Figure 5

Model of E. coli glucose processing effects on C. elegans. Glucose is processed/metabolized within the E. coli to produce AGEs. Carnosine supplementation abrogates this formation. Consumption of the glucose-fed bacteria with successive digestion and absorption leads to C. elegans transcriptional changes. High AGEs from the diet suppress gst-4 and glod-4; two genes which function to prevent reactive oxidants such as glyoxal and methylglyoxal from nonenzymatically binding with proteins and forming more AGEs. Thus, the inhibition of gst-4 and glod-4 cause a perpetuating oxidative glycation cycle, further limiting C. elegans ability to respond to AGEs/oxidants.