Excessive dietary ammonium markedly enhances progression of UPEC‐UTI as UPEC burden in mice experiencing NH4Cl‐acidosis is 2–3 orders of magnitude higher than normal‐infected controls (Figure 1a) and UPEC burden in NH4Cl‐A mice was comparable to Tlr4‐deficient HeJ mice that do not mount an effective innate immune response to urinary tract infection by gram‐negative bacteria (Haraoka et al., 1999; Ragnarsdottir & Svanborg, 2012; Shahin et al., 1987). Here, TLR4 is linked to bacterial urinary tract infection.