BDNF and Anxiety: Animal studies have revealed that Lactobacillus and Bifidobacterium species alleviate anxiety-like behaviors and modulate neuronal functions, potentially enhancing memory-related neurotransmitters such as acetylcholine and glutamate, and increasing the expression of neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and synapsin [12, 13].