The study, published in BMC Nutrition and funded by Nordic Biotics, observed significant improvements in symptoms in participants suffering from COVID-19 following 10 days of probiotic intake. In addition, patients experienced a shorter duration of post-COVID anxiety and fatigue.
"This study emphasizes the uniqueness of selected strains in enhancing antiviral immunity, particularly concerning Covid-19 infection,” Michal Jakubowski, CEO of Nordic Biotic, told NutraIngredients. “This mixture of strains can be utilized not only as probiotic products that alleviate infection symptoms but also in terms of protection from long-term complications after viral infections."
"It is necessary to underline that the natural response to viruses and probiotic-induced immunity, even if specific, can activate a global antiviral defence," he added. "The importance of the study findings lies in the provision of further evidence-based background for the role of probiotics in immune antiviral response in humans."
Probiotics for infection
The substantial prevalence of acute respiratory tract infections (ARTI) places significant pressure on healthcare systems, with 17.2 billion global cases reported in 2019 accounting for 43.8% of all causes of global disease burden. While many cases are mild, ARTIs significantly affect productivity and quality of life.
The COVID-19 pandemic added to this strain and highlighted the need for more effective preventative measures and treatment options to prevent further progression to more severe disease cases.
Patients with COVID-19 who also suffered with diarrhoea have a more severe disease, with significantly increased concentrations of inflammatory cytokines. The potential role of intestinal cells in enabling SARS-CoV-2 entry has led to an interest in the role of probiotics in interfering with the infection process.
The researchers recruited 73 symptomatic patients between the ages of 18 and 65 years who had tested positive for SARS-CoV-2, who received either a test dietary supplement (TDS) containing 5 billion CFU total of Bifidobacterium lactis, B. longum, Lactobacillus rhamnosus, L. casei and L. acidophilus or a placebo for 28 days.
Participants completed a patient global symptom score on day 10 of observation, as well as a Post-COVID-19 Questionnaire (PCQ-19) following a three-month period. In addition, blood was sampled for IgG to nucleocapsid protein (NCP) and receptor binding domain (RBD)/spike 1 (S1) protein.
At day 10, the researchers reported that the median global symptom score was significantly lower in the probiotic group, when compared to the control. Participants in this group also had a greater change in IgG concentrations after supplementation and reduced durations of fatigue and anxiety following COVID-19 infection.
"The results of our study indicate that a short-term use of probiotics plays a role in attenuation of symptoms caused by the SARS-CoV-2 infection, stimulates virus-neutralizing humoral responses, reduces duration of post-COVID-19 anxiety and fatigue," the researchers wrote.
They noted that the findings provide significant evidence for the effectiveness of probiotics for the potential prevention and treatment of viral infections.
"Further clinical trials need to be conducted to demonstrate the potential effect of the selected strains for global antiviral immunity," Jakubowski said. "We assume that among these patients, global antiviral immunity was enhanced, and this constitutes a crucial aspect for future research.
"Further research is also needed to elucidate the underlying mechanisms through which probiotics influence the immune system, both in the acute phase of infection and during the post-disease period. Mechanistic studies, such as exploring the impact of probiotics on specific immune cell populations and signalling pathways, can enhance our understanding of the immunomodulatory effects."
Source: BMC Nutrition
"The role of nutritional support with probiotics in outpatients with symptomatic acute respiratory tract infections: a multicenter, randomized, double‑blind, placebo‑controlled dietary study"
Authors: Pavlo O. Kolesnyk et al.