Posted by 
Immune cells in the brain-microglia become chronically inflamed with age. In this state, they produce chemicals that impair cognitive and motor function that make memory fades and other brain functions decline. According to a new study from the University of Illinois, dietary fibre may delay the inflammation. Dietary fiber promotes the growth of good bacteria in the gut. When these bacteria digest fiber, they produce short-chain-fatty-acids (SCFAs), including butyrate, as byproducts.
Butyrate have anti-inflammatory properties on microglia and improve memory in mice when administered pharmacologically. The new study reveals, in old mice, that butyrate inhibits production of damaging chemicals by inflamed microglia. One of those chemicals is interleukin-1, which has been associated with Alzheimer’s disease in humans. Diet has a major influence on the composition and function of microbes in the gut, diets high in fiber benefit good microbes, while diets high in fat and protein can have a negative influence on microbial composition and function.
Researchers fed low- and high-fiber diets to groups of young and old mice, then measured the levels of butyrate and other SCFAs in the blood, as well as inflammatory chemicals in the intestine. The high-fiber diet elevated butyrate and other SCFAs in the blood both for young and old mice. When old mice consumed the high-fiber diet, their intestinal inflammation was reduced dramatically, showing no difference between the age groups.
Dietary fiber can really manipulate the inflammatory environment in the gut. Researchers examined unique genes in microglia and found the high-fiber diet reduced the inflammatory profile in aged animals. Not getting enough fiber could have negative consequences for things you don’t even think about, such as connections to brain health and inflammation in general.