Lacto-N-triose II alleviates metabolic dysfunction-associated Steatotic liver disease via microbiota-dependent citrulline biosynthesis.

LNT II supplementation reduced body weight gain in HFD-induced MASLD mice.

• Mice were fed a high-fat diet (HFD) to induce MASLD and supplemented with Kluyveromyces lactis-derived LNT II.
• LNT II treatment resulted in reduced body weight gain compared to HFD control mice.
• LNT II was produced via probiotic Kluyveromyces lactis fermentation.

LNT II supplementation decreased blood lipid levels in HFD-induced MASLD mice.

• LNT II-treated mice showed decreased blood lipid levels relative to HFD controls.
• This finding was part of multi-parameter assessment of MASLD amelioration.
• The effect was attributed at least in part to microbiota-dependent metabolic changes.

LNT II supplementation attenuated inflammatory responses in HFD-induced MASLD mice.

• LNT II treatment resulted in attenuated inflammatory responses in MASLD mice.
• The anti-inflammatory effect was linked to enhanced gut microbiota-dependent glutamine-citrulline synthesis pathway.
• Citrulline, the key metabolite identified, is closely associated with reducing systemic inflammation.

LNT II supplementation improved hepatic steatosis in HFD-induced MASLD mice.

• Histological and biochemical evidence of improved hepatic steatosis was observed in LNT II-treated mice.
• Improvements were demonstrated as part of an integrated multi-omics analysis.
• The mechanism involved enhancement of the gut microbiota-dependent glutamine-citrulline synthesis pathway.

LNT II treatment enhanced the gut microbiota-dependent glutamine-citrulline synthesis pathway in MASLD mice.

• Integrated multi-omics analysis of MASLD mice revealed that LNT II treatment enhances the gut microbiota-dependent glutamine-citrulline synthesis pathway.
• The key metabolite identified was citrulline.
• This pathway alteration was dependent on changes in gut microbiota composition.

Citrulline is closely associated with improving insulin resistance, reducing systemic inflammation, and alleviating MASLD.

• Citrulline was identified as the key metabolite in the LNT II-mediated microbiota-dependent pathway.
• Citrulline was described as 'closely associated with improving insulin resistance, reducing systemic inflammation, and alleviating MASLD.'
• The relationship between citrulline and MASLD was examined both in the mouse model and in human cohort analyses.

Serum citrulline levels significantly correlate with the progression of MASLD in a human patient cohort.

• Population cohort analyses included mild-to-severe MASLD patients.
• A significant correlation between serum citrulline levels and the progression of MASLD was revealed.
• These findings reinforced citrulline's candidacy as a noninvasive diagnostic biomarker for MASLD.

Kluyveromyces lactis was used as a probiotic source to derive LNT II for supplementation studies.

• LNT II is described as 'an important member of the human milk oligosaccharides (HMOs)' with 'various prebiotic properties beyond infant nutrition.'
• The LNT II used in this study was derived from the probiotic yeast Kluyveromyces lactis.
• This represents a scalable production approach for an HMO with prebiotic properties.