TNF and Anxiety: We also found positive nominal correlation of the metabolite with plasma TNFa (rspearman = 0.34, p = 0.043), microglial soma size (rspearman = 0.50, p = 0.026) and antibiotics-induced anxiety-like behaviour in the NSF (latency to first approach to centre; rspearman = 0.34, p = 0.030), and in the EPM (time spent in the open arms; rspearman = −0.39, p = 0.021).