IL6 and major depressive disorder: Moreover, probiotics also help attenuate neuroinflammation by regulating cytokine production and reducing proinflammatory markers (IL-6 and TNF-α), which are increased in “patients suffering from depression and anxiety.” This is also a key mechanism in strengthening gut barrier integrity, preventing systemic inflammation, and immune activation in the setting of increased intestinal permeability (leaky gut), which is often associated with psychiatric disorders.