To explore the relationship between gut microbiota alterations associated with bariatric surgery and the microbial profiles observed in neurological disorders. This review highlights how microbial shifts may influence Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, depression, and autism spectrum disorder, and discusses emerging therapeutic strategies targeting the gut-brain axis (GBA).

The gut microbiota exerts an immense influence on human physiology, and alterations in its composition can either ameliorate or exacerbate disease states. Thus, the concept of the GBA emerged to describe the relationship between the gastrointestinal tract and the central nervous system and to provide a possible explanation for neuroinflammation. Emerging evidence suggests that microbial shifts may modulate neurological disorders through the GBA, although whether the post-surgical influence on microbiota is beneficial or harmful remains unclear.

A literature search was conducted on PubMed using the key terms “neuroinflammation,” “gut-brain axis,” and “microbiota.” Relevant studies were synthesized to summarize the current understanding of these topics and to identify overlapping gut microbial profiles reported in both neurological disorders and bariatric surgery.

Certain microbes have been directly implicated in disease processes, for example, metabolites from Pseudomonas and Escherichia coli can influence amyloid plaque deposition, while Enterobacteriaceae have been associated with α-synuclein aggregation. Overall, neurological disorders are characterized by an increase in pro-inflammatory microbes and a reduction in anti-inflammatory microbes. Several of these microbial patterns overlap with those observed after bariatric surgery, although post-surgical microbiota tend to retain some beneficial anti-inflammatory microbes. Other interventions, including GLP-1 agonists, probiotics, and fecal microbiota transplants, show promising effects on the GBA.

Bariatric surgery significantly alters gut microbiota, influencing both anti-inflammatory and pathogenic microbes linked to neurological disorders. These findings highlight a triad among bariatric surgery, gut microbiota, and neurological health, underscoring the need for targeted interventions such as probiotics, GLP-1 agonists, or fecal microbiota transplants to optimize outcomes.