Regulation of resistant starch, non-starch polysaccharides, resistant oligosaccharides and lignin on the gut microbiota and association with their health benefits

In recent years, substantial attention has been paid to the use of dietary approaches to regulate the composition and metabolic activity of the gut microbiota. Dietary fibres (DFs), including resistant starch, non-starch polysaccharides, resistant oligosaccharides, and lignin, are known to have multifaceted beneficial effects on human health. This review discusses available studies on the regulative effects of resistant starch, non-starch polysaccharides, resistant oligosaccharides, and lignin on the gut microbiota, and the association with their health benefits. Firstly, a total of 89 studies are included in this review, comprising 71 animal studies, 9 human trials, and 9 <i>in vitro</i> experiments. Secondly, the health benefits of DFs are closely related to the overall modulation of the gut microbiota, by affecting microbial diversity, decreasing the ratio of <i>Firmicutes</i>/<i>Bacteroidetes</i>, and selectively enriching beneficial bacteria like <i>Akkermansia</i>, <i>Bifidobacteria</i>, and <i>Ruminococcus</i>. Thirdly, the populations of short-chain fatty acid (SCFA)-producing bacteria can be regulated by DFs, suggesting a potential role of SCFAs in health benefits. Additionally, the degradation mechanisms of DFs through polysaccharide utilization locus systems of the gut microbiota and the potential negative effects of excessive DF intake are briefly discussed. By providing a comprehensive overview, this review is expected to deepen the understanding of the regulation of the gut microbiota by DFs, which may inspire further studies for better DF application in health areas.