Taisho Pharmaceutical Confirms Gut Health Benefits of Bifidobacterium G9-1 and Lactobacillus KS-13 in Cats

Taisho Pharmaceutical Co., Ltd. [Headquarters: Toshima-ku, Tokyo; President: Shigeru Uehara] (hereinafter "the Company") has revealed that continuous intake of Bifidobacterium bifidum G9-1 (Bifidobacterium G9-1) and Lactobacillus acidophilus KS-13 (Lactobacillus KS-13) alters the gut microbiota in cats, resulting in reduced intestinal putrefactive products and fecal odor. These results suggest that sustained intake of these two strains may improve feline gut health and contribute to overall well-being.

This research was presented at the 27th Annual Meeting of the Japanese Society of Pet Nutrition, held on July 12, 2026, where it received the Outstanding Presentation Award.

◇ Background

Probiotics such as lactic acid bacteria and bifidobacteria are defined as "live microorganisms which, when administered in adequate amounts, confer a health benefit on the host." They are known to help normalize gut environment and are expected to support health maintenance and disease prevention. While numerous studies on probiotics for human health have been reported, scientific evidence regarding their benefits for cat health remains limited.

Therefore, this study investigated the effects of administering Bifidobacterium G9-1 and Lactobacillus KS-13 as probiotics to healthy cats on their gut environment.

◇ Research Findings

【Finding 1: Bifidobacterium G9-1 and Lactobacillus KS-13 altered the gut microbiota in cats】

Healthy cats were given continuous daily intake of Bifidobacterium G9-1 and Lactobacillus KS-13 for 56 days, and changes in gut microbiota before and after intake were evaluated.

As a result, a statistically significant change in gut microbiota composition was observed after 56 days compared to baseline (Figure 1).

Figure 1. Changes in gut microbiota following intake of Bifidobacterium G9-1 and Lactobacillus KS-13

17 subjects; Weighted UniFrac distance; p = 0.005 (permutation ANOVA test).

(The similarity in bacterial types and proportions within each individual's gut microbiota is converted into a numerical distance, visualized as spatial relationships between individuals. Each point represents an individual cat; closer points indicate more similar gut microbiota compositions, while distant points indicate greater differences.)

【Finding 2: Bifidobacterium G9-1 and Lactobacillus KS-13 reduced intestinal putrefactive products and fecal odor】

Intestinal putrefactive products, associated with gut environment deterioration, are part of fecal odor components and are primarily produced by gut bacteria. Substances such as ammonia and p-cresol may enter the bloodstream and potentially cause adverse effects on various organs.

Measurements of putrefactive product concentrations in feces showed significant reductions in both ammonia and p-cresol (Figure 2). Additionally, fecal odor scores significantly decreased from day 14 through day 56, confirming sustained reduction in fecal odor (Figure 3).

Figure 2. Changes in intestinal putrefactive products following intake of Bifidobacterium G9-1 and Lactobacillus KS-13

(a) Ammonia concentration in feces, (b) p-Cresol concentration in feces

17 subjects; Mean ± Standard Error; *: p < 0.05 vs. pre-intake, Wilcoxon signed-rank test with Holm correction.

Figure 3. Changes in fecal odor following intake of Bifidobacterium G9-1 and Lactobacillus KS-13

17 subjects; Mean ± Standard Error; *: p < 0.05, **: p < 0.01, ***: p < 0.001 vs. pre-intake, Wilcoxon signed-rank test with Holm correction.

◇ Summary of Research Findings

This study confirmed that intake of Bifidobacterium G9-1 and Lactobacillus KS-13 alters the gut microbiota in cats, leading to reduced intestinal putrefactive products and fecal odor. These results suggest that sustained intake of these two strains may improve the feline gut environment and contribute to health maintenance.

The Company will continue advancing research on probiotics and gut microbiota to contribute to healthier and more fulfilling lives for people and their beloved pets.