# Arabinose, lactulose and polyols raised Salmonella Typhimurium loads over 100-fold in mice

- Published: 2026-11-05 01:08 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: Salmonella Typhimurium, low-digestible sugars, arabinose, lactulose, polyols, colonization resistance, gut microbiota, SPI-1, colitis in mice, Nature Communications
- URL: https://realtech.media/news/rt-99b681ec0cfa7a054ccb2257_arabinose_lactulose_and/

**In mice given two high doses of low-digestible sugars, Salmonella colonized the gut, spread to organs and caused colitis without antibiotic pretreatment.**

![Arabinose, lactulose and polyols raised Salmonella Typhimurium loads over 100-fold in mice](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/537be872b7a1f7b8.jpg)
*Rama, Wikimedia Commons, CC BY-SA 2.0 fr*

A study in Nature Communications reports that acute overconsumption of low-digestible sugars (LDSs) weakened colonization resistance against Salmonella enterica serovar Typhimurium (S.Tm) in mice [1]. The tested sugars were arabinose, lactulose and polyols, which are used as sugar substitutes. On day 1 after infection, mice given LDSs excreted more than 100 times more S.Tm in feces than PBS controls [1]. The experiments were done in mice, not in humans.

## Experimental design and infection course

C57BL/6 mice with a specified-pathogen-free microbiota received two oral gavages of 132 mg of a carbohydrate, one hour before and four hours after infection with 5 × 10^7 S.Tm [1]. The doses exceeded the typical daily intake of fermentable short-chain carbohydrates in mice on standard chow, 16–184 mg per day, assuming 3 g of food [1]. The LDSs were L- and D-arabinose, lactulose, erythritol, sorbitol and maltitol. Mice pretreated with 25 mg of streptomycin served as a comparison group.

Fecal S.Tm loads fell by day 2, then a second bloom followed. By days 3–4 the loads reached 10^(7–10)11 CFU/g of feces, comparable to streptomycin-pretreated mice [1]. S.Tm was also found in the liver, spleen and mesenteric lymph nodes. Fecal lipocalin, a marker of inflammation, was 10^(2–10)5 ng/g on days 2–4, and histopathology on day 4 showed colitis [1]. Inflammation was higher than in PBS controls but milder than in streptomycin-pretreated mice [1].

## Mechanism and virulence

The authors studied arabinose in more detail. Its rapid fermentation by the microbiota acidified the intestine, perturbed the microbial community, changed short-chain fatty acid levels and increased amino acid availability, which can support pathogen growth [1].

Arabinose intake was also associated with higher SPI-1 expression and a broader tissue tropism, including more translocation into Peyer's patches and ileal tissue and spread to the small intestine [1]. The authors report positive selection for invasive Salmonella [1]. Unlike after antibiotic perturbation, colonization in this model required both the SPI-1 and SPI-2 type III secretion systems, which links virulence to pathogen fitness [1]. According to the authors, dietary perturbations can both compromise colonization resistance and enhance pathogen virulence [1].

## Sources

1. [Nature Communications](https://doi.org/10.1038/s41467-026-78218-0)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-99b681ec0cfa7a054ccb2257_arabinose_lactulose_and/