The Effects of a Powdered Meal Replacement on Inflammation, Gut Microbiota, and Metabolism in People With Excess Body Weight-A Randomized Controlled Trial.

BACKGROUND

Excess body weight is associated with chronic low-grade inflammation and metabolic abnormalities, such as insulin resistance, and dyslipidemia.

OBJECTIVES

This study aimed to assess the impact of a soy protein-yogurt-honey powdered meal replacement (PMR) on inflammation, gut microbiota, and metabolism in individuals with excess body weight and in weight-stable conditions.

METHODS

The Powdered meal REplacement on MetabolIsm and gUt Microbiota (PREMIUM) Study was a 12-week, parallel-arm, randomized controlled trial. Participants (body mass index: 25-37 kg/m2) were randomized into either control (CON; usual diet, n = 34) or PMR (2 daily doses added to usual diet, n = 29) groups, maintaining a stable body weight. Assessments occurred at baseline, week 6, and week 12, and included inflammation markers (primary outcome: IL-6), gut microbiota diversity and composition (secondary outcome), metabolic blood markers (glucose and lipid profile), body composition (via dual-energy X-ray absorptiometry), and dietary intake. Data of completers were analyzed by 2-way repeated measures analysis of variance or generalized estimating equations with Bonferroni-corrected post hoc tests. Between-group differences in changes over time are expressed as mean and 95% confidence intervals.

RESULTS

Adherence to PMR was 98% of total doses, which increased protein intake [6.53% (5.04%, 8.02%), P < 0.001] and decreased fat intake [-5.23% (-7.10%, -3.35%), P < 0.001] compared with CON. By design, body weight remained stable. There were no changes in IL-6 [-0.01 (-0.47, 0.45) pg/mL, P = 0.412], with a low statistical power of 13.7%. Minor changes in gut microbiota composition included an increase in relative abundance of Subdoligranulum (0.72 Log2 fold-change, q = 0.002). In exploratory outcomes, PMR increased lean soft tissue [0.57 (0.12, 1.02) kg, P = 0.014] and reduced total cholesterol [-0.33 (-0.58, -0.08) mmol/L, P = 0.01] and low-density lipoprotein cholesterol [-0.28 (-0.46, -0.10) mmol/L, P = 0.003].

CONCLUSIONS

In this population, PMR intake did not improve chronic low-grade inflammation and had limited effects on gut microbiota, but was associated with improvements in lean soft tissue and lipid profile that warrant further exploration. This trial was registered at clinicaltrials.gov as NCT03235804 on August 1, 2017.