|KOECHER, KATIE - General Mills, Inc|
|MCKEOWN, NICOLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|SAWICKI, CALEIGH - Jean Mayer Human Nutrition Research Center On Aging At Tufts University|
|MENON, RAVI - General Mills, Inc|
|SLAVIN, JOANNE - University Of Minnesota|
Submitted to: Nutrition Reviews
Publication Type: Review Article
Publication Acceptance Date: 11/26/2018
Publication Date: 5/23/2019
Citation: Koecher, K., McKeown, N.M., Sawicki, C.M., Menon, R., Slavin, J.L. 2019. Effect of whole-grain consumption on changes in fecal microbiota: a review of human intervention trials. Nutrition Reviews. 77(7):487-497. https://doi.org/10.1093/nutrit/nuz008.
Technical Abstract: Whole-grain (WG) consumption is known to have beneficial effects on human health. However, the influence of WGs on the microbiota is not well understood. To evaluate how WG intake modulates the gut microbiota composition, a literature review of human intervention studies was conducted. Whole grain, whether a mixed WG food or diet (n=5) or specific WG intervention (WG wheat [n=5], barley [n=2], rye [n=2] or rice, corn, or oats [n=1 for each]), generally modified microbiota composition but did so inconsistently across measurements of microbial diversity and taxa. Interventions used both parallel and crossover designs and varied from single product substitutions to fully controlled diets with WG exposures of 3-12 weeks. The effect of amount of WG was difficult to capture due to variable reporting of WG. Methods used to measure microbiota varied in ability to resolve changes at different taxonomic levels, and comparisons of interventions using similar methods was lacking. Because many dietary components besides WGs alter gut microbiota, further research is needed, particularly in linking microbiota changes to health outcomes, and study design recommendations for future research on WGs and microbiota are warranted.