In recent years, growing interest has emerged in the use of psychobiotics and adaptogens for regulating stress and anxiety. However, it is essential to assess their effectiveness as treatment alternatives, particularly given the limitations of conventional approaches, such as adverse effects of pharmacological therapies and the limited remission rates associated with psychotherapy alone. This systematic review primarily aims to assess how effective psychobiotics and adaptogens are in alleviating stress- and anxiety-related psychophysiological symptoms. A secondary aim is to identify specific bacterial strains and herbal compounds most consistently linked to beneficial outcomes. An extensive search was conducted in PubMed, Scopus, ScienceDirect, and Google Scholar using the terms ((adaptogens) OR (psychobiotics)) AND (stress), resulting in 23 selected articles. The findings suggest that both psychobiotics and adaptogens show promise in reducing stress- and anxiety-related symptoms. Bifidobacterium longum and Lactobacillus rhamnosus were frequently associated with improved gut–brain axis regulation, while Withania somnifera and Rhodiola rosea demonstrated physiological benefits through cortisol reduction and stress adaptation. Although results are encouraging, further research is needed to confirm long-term efficacy and clarify the specific mechanisms and compounds responsible for these effects.