This cereal thrives in harsh, Northern soils from which it gains a distinctive rich flavour and warm aromes. Compared to other cereals, rye is a good source of vitamin B3 (niacin), B9 (folate), K and E. One study showed that sourdough fermentation of (whole) rye bread triggers a better insulin response than refined flours and bread-making techniques. This grain has a lot of dietary fiber (op to 14.6% of its mass) and it is source of fructooligosaccharides and arabinoxylans, prebiotic fibers that benefit the gut microbiome. In fact, studies on Scandinavians consuming rye bread indicates that it can increase levels of Firmicutes bacteria which are particularly good at breaking down dietary fiber, and an increase in butyrate production, an anti-inflammatory short-chain fatty acid that supports the integrity of the gut lining. Furthermore, wholemeal rye has also been shown to improve bowel function and lower the risk of colon cancer linked to transit time and frequency.