Editorial: Long COVID and its biomedical dimensions

By
Anil Philip Kunnath
Owen Kavanagh
Shing Cheng Tan
October 9, 2026

British Journal Of Biomedical Science

Overview

This editorial summarizes five studies in a British Journal of Biomedical Science Special Issue examining Long COVID through pulmonary imaging, carotid body morphology, serological biomarkers, and microbiota-directed treatment. The studies report associations between imaging or antibody findings and clinical measures, and a small randomized trial found a greater reduction in fatigue scores with probiotic supplementation than with placebo.

Background

Long COVID, also termed post-acute sequelae of SARS-CoV-2 infection (PASC), is described in the editorial as a heterogeneous, multisystem condition affecting millions globally. Reported manifestations include fatigue, cognitive dysfunction, and persistent respiratory compromise. The editorial states that the underlying pathophysiological mechanisms remain elusive, impeding development of effective therapies. Its five studies address complementary biomedical dimensions rather than treating the syndrome as a single-organ condition.

Data Highlights

Study focus	Reported finding
Thoracic imaging after severe COVID-19 ARDS	Reticulations/septal thickening positively correlated with symptomatic dyspnoea; parenchymal/atelectatic bands were associated with reduced forced vital capacity.
Ultra-low-dose CT	Diagnostic accuracy was 95.0%, rising to 98% in non-obese subjects; ULDCT was reported comparable to standard-dose CT for identifying persistent lung abnormalities.
Carotid body morphology	Carotid bodies were significantly enlarged in patients previously hospitalized for COVID-19 pneumonia.
Serological profiles	Among 275 patients with Omicron-related Long COVID, nucleocapsid N-antibody titers were positively associated with acute disease severity and antiviral immune responses; lower spike S-antibody titers correlated with memory impairment and poorer quality of life.
Probiotic trial	After 4 weeks, clinically relevant fatigue scores decreased by 24.24% with probiotics versus 6.06% with placebo.

Key Findings

Garg et al. linked specific CT patterns after severe COVID-19 ARDS with dyspnoea and reduced forced vital capacity.
Devkota et al. reported that ULDCT was comparable to standard-dose CT for detecting persistent lung abnormalities, with 95.0% diagnostic accuracy and 98% accuracy in non-obese subjects.
Goksu et al. found significantly enlarged carotid bodies in patients previously hospitalized for COVID-19 pneumonia; the editorial notes that the finding raises questions about direct viral injury and persistent hypoxic stimulation.
Kawaguchi et al. reported associations between N-antibody titers and acute disease severity and antiviral immune responses, while lower S-antibody titers correlated with memory impairment and poorer quality of life. The authors cautioned that vaccination status and time since infection should be considered when interpreting serological profiles.
In Amoroso et al.’s randomized, double-blind, placebo-controlled study, 4 weeks of probiotic supplementation produced a larger decrease in fatigue scores than placebo (24.24% versus 6.06%); the editorial notes that the limited sample size warrants caution.
The probiotic trial also reported changes in gut microbial taxa, microbiota-associated metabolites, and immune-related pathways alongside the clinical improvement.

Clinical Implications

The editorial presents imaging, serological, physiological, and microbiome-related assessments as complementary approaches to characterizing Long COVID, while noting that serological results require consideration of vaccination status and time since infection. It describes the probiotic trial as preliminary because of its limited sample size and states that further research across multiple approaches is needed.

Conclusion

The five studies portray Long COVID as a complex, multisystem syndrome with findings spanning pulmonary, vascular, immunological, and microbiome-related domains. The editorial calls for continued research combining these approaches to improve characterization, monitoring, and treatment.