Targeting the Human Gut Microbiota-Between Conventional Therapy and Precision Genetic Engineering.

Area of Science:

• Microbiome research
• Gut-brain axis
• Metabolic and immune system interactions

Background:

• The gut microbiota plays a crucial role in maintaining epithelial barrier integrity, producing metabolites, transforming bile acids, and regulating immune responses.
• It influences communication between the gut and distant organs, impacting various health conditions.
• Microbiome alterations are linked to metabolic, gastrointestinal, hepatic, cancer, and neuroimmune disorders.

Purpose of the Study:

• To review and synthesize evidence on the gut microbiota's involvement in diverse health conditions.
• To critically evaluate conventional and novel microbiota-targeted therapeutic strategies.
• To identify challenges and future directions for microbiome research and therapeutic development.

Main Methods:

• Structured narrative review of existing literature.
• Synthesis of evidence across multiple disease areas including metabolic syndrome, inflammatory bowel disease, obesity, type 2 diabetes, hypertension, colorectal cancer, Parkinson's disease, and autism spectrum disorder.
• Analysis of conventional and engineered microbial therapeutic approaches.

Main Results:

• Microbiome findings are biologically plausible but heterogeneous and context-dependent, influenced by diet, host genetics, and methodology.
• Conventional therapies (diet, prebiotics, probiotics, FMT) have broad, host-specific effects, with FMT primarily established for recurrent *Clostridioides difficile* infection.
• Engineered microbial therapeutics offer precision but are largely preclinical.

Conclusions:

• Microbial alterations should be viewed as context-dependent signals rather than universal causal markers.
• Current microbiota-targeted strategies have limitations in specificity and mechanistic clarity.
• Advancement requires robust human trials, standardized methods, mechanistic validation, safety monitoring, and transparent reporting for engineered microbial therapeutics.