In a recent study published in the journal Antioxidants, researchers explored the effects of micronutrition on the diversity of the gut microbiome.
Stady: Crop, host and gut microbiome variability influences microfeeding: an example of blueberries. Image credit: BukhtaYurii/Shutterstock.com
Nutrition research funding is increasingly focused on precision nutrition, which has recently gained a lot of attention. Fruit and vegetable consumption is associated with a lower risk of chronic diseases such as obesity, cardiovascular disease, diabetes, and neurocognitive diseases.
Berries, tea and cocoa contain (Poly) phenolic compounds that have been identified as having potential health benefits among the thousands of phytochemicals studied.
Epidemiological studies have prompted more research into the health benefits of blueberries and blueberry-rich foods. More research is needed to reveal the mechanisms of action behind these health benefits.
In this study, the researchers presented a variety of profiles of the polyphenols found in blueberries, examined the bioavailability of anthocyanins in blueberries in diverse forms, and explored their effect on the gut microbiome.
The anthocyanin profiles of 267 blueberry genotypes were analyzed at North Carolina State University’s Piedmont Research Station in Salisbury, North Carolina. Genotypes included both commercial cultivars and breeding selection.
Principal component analysis (PCA) was performed on 17 anthocyanins analyzed in each genotype using a multivariate statistical method. Blueberry genotypes with diverse anthocyanin profiles were selected based on their distinct PCa profiles.
These genotypes were then analyzed to determine their polyphenolic profiles. The bioavailability of flavonoids was further tested in mice whose ovaries had been removed, serving as a model for postmenopausal bone loss in women.
Six genotypes were selected for the study, including three interquartile genotypes (cranberry(including Montgomery, Ira, and Onslow, along with three Southern Highland genotypes)V. corybosum) as Sampson, Legacy, and SHF2B1-21:3.
Plasma was subjected to solid phase extraction (SPE) to extract flavonols, anthocyanins, and flavan-3-ole metabolites, which were subsequently analyzed.
The effect of blueberries on bone calcium retention in four-month-old Sprague Dawley rats was studied through microbiome analysis. The team extracted deoxyribonucleic acid (DNA) from stool samples and sequenced the resulting amplicons.
The study included 20 rats and 160 stool samples collected at various stages, including baseline, 10-day blueberry treatments, and washout stages for microbiota analysis.
The anthocyanins identified from plants belonging to the same genotype included cyanidin 3-O-galactoside, cyanidin 3-O-arabiniside, cyanidin 6-O-glucoside, cyanidin 3-O-glucoside, delphinidin 3-O-arabiniside, delphinidin 3 -O-galactoside, Delphindin 6-O-Glucoside, Delphindin 3-O-Glucoside, Malvidin 3-O-Galactoside, Malvidin 3-O-Galactoside, Malvidin 3-O-Glucoside, Malvidin 6-O-galactoside, Pionidine 3- O-galactoside, malvidin 6-o-glucoside, petonidine 3-o-glucoside, petonidine 6-o-glucoside, and petonidine 3-a-arabineside.
The study analyzed six blueberry genotypes and four members of the genus Vaccinium to determine the content of total phenolic (TP) and monomeric anthocyanins.
The results showed that raspberries and Lowbush Blueberry (LB) complex had higher levels of phenols as well as total monoamine anthocyanin levels than their highbush counterparts.
The total phenolic content ranged from 1951 to 4627 mg/100g of berries, while the total mono-anthocyanins ranged from 369 to 1722 mg/100g.
About 50% of all the phenols in blueberries were anthocyanins, which are the most abundant phenolic class in Vaccinium species. The 10 genotypes examined showed significant differences in the levels and ratios of different anthocyanins.
Compound raspberry and LB genotypes had the highest anthocyanin levels, which is consistent with higher total and phenolic monoaminergic anthocyanin levels.
Cranberry showed the most significant amounts of cyanidin and delphinidine species, while LB compound showed the highest levels of malvidin and anthocyanin acylene. Cranberries have a distinct anthocyanin profile compared to other berries, showing elevated levels of pionidin but low levels of malvidin, delphinidin, and ptonidin.
The genotypes tested showed different levels of glycosylation, with significant arabinoside and galactoside derivative content in the majority. Selected genotypes, such as Legacy, Ira, and Sampson, had significantly lower amounts of glucoside derivatives. Conversely, other genotypes, including Onslow, Wild Blueberry (WBB), bilberry, SHF2B1-21:3, and LB composite, showed amounts of glucoside derivative that were equal to or greater than arabinoside and galactoside derivatives.
Plasma samples from OVX mice showed the presence of various anthocyanin metabolites such as delphinidin-3-O-glycosides, cyanidin-3-O-glycosides, pionidin-3-O-glycosides, malvidin-3-O-glycosides, and petonidin-3-O-glycosides after acute dose.
Cyanidin-3-O-glycosides and malvidin-3-O-glycosides had higher bioavailability in Montgomery blueberries than in other berries.
The study found that blueberry dose significantly affected the Firmicutes-to-Bacteroidota ratio, which decreased with increasing dose. Percentages were highest in samples without a blueberry diet, and decreased progressively in samples with increasing blueberry concentrations.
In addition, comparisons of diversity in the gut microbiome in each sample showed significantly greater diversity among samples with higher blueberry treatments.
Moreover, the team observed that two actinomycetes, one from the family Bacteroidota Prevotellaceae_UCG-001, and the other from the family Firmicutes Anaerovoracaceae XIII_UCG-001 had higher proportions after blueberry treatments.
The results of the study show that the phenolic profiles of blueberries differ according to their genetic backgrounds, influencing the bioavailability and metabolism of polyphenols. The team also found evidence of a gut microbiome’s response to the blueberry dose.
The diversity found in crop systems, from growth to consumption to the gut microbiome, can be used to enhance crop selection, breeding methods, and identify critical genotypes. This information can help understand functional responses to health and develop accurate nutrition practices.