Safety and efficacy of probiotic supplements as adjunctive therapies in patients with COVID-19: A systematic review and meta-analysis

BACKGROUND AND AIMS

Oral probiotic supplementation may be a beneficial adjunctive therapy for patients with symptomatic COVID-19. However, its safety and efficacy are unclear. We aimed to investigate how probiotic supplementation impacts COVID-19 symptom trajectory and patient outcomes by conducting a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

RCTs randomizing patients with COVID-19 to probiotics were searched in PubMed Central, Embase, CINAHL, and Cochrane Library from inception to July 31, 2022. We performed a random-effects pairwise meta-analysis for all outcomes using the restricted maximum likelihood (REML) estimator. We used the GRADE approach to assess the certainty of the evidence.

RESULTS

A total of 1027 participants from eight RCT studies were included in the meta-analysis. Probiotic supplements probably reduce the incidence of diarrhea (RR 0.61 [0.43 to 0.87]; moderate certainty) and probably reduce cough or dyspnea compared to placebo/standard care (RR 0.37 [0.19 to 0.73]; moderate certainty). Probiotic supplements may improve composite endpoint measured by clinical escalation or mortality compared to placebo (RR 0.41 [0.18 to 0.93]; low certainty evidence); however, they may not significantly reduce the need for clinical escalation (RR 0.57 [0.31 to 1.07]; low certainty evidence) or mortality (RR 0.50 [0.20 to 1.29]; low certainty evidence). In addition, the probiotic supplement is associated with reduced adverse events (RR 0.62 [0.46 to 0.83]; moderate certainty).

CONCLUSION

Early probiotic supplement is a safe and effective adjunctive therapy that reduces the risk of symptoms and health care burden related to COVID-19 across all severity types.

Prevalence of oesophageal epidermoid metaplasia in 1048 consecutive patients and 58 patients with squamous neoplasms

AIMS

Oesophageal epidermoid metaplasia is defined by a dense granular layer with overlying hyperorthokeratosis, resembling the epidermis of skin. A possible association between epidermoid metaplasia, squamous dysplasia and squamous cell carcinoma has been proposed. The aim of this study was to compare the prevalence of epidermoid metaplasia in patients with oesophageal squamous neoplasms with that in a control cohort.

METHODS AND RESULTS

Medical records and slides from 1048 consecutive oesophageal biopsies and resections for any indication and 58 patients with oesophageal squamous neoplasms were reviewed. Two cases (0.19%) of epidermoid metaplasia were identified in the 1048-patient control group. The prevalence of epidermoid metaplasia was significantly higher (P < 0.05) in the 58 patients with oesophageal squamous neoplasms, two of whom (3.5%) had concurrent epidermoid metaplasia (odds ratio 18.1, 95% confidence interval 2.5-131). One case was associated with a verrucous carcinoma and the other with a well-differentiated, superficial (pT1), exophytic squamous cell carcinoma. No patients had epidermoid metaplasia in a biopsy prior to the diagnosis of squamous neoplasia.

CONCLUSIONS

The increased prevalence of epidermoid metaplasia observed in patients with squamous neoplasms provides some additional support for the proposed association. The hypothesis that epidermoid metaplasia is a precursor to squamous neoplasms remains unproven.