villi in the intestinal probiotic green bacteria human health care gut flora people microbiome 3d

anatomy background bacteria bacterium belly biology body bowel brain cancer care colon diet digestion digestive disease enteric flora food gastric gastrointestinal green gut health healthy human illustration intestinal intestine lactobacilli lactobacillus large medical medicine microbe microbiome microbiota microorganisms people probiotic probiotics render science sick small stomach system tract unhealthy villi white