D-allulose alleviates DSS-induced colitis via regulating gut microbiota and bile acid metabolism

D-Allulose and Ulcerative Colitis

D-allulose is best known as a low-calorie sweetener. This study from Food Research International tested whether it also protects the gut, using a mouse model of ulcerative colitis.

The researchers gave mice with DSS-induced colitis daily doses of allulose at 125, 250 and 500 mg/kg/day. Colitis symptoms — body weight loss, colon shortening, diarrhea, mucosal injury — all improved across the three dose groups.

The mechanism appears to run through gut bacteria and bile acids. Allulose shifted bile acid metabolism toward the secondary bile acids DCA and LCA, which act through the TGR5-PKA-NF-κB pathway to dampen inflammation.

Why This Matters for Manufacturers

Two things worth taking from this for anyone formulating with allulose.

First, the evidence keeps building that allulose is not an inert sweetener. It has biological effects beyond sweetness — this study adds gut anti-inflammatory activity to the list.

Second, it speaks to a question consumers actually ask: will a low-digestible sweetener upset my stomach? In this model the answer points the other way. Allulose did not harm the colonic ecosystem; it reduced inflammation in it.

That is relevant to digestive-tolerance positioning and to gut-friendly concepts in yogurt, drinks and bars.

A Quick Refresher on Allulose

Allulose (D-psicose) is a C-3 epimer of fructose — about 70% as sweet as sucrose, but with roughly 0.4 kcal per gram and no meaningful glycemic response. It shows up in keto, low-sugar and diabetic-friendly products.

What is less well known is that a decade of research has turned up physiological functions beyond calorie reduction:

• Lowering postprandial blood glucose (α-glucosidase inhibition, hepatic glucose uptake)
• Stimulating GLP-1 from intestinal L-cells
• Influencing fat metabolism
• Anti-inflammatory and antioxidant activity

The gut sits at the center of all of this. Allulose reaches the colon mostly undigested, so it meets the microbiome directly.

How the Study Was Run

DSS colitis is the standard preclinical model for ulcerative colitis. DSS in drinking water damages the colonic epithelium and produces the classic IBD symptoms: weight loss, diarrhea, bleeding, mucosal inflammation.

Mice were divided into groups receiving allulose at 125, 250 or 500 mg/kg/day during DSS treatment, with a DSS-only control.

The team tracked clinical symptoms, tissue damage, intestinal barrier proteins (tight junctions, mucins), immune cell infiltration (neutrophils, macrophages), inflammatory cytokines, bile acid metabolomics, and gut microbiota composition.

Key Findings

Colitis Symptoms Improved Across All Three Doses

Body weight loss and colon shortening — the two most reliable severity markers in this model — were both attenuated. Diarrhea and mucosal injury improved too.

The Intestinal Barrier Recovered

Colitis causes a "leaky gut": loss of tight junction proteins like ZO-1, occludin and claudins that seal the intestinal lining. Allulose restored these proteins and mucins. A tighter barrier means fewer bacterial products reach the bloodstream, which means less inflammation.

Inflammation Fell at the Cellular Level

Neutrophil and macrophage infiltration dropped, and proinflammatory cytokines were downregulated. The anti-inflammatory effect was active, not just "less tissue damage."

The Bile Acid Pathway Looks Central

The standout result came from the metabolomics. Allulose raised production of the secondary bile acids DCA and LCA, which signal through TGR5-PKA and suppress NF-κB-driven inflammation.

In plain terms:

Allulose (reaches colon undigested)
  → gut microbes convert primary bile acids to secondary ones
  → DCA and LCA activate TGR5
  → TGR5-PKA signaling blocks NF-κB
  → fewer inflammatory cytokines
  → less colitis

What This Means for Formulators

Application	Implication
Digestive-tolerance claims	Supports "gut-friendly" positioning
Prebiotic potential	Allulose is metabolized by gut bacteria and changes their output
Yogurt / dairy	Fits probiotic positioning
Functional foods	Directional support for inflammation-modulating concepts

One caution: this is an animal model. There is no human clinical evidence for allulose in IBD yet, and nobody should make a "gut health" or "anti-inflammatory" claim from this study alone. Treat it as mechanistic, directional evidence.

Allulose and Digestive Tolerance

Consumers often worry that low-digestible sweeteners cause gas and bloating — sorbitol and erythritol are the usual culprits. Allulose is partially absorbed in the small intestine; the rest is fermented in the colon. Human trials generally report good tolerance at moderate doses. This study adds animal data suggesting allulose interacts with the colonic ecosystem in a beneficial way rather than a disruptive one.

Frequently Asked Questions

Q: Does allulose cause digestive problems? At moderate doses, human studies generally show good tolerance; GI symptoms are mostly reported at high doses (30g+ in sensitive people). This mouse study found no harm and found protective effects in a colitis model.

Q: Can allulose be called a prebiotic? Not in a regulatory sense. This study shows allulose modulates gut bacteria and boosts beneficial secondary bile acids, but prebiotic classification needs defined human evidence and regulatory criteria.

Q: Does this study apply to humans with IBD? Only directionally. DSS colitis shares features with human ulcerative colitis, but human clinical trials are needed before any therapeutic claim is warranted.

Wrap-Up

A rare sugar once written off as inert turns out to reduce intestinal inflammation through a defined gut-microbiota–bile-acid–host pathway. For the industry, that supports digestive-tolerance and gut-health research lines — while the absence of human data keeps those lines directional for now.

Read the full paper: Food Research International | DOI: 10.1016/j.foodres.2025.117923