1.
Effect of Standardized Grape Powder Consumption on the Gut Microbiome of Healthy Subjects: A Pilot Study.
Yang, J, Kurnia, P, Henning, SM, Lee, R, Huang, J, Garcia, MC, Surampudi, V, Heber, D, Li, Z
Nutrients. 2021;(11)
Abstract
Grapes provide a rich source of polyphenols and fibers. This study aimed to evaluate the effect of the daily consumption of 46 g of whole grape powder, providing the equivalent of two servings of California table grapes, on the gut microbiome and cholesterol/bile acid metabolism in healthy adults. This study included a 4-week standardization to a low-polyphenol diet, followed by 4 weeks of 46 g of grape powder consumption while continuing the low-polyphenol diet. Compared to the baseline, 4 weeks of grape powder consumption significantly increased the alpha diversity index of the gut microbiome. There was a trend of increasing Verrucomicrobia (p = 0.052) at the phylum level, and a significant increase in Akkermansia was noted. In addition, there was an increase in Flavonifractor and Lachnospiraceae_UCG-010, but a decrease in Bifidobacterium and Dialister at the genus level. Grape powder consumption significantly decreased the total cholesterol by 6.1% and HDL cholesterol by 7.6%. There was also a trend of decreasing LDL cholesterol by 5.9%, and decreasing total bile acid by 40.9%. Blood triglyceride levels and body composition were not changed by grape powder consumption. In conclusion, grape powder consumption significantly modified the gut microbiome and cholesterol/bile acid metabolism.
2.
California strawberry consumption increased the abundance of gut microorganisms related to lean body weight, health and longevity in healthy subjects.
Ezzat-Zadeh, Z, Henning, SM, Yang, J, Woo, SL, Lee, RP, Huang, J, Thames, G, Gilbuena, I, Tseng, CH, Heber, D, et al
Nutrition research (New York, N.Y.). 2021;:60-70
Abstract
It was our hypothesis that foods high in polyphenols and fiber have prebiotic activity. This human intervention study aimed to determine if daily consumption of freeze-dried California strawberry powder (SBP) leads to changes in the intestinal microbiota, fecal cholesterol and bile acid (BA) microbial metabolites. Fifteen healthy adults consumed a beige diet+26 g of SBP for 4 weeks, followed by 2 weeks of beige diet only. Stool samples were collected at 0, 4, and 6 weeks. Fecal microbiota was analyzed by 16S rRNA sequencing; fecal cholesterol, BA, and microbial metabolites by gas chromatography. Confirming compliance, urine concentration of pelargonidin, urolithin A glucuronide and dimethylellagic acid glucuronide were present after 4 weeks of SBP consumption. Daily SBP altered the abundance of 24 operational taxonomic units (OTUs). Comparing week 4 to baseline the most significant increases were observed for one OTU from Firmicutes\Clostridia\ Christensenellaceae\NA, one OTU from Firmicutes\ Clostridia\Mogibacteriacea\NA, one OTU from Verrucomicrobia\ Verrucomicrobiaceae\Akkermansia\Muciniphila, one OTU from Actinobacteria\ Bifidobacteriaceae\Bifidobacterium\NA, and one OTU from Bacteroidetes\Bacteroidia\ Bacteroidaceae\Bacteroides and decrease of one OTU from Proteobacteria\ Betaproteobacteria\Alcaligenaceae\Sutterella. Comparing week 4 to 6, we observed a reversal of the same OTUs from C Christensenellaceae, V muciniphilia and C Mogibacteriaceae. Fecal short chain fatty acids and most of the fecal markers including cholesterol, coprostanol, primary and secondary BAs were not changed significantly except for lithocholic acid, which was increased significantly at week 6 compared to baseline. In summary, SBP consumption increased the abundance of gut microorganisms related to lean body weight, health and longevity, and increased fecal lithocholic acid at week 6 in healthy study participants.