pathophysiology of distinct specialized cell types on a single-cell basis in disease states. Described here is a workflow for the cryopreservation of endoscopically obtained human intestinal mucosal biopsies, subsequent preparation of this tissue to yield highly viable fluorescence-activated cell sorting (FACS)isolated human intestinal epithelial cell (IEC) single-cell suspensions compatible with successful library preparation and deep single-cell RNA sequencing (scRNAseq). We validated this protocol in deep scRNAseq of 59,653 intestinal cells in 10 human participants. Furthermore, primary intestinal cultures were successfully generated from cryopreserved tissue, capable of surviving in short-term culture and suitable for physiological assays studying gut peptide secretion from rare hormone-producing enteroendocrine cells in humans. This study offers an accessible avenue for single-cell transcriptomics and ex vivo studies from cryopreserved intestinal mucosal biopsies. These techniques may be used in the future to dissect and define novel aberrations to the intestinal ecosystem that lead to the development and progression of disease states in humans, even in rare IEC populations.

Effectiveness of anti-obesity medications approved for long-term use in a multidisciplinary weight management program: a multi-center clinical experience

BACKGROUND AND AIMS

Randomized clinical trials have proven the efficacy and safety of Food and Drug Administration (FDA) approved anti-obesity medications (AOMs) for long-term use. It is unclear whether these outcomes can be replicated in real-world clinical practice where clinical complexities arise. The aim of this study was to evaluate the effectiveness and side effects of these medications in real-world multidisciplinary clinical practice settings.

METHODS

We reviewed the electronic medical records (EMR) of patients with obesity who were prescribed an FDA-approved AOM for long-term use in academic and community multidisciplinary weight loss programs between January 2016 and January 2020.

INTERVENTION

We assessed percentage total body weight loss (%TBWL), metabolic outcomes, and side effect profile up to 24 months after AOM initiation.

RESULTS

The full cohort consisted of 304 patients (76% women, 95.2% White, median age of 50 years old [IQR, 39-58]). The median follow-up time was 9.1 months [IQR, 4.2-14.1] with a median number of 3 visits [IQR, 2-4]. The most prescribed medication was phentermine/topiramate extended-release (ER) (51%), followed by liraglutide (26.3%), bupropion/naltrexone sustained-release (SR) (16.5%), and lorcaserin (6.2%). %TBWL was 5.0%, 6.8%, 9.3%, 10.3%, and 10.5% at 3, 6, 12, 18, and 24 months. 60.2% of the entire cohort achieved at least 5% TBWL. Overall, phentermine/topiramate-ER had the most robust weight loss response during follow-up, with the highest %TBWL at 12 months of 12.0%. Adverse events were reported in 22.4% of patients. Only 9% of patients discontinued the medication due to side effects.

CONCLUSIONS

AOMs resulted in significant long-term weight loss, that was comparable to outcomes previously reported in clinical trials.

Association of gastric emptying with postprandial appetite and satiety sensations in obesity

OBJECTIVE

Satiety, defined as the duration of the sensation of fullness, is usually measured by validated visual analog scales (VAS) for appetite. Gastric function plays a key role in food intake regulation. However, the association between gastric emptying (GE) and VAS appetite is unknown.

METHODS

In this cross-sectional study, 134 participants (mean [SEM] age = 39 [0.8] years, mean [SEM] BMI = 38 [0.5] kg/m² , 67% females) completed simultaneous measurements of GE and VAS appetite. After a 320-kcal meal, GE was measured by scintigraphy and appetite by validated 100-mm VAS for 240 minutes. Satiation was defined as calories consumed to terminate meal and was measured by an ad libitum meal. GE, VAS, and ad libitum meal tests were measured on the same day. Percent of meal retention in the stomach, VAS area under curve (AUC_{0-240 min} ), and overall appetite score (OAS) were calculated. Pearson correlation (ρ) determined the association of GE with VAS appetite and satiation. Appetite components were also analyzed by quartiles based on GE_{120 min} .

RESULTS

GE_{120 min} was correlated with sensation of VAS hunger_{AUC(0-240 min)} (ρ = 0.24, p = 0.004), fullness_{AUC(0-240 min)} (ρ = 0.16, p = 0.05), and OAS_{AUC(0-240 min)} (ρ = 0.20, p = 0.02). Patients with rapid GE_{120 min} had a mean increase in VAS hunger_{AUC(0-240 min)} by 32 mm/min (15.62%, p = 0.03) compared with normal/slow GE_{120 min} .

CONCLUSIONS

GE is associated with the sensations of appetite, and rapid GE is associated with increased appetite, which may contribute to weight gain.