Kluyveromyces marxianus fermenta tion improves tomato sensory profile, functional metabolites, lycopene bioaccessibility, and human fecal microbiota composition

Kluyveromyces marxianus is a traditional fermentation starter, but the effects of K. marxianus fermentation on tomato remain largely unknown. Here, K. marxianus was employed for tomato puree fermentation under sterile conditions. Sensory evaluation revealed that K. marxianus decreased the unpleasant flavor components in fermented tomato puree (FTP). GC–MS analysis demonstrated that K. marxianus fermentation improved the flavor and aroma, primarily due to increases in alcohols (48.84 %) and esters (43.31 %) and enrichment of aroma-associated metabolites in volatile organic compounds. Widely targeted metabolomics showed that the fermentation significantly increased 37 phenolic compounds, potentially enhancing the antioxidant effects of FTP. The contents of lycopene isomers including cis -lycopene significantly increased in FTP (179.52 μg/g). Notably, FTP showed enrichment of beneficial genera, including Akkermansia and Pediococcus , in fecal microbiota. Collectively, these results indicate that K. marxianus fermentation is a viable approach to improving the sensory profile and potential health benefits of fermented tomato.