Inulin vs Allulose: which is worse?

What is Inulin?

Inulin is a naturally occurring prebiotic dietary fiber (fructan polysaccharide) found in chicory root, Jerusalem artichoke, garlic, onions, and bananas. Commercial inulin is extracted primarily from chicory root. It resists digestion in the small intestine and is fermented by beneficial gut bacteria in the colon, promoting growth of Bifidobacterium and Lactobacillus species.

What is Allulose?

Allulose (D-psicose) is a rare sugar monosaccharide naturally present in trace amounts in wheat, figs, raisins, and jackfruit. It has about 70% of sucrose's sweetness but provides only 0.4 kcal/g (about 10% of sucrose's calories) because it is absorbed but not metabolized. The FDA exempted allulose from the 'total sugars' declaration in 2019.

Documented risks

Inulin: Generally safe and beneficial. At doses above 15–20 g/day, inulin commonly causes bloating, gas, abdominal cramping, and diarrhea due to rapid fermentation in the colon. This is well documented in peer-reviewed research. It is contraindicated for people with fructan intolerance or irritable bowel syndrome following a low-FODMAP diet. At normal food fortification levels (3–8 g/serving), it is tolerated by most adults.

Allulose: Generally considered safe with a favorable glycemic profile. Human studies show that allulose does not raise blood glucose or insulin. GI effects (bloating, abdominal cramping, diarrhea) have been reported in dose-response studies above 0.4 g/kg body weight; a 2016 study in the journal Food & Chemical Toxicology established a no-observed-adverse-effect level (NOAEL) in humans. Compared to erythritol, no cardiovascular concerns have been raised in the literature.