probiotics, lactic acid bacteria. good bacteria and microorganisms for human health. microscopic probiotics, good bacterial flora

abstract acidophilus antibiotic bacillus background bacteria bacterial bacteriology bacterium bifidobacteria bifidobacterium biological biology biotechnology casei cell fermentation flora flu food germ good gut health healthy human icon illustration infection lactic lactobacillus lactococcus medical medicine micro microbe microbiology microorganism microscopic organism positive prebiotic probiotic propionibacterium set streptococcus thermophilus vector virus yoghurt