Impact Of Frequent Sweet Potato Ingestion On Gut Microbiome, Cholesterol, And Exercise Performance

The importance of the gut microbiome is being explored in relation to multiple facets of health. Numerous pre- and probiotics are being explored to determine their potential to improve health. PURPOSE: The purpose of this study was to explore the impact of frequent sweet potato ingestion on alterations to the gut microbiome which might in turn alter cholesterol levels and exercise performance. METHODS: Thirteen recreationally trained males had fecal and blood samples collected to determine baseline gut microbiome communities and cholesterol and follow-up samples after 4 weeks of no-intervention. Participants then performed cycling exercise to exhaustion at 65% VO2PEAK while ingesting a placebo (PLA) or a carbohydrate-electrolyte beverage (CHO; 60 g/h) separated by 7-days, in a randomized, cross-over design. Following preliminary testing, participants began a 6-week diet incorporating one sweet potato each day. After 28 days of the diet, participants provided fecal and blood samples and repeated cycling exercise to exhaustion with PLA and CHO in a randomized, cross-over design. DNA was extracted from fecal samples and bacterial communities were sequenced using Illumina NovaSeq. Blood samples were analyzed for Total Cholesterol (TC), HDL-C, LDL-C, and Triglycerides (TGL). Performance was analyzed comparing changes in time-to-exhaustion when ingesting PLA compared to CHO. RESULTS: Thirteen bacterial OTUs saw changes in abundance related to sweet potato ingestion including increases in the genera Faecalibacterium, Bacteroides, Parasutterella, Alistipes, Phascolarctobacterium, Oscollibacter, andClostrodium XIVa and decreases within the genera Dorea, Asaccharobacter, and Butyricicoccus. There were no differences observed in cholesterol (TC: 149 + 36 mg/dL vs. 154 + 25 mg/dL; p = 0.57; HDL-C: p = 0.72; LDL-C: p = 0.76; TGL: p = 0.35) or cycling time-to-exhaustion with and without carbohydrate (2.1 + 10.3 min vs -1.3 + 10.6 min; p = 0.43) following frequent sweet potato ingestion. CONCLUSIONS: These finding demonstrate the efficacy of frequent sweet potato ingestion in shifting key bacterial abundances in the gut, including those known to play major roles in gut health through short-chain fatty acid production. These changes however did not elicit significant changes cholesterol or exercise performance.