Dietary Grapes Promote Subtle Changes in the Human Microbiome, which May Affect Health

Several studies have shown that diet plays an important role in maintaining and altering the gut microbiota. In fact, the amount of fat, protein, phytoestrogens, polyphenols, and carbohydrates an individual consumes influences microbial diversity. The number and abundance of gut microbes influence the levels of metabolites such as acetate, butyrate and propionate that affect physiological function.

Recent scientific report Studies are investigating how grapes affect the human microbiome.

study: Effects of grape consumption on the human microbiome. Image credit: Andrew Hagan / Shutterstock.com

Background

The United States alone produces 6 million tons of grapes each year. Several studies have shown that grape consumption produces inflammation, gastrointestinal health, bladder function, vision, atherosclerosis, and a range of atherosclerosis-related reactions. In addition, mouse models revealed that eating grapes had significant effects on gene expression affecting several diseases of the liver and brain.

More than 1,600 phytochemicals have been identified in grapes, which alone or in combination with other compounds affect various physiological processes. The most common chemical constituent in grapes is resveratrol, which has been extensively studied.

Previous studies have shown that treatment of the human gut microbiota with total grape seed results in changes in short-chain fatty acid (SCFA) profiles and associated microbial populations. Mice fed a high-fat diet and grape powder had an increased number of microbes that synthesize butyrate.

When grape powder was added to standard mouse chow, the gut microbiota metabolites 5-hydroxyindole, gluconic acid and glyceric acid were excreted in the urine. my-inositol and 4-hydroxyphenylacetic acid were attenuated.In contrast, increases in certain metabolites such as Shiro-inositol, xylitol, 5-hydroxyindole, gluconic acid, 2′-deoxyribonic acid and mannitol were observed.

In humans, grape consumption may lead to an increase in the alpha-diversity index of the gut microbiota. Reductions in total bile acid and cholesterol levels are also correlated with grape intake.

About research

The trial recruited a total of 40 healthy free-living human participants and was conducted for two months. All participants followed a 2-week restricted diet (Day 15), a 2-week restricted diet supplemented with 3 servings of grapes per day (Day 30), and a 1-month washout period (Day 60). I received ).

Plasma, urine and fecal samples were then collected from each participant. Of the 40 participants originally recruited for the study, only 29 completed the trial.

research result

Alpha diversity reflects the richness and relative abundance of microbial populations in the gut. In the current study, no change in alpha diversity was observed among male participants aged 24 to 44. However, female participants aged 29 to her 39 years showed differences in alpha diversity on her day 60 compared to day 15.

Principal component analysis (PCA) and principal coordinate analysis (PCoA) were used to analyze beta diversity. Based on cluster analysis, no significant differences in beta diversity were observed during the study period, regardless of gender-based subgroup analysis.

Common microbial species found at 15, 30 and 60 days are: Faecalibacterium prausnitzii, Eubacterium rectal, prevotella cover, Aristipes fingoldi, Fusicatenibacter saccharivorans, Bacteroides vulgateus, all kinds of rot, feces of bacteroides, Parabacteroides meldae, Bacteroides uniformis, Bifidobacterium adolescentis, Bacteroides coprocora, and Corinthella aerofaciens.

Microbial taxonomic analysis revealed significant microbial changes at each time point. On the 30th day, the level increased. thermophilic streptococcus Observed.

Previous research has revealed that this bacterium produces lactic acid in the gut and is thought to be a probiotic. again, hold mania species was observed. A similar microbial profile was also recorded in the vegetarian diet.

On day 30, abundance increases. hold mania Got attention.However, no change thermophilic streptococcus Occurred. At day 60, a significant increase in microbial levels associated with metabolite production was observed. These findings indicate a delayed gut microbial response to grape ingestion, as no microbial changes were found at day 15.

Ingestion of grapes resulted in changes in certain enzyme levels. For example, an increase in catechol 2,3-dioxygenase levels was observed to trigger metabolic detoxification. Furthermore, (3S.A)-malyl-CoA thioesterase was observed to affect the microbial glyoxylate cycle.

A significant increase in error-prone DNA polymerases was observed on days 30 and 60 compared to day 15. These findings indicate a delayed effect of grape intake on enzyme levels.

Increased levels of cysteine ​​peptidases, decreased levels of ABC transporters and the Narl family were observed on day 30 compared to day 15. Additionally, increases in oxidoreductases, ABC transporters, and non-ribosomal peptide synthetases (NRPS) were observed compared to day 30. Reported on day 60.

Conclusion

The current study found that grape consumption did not alter the symbiotic state of the prevalent microbiome in healthy participants. Nevertheless, grape ingestion alters the taxonomic composition of the microbiome, KEGG pathways, enzyme levels and metabolic profile. Further research is needed to understand whether these changes will have broader health benefits in the future.