Kidney Week

Abstract: FR-OR128

Altered Gut Microbial Fermentation and Colonization with Methanobrevibacter smithii in Renal Transplant Recipients

Session Information

• Transplantation: Basic Research
  November 08, 2019 | Location: 150, Walter E. Washington Convention Center
  Abstract Time: 05:54 PM - 06:06 PM

Category: Transplantation

• 1901 Transplantation: Basic

Authors

• Knobbe, Tim J., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Tim J. Knobbe

• Douwes, Rianne M., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Rianne M. Douwes,

• Kremer, Daan, University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Daan Kremer,

• Swarte, J.c., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

J.c. Swarte,

• Eisenga, Michele F., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Michele F. Eisenga,

• Gomes Neto, Antonio Wouter, University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Antonio Wouter Gomes Neto,

• van Londen, Marco, University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Marco van Londen,

• Blokzijl, H., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

H. Blokzijl,

• Harmsen, Hermie, University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Hermie Harmsen,

• Nolte, Ilja M., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Ilja M. Nolte,

• Bakker, Stephan J.L., University Medical Center Groningen, Groningen, The Netherlands, Groningen, Netherlands

Stephan J.L. Bakker,

Background

The gut microbiota of kidney transplant recipients (RTR) differs from that of healthy controls (HC). This may have consequences for gut microbial fermentation. Breath hydrogen (H₂) and methane (CH₄) concentrations are markers of fermentation in the gut, of which CH₄ is mainly produced by Methanobrevibacter smithii (M. smithii). We aimed to investigate (1) whether breath H₂ and CH₄ concentrations differs between RTR and HC, (2) whether the presence of M. smithii in faeces differs between RTR and HC and (3) whether presence of M. smithii is related to breath H₂ and CH₄.

Methods

All study subjects participated in the TransplantLines biobank cohort study. Organ donors served as HC. Breath H₂ and CH₄ concentrations were analysed using solid state-sensor gas-chromatography. Presence of M. smithii in faeces was determined with real-time PCR.

Results

A total of 152 RTR and 77 HC were included. Breath H₂ concentrations of RTR were not significantly different from HC (median [IQR] 11.3 [4.0-30.0] ppm vs. 10.5 [4.5-28.3] ppm, p=0.92). However, RTR had significantly lower breath CH₄ concentrations compared to HC (7.5 [3.9-10.6] ppm vs. 16.0 [8.0-45.5] ppm, p<0.001). In addition, M. smithii was found less frequently in RTR compared to HC (86.4% vs. 28.6%, p<0.001). In absence of M. smithii, there was a significant positive correlation between breath H₂ and CH₄ (r = 0.88; p<0.001). There was no correlation if M. smithii was present (r = 0.09; p=0.50).

Conclusion

Breath CH₄ concentrations and the prevalence of M. smithii in faeces were significantly lower in RTR compared to HC, which indicates RTR have altered microbiota and altered gut microbial fermentation. In absence of M. smithii, CH₄ is highly dependent on H₂ production, while this is not the case in the presence of M. smithii. These findings provide novel insight in the alterations of gut microbiota secondary to renal transplantation and the use of immunosuppressants.

Funding

• Commercial Support –