fiber
8 interactions related to fiber
probiotics + prebiotics
Prebiotics are non-digestible fibers (like inulin, FOS, GOS) that selectively feed beneficial bacteria; combining them with probiotic strains creates a 'synbiotic' that improves colonization, short-chain fatty acid production, and gut barrier function more effectively than either alone.
psyllium + metformin
Psyllium forms a viscous gel that can physically trap metformin in the gut and slow its absorption, potentially reducing peak plasma levels and blood-glucose control when both are taken simultaneously. Soluble fiber can also independently lower postprandial glucose, which may compound metformin's hypoglycemic effect.
psyllium + warfarin
Psyllium is a soluble fiber that forms a viscous gel in the gut, which can trap warfarin and slow or reduce its absorption when taken at the same time. Significant changes in fiber intake may also alter gut flora vitamin K production, indirectly destabilizing INR.
glucomannan + metformin
Glucomannan is a highly viscous soluble fiber that swells dramatically in the gut and can bind metformin, reducing its absorption when both are taken together. Glucomannan also has independent glucose-lowering effects that may compound metformin's action and increase the risk of hypoglycemia.
flax seeds + warfarin
Flax seeds are high in alpha-linolenic acid (an omega-3 fatty acid) that can mildly inhibit platelet aggregation, and their soluble fiber and lignans can slow warfarin absorption when taken at the same time. Combined, these effects can shift INR in either direction, with case-level reports of altered anticoagulation.
chia seeds + warfarin
Chia seeds are high in alpha-linolenic acid (an omega-3 fatty acid) and soluble fiber. Omega-3 intake at high doses may mildly inhibit platelet aggregation and could theoretically enhance warfarin's anticoagulant effect, while the soluble fiber may also blunt warfarin absorption when taken at the same time.
levothyroxine + fiber
Dietary and supplemental fiber can adsorb levothyroxine in the gut and reduce its bioavailability, leading to higher TSH and unstable dosing when fiber intake is high or variable. The effect has been demonstrated with high-fiber diets and pharmaceutical fiber supplements such as psyllium.
flaxseed + warfarin
Flaxseed contains alpha-linolenic acid that can mildly reduce platelet aggregation and may add to warfarin's bleeding risk, particularly at high supplemental doses. Flaxseed is also very high in soluble fiber, which can bind warfarin in the gut and erratically reduce its absorption.