Organ transplantation is a life-saving treatment for patients with end-stage disease, but survival rates after transplantation vary considerably. There is now increasing evidence that the gut microbiome is linked to the survival of patients undergoing hematopoietic cell transplant, yet little is known about the role of the gut microbiome in solid organ transplantation. We analyzed 1370 fecal samples from 415 liver and 672 renal transplant recipients using shotgun metagenomic sequencing to assess microbial taxonomy, metabolic pathways, antibiotic resistance genes, and virulence factors. To quantify taxonomic and metabolic dysbiosis, we also analyzed 1183 age-, sex-, and body mass index–matched controls from the same population. In addition, a subset of 78 renal transplant recipients was followed longitudinally from pretransplantation to 24 months after transplantation. Our data showed that both liver and kidney transplant recipients suffered from gut dysbiosis, including lower microbial diversity, increased abundance of unhealthy microbial species, decreased abundance of important metabolic pathways, and increased prevalence and diversity of antibiotic resistance genes and virulence factors. These changes were found to persist up to 20 years after transplantation. Last, we demonstrated that the use of immunosuppressive drugs was associated with the observed dysbiosis and that the extent of dysbiosis was associated with increased mortality after transplantation. This study represents a step toward potential microbiome-targeted interventions that might influence the outcomes of recipients of solid organ transplantation.

Fatigue and impaired health-related quality of life (HRQoL) are common among kidney transplant recipients (KTR). We hypothesized that both may partially be attributable to poor sleep. Cross-sectional and longitudinal data of KTR enrolled in the TransplantLines Biobank and Cohort Study were used. Sleep quality was assessed using the Pittsburgh Sleep Quality Index questionnaire. Individual strength (i.e. a composite of fatigue, concentration, motivation and physical activity), societal participation and HRQoL were assessed using validated questionnaires. We included 872 KTR (39% female, age 56 ± 13 years) and 335 healthy controls. In total, 33% of male KTR and 49% of female KTR reported poor sleep quality, which was higher compared with male and female healthy controls (19% and 28%, respectively, P < .001 for both). In logistic regression analyses, female sex, anxiety, active smoking, low protein intake, physically inactive lifestyle, low plasma magnesium concentration, using calcineurin inhibitors, not using mTOR inhibitors and using benzodiazepine agonists were associated with poor sleep quality. In adjusted linear regression analyses, poor sleep was strongly and independently associated with lower individual strength [standardized β (st.β) = 0.59, 95% confidence interval (CI) 0.45 to 0.74, P < .001], poorer societal participation (frequency: st.β = −0.17, 95% CI −0.32 to −0.01, P = .04; restrictions: st.β = −0.36, 95% CI −0.51 to −0.21, P < .001; satisfaction: st.β = −0.44, 95% CI −0.59 to −0.28, P < .001) and lower HRQoL (physical: st.β = −0.53, 95% CI −0.68 to −0.38, P < .001; mental: st.β = −0.64, 95% CI −0.78 to −0.50, P < .001). The associations with poorer societal participation and lower HRQoL were strongly mediated by individual strength (P < .001 for all), yet the suggested direct effects of poor sleep quality on HRQoL remained significant (P_physical = .03, P_mental = .002). Longitudinal data of 292 KTR showed that sleep quality improves after kidney transplantation in males (P < .001), but not in females (P = .9). Poor sleep quality is common among KTR, and may be a potential target to improve fatigue, societal participation and HRQoL among KTR.

Kidney transplant recipients (KTR) have impaired health-related quality of life (HRQoL) and suffer from intestinal dysbiosis. Increasing evidence shows that gut health and HRQoL are tightly related in the general population. Here, we investigate the association between the gut microbiome and HRQoL in KTR, using metagenomic sequencing data from fecal samples collected from 507 KTR. Multiple bacterial species are associated with lower HRQoL, many of which have previously been associated with adverse health conditions. Gut microbiome distance to the general population is highest among KTR with an impaired physical HRQoL (R = −0.20, P = 2.3 × 10⁻⁶⁵) and mental HRQoL (R = −0.14, P = 1.3 × 10⁻³). Physical and mental HRQoL explain a significant part of variance in the gut microbiome (R² = 0.58%, FDR = 5.43 × 10⁻⁴ and R² = 0.37%, FDR = 1.38 × 10⁻³, respectively). Additionally, multiple metabolic and neuroactive pathways (gut brain modules) are associated with lower HRQoL. While the observational design of our study does not allow us to analyze causality, we provide a comprehensive overview of the associations between the gut microbiome and HRQoL while controlling for confounders.

Vitamin K deficiency is common among kidney transplant recipients (KTRs) and likely contributes to progressive vascular calcification and stiffness. In this single-center, randomized, double-blind, placebo-controlled trial, we aimed to investigate the effects of vitamin K supplementation on the primary end point, serum calcification propensity (calciprotein particle maturation time, T50), and secondary end points arterial stiffness (pulse wave velocity [PWV]) and vitamin K status in 40 vitamin K-deficient KTRs (plasma dephosphorylated uncarboxylated matrix Gla protein [dp-ucMGP] ≥500 pmol/L). Participants (35% female; age, 57 ± 13 years) were randomized 1:1 to vitamin K2 (menaquinone-7, 360 μg/day) or placebo for 12 weeks. Vitamin K supplementation had no effect on calcification propensity (change in T50 vs baseline +2.3 ± 27.4 minutes) compared with placebo (+0.8 ± 34.4 minutes; P_{between group} = .88) but prevented progression of PWV (change vs baseline -0.06 ± 0.26 m/s) compared with placebo (+0.27 ± 0.43 m/s; P_{between group} = .010). Vitamin K supplementation strongly improved vitamin K status (change in dp-ucMGP vs baseline -385 [-631 to -269] pmol/L) compared with placebo (+39 [-188 to +183] pmol/L; P_{between group} < .001), although most patients remained vitamin K-deficient. In conclusion, vitamin K supplementation did not alter serum calcification propensity but prevented progression of arterial stiffness, suggesting that vitamin K has vascular effects independent of calciprotein particles. These results set the stage for longer-term intervention studies with vitamin K supplementation in KTRs. TRIAL REGISTRY: EU Clinical Trials Register (EudraCT Number: 2019-004906-88) and the Dutch Trial Register (NTR number: NL7687).

Robust evidence for interventions to improve health-related quality of life (HRQoL) in people who receive a kidney transplant is scarce. We aimed to assess the effects of a lifestyle intervention in this context. We conducted a multicentre, open-label, parallel-group, randomised controlled trial among people who have received a kidney transplant. Participants from six hospitals across the Netherlands were randomly assigned 1:1:1 by an independent company into: usual care, exercise, and exercise plus diet. The exercise intervention encompassed two phases, a 3-month supervised exercise programme (twice weekly) followed by 12 months of lifestyle coaching, with 15 months of additional dietary counselling (12 sessions) for the exercise plus diet group. The primary outcome was HRQoL-domain physical functioning, assessed using the 36-item Short Form Survey at 15 months. From Oct 12, 2010 to Nov 18, 2016, 221 participants who had received a kidney transplant (138 [62%] male and 83 [38%] female, with a mean age of 52·5 [SD 13·5] years, who were a median of 5·5 [IQR 3·6-8·4] months post-transplant) were included and randomly assigned to usual care (n=74), exercise intervention (n=77), and exercise plus diet intervention (n=70). In the intention-to-treat analyses, at 15 months post-baseline, no significant differences in HRQoL-domain physical functioning were found for the exercise group (5·3 arbitrary units, 95% CI -4·2 to 14·9; p=0·27), and the exercise plus diet group (5·9 arbitrary units, -4·1 to 16·0; p=0·25) compared with control. Safety outcomes showed no safety concerns. After 3 months of supervised exercise intervention, HRQoL-domain physical functioning improved in the exercise group (7·3 arbitrary units, 95% CI 1·2 to 13·3; p=0·018) but not in the exercise plus diet group (5·8 arbitrary units, -0·5 to 12·1; p=0·072). A lifestyle intervention is safe and feasible in people who have received kidney transplants, paving the way for lifestyle intervention studies in other multimorbid populations with polypharmacy. However, improving HRQoL for people who have received a kidney transplant is challenging. The lifestyle interventions in the current study did not show significant improvements in HRQoL at the end of the study at the total group level. Dutch Kidney Foundation, Innovation Fund of the Dutch Medical Insurance Companies, and University Medical Center Groningen.

Background and objectives: Many kidney transplant recipients suffer from fatigue and poor health-related quality of life. Airflow limitation may be an underappreciated comorbidity among kidney transplant recipients, which could contribute to fatigue and lower health-related quality of life in this population. In this study, we compared the prevalence of airflow limitation between kidney transplant recipients and healthy controls and investigated associations of airflow limitation with fatigue and health-related quality of life in kidney transplant recipients. Design, setting, participants, & measurements: Data from the ongoing TransplantLines Biobank and Cohort study were used. Airflow limitation was defined as forced exhaled volume in 1 second less than the fifth percentile of the general population. Fatigue and health-related quality of life were assessed using checklist individual strength 20 revised (CIS20-R) and Short Form-36 (SF-36) questionnaires. Results: A total of 539 kidney transplant recipients (58% men; mean age 56±13 years) and 244 healthy controls (45% men; mean age 57±10 years) were included. Prevalence of airflow limitation was higher in kidney transplant recipients than in healthy controls (133 [25%] versus 25 [10%]). In multinomial regression models, airflow limitation was independently associated with fatigue severity (odds ratio moderate fatigue, 1.68; 95% confidence interval, 0.92 to 3.09 and odds ratio severe fatigue, 2.51; 95% confidence interval, 1.39 to 4.55; P=0.007) and lower physical health-related quality of life (−0.11 SDs; 95% confidence interval, −0.19 to −0.02; P=0.01) in kidney transplant recipients. In exploratory mediation analyses, fatigue accounted for 79% of the association of airflow limitation with physical health-related quality of life. Conclusions: Airflow limitation is common among kidney transplant recipients. Its occurrence is associated with more than two times higher risk of severe fatigue, and it is associated with lower physical health-related quality of life. Mediation analyses suggest that airflow limitation causes fatigue, which in turn, decreases physical health-related quality of life. Clinical Trial registry name and registration number: TransplantLines: The Transplantation Biobank, NCT03272841 Podcast: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_11_08_CJN06600521.mp3