Fig. 1

The continuous feeding of antibiotics (ABX) cocktail depletes majority of gut microbiota without affecting the behaviorally expressed thermal and mechanical sensory sensitivity in naïve mice. A Time course of the water intake in animals with SPF- and ABX-treatment. Two-way ANOVA with Sidak multiple comparison test **p < 0.01 (n = 3 in each group). B Representative images and statistical summary of the cecum from SPF and ABX-treated mice. The enlarged cecum and dark cecal content were shown in ABX-treated mice. Unpaired t-test **p < 0.01 (n = 6 in each group). C, D Representative images (C) and statistical summary (D) of colony-formation units (CFUs) of the fecal microbiota plated on TSA media. CFUs were reduced at day 7 and remained low at day 14 and 21 following ABX treatment. Two-way ANOVA with Sidak multiple comparison test, **p < 0.01 versus SPF (n = 6 in each group). E Effect of ABX treatment on the stool DNA concentration. One-way ANOVA with Dunnett multiple comparison test **p < 0.01 (n = 2–3). F Stacked bar-chart plot of the fecal microbiota composition of SPF and ABX-treated mice at phylum level. G The Principal Component Analysis of gut microbiota composition of SPF and ABX-treated mice (ABX: n = 4; SFP: n = 5). H 16S rRNA sequencing of fecal microbiota showing that the α-diversity of the microbiota was reduced in ABX-treated mice, compared to SPF mice. Unpaired t-test **p < 0.01(ABX: n = 4; SPF: n = 5). I–K ABX treatment did not alter the thermal (I) and mechanical sensory sensitivity (J) and capsaicin-induced licking (K) behavior. Unpaired t-test (n = 5 in each group). L, M 5-HT concentration in the spinal (L) and serum (M) of the SPF and ABX-treated mice. Unpaired t-test (L n = 8; M n = 5)