When we hear about prebiotics, we mostly think of fermentable foods for our flora, which include polysaccharides (seeds, tubers, corn, and resistant starch) and inulin (leeks, garlic, banana, and asparagus). What doesn’t get much love are Arabinoxylans. Recent studies show that maybe we should pay more attention to this power food for our flora.
Arabinoxylans are mostly found in cereal grains which include rye, wheat, barley, oats sorghum, maize, millet, psyllium, flaxseed, pangola grass, bamboo shoot and rye grass. The highest content can be found in rye along with wheat, barley, oats, rice and sorghum (Fibre-Rich and Wholegrain Foods: Improving Quality)
Before the Paleo movement decides to burn me at the stake in suggesting that we NEED to consume the big no-no’s of cereal grains, especially those with gluten, I think we need to take a closer look.
In a recent study, Arabinoxylans were compared to inulin in rats. These rats were inoculated with the gut microbiota of humans and were given both long chain arabinoxylans and inulin. Both produced beneficial results on their host, by increasing production of acetate, butyrate, and mucin. Fantastic!
They were also able to hone in on which groups of the microbiota that were being stimulated by these prebiotics. Those included (Roseburia intestinalis, Eubacterium rectale, Anaerostipes caccae) and bifidobacteria (B. longum). These guys are like the Bill Russell’s and Mario Rivera’s of gut bacteria. They belong on everyone’s fantasy gut bacterial team.
Dr. BG goes into great depth on the benefits of Roseburia intestinalis here. In particular, Roseburia plays a major role in the gut and synergistically works with our other microbes.
All disease protection appears to correlate directly with Roseburia caecal population increases.
And from the study mentioned above, the Roseburia strain most likely were able to outcompete mucin degrading bacteria:
Prebiotic administration also resulted in lower caecal abundances of the mucin-degrading Akkermansia muciniphila and potentially more mucin production by the host. Both factors might explain the increased caecal mucin levels for LC-AX (threefold) and IN (sixfold).
Bifidobacteria is a staple in most soil based probiotics. And for good reason. From Wikipedia:
As an important organism involved in the maintenance of the human gastrointestinal tract, B. longum is commonly used as a probiotic in various dairy products.Its presence has been associated with many health benefits including improving lactose tolerance and preventing diarrhea, food allergies, and colonization by pathogens. Some strains of B. longum were demonstrated to have an antioxidative effect by inhibiting linoleic acid peroxidation, a process that results in the creation of lipid hydroperoxides that decompose into highly reactive radicals associated with aging and age-related diseases. Additionally, B. longum can scavenge free radicals, lowering a person’s chance of atherosclerosis and stroke. The ability of B. longum to remove cholesterol from its environment by incorporating cholesterol into its membrane is thought to lower the serum cholesterol level in humans. B. longum may also bind and suppress resorption of bile acids, which also lowers serum cholesterol levels as bile salt replacement requires utilization of cholesterol within the body.B. longum supplementation was shown to significantly suppress tumor volume and incidence, although the exact mechanism is not clear. Since high colonic pH is thought to promote colorectal cancer, it is postulated that B. longum can inhibit colorectal cancer by producing bile acid and cholesterol metabolites that lower the intestinal pH.
With all these benefits, why not just chow down on wheat bread and bamboo shoots. Number one we aren’t pandas. Two, gluten is a real problem and by consuming some of the foods with arabinoxylans can cause major issues for some of us. Those issues most likely stem from a poor flora. Once the gut has been fully healed of inflammation and a bountiful amount of good flora takes residence in your gut, then you can introduce these once harmful foods back into the diet. Until then, getting the benefits of arabinoxylans is as easy as adding oats and rice to our already nutrient dense diet.