Author : Peter Demartino
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (136 download)
Book Synopsis Effects of Resistant Starch on the Human Gut Microbiome and Gut Health Outcomes by : Peter Demartino
Download or read book Effects of Resistant Starch on the Human Gut Microbiome and Gut Health Outcomes written by Peter Demartino and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gut microbiome plays an important role in modulating host health. Often, this is through fermentation of complex carbohydrates that are undigested by the human enzymes. The metabolites released from this fermentation, like butyrate a short chain fatty acid, have been found to promote improved gut health. Resistant starch (RS) is a type of dietary fiber that has been highly associated with butyrate production. The goal of this dissertation was to understand how the consumption of RS effects gut microbiota changes, corresponding butyrate production, and inflammatory levels in the gut. This was accomplished with 2 clinical trials that implemented small doses of RS from daily potato side dishes (2.0-2.9g/day) and larger quantities of 3 RS (24g/day). For the daily potato intake, alpha diversity decreased for the during the potato treatment, but beta diversity showed no significant clustering for the dietary treatments. During differential abundance analyses, two species in particular, H. xylanolytica and R. faecis, were significantly enriched during the potato treatment, which may be associated with RS3 from the cooked and cooled source. No changes were found for the main RS degraders, B.adolescentis and R.bromii at the low levels of RS supplementation, nor were there changes were found for fecal SCFA when consuming potato side dishes compared to an isocaloric serving of refined grains. It is unclear what are the physiological implications of the microbiota shift, and more work needs to be done to determine health outcome differences for modest dietary changes with whole food sources, like what was implemented in this study (2.0-2.9 g/day). The clinical trial with consumption of 3 different RS (PS, HM, and VF), with CS in-between, aimed to better understand how these RS impact the gut microbiota and gut inflammation levels (NGAL and calprotectin). Participants selected were either normal BMI (18.5 to 24.9 kg/m2) and obese BMI (>30kg/m2) to also determine differences in response between BMI groups. The RS treatments themselves had significant impacts on microbiome composition and inflammatory response, but responses between normal and obese BMI participants varied at times. Measures of alpha diversity showed decreases in diversity during RS supplementation, compared to baseline. Beta diversity was significantly different for RS treatment when factoring in BMI and gender. Overall, certain species with RS degrading and butyrate producing capabilities had clear associations with certain RS. B. adolescentis was significantly enriched during PS, while R. bromii and E. rectale were enriched for HM and VF. However, the only significant SCFA increase was acetate during PS, but no changes for butyrate. Additionally, certain species had associations with high and low NGAL levels, with an interesting one being OTU 00014 of R. bromii being more abundant with high NGAL levels. Conflicting results in species with high and low NGAL level associations may suggest that similar species are enriched during the RS treatments, but inflammatory responses may differ between individuals. Particularly, changes in NGAL levels differed when splitting the participants by BMI. Normal BMI participants showed significant decreases in NGAL during all of the RS treatments, whereas obese participants showed overall increases in NGAL, with VF and CS being significant. Previous studies have shown butyrate having pro-inflammatory effects with pre-existing inflammation, so caution may be necessary when recommending RS. RS degraders, B. adolescentis and R. bromii had differences in correlations with butyrate producers compared to each other, with differences even between R. bromii itself with its different OTUs (00014 and 00015). The OTUs of R. bromii seemed to have opposite patterns to one another, with OTU 00014 being negatively associated with the butyrate producers and OTU 00015 being positively associated with the butyrate producers. These differences in the interconnectedness RS degraders with the microbiota is further complicated by the interindividual presence of the RS degraders in participants. R bromii OTUs 00014 and 00015 appear to be mutually exclusive from one another, and proportions with B. adolescentis varied from individual to individual. It is likely that the presence or absence of these RS degraders is another key aspect for RS supplementation. Overall, this research has provided new findings for how RS affects the gut microbiome and inflammation, but more research needs to be done to investigate these effects at greater detail. Especially with the goal of personalized nutrition, interindividual differences and general grouping of individuals need to be better understood before having true confidence in choosing which RS is appropriate to consume.
