In line with previous findings in germ-free mice, antibiotics-treated mice colonized with R. gnavus exhibited lower insulin sensitivity and impaired glucose tolerance, and these insulin-desensitizing effects of R. gnavus were partially abrogated by EPPTB treatment (p < 0.05 in all cases, Fig. 7A–C), indicating inhibition of TAAR1 alleviated R. gnavus-induced insulin resistance. Here, TAAR1 is linked to Impaired glucose tolerance.