friendly and unfriendly gastrointestinal bacteria

acidophilus anatomy antibiotics bad bidifobacterium bifidum bowel disease duodenal duodenum dysenteriae dysentery education fermentum flora friendly gastritis gastrointestinal good gut health illustration intestinal intestine isolated jejunum lactobacillus longum medicine microbe microbiology microbiome microflora microorganism pathogen pathogenic probiotic rhamnosus science shigella stomach treatment unfriendly