Conclusions Whole flaxseed , but not flaxseed oil and lignan extract , has significant effects on improving glycemic control .
Context The results of human clinical trials investigating the effects of flaxseed on glucose control and insulin sensitivity are inconsistent .
Objective The present study aim ed to systematic ally review and analyze r and omized controlled trials assessing the effects of flaxseed consumption on glycemic control .
Dietary modulation of the gut microbiota – a randomised controlled trial in obese postmenopausal women
The gut microbiota has been implicated in obesity and its progression towards metabolic disease . Dietary interventions that target the gut microbiota have been suggested to improve metabolic health . The aim of the present study was to investigate the effect of interventions with Lactobacillus paracasei F19 or flaxseed mucilage on the gut microbiota and metabolic risk markers in obesity . A total of fifty-eight obese postmenopausal women were r and omised to a single-blinded , parallel-group intervention of 6-week duration , with a daily intake of either L. paracasei F19 ( 9·4 × 1010 colony-forming units ) , flaxseed mucilage ( 10 g ) or placebo . Quantitative metagenomic analysis of faecal DNA was performed to identify the changes in the gut microbiota . Diet-induced changes in metabolic markers were explored using adjusted linear regression models . The intake of flaxseed mucilage over 6 weeks led to a reduction in serum C-peptide and insulin release during an oral glucose tolerance test ( P < 0·05 ) and improved insulin sensitivity measured by Matsuda index ( P < 0·05 ) . Comparison of gut microbiota composition at baseline and after 6 weeks of intervention with flaxseed mucilage  showed alterations in abundance of thirty-three metagenomic species ( P < 0·01 ) , including decreased relative abundance of eight Faecalibacterium species . These changes in the microbiota could not explain the effect of flaxseed mucilage on insulin sensitivity . The intake of L. paracasei F19 did not modulate metabolic markers compared with placebo . In conclusion , flaxseed mucilage  improves insulin sensitivity and alters the gut microbiota ; however , the improvement in insulin sensitivity was not mediated by the observed changes in relative abundance of bacterial species
Conclusions Whole flaxseed , but not flaxseed oil and lignan extract , has significant effects on improving glycemic control .
Context The results of human clinical trials investigating the effects of flaxseed on glucose control and insulin sensitivity are inconsistent .
Objective The present study aim ed to systematic ally review and analyze r and omized controlled trials assessing the effects of flaxseed consumption on glycemic control .