Introduction

Intestinal transplantation (ITx) is the only cure for patients with irreversible intestinal failure and complications of parenteral nutrition, however, 5-year graft survival is only ~50%. We currently do not know why graft failure is highly prevalent and hypothesize that disturbed repopulation of recipient cells in the graft is associated with this imbalance leading to rejection. So far, answering this question has been hampered by technical limitations and limited patient numbers.

Aims & Methods

We performed single-cell mRNA sequencing of 28 longitudinally sampled Ileal graft biopsies of three transplanted patients from surgery up to six months post-transplantation, obtained through the TransplantLines Biobank. Using their differential genetic background, we identified 90,282 donor and recipient cells in the graft and characterized their composition and function during clinical follow-up and rejection.

Results

We found no consistent repopulation of recipient immune cells over time, nor disturbance of repopulation upon rejection. T cells in the graft were predominantly of donor origin (59% of donor immune cells) and myeloid cells originated from the recipient (16% of recipient immune cells). Induction therapy using anti-thymocyte globulin did achieve less than 50% T cell depletion in the graft. Instead, apoptotic pathways in epithelial cells during moderate rejection preceded pathology-defined mass rejection, indicating potential prognostic information in the transcriptomic profiles.

Conclusion

In conclusion, this is the first longitudinal study of the ITx graft at single-cell level. We see that molecular profiles precede histologic signs of mass rejection, which may be a useful biomarker for treatment intensification. Unexpectedly, we find no consistent repopulation of recipient immune cells and a variable response to drugs.

Disclosure

• E.A.M.F and W.T.C.U.V. were sponsored by a NVGE Gastrostart Grant
• W.T.C.U.V., E.V.B., R.K.W. and E.A.M.F were sponsored by an unrestricted research grant from Takeda Pharmaceuticals.
• R.K.W.: acted as a consultant for Takeda and received an unrestricted grant from Johnson and Johnson pharmaceuticals and speaker fees from AbbVie, MSD, Olympus and AstraZeneca.
• E.A.M.F.: is supported by a ZonMW Clinical Fellowship grant (project number 90719075) volgt
• G.D.: received speaker's fees from Janssen-Cilag, Abbvie, Takeda, and Pfizer. Received research grants from Royal DSM and Janssen-Cilag. Furthermore, a De Cock Foundation Grant was applied.
• N.K. supported by an MD/PhD trajectory grant (21-12) from the Junior Scientific Masterclass, University of Groningen.
• The TransplantLines Biobank and Cohort study was supported by grants from Astellas BV (project code: TransplantLines Biobank and Cohort study), Chiesi Pharmaceuticals BV (project code: PA-SP/PRJ-2020-9136), and NWO/TTW via a partnership program with DSM, Animal Nutrition and Health, The Netherlands (project code: 14939). The project was co-financed by the Dutch Ministry of Economic Affairs and Climate Policy by means of so-called PPP-allowances, made available by the Top Sector Life Sciences & Health to stimulate public-private partnerships (project code: PPP-2019-032 and PPP-2022-015). The funders had no role in the study design, data collection, analysis, reporting, or the decision to submit for publication.
• R.O., E.B, S.J., J.W.H, F.H: have nothing to declare

Introduction

The pathogenicity of Blastocystis spp. is still debated. Guidelines for donor feces screening differ in their advice to screen for Blastocystis spp., but when tested, its presence is a common reason for exclusion.¹Blastocystis spp. are correlated to increased bacterial alpha-diversity² and distinct bacterial groups³ and therefore its presence may indicate favorable efficacy of fecal microbiota transplantation (FMT). The latest European consensus report no longer advices to reject feces donors that test positive for Blastocystis spp.⁴ Only one paper has been published on human transmission of Blastocystis spp. via frozen FMT.⁵

Aims & Methods

We aimed to investigate the long-term effects of the application of Blastocystis-positive FMT, prepared with fresh feces.
In a FMT trial on FMT with refractory Irritable Bowel Syndrome (IBS) adolescents (age 16 – 20 years) received two administrations (at baseline and after 6 weeks) of fresh allogeneic FMT via nasoduodenal tube prepared with fecal samples from a Blastocystis spp. positive feces donor (NCT03074227). Blastocystis spp. presence and subtyping were determined using microscopy, PCR and Sanger sequencing.

Results

Three recipients received FMT from one donor colonized with Blastocystis subtype 3 (ST3). Two recipients were negative for Blastocystis spp. and one recipient carried ST2 at baseline prior to FMT. After FMT, the two prior-negative recipients tested positive for identical ST3 as the donor after FMT at 12 weeks, but lost carriership of this subtype at week 24 and week 48. The ST2 colonized recipient remained colonized with ST2 and did not acquire ST3 after FMT. Transient adverse events did occur, but did not differ from patients treated with Blastocystis spp.-negative FMT. No FMT-related serious adverse events occurred.

	Recipient	Baseline	Before FMT 1	Donor FMT 1	Before FMT 2	Donor FMT 2
		Week -2	Week 0	Week 0	Week 6	Week 6	Week 12	Week 24	Week 48
1	Woman, 18 y	negative	negative	ST3	ST 3	+, no seq	ST3	negative	negative
2	Woman, 20 y	negative	negative	ST3	+, no seq	ST3	ST 3	ST3	ST3
3	Woman, 16 y	ST2	ST2	ST3	+, no seq	ST3	ST2	ST2	ST2

Table 1: Sanger PCR sequencing results of frozen feces samples from three adolescents with IBS and one healthy donor. Samples were collected before, during and after the FMT treatment schedule with follow-up unto week 48. Light blue cells indicate a different sequence order of Blastocystis ST3 than the Blastocystis ST3 indicated in the dark blue cells. Grey cells indicate columns representing donor samples.
Abbreviations: FMT; fecal microbiota transplantation, ST; subtype, seq; sequence, y; years.

Conclusion

We present the first long-term results of Blastocystis spp. transmission by fresh FMT in three cases. Transient colonization with Blastocystis spp. did occur without the occurrence of FMT-related serious adverse events.

References

1. Benard MV, de Bruijn CMA, Fenneman AC, Wortelboer K, Zeevenhoven J, Rethans B, et al. Challenges and costs of donor screening for fecal microbiota transplantations. PLoS One. 2022;17(10):e0276323.
2. Tito RY, Chaffron S, Caenepeel C, Lima-Mendez G, Wang J, Vieira-Silva S, et al. Population-level analysis of Blastocystis subtype prevalence and variation in the human gut microbiota. Gut. 2019;68(7):1180-9.
3. Nieves-Ramirez ME, Partida-Rodriguez O, Laforest-Lapointe I, Reynolds LA, Brown EM, Valdez-Salazar A, et al. Asymptomatic Intestinal Colonization with Protist Blastocystis Is Strongly Associated with Distinct Microbiome Ecological Patterns. mSystems. 2018;3(3).
4. Keller JJ, Ooijevaar RE, Hvas CL, Terveer EM, Lieberknecht SC, Hogenauer C, et al. A standardised model for stool banking for faecal microbiota transplantation: a consensus report from a multidisciplinary UEG working group. United European Gastroenterol J. 2021;9(2):229-47.
5. Terveer EM, van Gool T, Ooijevaar RE, Sanders I, Boeije-Koppenol E, Keller JJ, et al. Human Transmission of Blastocystis by Fecal Microbiota Transplantation Without Development of Gastrointestinal Symptoms in Recipients. Clin Infect Dis. 2020;71(10):2630-6.

Disclosure

CYP has received research grants from Gilead and Perspectum, consultancy fee from Chemomab and NGM, and speaker’s fee from Tillotts. The other authors disclose no conflicts.

Introduction

Sarcopenia is a progressive, systemic skeletal muscle disease associated with aging that severely affects the quality of life and overall health of older adults. Emerging research demonstrates a strong association between the onset of sarcopenia and gut microbiota.

Aims & Methods

16 out of 30 sarcopenia patients who showed significant skeletal muscle improvement after fecal microbiota transplantation (FMT) were selected and validated by metagenomic, cultured and animal experiments.

Results

Our clinical observations show a marked improvement in sarcopenia symptoms among older patients post FMT, leading to a notable rise in muscle mass (P < 0.05). To delve deeper into this occurrence, we conducted metagenomic sequencing of patient fecal samples pre- and post-treatment. FMT distinctly modified the intestinal microbiota composition. Utilizing germ-free animal models and culturomics, we identified Roseburia inulinivorans as a potentially beneficial strain for the alleviation of sarcopenia. Further experimental validation displayed that Roseburia inulinivorans escalated MyoG and MyoD expression (P < 0.05), augmented muscle mass (P < 0.01) and grip strength (P < 0.01) in mice by boosting branched-chain amino acid metabolism within the host, diminishing sarcopenia symptoms in the process.

Conclusion

These outcomes not only validate the intestinal microbiota-sarcopenia relationship but also introduce novel insights and strategies for sarcopenia management.

References

[1] Tournadre A, Vial G, Capel F, Soubrier M, Boirie Y. Sarcopenia. Joint Bone Spine. 2019. 86(3): 309-314.
[2] DeJong EN, Surette MG, Bowdish D. The Gut Microbiota and Unhealthy Aging: Disentangling Cause from Consequence. Cell Host Microbe. 2020. 28(2): 180-189.
[3] Wang T. Searching for the link between inflammaging and sarcopenia. Ageing Res Rev. 2022. 77: 101611.
[4] Hanna BS, Wang G, Galván-Peña S, et al. The gut microbiota promotes distal tissue regeneration via RORγ+ regulatory T cell emissaries. Immunity. 2023. 56(4): 829-846.e8.
[5] Chen YM, Wei L, Chiu YS, et al. Lactobacillus plantarum TWK10 Supplementation Improves Exercise Performance and Increases Muscle Mass in Mice. Nutrients. 2016. 8(4): 205.
[6] Lee MC, Hsu YJ, Ho HH, et al. Lactobacillus salivarius Subspecies salicinius SA-03 is a New Probiotic Capable of Enhancing Exercise Performance and Decreasing Fatigue. Microorganisms. 2020. 8(4): 545.
[7] Liu X, Wu J, Tang J, et al. Prevotella copri alleviates sarcopenia via attenuating muscle mass loss and function decline. J Cachexia Sarcopenia Muscle. 2023. 14(5): 2275-2288.
[8] Chen LH, Chang SS, Chang HY, et al. Probiotic supplementation attenuates age-related sarcopenia via the gut-muscle axis in SAMP8 mice. J Cachexia Sarcopenia Muscle. 2022. 13(1): 515-531.

Introduction

Clostridioides difficile infection is a major challenge for healthcare systems. Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease, is a risk factor for primary and recurrent CDI (rCDI). Moreover, CDI itself often worsens the clinical picture of IBD, increasing the risk of complications. Fecal microbiota transplantation (FMT) is a highly effective treatment for rCDI, but data from patients with IBD and CDI are limited and often referred to mixed cohorts.

Aims & Methods

We aimed to report outcomes from a cohort of patients with UC treated with FMT for rCDI superinfection.
In a retrospective, single-centre cohort study we evaluated characteristics and outcomes of patients with UC who received FMT for rCDI. The primary outcome was negative C. difficile toxin 8 weeks after FMT.

Results

Thirty-five patients were included in the analysis. Sixteen patients were cured after single FMT, while 19 patients received repeat FMT. Overall, FMT cured rCDI in 32 patients (91%), and repeat FMT was significantly associated with sustained cure of CDI compared with single FMT (84% vs 50%, p= 0.018). Twenty-four patients (69%) experienced remission or an amelioration of UC activity. Serious adverse events were not observed.

Conclusion

In our cohort of patients with UC, FMT was highly effective in curing rCDI without severe adverse events, and repeat FMT was significantly associated with CDI cure. Most patients also experienced remission or amelioration of UC activity after FMT. Our findings suggest that a sequential FMT protocol may be used routinely in patients with UC and rCDI.