Study · Journal of the science of food and agriculture · 2025Abstract only

Sodium alginate, body fat and gut bacteria in rats

What it found

In rats, sodium alginate reduced body fat and blood triglycerides and changed gut bacteria, with effects that differed by sex and by the alginate's thickness (viscosity).

What they found

Animal and lab studies

Body fat

Both low-viscosity high-dose and high-viscosity sodium alginate significantly reduced body fat in the rats.

Blood triglycerides

Low-viscosity low-dose, low-viscosity high-dose and high-viscosity sodium alginate all decreased serum triglyceride levels and increased serum total bile acid levels.

Gut acids

Sodium alginate raised the levels of acetic and butyric acids in the rats' feces and changed the fecal bile acid profile, promoting excretion of 23-nordeoxycholic acid and increasing 3β-ursodeoxycholic acid.

Gut bacteria

Low-viscosity high-dose sodium alginate increased the relative abundance of Akkermansia and Bacteroides, while all three treatments reduced the abundance of Flavonifractor.

Sex differences

In female rats, 23-nordeoxycholic acid levels were positively correlated with Flavonifractor abundance; in male rats, 3β-ursodeoxycholic acid levels were positively correlated with Bacteroides abundance.

What the authors conclude

“Our study suggests that SA regulates lipid metabolism by modulating the gut microbiota, which in turn affects the profiles of short-chain fatty acids and bile acids.”
Chen Z, Ni M, Wang X, et al, 2025

Also in their conclusions

  • They suggest that sodium alginate regulates lipid metabolism by modulating the gut microbiota, which in turn affects the profiles of short-chain fatty acids and bile acids.
  • They say these effects vary by sex and viscosity, emphasizing the importance of precision in future nutritional interventions.

How it was done

Sodium alginate is a dietary fiber known to affect fat metabolism and gut bacteria, but the authors say its long-term effects of viscosity and dose, and differences between males and females, are not well studied.

They gave 120 male and female Sprague-Dawley rats sodium alginate of different viscosities and doses for 90 days, then measured body fat, blood fats, bile acids, fecal short-chain fatty acids and gut bacteria.

What it can’t tell you

  • We summarised it from the abstract only.
  • These are rat studies. They can't show what happens in people.
  • The study used specific doses and viscosities of sodium alginate, so the results may not apply to other amounts or types.

The paper

Title
The sex-specific effects of sodium alginate with varying viscosities on lipid metabolism and gut microbiota in rats
Type
Study
Evidence
Animals and lab studies
Summarised from
Abstract only
Cite
Chen Z, Ni M, Wang X, et al (2025). The sex-specific effects of sodium alginate with varying viscosities on lipid metabolism and gut microbiota in rats. Journal of the science of food and agriculture. doi:10.1002/jsfa.70018PubMed 40600413DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error