Thirty Days of Montmorency Tart Cherry Supplementation Has No Effect on Gut Microbiome Composition, Inflammation, or Glycemic Control in Healthy Adults

Abstract

Tart cherries possess properties that may reduce inflammation and improve glycemic control, however human data on supplementation and the gut microbiota is equivocal. Processing (i.e., juice concentrate, dried, frozen) may affect the properties of tart cherries, and therefore alter their efficacious health benefits. Therefore, the purpose of this study was to investigate the effect of 30 days of supplementation with Montmorency tart cherry (MTC) in concentrate or freeze-dried form on the gut microbiome and markers of inflammation and glycemic control. Healthy participants with no known disease (n = 58, age: 28 ± 10 y, height: 169.76 ± 8.55 cm, body mass: 72.2 ± 12.9 kg) were randomly allocated to four groups and consumed either concentrate or freeze-dried capsules or their corresponding placebos for 30 days. Venous blood samples were drawn at baseline, day 7, 14, and 30 and analyzed for inflammatory markers TNF-alpha, uric acid, C-reactive protein, and erythrocyte sedimentation rate and glycemic control markers glycated albumin, glucose and insulin. A fecal sample was provided at baseline, day 14 and 30 for microbiome analysis. TNF-alpha was significantly lower at 30 vs. 14 days (p = 0.01), however there was no other significant change in the inflammatory markers. Insulin was not changed over time (p = 0.16) or between groups (p = 0.24), nor was glycated albumin different over time (p = 0.08) or between groups (p = 0.56), however glucose levels increased (p < 0.001) from baseline (4.79 ± 1.00 mmol·L−1) to 14 days (5.21 ± 1.02 mmol·L−1) and 30 days (5.61 ± 1.22 mmol·L−1) but this was no different between groups (p = 0.33). There was no significant change in composition of bacterial phyla, families, or subfamilies for the duration of this study nor was there a change in species richness. These data suggest that 30 days of MTC supplementation does not modulate the gut microbiome, inflammation, or improve glycemic control in a healthy, diverse group of adults.Clinical Trail Registration:https://clinicaltrials.gov/ct2/show/NCT04467372, identifier: NCT04467372.

The beneficial effect of tart cherry on plasma levels of inflammatory mediators (not recovery after exercise): A systematic review and meta-analysis on randomized clinical trials

“…Nineteen articles were read in full text and nine studies were excluded due to the following reasons: they had no comparison group (n = 2), used other interventions besides TC (n = 1), consumed TC less than one week (n = 1), and measured the plasma concentration of other inflammatory mediators (n = 5). Finally, ten clinical trials were selected for this systematic reviews [41][42][43][44][45][46][47][48][49][50] (Fig. 1).…”

“…1). Since serum concentration of inflammatory mediators were not reported in one article, 50 meta-analysis was conducted on nine studies. [41][42][43][44][45][46][47][48][49]…”

“…The effect of TC on plasma CRP, IL-6, and TNF-α was assessed in 10, 41-50 4, 41,44,46,48 and 3 43,48,50 studies, respectively. Among the included studies, the freeze-dried powder, the juice, and the concentrated form of TC were consumed in 2, 41,50 5 42,43,48-50 and 4 [44][45][46][47] studies as interventions, respectively.…”

“…Concerning the study design, four and six RCTs had crossover design 41,42,48,49 and parallel design, [43][44][45][46][47]50 respectively. The duration of treatment was 2-12 weeks.…”

Essential Factors for a Healthy Microbiome: A Scoping Review

“…The data from a short-term human trial using cherry juice suggests that participants who consumed a Western-style diet showed different gut microbiota responses than other participants due to their reduced ability to metabolize polyphenols [ 66 ]. Healthy volunteers in a month-long trial of Montmorency tart cherry concentrate had no change in species richness or microbial composition [ 67 ]. Thus, habitual dietary pattern affects the ability of individuals to receive all of the health benefits from fruits and vegetables.…”