Effects of concurrent Helicobacter pylori infection and small intestinal bacterial overgrowth on the gut microbiota and metabolic profiles: A multi-omics study.

Neither Hp infection nor SIBO significantly altered alpha or beta diversity of the gut microbiota.

• 42 patients with gastrointestinal symptoms were recruited and divided into four groups based on Hp and SIBO status
• Group A: Hp+ SIBO+; Group B: Hp+ SIBO-; Group C: Hp- SIBO+; Group D: Hp- SIBO-
• Both alpha and beta diversity comparisons yielded P > 0.05 across groups
• Fecal samples were analyzed using metagenomic sequencing and untargeted metabolomic analysis

SIBO-positive groups showed significantly decreased abundance of short-chain fatty acid-producing bacteria, specifically Megamonas.

• Specific shifts in microbial abundance were observed despite no overall diversity changes
• Megamonas, a short-chain fatty acid-producing bacterium, was significantly decreased in SIBO+ groups (Groups A and C)
• Differential species screening was used to identify these specific abundance changes
• This finding suggests impaired short-chain fatty acid production in SIBO patients

The co-occurrence of Hp infection and SIBO (Group A) was associated with significant enrichment of inflammatory metabolites including prostaglandin derivatives.

• Untargeted metabolomic analysis identified inflammatory metabolite enrichment specific to Group A (Hp+ SIBO+)
• Prostaglandin derivatives were among the enriched inflammatory metabolites in Group A
• This pattern was not observed to the same degree in single-infection groups
• The synergistic effect suggests an additive enhancement of inflammatory response when both conditions co-occur

SIBO-positive groups exhibited disordered bile acid conjugates and nucleotide metabolism abnormalities.

• Chenodeoxycholylisoleucine was identified as a disordered bile acid conjugate in SIBO+ groups
• Nucleotide metabolism was also disrupted in SIBO+ groups (Groups A and C)
• These metabolic disturbances were identified through untargeted metabolomic analysis
• Disordered bile acid conjugation suggests disrupted bile acid transformation in SIBO patients

Hp-positive groups demonstrated abnormal lipid and carbohydrate metabolism pathways.

• Abnormal lipid metabolism pathways were identified in Hp+ groups (Groups A and B)
• Abnormal carbohydrate metabolism pathways were also observed in Hp+ groups
• These metabolic pathway alterations were distinct from those associated with SIBO
• Findings suggest Hp infection independently reshapes specific metabolic networks

Multi-omics integration revealed strong coupling between microbial structure and metabolic profiles.

• Procrustes analysis demonstrated significant coupling between gut microbiota and metabolic profiles (P < 0.05)
• Spearman correlation analysis was also used to evaluate microbiota-metabolite associations
• In Group A, Faecalibacterium and Hominenteromicrobium abundance were negatively correlated with bile acid levels
• The negative correlation between these bacteria and bile acid levels suggests impaired bile acid transformation in the Hp+ SIBO+ group

Co-occurrence of Hp infection and SIBO produces additive effects on gut ecological and metabolic disorders.

• The concurrent presence of Hp and SIBO (Group A) showed enhanced inflammatory response beyond either condition alone
• Disrupted bile acid circulation was identified as a key mechanism in the co-infection group
• The additive effects were proposed to explain aggravated clinical symptoms in patients with both conditions
• The study suggests interventions targeting microbiota-metabolite interactions, such as probiotics and bile acid modulators, as potential therapeutic strategies