biostudies-literatureYoun HYNational Research Foundation of Korea589-598https://www.ebi.ac.uk/biostudies/studies/S-EPMC9992467biostudies-literatureUnknown32(4)Kefir yeast, <i>Kluyveromyces marxianus</i>, has been evaluated for its potential probiotic properties-survivability, non-pathogenicity, and antioxidant and anti-microbial activities. However, host gut microbiota modulation of kefir yeasts remains unclear. Here, we compared kefir yeast strains <i>K</i>. <i>marxianus</i> A4 (Km A4) and <i>K. marxianus</i> A5 (Km A5) with <i>Saccharomyces boulardii</i> ATCC MYA-796 (Sb MYA-796) by investigating their adherence to colorectal adenocarcinoma (Caco-2) cells and gut microbiota modulation in BALB/c mice. The kefir yeast strains exhibited higher intestinal cell adhesion than Sb MYA-796 (<i>p</i> < 0.05). Bacteroidetes, Bacteroidales, and <i>Bacteroides</i> were more abundant in the 1 × 10⁸ CFU/mL of Km A4 treatment group than in the control group (<i>p</i> < 0.05). Moreover, 1 × 10⁸ CFU/mL of Km A5 increased Corynebacteriales and <i>Corynebacterium</i> compared to the 1 × 10⁸ CFU/mL of Km A4 treatment group (<i>p</i> < 0.01). The results showed that Km A4 and Km A5 had good Caco-2 cell adhesion ability and modulated gut microbiota upon short-term administration in healthy mice.<h4>Supplementary information</h4>The online version contains supplementary material available at 10.1007/s10068-023-01268-3.Food science and biotechnologyGut microbiota modulation via short-term administration of potential probiotic kefir yeast <i>Kluyveromyces marxianus</i> A4 and A5 in BALB/c mice.PMC99924672021R1A2C2006817Kim DHSeo KHYoun HYKim HKim HJJang YSfalseGut microbiota modulation via short-term administration of potential probiotic kefir yeast <i>Kluyveromyces marxianus</i> A4 and A5 in BALB/c mice.Kefir yeast, <i>Kluyveromyces marxianus</i>, has been evaluated for its potential probiotic properties-survivability, non-pathogenicity, and antioxidant and anti-microbial activities. However, host gut microbiota modulation of kefir yeasts remains unclear. Here, we compared kefir yeast strains <i>K</i>. <i>marxianus</i> A4 (Km A4) and <i>K. marxianus</i> A5 (Km A5) with <i>Saccharomyces boulardii</i> ATCC MYA-796 (Sb MYA-796) by investigating their adherence to colorectal adenocarcinoma (Caco-2) cells and gut microbiota modulation in BALB/c mice. The kefir yeast strains exhibited higher intestinal cell adhesion than Sb MYA-796 (<i>p</i> < 0.05). Bacteroidetes, Bacteroidales, and <i>Bacteroides</i> were more abundant in the 1 × 10⁸ CFU/mL of Km A4 treatment group than in the control group (<i>p</i> < 0.05). Moreover, 1 × 10⁸ CFU/mL of Km A5 increased Corynebacteriales and <i>Corynebacterium</i> compared to the 1 × 10⁸ CFU/mL of Km A4 treatment group (<i>p</i> < 0.01). The results showed that Km A4 and Km A5 had good Caco-2 cell adhesion ability and modulated gut microbiota upon short-term administration in healthy mice.<h4>Supplementary information</h4>The online version contains supplementary material available at 10.1007/s10068-023-01268-3.2023-01-01T00:00:00Z2023 Mar2025-04-18T20:55:57.389Z2025-04-07T08:59:25.363ZS-EPMC99924673691133410.1007/s10068-023-01268-3