585 - ‘Whole grain-rich diet reduces body weight and systemic low-grade inflammation without inducing major changes of the gut microbiome: a randomised cross-over trial’. Gut (BMJ). 68(1):83-93

Reference Number: 585

Year: 2017

Authors: Henrik Munch Roager, Josef K Vogt, Mette Kristensen, Lea Benedicte S Hansen, Sabine Ibrügger, Rasmus B Mærkedahl, Martin Iain Bahl, Mads Vendelbo Lind, Rikke L Nielsen, Hanne Frøkiær, Rikke Juul Gøbel, Rikard Landberg, Alastair B Ross, Susanne Brix, Jesper Holck, Anne S Meyer, Morten H Sparholt, Anders F Christensen, Vera Carvalho, Bolette Hartmann, Jens Juul Holst, Jüri Johannes Rumessen, Allan Linneberg, Thomas Sicheritz-Pontén, Marlene D Dalgaard, Andreas Blennow, Henrik Lauritz Frandsen, Silas Villas-Bôas, Karsten Kristiansen, Henrik Vestergaard, Torben Hansen, Claus T Ekstrøm, Christian Ritz, Henrik Bjørn Nielsen, Oluf Borbye Pedersen, Ramneek Gupta, Lotte Lauritzen, Tine Rask Licht

Link: Link to original paper

Health: Cardiometabolic diseases | Diabetes | Gut Microbiome - Creating Healthier Bread to Support Optimal Gut Health | Metabolic syndrome

Nutrition: Whole grain

Summary

Objective: To investigate whether a whole grain diet alters the gut microbiome and insulin sensitivity, as well as biomarkers of metabolic health and gut functionality.

Design: 60 Danish adults at risk of developing metabolic syndrome were included in a randomised cross-over trial with two 8-week dietary intervention periods comprising whole grain diet and refined grain diet, separated by a washout period of ?6 weeks. The response to the interventions on the gut microbiome composition and insulin sensitivity as well on measures of glucose and lipid metabolism, gut functionality, inflammatory markers, anthropometry and urine metabolomics were assessed.

Results: 50 participants completed both periods with a whole grain intake of 179±50 g/day and 13±10 g/day in the whole grain and refined grain period, respectively. Compliance was confirmed by a difference in plasma alkylresorcinols (p<0.0001). Compared with refined grain, whole grain did not significantly alter glucose homeostasis and did not induce major changes in the faecal microbiome. Also, breath hydrogen levels, plasma short-chain fatty acids, intestinal integrity and intestinal transit time were not affected. The whole grain diet did, however, compared with the refined grain diet, decrease body weight (p<0.0001), serum inflammatory markers, interleukin (IL)-6 (p=0.009) and C-reactive protein (p=0.003). The reduction in body weight was consistent with a reduction in energy intake, and IL-6 reduction was associated with the amount of whole grain consumed, in particular with intake of rye.

Conclusion: Compared with refined grain diet, whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and systemic low-grade inflammation.

Significance of this study to the baker:

In this study, a refined what grain diet was compared with a whole grain diet. The result? Compared to a refined wheat grain diet, the whole grain diet did not alter insulin sensitivity and gut microbiome but reduced body weight and low-grade systemic inflammation.

This study suggests the health benefits of consuming whole-grain foods. Considering these are often high in gluten, this study challenge claims made by the gluten-free movement that gluten can cause inflammation or weight gain.