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

An overview on the cellular mechanisms of anthocyanins in maintaining intestinal integrity and function

Structural and functional changes of the intestinal barrier, as a consequence of a number of (epi)genetic and environmental causes, have a main role in penetrations of pathogens and toxic agents, and lead to the development of inflammation-related pathological conditions, not only at the level of the GI tract but also in other extra-digestive tissues and organs. Anthocyanins (ACNs), a subclass of polyphenols belonging to the flavonoid group, are well known for their health-promoting properties and are widely distributed in the human diet. There is large evidence about the correlation between the human intake of ACN-rich products and a reduction of intestinal inflammation and dysfunction. Our review describes the more recent advances in the knowledge of cellular and molecular mechanisms through which ACNs can modulate the main mechanisms involved in intestinal dysfunction and inflammation, in particular the inhibition of the NF-κB, JNK, MAPK, STAT3, and TLR4 proinflammatory pathways, the upregulation of the Nrf2 transcription factor and the expression of tight junction proteins and mucins.

Health Benefits of Montmorency Tart Cherry Juice Supplementation in Adults with Mild to Moderate Ulcerative Colitis: A Protocol for a Placebo Randomized Controlled Trial

Ulcerative colitis, characterized by its relapsing and remissive nature, negatively affects perception, body image, and overall quality of life. The associated financial burden underscores the need for alternative treatment approaches with fewer side effects, alongside pharmaceutical interventions. Montmorency tart cherries, rich in anthocyanins, have emerged as a potential natural anti-inflammatory agent for ulcerative colitis. This manuscript outlines the study protocol for a randomized placebo-controlled trial investigating the effects of Montmorency tart cherry in individuals with ulcerative colitis. The trial aims to recruit 40 participants with mild to moderate disease activity randomly assign them to either a Montmorency tart cherry or placebo group. The intervention will span 6 weeks, with baseline and 6-week assessments. The primary outcome measure is the Inflammatory Bowel Disease Quality of Life Questionnaire. Secondary outcomes include other health-related questionnaires and biological indices. Statistical analysis will adhere to an intention-to-treat approach using linear mixed effect models. Ethical approval has been obtained from the University of Hertfordshire (cLMS/SF/UH/05240), and the trial has been registered as a clinical trial (NCT05486507). The trial findings will be disseminated through a peer-reviewed publication in a scientific journal.

Health benefits of anthocyanin-containing foods, beverages, and supplements have unpredictable relation to gastrointestinal microbiota: A systematic review and meta-analysis of random clinical trials

Anthocyanins are a type of natural pigment that has numerous health benefits. In recent years, the interaction of anthocyanins with gastrointestinal (GI) microbiota has been presented as a viable paradigm for explaining anthocyanin activities. The current study performed a systematic review and meta-analysis to determine the potential modulation of GI microbiota by anthocyanins in human health improvement. Clinical trials were retrieved from PubMed, Cochrane, Web of Knowledge, China Biology Medicine, China National Knowledge Infrastructure, and ClinicalTrials.gov with no language restrictions. Eight clinical trials (252 participants) were selected from the 1121 identified studies and the relative phylum abundance extracted from the trials was analyzed using a random-effects model. Based on the analysis, anthocyanins had no effect on the relative abundance of Firmicutes (standard mean difference [SMD]: -0.46 [-1.25 to 0.34], P = .26), Proteobacteria (SMD, -0.32 [-0.73 to 0.09], P = .13), nor Actinobacteria (SMD, -0.19 [-0.50 to 0.12], P = 0.24), but influenced the abundance of Bacteroidetes (SMD, 0.84 [0.17 to 1.52], P = .01) when compared with placebo/control. No significant influence on the relative abundance was detected when the data were analyzed following the "posttreatment vs. pretreatment" strategy. Our preliminary analysis revealed that the effects of anthocyanins on human GI microbiota vary between studies and individuals, and at the current stage, the clinical trials regarding the effects of anthocyanin interventions on human GI microbiota are lacking. More trials with larger sample sizes are needed to promote the clinical application of anthocyanins.

Effects of tart cherry juice consumption on cardio-metabolic risk factors: A systematic review and meta-analysis of randomized-controlled trials

BACKGROUND

Tart cherries are rich in bioactive compounds, such as anthocyanins and other phytochemicals known to have antioxidant properties and exert cardiovascular protective effects. However, there is no definitive consensus on this context. The present systematic review and meta-analysis aimed to investigate the effect of tart cherry juice consumption on cardio-metabolic risk factors.

METHODS

A systematic search was conducted on electronic databases, including PubMed, Web of Science, Scopus, and Google Scholar from inception up to December 2021 to identify eligible RCT studies. A random-effect model was utilized to estimate the weighted mean difference (WMD) and 95% confidence (95% CI).

RESULTS

Ten RCTs were included in the present meta-analysis. The pooled analysis revealed that tart cherry juice consumption led to a significant reduction in the fasting blood sugar (FBS) levels (WMD = -0.51 mg/dl [95% CI: -0.98, -0.06]). This lowering effect of FBS was robust in subgroups with cross-over studies, participants with age range ≥ 40, duration of follow-up ≤ 4 weeks, and baseline BMI ≥ 30. In contrast, tart cherry juice had no effect on total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), insulin, body mass index (BMI), fat mass, systolic and diastolic blood pressure. However, in the subgroup analysis, some significant effects were observed for insulin, TG, TC, LDL-C, and HDL-C.

CONCLUSION

In summary, this meta-analysis showed that tart cherry juice mostly had a favorable effect on FBG levels. However, further RCTs with long-term intervention with different doses of administration are needed.

Essential Factors for a Healthy Microbiome: A Scoping Review

Recent discoveries of the purpose and potential of microbial interactions with humans have broad implications for our understanding of metabolism, immunity, the host−microbe genetic interactions. Bioavailability and bioaccessibility of phytonutrients in foods not only enrich microbial diversity in the lower human gastrointestinal tract (GIT) but also direct the functioning of the metagenome of the microbiota. Thus, healthy choices must include foods that contain nutrients that satisfy both the needs of humans and their microbes. Physical activity interventions at a moderate level of intensity have shown positive effects on metabolism and the microbiome, while intense training (>70% VO2max) reduces diversity in the short term. The microbiome of elite endurance athletes is a robust producer of short-chain fatty acids. A lifestyle lacking activity is associated with the development of chronic disease, and experimental conditions simulating weightlessness in humans demonstrate loss of muscle mass occurring in conjunction with a decline in gut short-chain fatty acid (SCFA) production and the microbes that produce them. This review summarizes evidence addressing the relationship between the intestinal microbiome, diet, and physical activity. Data from the studies reviewed suggest that food choices and physical fitness in developed countries promote a resource “curse” dilemma for the microbiome and our health.

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

BACKGROUND

Chronic inflammation has been classified as one of the most important threats to health. Scientists suggested that tart cherry (TC) can reduce plasma levels of inflammatory mediators. Therefore, the aim of this study was to summarize the effect of TC on circulating C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) among adult participants in non-exercise randomized clinical trials (RCTs).

METHODS AND MATERIALS

The eligible English-language RCTs were found by searching databases including PubMed, Web of Science, Cochrane Library, Scopus, and clinical Trials.gov up to May 2022, with no time limit. We used the mean change from baseline and its standard deviation for both intervention and comparison groups to calculate the effect size. The random-effects model proposed by DerSimonian and Laird was used to estimate the overall summary effect and the heterogeneity. We used PRISMA 2020 guidelines to report this study.

RESULTS

Ten RCTs were included in this study. The results demonstrated that TC had a significant decreasing effect on plasma CRP level compared with the comparison group (weighted mean differences (WMD) = -0.55 mg/L; 95% confidence interval (CI): - 1.03, - 0.06; p = 0.029), but had no significant effect on plasma IL-6 compared with comparison group (WMD = 0.08 pg/mL; 95% CI: -0.02, 0.17; p = 0.10). The effect of TC consumption on plasma TNF-α level was evaluated in only three studies that showed no significant effects (p>0.05).

CONCLUSION

Our results confirmed a significant decreasing effect of TC on CRP. Regarding IL-6 and TNF-α, our study did not present any significant effect of TC.