Effects of Daily Saskatoon Berry Supplementation on Cardiometabolic Health, Gut Microbiota, and Short-Chain Fatty Acids in Healthy Adults.

Saskatoon berry (SB), a traditional food of Indigenous people, has been associated with cardiometabolic benefits in animal models; however, its effects on humans remain unclear. This study investigated the effects of dried SB consumption on cardiometabolic outcomes, gut microbiota, and short-chain fatty acids (SCFAs) profiles in healthy adults. In a 10-week, single-arm, and open-label trial, 20 healthy adults consumed 40 g/day of freeze-dried whole SB. Biochemical measures, physical exams, dietary records, participant feedback, and fecal samples were collected before and after the intervention. Gut microbiota composition and fecal SCFAs were profiled using 16S-rRNA sequencing and gas chromatography-mass spectrometry, respectively. SB intake significantly reduced fasting plasma glucose, total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), non-high-density lipoprotein-cholesterol (non-HDL-c), systolic blood pressure, and high-sensitivity C-reactive protein, while increasing dietary fiber intake. Fiber intake was negatively correlated with TC, LDL-c and non-HDL-c (p < 0.05). The relative abundance of fecal Prevotellaceae increased after SB consumption and was positively correlated with multiple fecal SCFAs (p < 0.05-0.0001), while being negatively associated with lipid profiles and blood pressure. No adverse cardiovascular, hepatic, or renal dysfunction were observed; however, the significant increase in sugar intake may pose a risk for elevated blood glucose. Therefore, limiting other high-sugar foods during SB supplementation may be advisable for individuals with glucose intolerance. Overall, SB intake improved glucose and lipid metabolism and lowered blood pressure and inflammatory markers in healthy adults. These cardiometabolic benefits may be mediated by fiber and anthocyanins in SB and through modulation of gut microbiota and SCFA production; however, further confirmation is needed in subsequent randomized controlled trials.