probiotic bacteria logo. bifidobacteria lactobacillus gut acidophilus. lactic prebiotic healthy flora care

probiotic logo icon bacteria prebiotic bifidobacteria lactobacillus gut vector acidophilus lactic acid care healthy flora microbiome microbe background diet virus illustration molecule food stomach badge yoghurt white immune milk human design digestion concept bacterium microorganism bacterial microbiology biological symbol bacillus fermentation sign colony label contain biology yogurt graphic intestine system