# Rutgers: gut bacteria molecule N-MNA restores NAD and repairs the intestinal lining in mice and flies

- Published: 2026-11-14 08:00 UTC
- Section: Life & Health › Biology & biochemistry
- Tags: N-methylnicotinamide, NAD precursor, gut bacteria, intestinal epithelium repair, Preiss-Handler pathway, SIRT1, inflammatory bowel disease, probiotics, stem cell regeneration, Rutgers Health
- URL: https://realtech.media/news/rt-e8d2e2a701d07b67d7a30bc6_rutgers_gut_bacteria/

**Rutgers researchers found that the bacterial molecule N-MNA is converted to NAD and promotes intestinal stem cell regeneration in mice and flies; human cells were tested in culture.**

![Rutgers: gut bacteria molecule N-MNA restores NAD and repairs the intestinal lining in mice and flies](https://realtech.media/media/2026/11/b62363b887b6aae3.jpg)
*newswise.com*

Researchers at Rutgers Health reported in Science Advances that some commensal gut bacteria, including specific probiotic species, produce (amide-)N-methylnicotinamide (N-MNA), a precursor of the coenzyme NAD. The experiments used fruit flies, mice and human cells. According to the authors, N-MNA promotes regeneration of the intestinal epithelium. [1] The first author is Jiangmeng Han; the senior authors include Nan Gao and Xiaoyang Su.

NAD levels decline with age and are associated with chronic and inflammatory diseases. N-MNA is a structural isomer of methylnicotinamide, a product of nicotinamide breakdown. Unlike that metabolite, N-MNA can be converted back into NAD. [1]

## How N-MNA becomes NAD

Stable isotope tracing showed that N-MNA is rapidly taken up and incorporated into NAD reactions by intestinal epithelial cells and other cells of flies, mice and humans. [1] Genetic and pharmacological analyses suggest that the conversion goes through the Preiss-Handler pathway, independent of the salvage pathway. [1] In human colon cells, N-MNA supplied about 22% of NAD within 24 hours. It also became NAD in human neurons, liver cells and kidney cells. According to the authors, unlike known NAD precursors, N-MNA brings a methyl group into host cells. [1]

## Gut repair in animals and patient samples

Cell-type-specific ablation or overexpression of SIRT1, an NAD-consuming enzyme, in Drosophila, together with intestinal stem cell lineage tracing in mice, indicated that systemic N-MNA supplementation promotes stem cell regeneration and epithelial repair. [1] In mice with inflamed and damaged colons, untreated animals lost 20% of body weight and died, while animals injected with N-MNA lost 5% and recovered. In flies with damaged guts, seven-day survival rose from 43% to 78%.

The team also analysed stool samples from 54 patients with inflammatory bowel disease and 20 healthy volunteers. Patients with gut dysbiosis and inflammation had reduced stool N-MNA, and those with low N-MNA had significantly higher levels of gut inflammation markers. [1]

The work is preclinical. N-MNA was not tested as a treatment in patients with inflammatory bowel disease. The researchers also did not test whether probiotic strains that make it, including Lactobacilli, raise NAD in people. The human enzymes that process N-MNA have not yet been identified, and Gao's laboratory is mapping the bacterial genes that produce the molecule. Ching-On Wong, a senior author, said that this compound may be sufficient on its own, but that other, better compounds cannot be ruled out.

## Sources

1. [Science Advances](https://doi.org/10.1126/sciadv.aef2882)
2. [newswise.com](https://www.newswise.com/articles/a-microbe-made-molecule-linked-to-aging-reverses-gut-damage-in-mice-and-flies)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-e8d2e2a701d07b67d7a30bc6_rutgers_gut_bacteria/