Higher dietary fiber is associated with less risk of cardiovascular disease, diabetes, certain cancers and all cause mortality but what biological mechanisms can explain these findings? Hydrogen is produced along with short chain fatty acids in the colon from fiber fermentation. The numerous mechanisms of health benefits of SCFA's are well documented but the importance of hydrogen as a selective biological free radical scavenger was identified in 2007. Since then it has been used as a medical gas in Japan and China in medical emergencies such as stroke, heart attack, organ rejection and other situations of oxygen starvation and inflammation. Animal studies have shown hydrogen produced from fiber fermentation is protective in several circumstances of experimentally induced organ damage. The graph below shows breath hydrogen after drinking hydrogen water or 300 ml of milk by subjects with lactose intolerance. Around 15 g of lactose contained in 300 ml milk produced sustained increased H2 levels that rapidly diffuse through all body fluids and tissues as H2 is the smallest most permeable molecule known. Could it be that much of the beneficial health effects of fiber is due to H2 as well as short chain fatty acids and other nutrients produced by gut microbes.
Who would have thought milk would function as a pre-biotic in people with lactose intolerance?
As well as a selective anti-oxidant, hydrogen is a cell signaling molecule activating anti-inflammatory and stress protection pathways (figure below).
Below is the abstract of a 2017 review, click for link to original paper.