This post examines the potential link between gut bacteria, environmental contaminants like diethanolamine, and their effects on mental health, particularly depression. Several user comments suggest personal experiences with dietary changes (like fasting and ketogenic diets) affecting mood, highlighting the role of the microbiome in mental wellness. The discussion extends to the impact of substances like diethanolamine found in everyday products, raising concerns about their safety and possible connection to both physical and mental health issues. Additionally, the dialogue touches on the need for more rigorous consumer protection and better understanding of how environmental factors influence gut health and neurotransmitter production, specifically serotonin, in the context of conditions like Long Covid.