Fig. 3.

Chronic antibiotic administration and faecal microbiota transfer do not alter respiratory timing variability, or the prevalence of apnoeas and sighs in behaving rats during quiet rest.

Poincaré plots of breath-to-breath (BBn) and subsequent breath-to-breath (BBn + 1) interval of expiratory duration (T_e; a, c) and total breath duration (T_tot; b, d) for 200 consecutive breaths for VEH and ABX (a, b) and VEH-FMT and ABX-FMT rats (c, d). Group data for T_e short-term variability (SD1; e) and long-term variability (SD2; f) and T_tot SD1 (g) and SD2 (h) in VEH, ABX, VEH-FMT and ABX-FMT rats during normoxia. Representative respiratory flow traces (downward deflections represent inspiration) illustrating a spontaneous sigh followed by an apnoea (i), a spontaneous apnoea (j) and a spontaneous sigh (k). Group data of apnoea index (l), apnoea duration (m) and sigh frequency (n). VEH, autoclaved deionised water; ABX, antibiotic-treated; VEH-FMT, VEH followed by faecal microbiota transfer; ABX-FMT, antibiotic-treated followed by faecal microbiota transfer. Groups (e-h, l-n) are expressed as box and whisker plots (median, IQR and minimum to maximum values); n = 10 for all groups. Groups were statistically compared by one-way ANOVA or non-parametric Kruskal-Wallis with Dunn's post hoc, where appropriate. $ p < .05, VEH-FMT versus VEH, Dunn's post hoc test.