#Bacteria are #essential. There’s almost no #function in your #body that your #microbes and their #metabolites aren’t connected to.⠀ ⠀ They help #digest #foods we otherwise couldn’t, #synthesize key #vitamins, metabolites, and #neurotransmitters, break down #toxins and #hazardous #chemicals, gate-keep the gut barrier, and protect from #intruders and other #pathogenic bacteria. Perhaps most importantly, they teach our #immune #system to recognize #friend vs. #foe and control our responsiveness and #sensitivity to immune #responses.⠀ ⠀ Bacteroides fragilis, pictured above, is one such example. A common resident in our guts, B. fragilis produces a #molecule called #polysaccharide A (PS-A). PS-A boosts numbers of helper T-cells, a type of white blood cell that actively participates in immune response. As long as B. fragilis stays in the gut, it participates in a deeply #symbiotic #relationship with the human host.⠀ ⠀ ______________⠀⠀⠀ ⠀ Bacteroides fragilis bacteria. Science Photo Library....