FMT eases anxiety, sleep disturbance in postacute COVID-19 syndrome patients

Patients with postacute COVID-19 syndrome (PACS) may benefit from faecal microbiota transplantation (FMT) treatment, which helps reduce anxiety and improve sleep quality, suggests a study.

“PACS affects sleep and neuropsychiatric functions, but treatment is limited,” said lead author Dr Raphaela Iris Lau from the Microbiota I-Center, Hong Kong SAR, China, who presented the results of their study at DDW 2024.

Lau and her team conducted an open-label pilot trial to examine the efficacy of FMT in easing post-COVID insomnia and anxiety. Sixty patients (mean age 46.6 years, 57.6 percent female) with an Insomnia Severity Index (ISI) score of ≥8 (mean ISI 16.5) at least 4 weeks after COVID-19 were recruited between September 2022 and June 2023 and then assigned 1:1 to either the FMT group or the control group.

The FMT group received treatment via oesophagogastroduodenoscopy (OGD) at baseline, 2, 4, and 8 weeks, and via flexible sigmoidoscopy (FS) at baseline. On the other hand, the control group did not receive treatment with FMT.

Insomnia remission, the primary outcome, was defined as a change in ISI from ≥8 (subthreshold to clinical insomnia) to <8 (no clinically significant insomnia) by 12 weeks. Other outcomes assessed were changes in Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Generalized Anxiety Disorder-7 (GAD-7) scores, blood cortisol or melatonin, and gut microbiome.

Independent predictors of insomnia remission were identified using multivariable stepwise logistic regression. The authors quantified blood cortisol and melatonin using ELISA tests and profiled the gut microbiome using shotgun metagenomic sequencing.

Insomnia remission

Significantly more patients in the FMT group than those in the control group achieved insomnia remission at 12 weeks (37.9 percent vs 10.0 percent; p=0.018). The mean ISI score of patients treated with FMT markedly improved from 17.1 to 8.5 at week 12 (p<0.0001), and ISI scores were significantly lower in this group (p=0.0001). [DDW 2024, abstract 378]

These findings were supported by the result of the multivariate analysis, which revealed that FMT treatment was the only factor significantly associated with insomnia remission (odds ratio, 5.500, 95 percent confidence interval, 1.344‒22.506; p=0.018).

In addition, patients treated with FMT achieved significant improvements in sleep quality (PSQI: from 12.9 to 6.8; p<0.0001), daytime sleepiness (ESS: from 11.3 to 8.7; p=0.0057), and anxiety (GAD-7: from 9.8 to 5.3; p=0.0019). Those in the control group, however, showed no substantial improvements in ISI, PSQI, ESS, and GAD-7 scores.

Patients in the FMT group also demonstrated significantly lower blood cortisol concentration at week 12 (p=0.035). Their faecal microbiome also showed an enrichment of Gemmiger formicilis and a reduction of Bacteroides xylanisolvens and microbial pathways producing menaquinol derivatives at 12 weeks.

“Treatment with FMT alleviates sleep disturbance and anxiety in patients with PACS,” Lau said. “Further controlled studies are warranted to explore the effects on sleep and mental health.”

This study was funded by the Hui Hoy & Chow Sin Lan Charity Fund Limited, and the authors received partial support from InnoHK and the government of Hong Kong SAR.