Tart Cherry Concentrate Does Not Alter the Gut Microbiome, Glycaemic Control or Systemic Inflammation in a Middle-Aged Population

Abstract

Limited evidence suggests that the consumption of polyphenols may improve glycaemic control and insulin sensitivity. The gut microbiome produces phenolic metabolites and increases their bioavailability. A handful of studies have suggested that polyphenol consumption alters gut microbiome composition. There are no data available investigating such effects in polyphenol-rich Montmorency cherry (MC) supplementation. A total of 28 participants (aged 40–60 years) were randomized to receive daily MC or glucose and energy-matched placebo supplementation for 4 wk. Faecal and blood samples were obtained at baseline and at 4 wk. There was no clear effect of supplementation on glucose handling (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Gutt indices), although the Matsuda index decreased significantly in the MC group post-supplementation, reflecting an increase in serum insulin concentration. Contrastingly, placebo, but not MC supplementation induced a 6% increase in the Oral Glucose Insulin Sensitivity (OGIS) estimate of glucose clearance. Serum IL-6 and C reactive protein were unaltered by either supplement. The faecal bacterial microbiome was sequenced; species richness and diversity were unchanged by MC or placebo and no significant correlation existed between changes in Bacteroides and Faecalibacterium abundance and any index of insulin sensitivity. Therefore, 4 weeks of MC supplementation did not alter the gut microbiome, glycaemic control or systemic concentrations of IL-6 and CRP in a middle-aged population.

A Polyphenol Enriched Variety of Apple Alters Circulating Immune Cell Gene Expression and Faecal Microbiota Composition in Healthy Adults: A Randomized Controlled Trial

“…A number of other studies which have investigated the impact of polyphenol consumption have been of a greater duration, however this has not necessarily meant the observation of clearer effects of the intervention. For example, an intervention investigating the impact of a polyphenol-rich tart cherry extract (4 weeks) did not show any impact on the gut microbiome [60]. Conversely, several studies are reported in which significant differences in metabolic and/or microbial responses have been seen with an intervention of two weeks' duration or less, for example pomegranate juice [61] or cranberries [41].…”

Differentiation of Blastocystis and parasitic archamoebids encountered in untreated wastewater samples by amplicon-based next-generation sequencing

“…18S rRNA gene segments were amplified by PCR using a total of three primer sets as previously described (Krogsgaard et al, 2018; Ring et al, 2017; Lear et al, 2019); G3F1/G3R1 (5′-GCCAGCAGCCGCGGTAATTC-3′/5′-ACATTCTTGGCAAATGCTTTCGCAG-3′), G4F3/G4R3 (5′-CAGCCGCGGTAATTCCAGCTC-3′/5′-GGTGGTGCCCTTCCGTCAAT-3′) and G6F1/G6R1 (5′-TGGAGGGCAAGTCTGGTGCC-3′/5′-ACGGTATCTGATCGTCTTCGATCCC-3′). G3 and G6 primers target the hyper-variable regions V3-V4 of the 18S rRNA gene, and G4 primers target V3-V5.…”

“…We recently developed a NGS-based platform for detection and differentiation of prokaryotic and eukaryotic nuclear ribosomal DNA, which has already been used in a few studies (Krogsgaard et al, 2018; Ring et al, 2017; Lear et al, 2019). In the present study, we used this method to reveal and differentiate taxa within several CLIPP genera in samples from Swedish sewage treatment plants.…”

Lack of a Synergistic Effect on Cardiometabolic and Redox Markers in a Dietary Supplementation with Anthocyanins and Xanthophylls in Postmenopausal Women

“…Even if we showed some years ago that anthocyanins have an influence on human gut microbiota in vitro [31], recent studies contradict these results in vivo, showing a lack of effect on gut microbiota of a daily anthocyanin dose as high as 293 mg [32]. However, either by modulation of the microbiota or by influencing its metabolic capacity, the fact is that the regulation of the levels of metabolites derived from the action of such microbiota has been largely reported and agrees with our results [33,34,35].…”