Meysam Hasannejad-Bibalan - ۱Department of Microbiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
Hamed Kekmatnezhad - Department of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

The colonic microbiota play a key role in human gastrointestinal tract physiology include maintaining homeostasis of the large bowel and modulating the host immune response. Lactic acid bacteria (LAB) especially Lactobacillus and Bifidobacterium are the main part of gut microbiota, which are considered as health beneficial probiotic bacteria with valuable effects in humans [۱, ۲].Probiotic bacteria are currently used in industrial food production and therapeutically procedures [۳]. The lactic acid produced by probiotic bacteria in the fermentation process causes decrease pH to inhibit the growth of putrefactive and pathogenic bacteria. Besides, LAB could have improvement effects on the nutritional value of fermented products through increase the production of the main food components such as vitamins, essential minerals, and amino acids [۴]. Probiotics have been shown to be effective in preventing and treating different disorders such as atopic dermatitis, urinary tract-infections, colorectal cancer, and rheumatoid arthritis [۵]. Competition with disease-causing microbes, producing antimicrobial peptides (AMPs), modulate the microenvironment and regulate the host immune system makes probiotics a very interesting field for infectious disease research [۶].

Probiotic, Lactic acid bacteria, COVID-۱۹, SARS-CoV-۲