Ramadan fasting–induced modulation of beneficial and pathobiont gut bacteria in a healthy Iranian population

Ramadan fasting induces dietary and metabolic changes that may alter gut microbiota, but species-level effects are not well studied in Middle Eastern populations. Fecal samples were collected from 30 healthy fasting and 30 non-fasting adults in Shiraz, Iran. Species-level bacterial abundance was quantified using culture-based isolation and SYBR Green qRT-PCR with universal and species-specific primers. Beneficial bacteria—including Bacteroides vulgatus (Ab.352 TH, NCBI PX796484), Bacteroides ovatus (Ab.353 TH, NCBI PX796487), and Odoribacter splanchnicus (Ab.354 TH, NCBI PX796490)—were significantly increased in fasting individuals, while pathobionts such as Prevotella stercorea (Ab.355 TH, NCBI PX796493), Alistipes putredinis (Ab.356 TH, NCBI PX796496), Collinsella aerofaciens (Ab.357 TH, NCBI PX796499), and Enterobacter cloacae (Ab.358 TH, NCBI PX796500) were reduced. Ramadan fasting promotes a gut microbiota enriched in SCFA-producing beneficial bacteria and depleted of inflammation-associated pathobionts, suggesting species-specific microbial adaptations that may enhance gastrointestinal, immunological, and systemic health. Workflow and key findings of the study investigating Ramadan fasting–induced modulation of gut microbiota in healthy Iranian adults. Fecal samples were collected from 30 fasting and 30 non-fasting individuals in Shiraz. Target bacterial species were isolated and quantified using DNA extraction and qRT-PCR. Ramadan fasting led to enrichment of beneficial bacteria ( Bacteroides vulgatus, Bacteroides ovatus, Odoribacter splanchnicus ) and reduction of pathobionts ( Prevotella stercorea, Alistipes putredinis, Collinsella aerofaciens, Enterobacter cloacae ), highlighting species-specific microbial adaptations with potential benefits for gut, immune, and systemic health.