Introduction: Antibiotic treatments cause changes in gut microbiota. Dysbiosis of gut microbiota has been linked to metabolic diseases such as type 2 diabetes mellitus (T2DM). Objective: To evaluate whether changes in gut microbiota due to antibiotic treatment in patients colonized by H. pylori, could be related to improvements in carbohydrate metabolism.

Material and Method: A prospective case-control study were performed. Clinical data, carbohydrate metabolism, and microbiota composition in feces (determined by 16S rRNA gene (V3-V4) sequencing using the Illumina Miseq) before and 2 months after eradication treatment were analyzed.

Results: We studied 40 cases and 20 controls (60% women, respectively). Average age was 47.0 ± 2 vs. 43.6 ± 2.7 years old. 70% vs. 60% had family history of digestive disorders and 42.5% vs. 40% clinical history of gastrointestinal disease. After antibiotics, we found significant changes in gut microbiota profile at phylum, family, genus and species levels. The Chao and Shannon indices showed a decreased in bacterial richness and diversity in patients (pre and post H. pylori eradication) compared to controls. We observed an improvement in glucose homeostasis in cases 2 month after H. pylori eradication treatment, with decrease in HbA1c (p=0.014), 60’ (p=0.018) and 120’ (p=0.019) glucose post OGTT. Changes in Rikenellaceae, Butyricimonas, E. biforme, B. fragilis, and Megamonas were inversely associated with changes in glucose level and Hb1Ac in patients which got H. pylori eradication.

Conclusion: H. pylori eradication treatment causes alteration in human gut microbiota. The glucose homeostasis improvement found after antibiotic treatment was related to changes in microbial community, particularly in Megamonas and Butyricimonas genus, Rikenellaceae family and E. biforme and B. fragilis species. SCFA-producing and glucose remover bacterias could play an important role in these associations.


I. Cornejo-Pareja: None. G. Martin-Nuñez: None. M. Roca-Rodriguez: None. I. Moreno-Indias: None. L. Vinuela: None. L. Coin-Arangüez: None. I. Mancha-Doblas: None. F. Tinahones: None.

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