Background: The house cricket (Acheta domesticus) has recently emerged as a promising source of novel probiotic bacteria and bioactive compounds, yet comprehensive systematic reviews of its gut microbiota isolation and characterization are lacking. This review provides a critical synthesis of isolation methodologies, characterization approaches, and functional properties of cricket-derived bacteria with translational potential for probiotic and pharmaceutical applications.

Methods: A systematic literature review was conducted covering studies on the isolation, cultivation, and characterization of gut microbiota from Acheta domesticus. Methodological approaches were critically evaluated, including sample collection and preparation, culture-dependent techniques, culture-independent metagenomic analyses, targeted functional group isolation, phenotypic and genotypic characterization, and functional and safety assessments. Data on microbial diversity, functional activities, and probiotic potential were systematically extracted and analyzed.

Results: The cricket gut microbiota is dominated by Proteobacteria (44%), Firmicutes (31.5%), and Bacteroidetes (24.25%) at the phylum level. Notable isolates include Lacticaseibacillus paracasei AL01, Pediococcus pentosaceus GL05, and cellulolytic Lactobacillus sp. FF02041. These strains exhibit diverse functional properties including uric acid clearance (90–100% of aerobic isolates), antifungal activity against Aspergillus flavus, exopolysaccharide (EPS) production with antioxidant (DPPH: 15.93% at 10 mg/mL; ABTS: 25.59% at 10 mg/mL) and α-amylase inhibitory (49.61% at 10 mg/mL) activities. Selected isolates meet probiotic criteria including gastric pH tolerance (>80% survival at pH 2.5–3.0 for 2 hours), bile salt tolerance (>70% survival at 0.3% oxgall), and favorable safety profiles (γ-hemolysis, absence of mucinolytic and gelatinase activities).

Conclusion: Acheta domesticus harbors functionally diverse bacteria with significant probiotic and pharmaceutical potential. The identification of LAB with anti-Aspergillus activity, cellulolytic capabilities, and EPS with dual antioxidant and α-amylase inhibitory properties represents novel discoveries. However, translational gaps remain including limited strain collections, absence of human clinical trial data, and incomplete mechanistic understanding. Standardized methodologies, expanded isolation campaigns, rigorous in vivo testing, and progression to human studies are essential to realize the translational potential of cricket-derived microbiota.